Fabrication of high capacity lini0 8mn0 1co0 1o2 zno cathodes for application in lithium ion batteries

MINISTRY OF EDUCATION AND TRAINING PHENIKAA UNIVERSITY VU TUE ANH FABRICATION OF HIGH-CAPACITY APPLICATION IN LITHIUM-ION BATTERIES MASTER THESIS Hanoi - 2024 Copies for internal us

INTRODUCTION

Introduction to lithium-ion batteries

Lithium, the lightest metal with the highest electrochemical potential and energy capacity, was first explored for its ion potential by G.N Lewis in 1912 at the University of California, Berkeley It wasn't until the early 1970s that M.S Whittingham, a British chemist at Exxon, developed the first commercially viable rechargeable lithium battery using titanium (IV) sulfide and lithium metal as electrodes However, this initial battery design faced practical challenges, as titanium disulfide required vacuum synthesis, resulting in high costs of approximately 1000 USD per kg in the 1970s.

In 1980, American physicist John Goodenough revolutionized battery technology by inventing a new type of rechargeable lithium battery, utilizing lithium cobalt oxide (LCO) as the cathode He predicted that using metal oxide instead of metal sulfide could achieve a higher voltage, and his innovation allowed lithium ions to move efficiently between electrodes Goodenough's design demonstrated a voltage output of up to 4 volts, significantly enhancing the energy capacity of lithium-ion batteries This breakthrough not only doubled the operating voltage but also paved the way for more powerful and practical rechargeable batteries, thanks to the stable positive charge conduction properties of LCO.

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Figure 1.1 The structure of Goodenough's battery [3]

In 1983, Akira Yoshino, a professor at Meijo University in Japan, pioneered the development of a prototype rechargeable lithium-ion battery (LIB) using lithium cobalt oxide as the cathode and polyacetylene as the anode This innovative design allowed lithium ions (Li+) to transfer between the cathode and anode during charging, resulting in a safe, lightweight, and durable battery capable of enduring hundreds of charge cycles with minimal performance loss Unlike traditional batteries that rely on chemical reactions that degrade electrodes, Yoshino's LIB technology is based on the reversible movement of Li+ ions, marking a significant advancement in energy storage solutions and laying the groundwork for modern LIB technology.

Lithium-ion batteries (LIBs) were first commercialized by Sony Energytech in 1991 and have since revolutionized energy storage The performance and safety of LIBs can vary based on the transition metal used, providing flexibility in application Compared to traditional battery technologies, LIBs utilize electrolytes containing lithium salts, enabling them to store a substantial amount of energy in a compact size This unique characteristic makes them ideal for modern devices and applications.

Phenikaa University focuses on developing advanced technologies and devices that necessitate compact, high-capacity, safe, and rechargeable batteries Currently, lithium-ion batteries are the leading choice globally for mobile devices and uninterruptible power supply systems, especially in the electric vehicle sector.

The development of lithium-ion batteries (LIBs) has revolutionized our society, paving the way for a fossil fuel-free future and a wireless technological landscape filled with advantages These batteries are essential in a wide array of electronic devices, from everyday gadgets to high-end products, including smartphones, home appliances, wearables, electric vehicles, aircraft, and advanced spacecraft systems The significance of LIBs in contemporary life was underscored when three scientists received the 2019 Nobel Prize in Chemistry for their contributions to creating "a rechargeable world."

Figure 1.2 The structure of Yoshino's battery [4]

Research on electrode materials for lithium-ion batteries (LIBs) in Vietnam remains limited Most studies to date have primarily focused on materials for supercapacitors or

Due to technological limitations, Phenikaa University restricts the use of lead-acid batteries to internal purposes only However, several research groups at various institutions have recently begun exploring electrode materials for lithium-ion batteries (LIBs).

Prof Le Thi Thu Hang’s team at Hanoi University of Science and Technology (HUST) is making significant advancements in anode materials for lithium-ion batteries (LIBs) Concurrently, Dr Bui Thi Hang's group at the International Training Institute for Materials Science (ITIMS) – HUST is investigating iron oxide-carbon nanocomposites for use in metal-air batteries and as anode materials for LIBs.

Prof Le Loan My Phung's research team at Ho Chi Minh City University of Science has focused on developing anode materials and traditional cathode materials, including LiFePO4 and LiMn2O4, for lithium-ion batteries (LIBs).

Currently, there are no research groups in Vietnam focusing on lithium-rich manganese-based (LMR) cathode materials for lithium-ion batteries (LIBs), even though there is considerable global interest in this field.

Structure of a lithium-ion battery

The structure of a lithium-ion cell includes: a cathode, an anode, a separator, an electrolyte, and two current collectors

The cathode, serving as the positive electrode in batteries, is usually composed of lithium-based compounds like lithium cobalt oxide (LCO), lithium iron phosphate (LFP), or nickel-manganese-cobalt (NMC) The selection of cathode material significantly influences the battery's energy density, power output, and safety features.

Anode: The negative electrode, generally made from graphite During charging, lithium ions are stored in the anode; during discharge, they move back to the cathode, creating an electrical current

The electrolyte serves as the essential medium for lithium ions to move between the cathode and anode in lithium-ion batteries Typically composed of a lithium salt like LiPF₆ dissolved in organic solvents, the electrolyte must maintain stability to facilitate ion transport while effectively blocking direct electron flow between the electrodes.

A separator is a thin, porous membrane situated between the cathode and anode in a battery Its primary function is to prevent the electrodes from making contact, which could lead to a short circuit, while simultaneously allowing lithium ions to pass freely through the electrolyte.

Current collectors, made of thin metal foils such as aluminum for the cathode and copper for the anode, play a crucial role in lithium-ion batteries (LIBs) by collecting and supplying electrons during discharge and charging These components are arranged in either a layered or spiral configuration, depending on the battery design, and are housed within various casing types, including cylindrical, prismatic, coin-type, or pouch-type, tailored to specific applications This structural design allows LIBs to achieve high energy density, making them ideal for a diverse array of devices, from consumer electronics to electric vehicles.

Working principle of LIB

In a lithium-ion battery (LIB), the electrochemical reaction involves the anode and cathode materials, along with an electrolyte solution that facilitates the movement of lithium ions between the electrodes During discharge, this process generates an electric current that flows through the external circuit of the battery.

During operation, lithium ions migrate between the electrodes, with current materials engineered to facilitate their entry into the crystal lattice with minimal atomic disruption, a process termed lithiation Conversely, during delithiation, lithium ions are extracted from the lattice structure.

During battery discharge, lithium ions migrate from the anode, typically composed of graphite, through the electrolyte to the cathode, where they react with the cathode material To ensure charge balance, each lithium ion moving to the cathode corresponds with one electron traveling through the external circuit from the anode, creating a current flow This process highlights the essential role of lithium ions and electrons in generating electrical energy in lithium-ion batteries.

During the charging process, electrons are driven from the battery's cathode, which functions as the anode, while lithium ions detach from the cathode and migrate back to the anode This polarity reversal occurs during both charging and discharging, with the designation of electrodes as anode or cathode depending on the reaction type and the battery's state.

The half-reaction at the cathode for layered LCO material can be written as follows (forward for charging, reverse for discharging):

The half-reaction at the anode for graphite material is as follows (forward for charging, reverse for discharging):

The overall reaction of the battery (forward for charging, reverse for discharging) is:

Besides intercalation/insertion mechanism, alloying in lithium-ion batteries refers to the use of electrode materials, primarily for anodes, that form alloys with lithium during the

Phenikaa University is exploring the charging process using advanced materials such as silicon (Si), tin (Sn), germanium (Ge), and antimony (Sb), which boast significantly higher theoretical capacities than traditional graphite anodes For example, silicon's theoretical capacity reaches approximately 4200 mAh/g, nearly ten times greater than graphite's 372 mAh/g These materials form lithium-rich alloys like Li15Si4 during lithiation, enhancing lithium storage capabilities However, a major challenge arises from the substantial volume expansion—up to 300% for silicon—during charge-discharge cycles, resulting in particle cracking, loss of electrical contact, and diminished cycling stability This expansion also disrupts the solid electrolyte interphase (SEI), leading to electrolyte decomposition and a decline in capacity.

Figure 1.3 Working principles of LIB [9]

Layered lithium transition metal oxides, denoted as LiMO2 (where M typically includes Co, Ni, or Mn), are prominent cathode materials in lithium-ion batteries (LIBs) due to their high energy density and efficient lithium-ion mobility These compounds feature a face-centered cubic (fcc) oxygen lattice, with lithium and transition metal ions organized in alternating layers This unique layered structure facilitates the intercalation and deintercalation of lithium ions, which is crucial for the charging and discharging cycles of LIBs.

Figure 1.4 Layered crystal structure of LiMO₂, highlighting transition metal ions

(blue) and lithium ions (red) [11]

LiCoO2, recognized as the first commercially utilized layered cathode material, has played a crucial role in the advancement of modern lithium-ion batteries (LIBs) Its ability to deliver stable cycling and high energy density has made it a favored option for portable electronic devices Despite its advantages, LiCoO2 faces significant limitations, including a practical reversible capacity of around 140 mAh g -1, which is merely 50% of its theoretical capacity This limitation arises from structural instability when extracting more than half of the lithium ions, particularly at elevated states of charge.

Internal use copies at Phenikaa University may lead to lattice collapse and oxygen release, jeopardizing safety Additionally, the high cost and environmental issues associated with cobalt, stemming from its scarcity and mining difficulties, have prompted researchers to investigate alternative layered materials that provide comparable or enhanced performance while reducing dependence on cobalt.

A further strategy involves developing lithium-rich layered oxides, such as

Li1⁃xNi0.33Mn0.66O2 is a promising cathode material that can exceed conventional capacity limits by incorporating additional lithium, potentially reaching over 250 mAh g -1 due to increased lithium ion participation in electrochemical reactions However, these lithium-rich layered oxides face significant initial capacity loss and voltage fade during cycling, attributed to complex structural changes and oxygen release in the initial charge Recent research has focused on methods like gradient doping and surface coatings to address these challenges and improve long-term stability, yet achieving a commercially viable cycle life remains a hurdle.

Optimizing LiMO2-type layered oxides is essential for enhancing lithium-ion battery (LIB) performance in consumer electronics and electric vehicles Ni- and Mn-based layered materials present a viable solution for achieving higher energy density and reducing cobalt dependency However, improving cycling stability and rate capability continues to be a key area of research.

Layered LiMO2 compounds are essential for lithium-ion battery (LIB) technology, especially in high-energy applications The transition from cobalt-rich LiCoO2 to nickel- and manganese-substituted compounds marks a move towards more sustainable and cost-effective options while maintaining energy density As LIB technology advances, improvements in layered oxide cathodes are expected to enhance battery performance further.

Copies for internal use only in Phenikaa University safety, efficiency, and capacity, ultimately supporting the growing demand for high- performance, rechargeable energy storage across various sectors

Ni-rich layered oxide cathode materials

Nickel-rich layered oxide cathode materials, specifically LiNixCoyMnzO2 (NMC) and LiNixCoyAlzO2 (NCA), are pivotal in enhancing lithium-ion battery (LIB) technology due to their high capacity, advantageous working potential, and cost-effectiveness With a nickel content typically greater than or equal to 0.8, these materials significantly boost the energy density of batteries As a result, nickel-rich cathodes are crucial for high-energy applications, including electric vehicles and grid storage systems, where extended range and high power output are essential.

Ni-rich cathodes offer advantages but face critical challenges affecting their stability and safety Key issues include performance degradation over time, evident in capacity fading and voltage decay, primarily due to structural instability from phase transitions as lithium ions cycle in and out The high nickel content exacerbates these challenges by destabilizing the crystal lattice, increasing susceptibility to microcracking and phase shifts from layered to less active spinel and rocksalt structures These transitions, particularly at elevated voltages, can lead to oxygen release, heightening the risk of thermal runaway, a major safety concern for lithium-ion batteries (LIBs).

To address the challenges associated with Ni-rich cathodes, effective strategies have been implemented, including doping with aluminum (Al) and magnesium (Mg) to enhance structural stability by minimizing nickel migration and strengthening oxygen bonds Additionally, surface coating techniques such as atomic layer deposition (ALD) are essential for stabilizing these cathodes, as they create thin, uniform coatings that improve overall performance.

Copies for internal use only in Phenikaa University protective barrier that reduces undesirable reactions between the cathode and electrolyte, particularly under high-voltage conditions [22]

Ni-rich layered oxide cathodes present significant energy density potential for lithium-ion batteries (LIB), but challenges related to nickel-induced instability necessitate continuous research and innovation To enhance the long-term stability, safety, and commercial feasibility of these materials in high-energy applications, advanced strategies like gradient doping and robust coating techniques are essential.

Spatial atomic layer deposition (SALD) method

To improve the electrochemical performance of Li-rich NMC811 batteries, various strategies are employed, including morphology control, element doping, and coating design While morphology control and doping involve complex synthesis procedures and are limited to specific materials, coating design is a more straightforward method applicable to a broader range of materials This approach creates a protective barrier between the Ni-rich layered cathode and the electrolyte, reducing side reactions and preventing cathode degradation caused by hydrofluoric acid (HF) attack.

Direct interaction between LiPF6 and moisture in cells is crucial for maintaining a stable cathode electrolyte interphase Studies indicate that using coatings made of inorganic compounds, particularly metal oxides like SiO2, can enhance this stability.

The incorporation of materials such as WO3, Co3O4, ZrO2, ZnO, Al2O3, phosphates like Mn3(PO4)2, and fluorides such as AlF3 significantly enhances the structural stability of cathodes These materials effectively prevent the dissolution of transition metal ions by blocking direct contact with the electrolyte, while also protecting the material's structure from degradation during charge and discharge cycles Among these options, ZnO is particularly advantageous due to its low cost, ease of application, and high electrical conductivity Various methods, including the sol-gel method, wet-chemical method, and sputtering method, have been developed to apply ZnO coatings to cathode materials; however, these coatings often suffer from issues related to completeness, consistency, and uniformity.

The Atomic Layer Deposition (ALD) technique is increasingly favored for its precise control over coating thickness at the sub-nanometer level and its ability to conformally coat high-aspect ratio surfaces However, traditional vacuum-based ALD is not suitable for high-throughput roll-to-roll battery electrode production In contrast, Spatial Atomic Layer Deposition (SALD) has gained attention for its high growth rate and compatibility with roll-to-roll processing, although its application in thin-film batteries remains limited Notably, ultrathin ALD films do not disrupt the electrical pathways within the electrode, thereby maintaining overall capacity Research by Kong et al demonstrated that an ultrathin amorphous ZnO layer applied to NMC532 cathode materials through ALD significantly improved discharge capacity and cyclability compared to uncoated materials, particularly at elevated temperatures where the uncoated electrodes exhibited reduced performance.

Phenikaa University has demonstrated that their internal use batteries retain only 87% of their initial capacity after 60 cycles at a 2C rate In contrast, ZnO-coated samples exhibited a higher retention of up to 92% under the same electrochemical conditions Additionally, research by Hsieh et al highlighted the effectiveness of Atomic Layer Deposition (ALD) of TiO2 in enhancing the stability of Li-ion pouch cells Their study found that cells with ALD-treated Ni-rich NCM523 cathodes and natural graphite anodes achieved a cyclic capacity retention of up to 90% after 100 cycles at 25°C, significantly outperforming untreated cells.

SALD, or Spatial Atomic Layer Deposition, is a highly precise thin-film deposition technique that excels at the atomic scale, making it particularly suitable for energy storage applications like lithium-ion batteries (LIBs) Originating in the 1970s, ALD has evolved into a vital method for achieving conformal and uniform thin films, thanks to its unique self-limiting surface reaction mechanism The ALD process consists of multiple cycles of sequential reactions, which are essential for accurately controlling film thickness and composition.

An atomic layer deposition (ALD) cycle involves four key steps: precursor exposure, purging, co-reactant exposure, and a second purge Initially, the substrate is exposed to a precursor like a metal halide, which chemisorbs onto the surface, forming a self-limiting monolayer due to surface saturation Following this, a purging step eliminates any unreacted precursor and byproducts The process continues with the introduction of a co-reactant, such as water or oxygen, which reacts with the precursor to create a thin film Finally, a second purge removes any leftover byproducts and unreacted co-reactants, allowing the cycle to repeat for achieving the desired atomic-scale film thickness.

ALD is particularly beneficial for energy storage materials, such as LiNi0.8Co0.1Mn0.1O2

NMC811 cathodes in lithium-ion batteries (LIBs) necessitate uniform and precise coatings to improve their stability and performance Atomic Layer Deposition (ALD) offers a significant advantage in this context by creating ultrathin, conformal layers that safeguard active materials from degradation due to interactions with electrolytes.

Aim and Objective

This thesis focuses on enhancing the cycling stability and high-rate capacity of NMC811 cathode materials through the use of the SALD method, which allows for precise atomic-scale coating thickness under atmospheric conditions, making it suitable for large-scale production The coating is designed to reduce surface degradation, limit side reactions with the electrolyte, and improve the structural stability of the cathode A comparative analysis of coated versus uncoated cathodes will highlight the superior electrochemical performance of the coated materials The anticipated results aim to advance the development of durable, high-performance lithium-ion batteries for real-world applications.

EXPERIMENT

Preparation of cathode materials

No Chemicals Chemical formula Grade

1 NMC811 LiNi0.8Co0.1Mn0.1O2 Battery BTR New

3 Poly(vinylidene fluoride) -(C2H2F2)n- Battery Sigma-Aldrich

4 N-methyl-2-pyrrolidone C5H9NO Battery Sigma-Aldrich

5 Diethylzinc (C2H5)2Zn Analytical Sigma-Aldrich

9 Ethylene carbonate C3H4O3 Analytical Sigma-Aldrich

10 Dimethyl carbonate C3H6O3 Analytical Sigma-Aldrich

Vacuum drying oven, convection drying oven electrode foil casting machine

Figure 2.1 (a) SALD system(b) Ozone generator (c) Spray nozzle (d) Details of the components of the SALD system The basic components of the SALD system are described in Figure 2.1, including:

1 Bubbler: contains metal precursors or reactant co-reactants

2 Gas lines: includes the line for the precursor and the dilution line (using N2 as the carrier gas)

3 Spray nozzle: designed with gas channels, including metal precursors, reactant co-reactants, inert gas, and an exhaust channel

4 Sample holder: capable of heating up to 300°C

6 System control software includes controls for motion, gas flow rate, and temperature."

2.1.3 Preparation for ZnO coating on NMC811

To assess the performance of NMC811 in lithium-ion batteries (LIBs), a slurry was prepared by mixing 90% NMC811, 5% Super-P as a conductive additive, and 5% poly(vinylidene fluoride) (PVDF) as a binder This mixture was milled for 30 minutes using a mortar and pestle before incorporating an N-methyl-2-pyrrolidone (NMP) solution The resulting slurry was then applied to an aluminum foil current collector using a doctor blade and dried at 120 °C for 12 hours under vacuum conditions.

The schematic diagram in Figure 2.2 illustrates the coating process utilizing precursors for ZnO deposition on the NMC811 cathode This process was conducted using a home-built Spatial Atomic Layer Deposition (SALD) system, employing diethylzinc (C2H5)2Zn (DEZ) and water vapor (H2O) as the precursors The deposition was carried out at a controlled temperature of 100 °C, with samples positioned 200 μm from the injection head and oscillating at a speed of 3 cm/s Additionally, nitrogen (N2) bubbling flow rates were maintained through the DEZ during the process.

H2O bubblers were kept at 30 sccm and 150 sccm, respectively Before reaching the substrate surface, the flows through the DEZ and H2O bubblers were diluted with 170 sccm and 150 sccm of N2, respectively

The samples NMC811 with 50, 100, 150 cycles of ZnO were represented 50c coated cathode, 100c coated cathode and 150c coated cathode, respectively

Figure 2.2 Processing of ZnO deposition on NMC 811 via ALD

To assess the electrochemical performance of the cathode, a circular cathode with a diameter of 15 mm was constructed into a CR-2032 coin cell This cell incorporated a polypropylene separator and utilized a 1M LiPF6 electrolyte solution, comprised of a 1:1 blend of ethylene carbonate and dimethyl carbonate, alongside a lithium metal anode.

Figure 2.3 Structure of the CR2032 button cell battery

Material characterization

X-ray diffraction (XRD) is a powerful analytical technique used to study the atomic and molecular structure of crystalline materials By directing X-rays onto a sample, XRD provides detailed information about the crystal structure, chemical composition, and physical properties of materials The technique relies on the fact that the wavelength of X-rays, typically between 0.2 and 10 nm, is like the distance between atoms in a crystal lattice When X-rays interact with the crystal lattice, they are scattered in various directions, creating a unique diffraction pattern that can be measured and analyzed

The structure of the sample was analyzed using X-ray diffraction (XRD, Rigaku Miniflex 600) in in the range 10 ≤ 2 θ ≤ 70° with a step size of 0.026°

Scanning Electron Microscopy (SEM) is a powerful technique for examining the surface structure and composition of materials at extremely high magnifications, making it invaluable in materials science, biology, and forensics By directing a focused beam of high-energy electrons at a sample's surface, SEM generates signals, including secondary electrons, backscattered electrons, and characteristic X-rays The secondary electrons provide high-resolution images that showcase the topography of the sample, while backscattered electrons enhance contrast based on atomic number, aiding in the identification of compositional differences.

SEM images were acquired using Hitachi TM4000 Plus

Energy Dispersive X-ray Spectroscopy (EDX or EDS) is an analytical technique used to determine the composition of solid samples by analyzing the X-ray spectrum emitted when the sample interacts with high-energy radiation, such as electron beams in electron microscopes.

Energy Dispersive X-ray Spectroscopy (EDX) analyzes the unique frequencies of X-rays emitted by different elements in a solid material By capturing the emitted X-ray spectrum, EDX reveals the chemical elements within the sample and their relative abundances, providing valuable insights into its composition.

EDX spectra were acquired using Hitachi TM4000 Plus.

Electrochemical measurement

The charge and discharge mechanism of NMC811 (LiNi₀.₈Co₀.₁Mn₀.₁O₂) is driven by the movement of lithium ions within its layered crystal structure As a nickel-rich cathode in lithium-ion batteries (LIBs), NMC811 offers exceptional energy density due to its high nickel content, as illustrated in its charge/discharge profile shown in Figure 2.4.

Charge-discharge measurements were conducted utilizing a battery testing system, Neware between 2.7 and 4.3 V vs Li + /Li

The cyclic voltammetry (CV) mechanism of NMC811 reveals its redox activity, stability, and lithium-ion transport dynamics Distinct redox peaks observed during CV analysis indicate the intercalation and deintercalation processes of lithium ions The electrochemical behavior is predominantly influenced by nickel, which plays a crucial role in these transitions.

The Ni 2+/Ni 4+ ratio, with minor contributions from cobalt and manganese remaining in the Mn 4+ state, serves as a structural stabilizer in NMC811 Cyclic voltammetry (CV) studies indicate that lithium insertion and extraction occurs within a voltage range of 3.0 V to 4.4 V; however, exceeding cutoff voltages of 4.2 V can lead to undesirable side reactions, including electrolyte oxidation, which degrades performance Over multiple cycles, shifts or reductions in CV peaks signify structural transformations and capacity losses caused by parasitic reactions at the electrode/electrolyte interface.

In Phenikaa University, phase reactions occur at moderate charge states, but elevated voltages can lead to lattice strain and parasitic reactions These effects can either broaden or diminish cyclic voltammetry (CV) peaks, indicating a decrease in electrode stability.

Figure 2.45 CV curve of NMC811 [49]

Cyclic voltammetry (Biologic SP-300) was recorded in voltage range of 2.7 ‒ 4.5V at a scan rate of 0.1 mV.s -1

Electrochemical Impedance Spectroscopy (EIS) is a crucial method for analyzing the electrochemical behavior of NMC811 lithium-ion batteries It involves applying a small alternating current signal and measuring the voltage response across various frequencies, revealing the battery's impedance, which includes both resistance and reactance This impedance is typically visualized in a Nyquist plot, where resistance is displayed on the x-axis and reactance on the y-axis The impedance data can be effectively modeled using an equivalent circuit that incorporates components such as bulk resistance (Rs).

In Phenikaa University, the internal study of battery performance focuses on key factors such as the resistance of the electrolyte and conductive paths, charge transfer resistance (Rct), which indicates electron flow resistance, and double layer capacitance (Cdl), reflecting the capacitive behavior at the electrode/electrolyte interface Additionally, Warburg impedance is analyzed to understand the diffusion of lithium ions, offering valuable insights into ion transport dynamics within the battery.

Figure 2.56 Nyquist plots in impedance spectra of NMC811 [50]

The Li-ion diffusion coefficients for all samples were calculated using the following equation:

𝑅 is the gas constant, 𝑇 is the absolute temperature,

𝐴 is the surface area of the cathode,

𝑛 is the number of electrons transferred in the half-reaction for the redox couple,

𝐹 is the Faraday constant, is the concentration of Li ions in the solid, is the diffusion coefficient (cm²/s),

𝜎 is the Warburg factor, which is related to 𝑍

EIS was recorded by Biologic SP-300 in frequency range of 0.01-10 6 Hz

RESULT AND DISCUSSION

Studying characterization material and electrochemical performance of

To distinguish between the two types of cathodes produced, we will refer to the directly coated cathode as the "coated" cathode, and the uncoated electrode as the "bare" cathode

The XRD spectrum of NMC811, shown in Figure 3.1, reveals diffraction peaks that correspond to the hexagonal α-NaFeO2 structure within the trigonal crystal system, specifically the R-3m space group The absence of additional peaks indicates there are no secondary phases or impurities present Furthermore, the splitting observed in the (006)/(102) and (108)/(110) peak pairs across all samples confirms the establishment of a well-defined layered structure.

Copies for internal use only in Phenikaa University b SEM images

The SEM images of NMC811, shown in Figure 3.2 at magnifications of 5000 and 1000, reveal that the bare particle surface consists of spherical nanosized particles that aggregate into larger particles, approximately 5 micrometers in size This nanostructured material enhances the diffusion of Li+ ions in the solid phase, offering significant advantages for performance.

Copies for internal use only in Phenikaa University active sites, leading to the improvement of the specific capacity and rate performance of the cathode

The charge/discharge profile of the NMC811 cathode, depicted in Figure 3.3, shows a voltage versus specific capacity curve at a low rate of 0.1C (1C = 200 mA g⁻¹) within a voltage range of 2.7–4.3V This profile highlights the characteristic features of the NMC811 material, revealing three distinct plateaus that indicate phase transition points during the charging and discharging cycles, which reflect the electrochemical behavior of the cathode The initial charge capacity recorded for the cathode is 225 mAh g⁻¹.

The cycling performance of the NMC811 cathode at 50 °C, within a voltage range of 2.7–4.3 V and a 1C current rate, reveals significant capacity fading Initially, the cathode exhibits a discharge capacity of 175 mAh g⁻¹, but over time, capacity retention diminishes to only 51% This substantial degradation underscores the cathode's limited stability and performance when subjected to high temperatures and elevated current rates.

D is ch a rg e C a p a ci ty ( m A h g -1 )

Coating ZnO by SALD

Figure 3.5 XRD spectrum of coated cathode

Figure 3.5 shows that the peak positions and intensities of the sample remain consistent with the original, although the lack of the ZnO phase may be due to its amorphous nature, which has a limited effect on the material's structure The integrated intensity ratio of (003)/(104) is a key indicator of cation mixing within the lattice; values below 1.2 alongside merging of the (108)/(110) pair indicate Ni and Li-ion mixing The bare sample exhibits a ratio of 1.8, while the coated sample shows a ratio of 2, with distinct peaks for (108)/(110) observed between 2θ = 62 to 72° The coated sample's ratio exceeds 1.2, indicating a well-structured α-NaFeO2 arrangement with minimal cation mixing, while crystalline presence is notably absent.

ZnO peaks indicates that the ZnO coating on the electrode surface is in an amorphous form

Copies for internal use only in Phenikaa University b SEM images and EDX spectrum

Figure 3.6 SEM (a-,b) and EDX mapping (c-f) of coated cathode

After the application of a ZnO coating, the morphology of the electrode remains unchanged, but the surface becomes smoother, as shown in Figure 3.6 a-b Figures 3.6c to 3.6f present EDS mapping of Zn, Co, Mn, and Ni across a large area of the electrode, indicating that all elements are uniformly distributed The EDS data confirms the presence of the ZnO coating, demonstrating a consistent distribution of ZnO over the cathode surface.

Figure 3.7 Concept Li + and e pathway in cathode Formatted: Superscript

Figure 3.7 illustrates the process of direct coating on the cathode, highlighting the efficient transport of Li+ ions and electrons through NMC811 particles within the electrode Jung et al emphasize that direct coating on a pre-fabricated cathode enhances electrical conductivity and facilitates rapid electron transport, as it minimizes the resistance of the coating layer on individual powder particles compared to atomic layer deposition (ALD) methods.

3.2.2 Optimizing thickness of coating layer a Coating cathode with 50 cycles of ZnO by SALD method (50c coated cathode)

Figure 3.8 Charge/discharge profile of 50c coated cathode Figure 3.8 illustrates the initial charge and discharge profiles of a 50c-coated NMC

811 cathode sample, tested at a current density of 0.1C (1C = 200 mA g -1 g⁻ạ) within

Specific Capacity (mAh g -1 ) 50c coated cạthode 0.1C

The NMC 811 cathode material, used within a voltage range of 2.7–4.3V, demonstrates distinct electrochemical behavior characterized by three phase transition plateaus during charge and discharge The initial charge capacity is recorded at 223 mAh g⁻¹, reflecting strong performance in the first cycle Additionally, a first Coulombic efficiency (FCE) of 92% indicates the battery's high efficiency in charge-discharge cycling, showcasing minimal energy loss.

Figure 3.9 demonstrates the cycling performance of a 50c coated cathode at a temperature of 50 °C, tested within a voltage range of 2.7–4.3 V and under a current rate of 1C The results indicate notable capacity degradation, with the cathode providing a discharge capacity of 171 mAh g⁻¹.

Discharge capacity 50c coated cathode (mAh g -1 ) Coulumbic efficiency (%)

The coated cathode exhibits a capacity retention of only 55% at 1C, with coulombic efficiency becoming unstable after 50 cycles This instability is largely attributed to secondary reactions at the cathode-electrolyte interface, alongside the dissolution of transition metal ions caused by acidic HF in the electrolyte These factors highlight the performance limitations of the coated cathode during prolonged cycling, particularly after 100 cycles of ZnO application using the SALD method.

Figure 3.10 Charge/discharge profile of 100c coated cathode

Figure 3.10 displays the initial charge and discharge profiles of a 100c-coated cathode sample, tested at a current density of 0.1C (with 1C defined as 200 mA g -1 g⁻ạ) within a

Specific Capacity (mAh g -1 ) 100c coated cạthode 0.1C

In Phenikaa University, the voltage range for internal use is between 2.7 and 4.3 V, where the charge-discharge profiles of the NMC 811 cathode material reveal three distinct plateaus indicative of its phase transition points The initial charge capacity is recorded at 207 mAh g⁻¹, showing a slight capacity loss during discharge, a common trait in lithium-ion batteries due to irreversible processes Notably, the cathode achieves a first Coulombic efficiency (FCE) of 97%, reflecting high efficiency in charge-discharge cycling, minimal energy loss, and outstanding performance, especially for high-rate applications.

Figure 3.11 The cycling performance at 1C for 100c coated cathode

Cycle D is ch a rg e c a p a ci ty ( m A h g -1 )

C o u lu m b ic e ff ic ie n cy ( % )

Figure 3.11 illustrates the cycling performance of the 100c-coated cathode, tested at

At 50°C and within a voltage range of 2.7–4.3 V at a current rate of 1C, the cathode exhibits significant capacity degradation, achieving a discharge capacity of 182 mAh g⁻¹ and maintaining a capacity retention of 77% The coulombic efficiency remains stable over 100 cycles, indicating minimal side reactions and enhanced compatibility between the cathode and electrolyte These findings emphasize the performance characteristics of the 50C-coated cathode, shedding light on its electrochemical behavior under elevated temperatures and extended cycling, particularly after being coated with ZnO using the SALD method for 150 cycles.

Figure 3.12 presents the charge and discharge profiles of a 150c-coated cathode sample tested at a current density of 0.1C (1C = 200 mA g⁻¹) within a voltage range of 2.7–4.3 V The charge-discharge behavior aligns with that of the NMC811 cathode material, showcasing three distinct voltage plateaus linked to its phase transitions The initial charge capacity of the coated cathode is 188 mAh g⁻¹, while the initial discharge capacity is measured at 187 mAh g⁻¹ for both coated and uncoated cathodes, indicating a high level of efficiency in energy storage.

(FCE) is calculated to be 99%, indicating minimal irreversibility during the initial cycle

These findings suggest that the 150C coating does not significantly impact the electrochemical performance of the NMC811 cathode, preserving its inherent charge- discharge behavior and efficiency

Figure 3.12 Charge/discharge profile of 150c coated cathode Figure 3.13 presents the cycling performance of the 150c-coated cathode, evaluated at

At 50 °C and a voltage range of 2.7–4.3 V with a current rate of 1C, the cathode exhibits significant capacity degradation, achieving a discharge capacity of 142 mAh g⁻¹ at 1C and maintaining a capacity retention of 84% after 100 cycles Notably, the coulombic efficiency (CE) remains stable throughout these cycles, suggesting a reduction in side reactions and electrolyte decomposition These findings highlight the thermal stability and cycling performance of the 150C-coated cathode, providing valuable insights into its behavior under high-temperature and prolonged cycling conditions.

Figure 3.13 The cycling performance at 1C for 150c coated cathode d Comparison of the electrochemical properties under different ZnO coating conditions

Figure 3.14 illustrates the charge-discharge voltage profiles of cathodes coated with varying cycles (50, 100, and 150) at a current density of 0.1C Each sample displays clear charge-discharge plateaus, indicative of phase transitions in cathode materials Notably, the 100c-coated cathode demonstrates the highest specific capacity, reflecting the optimal coating conditions for enhanced electrochemical performance Conversely, the 150c-coated cathode reveals the lowest capacity due to structural degradation, while the 50c-coated cathode shows moderate performance, likely resulting from incomplete coating or insufficient application.

Cycle D is ch a rg e c a p a ci ty ( m A h g -1 )

C o u lu m b ic e ff ic ie n cy ( % )

Copies for internal use only in Phenikaa University crystallinity Overall, the coating layers significantly impacts the specific capacity and voltage profile

Figure 3.14.Charge/discharge profile of 50, 100, and 150c coated cathodes

50c coated cathode 100c coated cathode 150c coated cathode 0.1C

Figure 3.15 The cycling performance at 1C for 50, 100, and 150c coated cathodes

Figure 3.15 illustrates the cycling performance of cathodes coated at varying cycles (50,

The cathode coated at 100°C shows the best performance, maintaining the highest discharge capacity over 100 cycles at 1C, indicating optimal coating quality In contrast, the cathode coated at 50°C suffers significant capacity degradation, suggesting issues with coating durability or interfacial stability Meanwhile, the cathode coated at 150°C, despite having the lowest initial capacity, exhibits stable cycling behavior, likely due to reduced reactivity or enhanced structural integrity at higher temperatures.

50c coated cathode 100c coated cathode 150c coated cathode

Copies for internal use only in Phenikaa University emphasize the critical role of coating layers in determining the electrochemical stability and capacity retention of cathode materials over extended cycling.

Comparison electrochemical measurements of bare and coated cathodes

Figure 3.16 illustrates the initial charge and discharge profile of both bare and coated samples at a current density of 0.1C (1C = 200 mA g -1 ) in the voltage range of 2.7 – 4.3V

The two cathodes demonstrate similar electrochemical characteristics typical of Ni-rich cathodes, featuring three voltage plateaus at 3.7, 4.02, and 4.22 V, which correspond to multiphase transitions from hexagonal to monoclinic and between hexagonal phases The initial charge capacities are 222 mAh g -1 for the bare cathode and 207 mAh g -1 for the coated cathode, while the initial discharge capacities are 191 mAh g -1 and 203 mAh g -1, respectively, indicating that the ZnO coating does not diminish cathode capacity The first Coulombic efficiencies (FCE) are 85% for the bare sample and 97% for the coated sample, with the latter benefiting from a smoother surface that reduces Li + ion consumption for forming the cathode electrolyte interface (CEI) layer By the second cycle, the CEI for both cathodes increased to 87% and 98%, respectively, highlighting the enhanced stability provided by the CEI protective layer.

Figure 3.16 Charge/discharge profile of bare and ZnO-coated NMC811 at 0.1C

Specific Capacity (mAh g -1 ) coated cathode

Figure 3.17 CV currve of bare and ZnO-coated NMC811

The CV measurement was conducted to analyze the extraction and intercalation behavior of Li+ ions, revealing three redox peaks at 3.78, 4.04, and 4.23 V, which correspond to phase transitions from hexagonal to monoclinic and back to hexagonal structures The first anodic curve shows that the peak at 3.78 V marks the transition from Ni2+ to Ni4+ In the bare sample, a noticeable decrease in discharge voltage at approximately 3.78 V and a decline in peak intensity after two cycles indicate increased impedance during the charge/discharge process, leading to rapid capacity loss Conversely, the coated sample demonstrates minimal changes in peak intensity after two cycles, suggesting improved electrochemical performance.

Figure 3.18 The rate capacity of bare and ZnO-coated NMC811

Figure 3.18 illustrates the rate capacity comparison between bare and coated samples tested at 25°C The cells underwent charge/discharge cycles at rates from 0.1C to 2C for every five cycles, followed by cycling at 0.1C The results clearly show that the coated cathode exhibits superior rate capacity compared to the uncoated cathode, with the coated cathode discharging a satisfactory capacity.

The study reveals that the tested material achieved a discharge capacity of 171 mAh g -1 at a rate of 1C and 144 mAh g -1 at 2C, retaining 84.23% and 70.93% of its initial capacity of 203 mAh g -1 at 0.1C, respectively In comparison, the bare cathode demonstrated inferior performance, with a discharge capacity of only 161 mAh g -1 at 1C.

The application of a ZnO coating significantly enhances the rate capability of NMC811, as evidenced by the observed increase in capacity to 120 mAh g -1 at 2C Figures 3.13b and 3.13c illustrate that the average operating voltage notably decreases at high C rates due to polarization, highlighting the importance of reducing polarization to improve performance.

The cycling performance of uncoated and coated cathode samples was assessed within a voltage range of 2.7 – 4.3V at 50 °C The uncoated cathode showed significant capacity degradation at 1C, primarily due to secondary reactions with the electrolyte and the dissolution of transition metal ions from acidic HF in the electrolyte This issue is further intensified by electrolyte decomposition linked to increased oxidation during high-potential charge/discharge cycles In contrast, the coated cathode demonstrated a discharge capacity of 182 mAh g -1 at 1C, achieving 77.47% capacity retention, while the uncoated cathode only retained 51.72% Thus, the ZnO coating layer markedly improves the cycling performance of cathode materials, with both types exhibiting a Coulombic efficiency (CE) of approximately 98-99%.

Figure 3.19 The cycling performance at 1C for bare and ZnO-coated NMC811

This study utilized Electrochemical Impedance Spectroscopy (EIS) to evaluate the effects of ZnO-coated NMC811 cathodes The Nyquist plots for both bare and coated cathodes, illustrated in Figures 3.20 and 3.21, exhibit similar shapes before and after cycling at 1C and 50 °C Notably, the semicircle in the plots indicates the charge transfer resistance (Rct), which decreased from 89 Ω for the bare cathode to 76 Ω for the coated cathode after 100 charge/discharge cycles This reduction in Rct highlights the effectiveness of the ZnO coating in mitigating side reactions, reinforcing its positive impact on cathode performance.

ALD coating on the layered NMC811 cathode, further reinforcing the ability to improve both rate performance and cycling stability

Figure 3.20.Nyquist plots of bare and coated NMC811 fresh cells

Figure 3.21 Nyquist plots of bare and coated NMC811 after 100cycles charge/discharge at 1C

The coated sample exhibits a higher Li+ ion diffusion coefficient than the bare sample, demonstrating that Li+ ions can move more freely within the coated sample This enhanced mobility results in superior C-rate performance for the coated sample compared to its bare counterpart.

The enhanced diffusion of Li+ ions in the coated sample indicates that the ZnO coating significantly improves the electrochemical performance of lithium-ion batteries (LIBs) by facilitating ion transport and stabilizing the solid electrolyte interphase (SEI) layer This improvement contributes to better overall capacity retention, underscoring the beneficial effects of the ZnO coating on cathode performance in LIBs.

Table 3.1: Diffusion coefficient of Li + ion in bare cathode and coated cathode before and after 100 cycles

The results illustrated in Figure 3.19 indicate that the XRD patterns of the coated sample maintain consistent peak intensity and position after 100 cycles at 1C In comparison, the bare sample experiences notable changes following the same testing conditions.

100 charge-discharge cycles at 1C, especially in the structure of NMC811 Notably, the intensity ratio of the (003)/(104) peaks is significantly reduced compared to the initial

Phenikaa University has observed that the reduction in peak intensity indicates a mixing of Li+ and Ni+ ions Such structural alterations are typically linked to performance degradation over extended cycling periods.

Figure 3.23 XRD patterns of the NMC811 bare and ZnO-coated NMC 811 after charging/discharging 100 cycles at 1C

CONCLUSION

The ALD technique was effectively utilized to apply a layer of amorphous ZnO onto bare NMC811, significantly enhancing the electrode's electrochemical performance

The application of 100 ALD layers significantly improved the discharge capacity and cycle life of the coated cathode material compared to uncoated samples The ZnO coating plays a crucial role in promoting the conversion of Ni 2+ to Ni 3+, which effectively reduces the interaction between Li + ions and Ni 2+.

After 100 cycles at 1C, the discharge capacity of 100C ZnO is 142 mAh g -1 , higher than

51 mAh g -1 bare NMC811 Moreover, at a high rate 2C, the discharge capacity of 100- cycle ZnO-NMC811 stands at 144 mAh g -1 , surpassing the 82 mAh g -1 of bare NMC811

The improvement in battery performance is due to a high-quality, uniform ZnO coating layer that effectively prevents metallic dissolution and HF corrosion, while also enhancing structural stability at high voltages This coating facilitates continuous lithium-ion transport into cathode particles during charging and discharging, making the atomic layer deposition (ALD) process a promising solution for the battery industry It enables the development of high-performance electrodes that can withstand high-rate cycling, even under elevated temperatures.

The modification of ZnO coatings significantly improves the electrochemical performance of NMC811 cathode materials This study advances the atomic layer deposition (ALD) coating strategy, offering a simplified process to enhance NMC811 for industrial and commercial applications.

1 Nie M., Xia Y.-F., Wang Z.-B et al (2015), Effects of precursor particle size on the performance of LiNi0.5Co0.2Mn0.3O2 cathode material, Ceramics International, 41 15185-15192

2 Hou P., Yin J., Ding M et al (2017), Surface/Interfacial Structure and Chemistry of High-Energy Nickel-Rich Layered Oxide Cathodes: Advances and Perspectives, Small, 13

3 Bruce P G., Freunberger S A., Hardwick L J et al (2012), Li–O2 and Li–S batteries with high energy storage, Nature Materials, 11 19-29

4 Manthiram A., Chung S H.,Zu C (2015), Lithium–sulfur batteries: progress and prospects, Advanced materials, 27 1980-2006

5 Ngo D T., Le H T T., Pham X.-M et al (2017), Facile Synthesis of Si@SiC Composite as an Anode Material for Lithium-Ion Batteries, ACS Applied Materials & Interfaces, 9 32790-32800

6 Hang B T., Okada S.,Yamaki J.-i (2008), Effect of binder content on the cycle performance of nano-sized Fe2O3-loaded carbon for use as a lithium battery negative electrode, Journal of Power Sources, 178 402-408

7 Tran H H., Nguyen P H., Cao V H et al (2019), SnO2 nanosheets/graphite oxide/g-C3N4 composite as enhanced performance anode material for lithium ion batteries, Chemical Physics Letters, 715 284-292

8 Huynh L T N., Tran T T D., Nguyen H H A et al (2018), Carbon-coated LiFePO4–carbon nanotube electrodes for high-rate Li-ion battery, Journal of Solid

9 Ajayi S O., Dolla T H., Sikeyi L L et al (2024), Current update and prospects in the development of conductive metal-organic framework electrodes for lithium-based batteries, Materials Today Sustainability, 27 100899

10 He P., Yu H.,Zhou H (2012), Layered lithium transition metal oxide cathodes towards high energy lithium-ion batteries, Journal of Materials Chemistry, 22

11 Xu B., Qian D., Wang Z et al (2012), Recent progress in cathode materials research for advanced lithium ion batteries, Materials Science Engineering, 73

12 Wu Q., Zhang B.,Lu Y (2022), Progress and perspective of high-voltage lithium cobalt oxide in lithium-ion batteries, Journal of Energy Chemistry, 74 283-308

In the study by Aktekin et al (2019), titled "Cation Ordering and Oxygen Release in LiNi0.5–xMn1.5+xO4–y (LNMO): In Situ Neutron Diffraction and Performance in Li Ion Full Cells," published in ACS Applied Energy Materials, the authors investigate the cation ordering and oxygen release mechanisms in LNMO materials Utilizing in situ neutron diffraction, the research highlights the performance characteristics of Li-ion full cells, revealing significant insights into the material's structural properties and their impact on battery efficiency.

14 Fell C R., Carroll K J., Chi M et al (2010), Synthesis–structure–property relations in layered,“Li-excess” oxides electrode materials Li

[Li1/3−2x/3NixMn2/3−x/3] O2 (x= 1/3, 1/4, and 1/5), Journal of The Electrochemical

15 Liu M.-H., Huang H.-T., Lin C.-M et al (2014), Mg gradient-doped LiNi0.5Mn1.5O4 as the cathode material for Li-ion batteries, Electrochimica Acta,

16 Kim J W., Kim D H., Oh D Y et al (2015), Surface chemistry of LiNi0.5Mn1.5O4 particles coated by Al2O3 using atomic layer deposition for lithium-ion batteries,

17 Wang S., Sun C., Wang N et al (2019), Ni- and/or Mn-based layered transition metal oxides as cathode materials for sodium ion batteries: status, challenges and countermeasures, Journal of Materials Chemistry A, 7 10138-10158

18 McNulty R C., Hampson E., Cutler L N et al (2023), Understanding the limits of Li-NMC811 half-cells, Journal of Materials Chemistry A, 11 18302-18312

19 Kim J., Lee H., Cha H et al (2018), Prospect and reality of Ni‐rich cathode for commercialization, Advanced energy materials, 8 1702028

20 Lu J., Xu C., Dose W et al (2024), Microstructures of layered Ni-rich cathodes for lithium-ion batteries, Chemical Society Reviews, 53 4707-4740

21 Li H., Zhou P., Liu F et al (2019), Stabilizing nickel-rich layered oxide cathodes by magnesium doping for rechargeable lithium-ion batteries, Chemical Science,

Muñoz-Rojas et al (2017) discuss Spatial Atomic Layer Deposition (SALD) as an innovative technique for fabricating energy materials This method shows promise in the development of next-generation photovoltaic devices and transparent conductive materials, highlighting its significance in advancing renewable energy technologies The findings are published in Comptes Rendus Physique, volume 18, pages 391-400.

23 Tang L., Cheng X., Wu R et al (2022), Monitoring the morphology evolution of LiNi0.8Mn0.1Co0.1O2 during high-temperature solid state synthesis via in situ SEM, Journal of Energy Chemistry, 66 9-15

24 Ulu Okudur F., D'Haen J., Vranken T et al (2018), Ti surface doping of LiNi0.5Mn1.5O4−δ positive electrodes for lithium ion batteries, RSC Advances, 8 7287-7300

25 Zhang W., Du F.-Y., Dai Y et al (2023), Strain engineering of Li + ion migration in olivine phosphate cathode materials LiMPO4 (M = Mn, Fe, Co) and (LiFePO4)n(LiMnPO4)m superlattices, Physical Chemistry Chemical Physics, 25 6142-6152

26 Dimesso L., Fửrster C., Jaegermann W et al (2012), Developments in nanostructured LiMPO4 (M, Co, Ni, Mn) composites based on three dimensional carbon architecture, Chemical Society Reviews, 41 5068-5080

27 Simon B., Bachtin K., Kiliỗ A et al (2016), Proposal of a framework for scale‐up life cycle inventory: A case of nanofibers for lithium iron phosphate cathode applications, Integrated environmental assessment management, 12 465-477

28 Hu J., Huang W., Yang L et al (2020), Structure and performance of the LiFePO4 cathode material: from the bulk to the surface, Nanoscale, 12 15036-15044

29 Tamaru M., Barpanda P., Yamada Y et al (2012), Observation of the highest

Mn 3+ /Mn 2+ redox potential of 4.45 V in a Li2MnP2O7 pyrophosphate cathode,

30 Aravindan V., Gnanaraj J., Lee Y.-S et al (2013), LiMnPO4 – A next generation cathode material for lithium-ion batteries, Journal of Materials Chemistry A, 1

31 Wang J.,Sun X (2015), Olivine LiFePO4: the remaining challenges for future energy storage, Energy & Environmental Science, 8 1110-1138

32 Mubarok M., Syafi'ul W., Fakhrudin M et al Ce-doped NMC 811 synthesis as cathode material in AIP Conference Proceedings 2022 AIP Publishing

33 Bi Y., Liu M., Xiao B et al (2020), Highly stable Ni-rich layered oxide cathode enabled by a thick protective layer with bio-tissue structure, Energy Storage Materials, 24 291-296

34 Yang L., Takahashi M.,Wang B (2006), A study on capacity fading of lithium-ion battery with manganese spinel positive electrode during cycling, Electrochimica

35 Kim A.-Y., Strauss F., Bartsch T et al (2019), Stabilizing effect of a hybrid surface coating on a Ni-rich NCM cathode material in all-solid-state batteries, Chemistry of Materials, 31 9664-9672

36 Kang C., Park Y., Kim Y et al (2023), Solution-processed ZnO coated on LiNi0

8Mn0 1Co0 1O2 (NMC811) for enhanced performance of Li-ion battery cathode,

37 Nisar U., Muralidharan N., Essehli R et al (2021), Valuation of Surface Coatings in High-Energy Density Lithium-ion Battery Cathode Materials, Energy Storage

38 Li Y., Li X., Hu J et al (2020), ZnO interface modified LiNi0.6Co0.2Mn0.2O2 toward boosting lithium storage, Energy Environmental Materials, 3 522-528

39 Kim H K., Kang H S., Santhoshkumar P et al (2021), Surface modification of Ni-rich LiNi0.8Co0.1Mn0.1O2 with perovskite LaFeO 3 for high voltage cathode materials, RSC advances, 11 21685-21694

40 Ameen M., Beeker I., Haverkate L et al Next-Generation Li-ion Batteries Made with Spatial Atomic Layer Deposition as an Enabling Technology in Electrochemical Society Meeting Abstracts prime2020 2020 The

41 Park J S., Mane A U., Elam J W et al (2017), Atomic layer deposition of Al–

W–Fluoride on LiCoO2 cathodes: Comparison of particle-and electrode-level coatings, ACS omega, 2 3724-3729

42 Kong J.-Z., Ren C., Tai G.-A et al (2014), Ultrathin ZnO coating for improved electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode material, Journal of

43 Gordon R G (2013), ALD precursors and reaction mechanisms, Atomic Layer Deposition for Semiconductors, 15-46

44 Miikkulainen V., Leskelọ M., Ritala M et al (2013), Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends, Journal of

45 Wang F., Hong R., Lu X et al (2021), Improvement of long-term cycling performance of high-nickel cathode materials by ZnO coating, Nanotechnology

46 Riesgo-González V., O'Keefe C A., Grey C P et al (2024), Improving long-term capacity retention of NMC811 via lithium aluminate coatings using mixed-metal alkoxides, Journal of Materials Chemistry A, 12 22248-22261

47 Li J., Downie L E., Ma L et al (2015), Study of the failure mechanisms of LiNi0.8Mn0.1Co0.1O2 cathode material for lithium ion batteries, Journal of The Electrochemical Society, 162 A1401

48 Li T., Li D., Zhang Q et al (2022), Improving Fast Charging-Discharging Performances of Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathode Material by Electronic Conductor LaNiO3 Crystallites, Materials, 15 396

49 Heist A.,Lee S.-H (2019), Electrochemical Analysis of Factors Affecting the Kinetic Capabilities of an Ionic Liquid Electrolyte, Journal of The Electrochemical Society, 166 A1677

50 Yu H., Gao Y.,Liang X (2019), Slightly Fluorination of Al2O3 ALD Coating on

Li1.2Mn0.54Co0.13Ni0.13O2 Electrodes: Interface Reaction to Create Stable Solid Permeable Interphase Layer, Journal of The Electrochemical Society, 166 A2021

51 Tu Z., Yang G., Song H et al (2017), Amorphous ZnO quantum dot/mesoporous carbon bubble composites for a high-performance lithium-ion battery anode, ACS

52 Noh H.-J., Youn S., Yoon C S et al (2013), Comparison of the structural and electrochemical properties of layered Li [NixCoyMnz]O2 (x= 1/3, 0.5, 0.6, 0.7, 0.8 and 0.85) cathode material for lithium-ion batteries, Journal of power sources,

53 Kim T., Ono L K.,Qi Y (2023), Understanding the active formation of a cathode– electrolyte interphase (CEI) layer with energy level band bending for lithium-ion batteries, Journal of Materials Chemistry A, 11 221-231

54 Scrosati B.,Garche J (2010), Lithium batteries: Status, prospects and future,

55 Rinkel B L., Vivek J P., Garcia-Araez N et al (2022), Two electrolyte decomposition pathways at nickel-rich cathode surfaces in lithium-ion batteries,

1 Nie M., Xia Y.-F., Wang Z.-B et al (2015), Effects of precursor particle size on the performance of LiNi0.5Co0.2Mn0.3O2 cathode material, Ceramics International, 41 15185-15192

2 Hou P., Yin J., Ding M et al (2017), Surface/Interfacial Structure and Chemistry of High-Energy Nickel-Rich Layered Oxide Cathodes: Advances and Perspectives, Small, 13

3 Bruce P G., Freunberger S A., Hardwick L J et al (2012), Li–O2 and Li–S batteries with high energy storage, Nature Materials, 11 19-29

4 Manthiram A., Chung S H.,Zu C (2015), Lithium–sulfur batteries: progress and prospects, Advanced materials, 27 1980-2006

5 Ngo D T., Le H T T., Pham X.-M et al (2017), Facile Synthesis of Si@SiC Composite as an Anode Material for Lithium-Ion Batteries, ACS Applied Materials & Interfaces, 9 32790-32800

6 Hang B T., Okada S.,Yamaki J.-i (2008), Effect of binder content on the cycle performance of nano-sized Fe2O3-loaded carbon for use as a lithium battery negative electrode, Journal of Power Sources, 178 402-408

7 Tran H H., Nguyen P H., Cao V H et al (2019), SnO2 nanosheets/graphite oxide/g-C3N4 composite as enhanced performance anode material for lithium ion batteries, Chemical Physics Letters, 715 284-292

8 Huynh L T N., Tran T T D., Nguyen H H A et al (2018), Carbon-coated LiFePO4–carbon nanotube electrodes for high-rate Li-ion battery, Journal of Solid State Electrochemistry, 22 2247-2254

9 Ajayi S O., Dolla T H., Sikeyi L L et al (2024), Current update and prospects in the development of conductive metal-organic framework electrodes for lithium-based batteries, Materials Today Sustainability, 27 100899

10 He P., Yu H.,Zhou H (2012), Layered lithium transition metal oxide cathodes towards high energy lithium-ion batteries, Journal of Materials Chemistry, 22

11 Xu B., Qian D., Wang Z et al (2012), Recent progress in cathode materials research for advanced lithium ion batteries, Materials Science Engineering, 73

12 Wu Q., Zhang B.,Lu Y (2022), Progress and perspective of high-voltage lithium cobalt oxide in lithium-ion batteries, Journal of Energy Chemistry, 74 283-308

13 Aktekin B., Valvo M., Smith R I et al (2019), Cation Ordering and Oxygen Release in LiNi0 5–x Mn1 5+ x O4–y (LNMO): In Situ Neutron Diffraction and Performance in Li Ion Full Cells, ACS Applied Energy Materials, 2 3323-3335

14 Fell C R., Carroll K J., Chi M et al (2010), Synthesis–structure–property relations in layered,“Li-excess” oxides electrode materials Li [Li1/3− 2x/3NixMn2/3− x/3] O2 (x= 1/3, 1/4, and 1/5), Journal of The Electrochemical

15 Liu M.-H., Huang H.-T., Lin C.-M et al (2014), Mg gradient-doped LiNi0 5Mn1 5O4 as the cathode material for Li-ion batteries, Electrochimica Acta, 120 133-

16 Kim J W., Kim D H., Oh D Y et al (2015), Surface chemistry of LiNi0 5Mn1 5O4 particles coated by Al2O3 using atomic layer deposition for lithium-ion batteries, Journal of power sources, 274 1254-1262

17 Wang S., Sun C., Wang N et al (2019), Ni- and/or Mn-based layered transition metal oxides as cathode materials for sodium ion batteries: status, challenges and countermeasures, Journal of Materials Chemistry A, 7 10138-10158

18 McNulty R C., Hampson E., Cutler L N et al (2023), Understanding the limits of Li-NMC811 half-cells, Journal of Materials Chemistry A, 11 18302-18312

19 Kim J., Lee H., Cha H et al (2018), Prospect and reality of Ni‐rich cathode for commercialization, Advanced energy materials, 8 1702028

20 Lu J., Xu C., Dose W et al (2024), Microstructures of layered Ni-rich cathodes for lithium-ion batteries, Chemical Society Reviews, 53 4707-4740

21 Li H., Zhou P., Liu F et al (2019), Stabilizing nickel-rich layered oxide cathodes by magnesium doping for rechargeable lithium-ion batteries, Chemical Science,

Muñoz-Rojas et al (2017) discuss Spatial Atomic Layer Deposition (SALD) as a novel technique for energy materials, highlighting its potential applications in next-generation photovoltaic devices and transparent conductive materials Their research, published in Comptes Rendus Physique, emphasizes the significance of SALD in advancing energy technology.

23 Tang L., Cheng X., Wu R et al (2022), Monitoring the morphology evolution of LiNi0.8Mn0.1Co0.1O2 during high-temperature solid state synthesis via in situ SEM, Journal of Energy Chemistry, 66 9-15

24 Ulu Okudur F., D'Haen J., Vranken T et al (2018), Ti surface doping of LiNi0.5Mn1.5O4−δ positive electrodes for lithium ion batteries, RSC Advances,

25 Zhang W., Du F.-Y., Dai Y et al (2023), Strain engineering of Li+ ion migration in olivine phosphate cathode materials LiMPO4 (M = Mn, Fe, Co) and (LiFePO4)n(LiMnPO4)m superlattices, Physical Chemistry Chemical Physics,

26 Dimesso L., Fửrster C., Jaegermann W et al (2012), Developments in nanostructured LiMPO4 (M = Fe, Co, Ni, Mn) composites based on three dimensional carbon architecture, Chemical Society Reviews, 41 5068-5080

27 Simon B., Bachtin K., Kiliỗ A et al (2016), Proposal of a framework for scale‐up life cycle inventory: A case of nanofibers for lithium iron phosphate cathode applications, Integrated environmental assessment management, 12 465-477

28 Hu J., Huang W., Yang L et al (2020), Structure and performance of the LiFePO4 cathode material: from the bulk to the surface, Nanoscale, 12 15036-15044

29 Tamaru M., Barpanda P., Yamada Y et al (2012), Observation of the highest Mn3+/Mn2+ redox potential of 4.45 V in a Li2MnP2O7 pyrophosphate cathode,

30 Aravindan V., Gnanaraj J., Lee Y.-S et al (2013), LiMnPO4 – A next generation cathode material for lithium-ion batteries, Journal of Materials Chemistry A, 1

31 Wang J.,Sun X (2015), Olivine LiFePO4: the remaining challenges for future energy storage, Energy & Environmental Science, 8 1110-1138

32 Mubarok M., Syafi'ul W., Fakhrudin M et al Ce-doped NMC 811 synthesis as cathode material in AIP Conference Proceedings 2022 AIP Publishing

33 Bi Y., Liu M., Xiao B et al (2020), Highly stable Ni-rich layered oxide cathode enabled by a thick protective layer with bio-tissue structure, Energy Storage Materials, 24 291-296

34 Yang L., Takahashi M.,Wang B (2006), A study on capacity fading of lithium-ion battery with manganese spinel positive electrode during cycling, Electrochimica

35 Kim A.-Y., Strauss F., Bartsch T et al (2019), Stabilizing effect of a hybrid surface coating on a Ni-rich NCM cathode material in all-solid-state batteries, Chemistry of Materials, 31 9664-9672

36 Kang C., Park Y., Kim Y et al (2023), Solution-processed ZnO coated on LiNi0 8Mn0 1Co0 1O2 (NMC811) for enhanced performance of Li-ion battery cathode, Frontiers in Energy Research, 11 1235721

37 Nisar U., Muralidharan N., Essehli R et al (2021), Valuation of Surface Coatings in High-Energy Density Lithium-ion Battery Cathode Materials, Energy Storage

38 Li Y., Li X., Hu J et al (2020), ZnO interface modified LiNi0 6Co0 2Mn0 2O2 toward boosting lithium storage, Energy Environmental Materials, 3 522-528

39 Kim H K., Kang H S., Santhoshkumar P et al (2021), Surface modification of Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 with perovskite LaFeO 3 for high voltage cathode materials, RSC advances, 11 21685-21694

40 Ameen M., Beeker I., Haverkate L et al Next-Generation Li-ion Batteries Made with Spatial Atomic Layer Deposition as an Enabling Technology in

Electrochemical Society Meeting Abstracts prime2020 2020 The

41 Kang C., Park Y., Kim Y et al (2023), Solution-processed ZnO coated on LiNi0 8Mn0 1Co0 1O2 (NMC811) for enhanced performance of Li-ion battery cathode, 11 1235721

42 Park J S., Mane A U., Elam J W et al (2017), Atomic layer deposition of Al–

W–Fluoride on LiCoO2 cathodes: Comparison of particle-and electrode-level coatings, ACS omega, 2 3724-3729

43 Kong J.-Z., Ren C., Tai G.-A et al (2014), Ultrathin ZnO coating for improved electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode material,

44 Gordon R G (2013), ALD precursors and reaction mechanisms, Atomic Layer Deposition for Semiconductors, 15-46

45 Miikkulainen V., Leskelọ M., Ritala M et al (2013), Crystallinity of inorganic films grown by atomic layer deposition: Overview and general trends, Journal of

46 Wang F., Hong R., Lu X et al (2021), Improvement of long-term cycling performance of high-nickel cathode materials by ZnO coating, Nanotechnology

47 Riesgo-González V., O'Keefe C A., Grey C P et al (2024), Improving long-term capacity retention of NMC811 via lithium aluminate coatings using mixed-metal alkoxides, Journal of Materials Chemistry A, 12 22248-22261

48 Li J., Downie L E., Ma L et al (2015), Study of the failure mechanisms of LiNi0 8Mn0 1Co0 1O2 cathode material for lithium ion batteries, Journal of The Electrochemical Society, 162 A1401

49 Li T., Li D., Zhang Q et al (2022), Improving Fast Charging-Discharging Performances of Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathode Material by Electronic Conductor LaNiO3 Crystallites, Materials, 15 396

50 Heist A.,Lee S.-H (2019), Electrochemical Analysis of Factors Affecting the Kinetic Capabilities of an Ionic Liquid Electrolyte, Journal of The Electrochemical Society, 166 A1677

51 Yu H., Gao Y.,Liang X (2019), Slightly Fluorination of Al2O3 ALD Coating on Li1.2Mn0.54Co0.13Ni0.13O2 Electrodes: Interface Reaction to Create Stable Solid Permeable Interphase Layer, Journal of The Electrochemical Society, 166 A2021

52 Tu Z., Yang G., Song H et al (2017), Amorphous ZnO quantum dot/mesoporous carbon bubble composites for a high-performance lithium-ion battery anode, ACS

53 Noh H.-J., Youn S., Yoon C S et al (2013), Comparison of the structural and electrochemical properties of layered Li [NixCoyMnz] O2 (x= 1/3, 0.5, 0.6, 0.7,

Tiêu đề	Fabrication Of High-Capacity LiNi0.8Mn0.1Co0.1O2/ZnO Cathodes For Application In Lithium-Ion Batteries
Tác giả	Vu Tue Anh
Người hướng dẫn	Dr. Ngoc Hung Vu, Assoc. Prof. Dr. Van-Duong Dao
Trường học	Phenikaa University
Chuyên ngành	Chemical Engineering
Thể loại	master thesis
Năm xuất bản	2024
Thành phố	Hanoi

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Số trang	79
Dung lượng	1,86 MB