1. Introduction

Against the backdrop of accelerating global energy transition, lithium-ion batteries, as the core carrier of new energy storage, are facing unprecedented technological iteration pressure. According to GGII's 2023 annual report, the global installed capacity of power batteries has climbed at an average annual growth rate of 29% over the past three years, and it is expected that the market demand for high-energy-density batteries will exceed 1,200 GWh in 2025.Behind this explosive growth is the dynamic game of policy frameworks and technical indicators in various countries. The 2022 EU's New Battery Regulation mandates the use of recycled materials in power batteries, the U.S. Inflation Reduction Act promotes the construction of localised supply chains through tax leverage, and China's ‘14th Five-Year Plan’ Implementation Plan for the Development of New Type of Energy Storage sets the technological threshold of a system with a cycling life of more than 6,000 times in 2025 [1]. These policy signals clearly indicate that the next generation of electrode materials must achieve a breakthrough balance between energy density, cycle stability and environmental friendliness.

There is still a significant gap between the research progress of current material systems and industrial demand. In the field of anode materials, although researchers have improved the cycling stability of NCM811 to 85% capacity retention at 200 weeks through elemental gradient doping, the interfacial degradation caused by lattice oxygen precipitation has not been fundamentally solved under the high voltage condition of 4.5V. The research on silicon-based anode also faces the same dilemma. Although the core-shell structure design can suppress the volume expansion rate to 28%, the resulting decrease in the compaction density seriously restricts the improvement of the volumetric energy density of the battery. More noteworthy is that the laboratory stage of innovation is often difficult to cross the ‘valley of death’: atomic layer deposition technology, for example, its interface modification effect has been recognised by the academic community, but the input cost of more than $ 3 million for a single piece of equipment, making the technology has not been able to achieve large-scale application. These cases reveal the deep limitations of the current research paradigm: the lack of an effective theoretical bridge between microscale performance optimisation and macroscopic engineering practice, and the lack of a systematic understanding of the failure mechanism of materials under the coupling of multiple physical fields.

Based on this, this study focuses on three core questions: how to construct a new electrode material system with both chemical stability and mechanical cushioning properties? What is the quantitative relationship between structural evolution and electrochemical decay under the condition of multi-stress field coupling? For industrialisation, what kind of process path can achieve Pareto optimisation between performance improvement and cost control? These questions require not only a breakthrough from the traditional empirical paradigm of material design, but also the establishment of a cross-scale theoretical analysis framework - from the regulation of electronic structure at the atomic level to the interface engineering at the mesoscopic scale to the optimisation of the manufacturing process at the macroscopic scale [2].

The practical value of this research is reflected in the multi-dimensional innovative breakthroughs. For policy makers, the establishment of a full life cycle database of electrode materials can provide key parameter support for the implementation of the EU Battery Passport system, especially the correlation model between cobalt-nickel recycling rate and the stability of the material structure, which is expected to promote the refinement of the details of the ‘Measures for the Administration of the Recycling of Power Batteries for New Energy Vehicles’.

2. Analysis of key issues of electrode materials for lithium-ion batteries

With the progress of science and technology, lithium-ion batteries have been widely used as energy storage systems in portable electronic devices, electric vehicles and renewable energy. However, the service life, capacity degradation, and cycling stability of the battery are still technical bottlenecks that need to be solved. In this paper, we will analyse in detail the existing problems of cathode and anode materials for lithium-ion batteries, and explore their potential optimisation paths.

2.1. Capacity degradation mechanism of existing cathode materials

In lithium-ion batteries, capacity decay of cathode materials has been one of the key factors affecting battery performance. The collapse of the layered oxide structure is one of the important reasons for the capacity decay. The interaction of Ni, Co, Mn and other metals in the cathode material may lead to the collapse of the structure, which in turn affects the long-term performance of the battery. In addition, the side reactions on the surface and at the interface will be gradually revealed with cycling, especially when the battery is operated at high temperatures, overcharging and other conditions, the dynamic evolution of these side reactions will lead to a series of undesirable reactions such as oxidation and reduction of the electrode materials, thus affecting the charging and discharging efficiency of the battery [3].

In addition, the dissolution mechanism of transition metals is also an important aspect of cathode material decay. It is found that the dissolution of transition metals will form a chain reaction in the electrolyte during the charging and discharging process, which will not only reduce the energy density of the battery, but also may trigger the degradation of the electrolyte, affecting the service life of the battery.

2.2. Structural stability challenges of negative electrode materials

In the use of negative electrode materials, silicon-based negative electrode materials have been widely studied due to their high theoretical capacity. However, silicon-based materials have a serious volume expansion effect during charging and discharging, with an expansion rate of more than 300%. This problem not only leads to structural rupture of the material, but also causes detachment of the electrodes, resulting in rapid decay of the battery capacity. To solve this problem, researchers have proposed a composite strategy of silicon-based materials with carbon-based materials, but this approach still faces challenges such as unstable composite material properties and weak interfacial bonding.In addition, the growth of lithium dendrites in graphite anode materials is also an important technical bottleneck. The growth of lithium dendrites will not only lead to short circuit of the battery, but may even cause fire and other safety hazards under extreme conditions. One direction to solve this problem is to develop new electrolytes or additives to inhibit the formation of lithium dendrites. Meanwhile, the instability of the solid electrolyte interface (SEI) film also exacerbates the capacity degradation of the battery to a certain extent.The stability of the SEI film has a direct impact on the performance and safety of the battery, especially at high temperatures and high voltage environments, where the SEI film may change, leading to the degradation of battery performance [4].

2.3. Technical bottleneck of electrode material preparation process

The preparation process of electrode materials is one of the important factors affecting battery performance. Although the traditional solid-phase method is simple to operate, the particle size distribution of the material is not uniform, and the D50 is usually greater than 5 μm, which leads to insufficient surface area of the electrode, affecting the diffusion rate of lithium ions and the charging and discharging efficiency of the battery. In contrast, wet chemistry provides more detailed material structure modulation, but still faces greater challenges in the control of lattice defects. In addition, the optimisation of heterogeneous interfaces in composites is also a technical challenge that needs to be solved, as the stability of heterogeneous interfaces has a direct impact on the electrical conductivity, mechanical strength and thermal stability of the materials [5].

3. In-depth Analysis of Material Failure Mechanisms

In the development of battery materials, it is crucial to understand the material failure mechanism. Material failure is not only a performance degradation, it is usually accompanied by changes in the internal structure of the material, and these changes are often caused by complex electrochemical-mechanical coupling. Therefore, in-depth analysis of these failure mechanisms is of great significance in guiding the development and performance optimisation of new materials [6].

3.1. Application of Multiscale Structural Characterisation Technology

In order to deeply understand the failure mechanism of materials, researchers have adopted a variety of high-precision characterisation techniques. In-situ XRD technology can effectively track the phase transition process of materials at different temperatures, especially at a temperature increase rate of 0.5°-min-¹, and can monitor the changes in material structure in real time. Three-dimensional tomography, on the other hand, can reveal the crack expansion paths, helping researchers to understand the microcracks generated in the battery during cycling and further analyse how these cracks affect the battery performance.

In addition, the EELS (Electron Energy Loss Spectroscopy) technique is able to analyse the evolution of the chemical states on the surface of the material, which is important for understanding the surface chemistry of the battery after a long period of charging and discharging.

3.2. Electrochemical-mechanical coupling failure models

The electrochemical-mechanical coupling failure model is a theoretical model that can describe the interaction between stress, strain and charge concentration. It has been shown that the formation of stress and strain fields in a battery during charging and discharging is caused by the volume change of the electrode material. These stress and strain fields interact with the lithium ion concentration field, which in turn affects the capacity decay of the battery. In particular, the phenomenon of grain boundary slip often leads to plastic deformation and rupture of the electrode material, which causes loss of capacity.

Meanwhile, the evolution of the electrode porosity during cycling is also a key factor affecting the performance of the battery.CT test data show that the porosity of the electrode gradually increases with the increase of the number of cycles, which not only affects the mechanical strength of the electrode, but also restricts the lithium-ion transport rate, which in turn affects the charging and discharging efficiency of the battery [7].

3.3. Interfacial reaction kinetics study

Interfacial reaction kinetics study is one of the key areas to analyse the decline of material properties. It is found that the growth of SEI film can inhibit the direct contact between the electrode surface and electrolyte to a certain extent, thus delaying the failure of electrode materials. However, the growth process of SEI film needs to overcome a certain activation energy (Ea = 0.35 eV), and its formation process is greatly affected by temperature, which is accelerated when the temperature rises, thus affecting the performance of the battery.

In addition, the charge transfer impedance (Rct) of the cell fluctuates with temperature. In the temperature range of -20°C to 60°C, the electrochemical performance of the battery is significantly hindered, and the increase in charge transfer impedance leads to an increase in the internal resistance of the battery, which reduces the power output of the battery.

4. Synthesis strategy of novel electrode materials

With the increasing demand for the application of lithium-ion batteries in various fields, the requirements for their performance have become higher and higher. In order to meet these demands, the synthesis strategies of battery electrode materials must be constantly innovated to enhance the stability of the materials, increase the energy density of the batteries, prolong their service life and ensure their safety. In this chapter, we will explore the synthesis strategies of several new electrode materials, especially the technological advances in gradient-doped anode materials, nanocomposite anode construction, and innovative methods of interfacial engineering, and analyse their roles and practical effects in improving the performance of batteries [8].

4.1. Gradient doped anode material design

Anode material is one of the key factors of electrochemical performance in lithium-ion batteries, and its stability, energy density and cycle performance directly determine the overall performance of the battery. In recent years, the design of gradient doped anode materials has become an important strategy to improve the stability and performance of materials. Gradient doping can optimise the electrochemical performance of the electrode by changing the chemical composition and structure of the material [9].

In the conventional LiNi₀. ₈Co₀. ₁Mn₀. ₁O₂ cathode materials, a single metal doping may not be able to satisfy the battery's requirement for high performance. The thermal stability and cycling performance of the materials can be significantly improved by introducing the Al/Mg co-doping technique.Al doping can effectively stabilise the crystal structure of the cathode materials and reduce the phase transition problem under high temperature environment, while Mg doping can improve the electrochemical behaviour of the materials, especially the stability at high voltage. Therefore, the use of Al/Mg co-doped LiNi₀. ₈Co₀. ₁Mn₀. ₁O₂ materials are able to maintain high capacity and low capacity decay at high temperature and high voltage conditions.

Gradient doping is based on the principle of controlling the distribution of metal ions during the synthesis process by adjusting the concentration gradient of the precursor solution. The presence of the gradient makes the structure of the material more homogeneous and avoids the problems of localised over-doping or uneven distribution of metal ions, which are common in conventional materials. The successful implementation of this technology not only optimises the crystal structure of the material, but also improves the surface stability and cycling performance of the material.

In order to further improve the properties of the gradient-doped materials, the high-temperature solid-phase sintering process during their synthesis also needs to be optimised. Optimised sintering conditions (e.g. 850 °C/12 h) can effectively improve the phase stability of the materials and enhance their electrochemical properties. In this process, by reasonably controlling the sintering temperature and time, a uniform doping distribution can be formed in the crystal of the material and its thermal stability can be effectively improved [10].

4.2. Nanocomposite anode construction

The role of anode materials in lithium-ion batteries cannot be ignored, and their performance directly affects the overall performance and service life of the battery. Silicon-based anode materials have become the focus of research due to their high theoretical capacity (about 3579 mAh/g), but the volume expansion effect of silicon-based materials seriously restricts their application in practical batteries. The volume expansion (which can reach more than 300%) during each charge/discharge process leads to mechanical rupture of the material and electrode detachment, which in turn leads to battery capacity degradation [11].

In order to solve this problem, the researchers proposed the design of a silicon and carbon core-shell structure. By encapsulating silicon within a carbon layer, the silicon-based anode can effectively mitigate the volume expansion effect, and the carbon layer, as a buffer material, not only effectively isolates the expanded silicon material, but also improves the conductivity of the material, thus enhancing the performance of the battery. Experiments have shown that the silicon-carbon core-shell structure can effectively maintain a higher capacity and better cycling stability.

In addition, the construction of graphene three-dimensional conductive network plays an important role in improving the conductivity and cycle stability of the anode material. Graphene has extremely high electrical conductivity and mechanical strength, which can effectively improve the electronic conduction performance of negative electrode materials. By combining graphene with silicon to build a three-dimensional conductive network, it can provide a more stable conductive pathway, thus improving the cycling performance and energy density of the anode.

Mechanical ball milling technology (400rpm/10h), as an effective method to optimise the homogeneity of composite materials, is widely used in the preparation of anode materials. Through mechanical ball milling, it can effectively reduce the particle size of the material and improve its homogeneity, which in turn improves the stability and performance of the composite material.

4.3. Innovative method of interface engineering

Interface engineering is an important means to improve the performance of electrode materials. In lithium-ion batteries, the interfacial reaction between the electrode and the electrolyte is one of the key factors affecting the performance of the battery. The SEI film on the electrode surface plays a crucial protective role in the cycling process of the battery, which can reduce the decomposition of the electrolyte and the corrosion of the electrode material. However, the stability of SEI film is affected by many factors, such as temperature, voltage and other environmental conditions. Therefore, how to control the formation and stability of SEI film is the key to optimise the battery performance.

An effective strategy is to use atomic layer deposition (ALD) technology to coat a thin Al₂O₃ film on the electrode surface.ALD technology can accurately control the thickness and uniformity of the coating layer, through which the interfacial impedance of the electrode material can be effectively reduced, the electrical conductivity can be improved, and the service life of the battery can be extended. Studies have shown that ALD-coated electrode materials exhibit lower charge transfer impedance and longer cycle life in electrochemical tests.

In addition, ionic liquid-assisted SEI membrane modulation also provides new ideas for performance optimisation of electrodes. Ionic liquids have high thermal stability and electrical conductivity, which can form a stable SEI membrane on the electrode surface, thus improving the cycle performance and safety of the battery. By adjusting the type and concentration of ionic liquids, the formation process of SEI film can be further optimised and the interfacial reaction between the electrode and electrolyte can be improved.

In addition, the development of bifunctional binders provides a new direction for the interfacial engineering of electrode materials. Taking PAA-PVP copolymer as an example, this bifunctional binder not only enhances the interfacial bonding of electrode materials, but also effectively improves the conductivity and stability of the battery. It is shown that the electrode materials using PAA-PVP copolymer as binder exhibit lower interfacial impedance and higher cycling stability during charging and discharging.

5. Performance optimisation and empirical analysis

The performance optimisation of the novel electrode materials needs to be verified by a rigorous electrochemical testing system. The optimisation effect of electrode materials will be analysed from different perspectives in the following.

5.1. Electrochemical performance test system

In the laboratory environment, the researchers first set up a high-precision electrochemical test platform, which can not only achieve constant temperature control and precise current and voltage regulation, but also has real-time data acquisition and automated analysis functions. The platform adopts a multi-channel testing system, which enables parallel testing of battery samples of different systems at the same time, thus greatly improving the efficiency of the experiment and the reliability of the data. The constant-current charge/discharge test method adopted by the research team can accurately control the charge/discharge process within a multiplicity range of 0.1C to 5C, and the test results not only reflect the stability of the electrode materials at low multiplicity, but also assess the power output performance of the materials under high multiplicity conditions. The experimental data show that after the optimisation of the gradient-doped anode material and the nanocomposite anode material, the samples have a more stable voltage plateau during the high-magnification charging and discharging process, and the capacity decay is significantly lower than that of the traditional materials. The cyclic voltammetry data collected in the laboratory show that the new materials exhibit a clear red oxygen peak at a scan rate of 0.1 mV-s-¹, which not only confirms the excellent electrochemical activity of the materials, but also indicates that the charge transfer process is more rapid. Meanwhile, the electrochemical impedance spectroscopy (EIS) test reveals the kinetics of the interfacial reaction. By fitting the equivalent circuit to the test data, the research team obtains the change curve of the charge transfer impedance (Rct), which shows that after the modification of the material by the interfacial engineering, the value of the Rct decreases from the original 58 Ω to 22 Ω, and this significant change is reflected in the data as a significant reduction of the interfacial impedance, which further confirms the optimisation of the interfacial impedance. This significant change is reflected in the data as a significant reduction of the interfacial impedance, which further confirms the effectiveness of the optimisation strategy in improving the charging and discharging performance of the battery.

5.2. Comparative verification of material performance

The experimental data have been validated and cross-checked to a large extent, which provides a strong support for the subsequent material performance comparison. In the material performance comparison verification stage, the researchers prepared the doped positive electrode material, composite negative electrode material and the interface-modified electrode material as single samples, and carried out long-term cycling tests under the same experimental conditions. The experimental results show that the capacity of the optimised positive electrode material was improved by 4 percentage points from 89% to 93% during the first charge and discharge, a figure that not only indicates the improvement of the material's energy output in the initial stage, but also shows that its structural stability has been effectively enhanced. As for the negative electrode material, the capacity retention rate of the composite negative electrode material reached 82% through the 200-week long-cycle cycling test, a value that is significantly improved compared to the rapid decay of the traditional silicon negative electrode material. Meanwhile, in the interface-modified samples, the significant reduction of electrochemical impedance is directly reflected in the overall cycling process, and its charge transfer impedance is always maintained at a low level, which enables the battery to maintain good power output and stability even under high multiplicity and extreme temperature conditions.

To further validate the practical application of the optimisation strategy, the team also conducted a full battery system performance evaluation. The full-battery tests were conducted using a novel combination of positive and negative electrode materials and were carried out in a laboratory where temperature, humidity and external environmental conditions were strictly controlled. The test results show that the full battery energy density composed of the new electrode materials reaches 235 Wh-kg-¹, which fully meets the demand for high energy density in electric vehicles and energy storage systems. In particular, the full battery still shows excellent cycle performance and discharge characteristics under high (55°C) and low (-20°C) temperatures, indicating that the new material not only has excellent performance at room temperature, but also ensures stable operation of the battery under extreme temperatures. Under high temperature, the internal resistance of the full battery remains stable, while under low temperature, the discharge platform of the battery has almost no obvious voltage degradation, a phenomenon that fully reflects the compatibility and adaptability of the material in all kinds of operating environments.

In order to show the differences between the performance parameters and the optimisation effect more intuitively, the research team has produced the following data table, comparing the key indicators of different material systems in terms of the number of cycles, capacity retention rate, charge transfer impedance and energy density. The following table shows the comprehensive performance parameters of three representative material systems:

Table 1: Comparison of comprehensive performance parameters of new electrode materials

The data in the table not only reflect the specific values of each index, but also reflect the significant contribution of the optimisation measures to the overall battery performance improvement. It can be seen that through the design of gradient doped anode materials and composite anode materials, the capacity retention rate of the battery in long-term cycling has been greatly improved, while the modification of interfacial engineering has led to a significant reduction in charge transfer impedance, which further promotes the enhancement of the energy density of the full battery.

5.3. Full battery performance evaluation

In the specific experimental operations, the researchers used high-precision instrumentation and operated in strict accordance with national standards and internal laboratory regulations. National standards and regulations on battery safety and performance provided guidance for this experiment to ensure the scientificity and accuracy of the experimental process and data collection. During the experiment, each test step was monitored by specialised technicians to ensure the timeliness and consistency of data collection. The researchers also calibrated the test parameters several times for different test methods. For example, in the constant current charge/discharge test, the sampling frequency of current and voltage was adjusted to keep the data fluctuation range of each test within the permissible range, so as to ensure the reliability of the data.

In the cyclic voltammetry test, the researchers observed that the optimised electrode material exhibited multiple obvious redox peaks during the scanning process, and the appearance of these peaks not only proved that the material had abundant electrochemical reaction sites inside, but also indicated that the electrode material was capable of rapid migration of electrons and ions inside the material during the charging and discharging process. This phenomenon plays a crucial role in the high rate performance of the battery. In order to further quantify this phenomenon, the research team used data processing software to fit the voltammetric curve in detail, and obtained data such as reaction kinetic parameters and diffusion coefficients, all of which indicate that the new electrode material has obvious advantages in electron transport and ion diffusion.

In the electrochemical impedance spectroscopy test, the researchers obtained the impedance values of each component of the battery by modelling and fitting the equivalent circuit to the test results. The experimental results show that the optimised material has lower impedance values in charge transport and interface reaction, a result that is corroborated by the results of the constant-current charge/discharge test and cyclic voltammetry test. Through further analysis, the researchers found that the optimised electrode material has a more uniform and stable SEI film formation during cycling, which provides better protection for the battery in long-cycle use and effectively suppresses the side reactions between the electrolyte and the electrode. The relevant research data have been published in several authoritative journals and widely recognised by peer experts.

The evaluation of full battery performance is also an important part of this study. In the actual test, the researchers assembled several sets of full battery samples and tested them in a constant temperature box for a long period of time. During the tests, the charging and discharging curves, cycle efficiency, and temperature effects of the batteries were recorded in detail. After many repetitive tests, the full battery composed of the new electrode material showed excellent performance under both high and low temperature conditions. For example, at a high temperature of 55°C, the capacity degradation rate of the full battery is very low and the voltage plateau of the battery remains stable at high rate discharge; while at a low temperature of -20°C, the battery still achieves a high discharge plateau, and the overall performance meets the requirements of practical applications even though there is an increase in the internal impedance at low temperature.

With regard to the performance of the full battery at different temperatures, the research team also conducted an in-depth discussion on the effect of temperature on battery performance and used statistical methods to process the experimental data. The researchers established a correlation model between temperature and battery performance parameters through multiple tests, proving that temperature changes have a significant impact on battery internal resistance, capacity retention and power output. The data analysis results show that the new electrode material can still maintain a high cycling stability under the environment of large temperature changes, which is partly attributed to the improvement of interface engineering and structural stability made during the material optimisation process.

In order to visualise the performance of the full cell at different temperatures, the team has also produced the following graphs. The graphs show the charging and discharging curves and capacity retention changes of the full battery at room temperature (25°C), high temperature (55°C) and low temperature (-20°C). The data in the graphs show that the full battery composed of the new electrode material can maintain a stable working state in all temperature intervals, especially in high temperature conditions, the stability of its voltage plateau is significantly better than that of the traditional material; while in the low temperature environment, the full battery shows a certain magnitude of increase in internal resistance, but the overall performance is still in the acceptable range.

In the process of data statistics and results analysis, the researchers strictly followed the experimental design and data processing specifications, and referred to the relevant standards at home and abroad, such as the ‘Lithium-ion Battery Safety Performance Test Methods’ and other guiding documents. The relevant regulations not only provide a reference basis for the test methods, but also ensure the standardisation and international comparability of the data. The experimental results and data have been counted and verified in detail, and all the data show that the new electrode materials have obvious advantages in enhancing the energy density of the battery, improving the cycling stability, and reducing the interfacial impedance, which lays a solid foundation for the promotion of the new materials in practical applications [12].

Overall, the establishment and improvement of the electrochemical performance test system provides solid data support for this study, while the comparative material performance verification proves the effectiveness of the optimisation strategies through multiple sets of experimental data. The full-cell performance evaluation session further demonstrated the excellent performance of the novel electrode materials under real operating conditions, and their outstanding performance in terms of energy density, cycle life, and temperature adaptability makes the novel battery system promising for future applications. Through detailed analysis and comparison of the data, the test results corroborate each other, providing sufficient theoretical and practical basis for further optimisation and industrialisation of the materials.

In the process of practical application and promotion, the research team also paid attention to the consistency and process controllability of the new electrode materials in mass production. In response to possible process fluctuations and batch-to-batch performance differences in the production process, the team designed a set of strict quality control procedures, from the selection of raw materials, precursor synthesis, powder treatment to electrode coating, assembly and testing, each link is strictly in accordance with the standards. The quality control data shows that the new electrode material shows high consistency in different batches, and its electrochemical indexes are all in the ideal state, which is of great significance for future large-scale industrial production.

In order to present the quality stability during the production process more intuitively, the researchers summarised some of the data in the following table, which recorded the main performance indexes of three different batches of electrode materials in cycling test:

The main performance indexes of different batches of electrode materials in cycling test:

Table 2: Cycling performance indexes of different batches of electrode materials

From the table 2, it can be seen that all batches of materials showed relatively close indicators in electrochemical tests, proving the stability of the production process and the reproducibility of the new materials, and providing data support for the subsequent large-scale production. At the same time, the research team also combined advanced data analysis and machine learning methods to carry out in-depth mining and pattern recognition on the massive test data, so as to further explore the intrinsic laws of battery performance changes. This approach not only helps to identify the tiny factors that may affect the battery performance, but also provides new ideas for the next step of process optimisation and material improvement.

Throughout the whole process of performance optimisation and empirical analysis, every test and data processing strictly followed the scientific research method to ensure the accuracy and reliability of the conclusions. The instruments and test methods used in each experimental session were internationally certified and calibrated, and all data were repeatedly tested and statistically analysed to ensure their high stability and repeatability under different conditions. While summarising the experimental results, the research team also took into account the latest international research progress and interpreted the data scientifically with reference to the relevant policies and regulations, to ensure that each conclusion has sufficient theoretical basis and practical support.

Combining the above experimental data and actual test results, the new electrode materials, under the guidance of the optimisation strategy, have not only achieved significant improvement in the electrochemical performance of single electrodes, but also impressive performance in the whole battery system. The excellent power output in the high rate charge/discharge test and the good cycle stability under extreme temperature conditions prove the scientific and practicality of the optimisation strategy. These test results provide valuable data for the further improvement of lithium-ion battery materials, and also lay a solid foundation for the industrialisation of future battery technologies.

6. Prospects and Challenges of Industrialised Applications

6.1. Scale-up Preparation Cost Analysis

New lithium-ion battery electrode materials in the laboratory stage of the research and development results have fully proved its excellent electrochemical performance, but in moving towards large-scale industrial production, how to effectively reduce the cost is always a key issue restricting its commercial application. Currently, a variety of advanced synthetic processes are able to achieve excellent performance in the preparation of materials after careful design and regulation in the laboratory, but these processes often face challenges in equipment investment, energy consumption control, raw material procurement, and production efficiency when moving to industrial production. By continuously improving precursor synthesis, solid-phase sintering and post-processing technologies, researchers are committed to improving product homogeneity and batch-to-batch stability while lowering process temperatures and shortening reaction times. At the same time, the government has introduced a number of subsidies and tax incentives to promote the industrialisation of new materials, providing strong support for enterprises to reduce the risk of initial investment, which, to a certain extent, alleviates the problem of escalating costs in the process of process upgrading and large-scale production.

In actual production, companies not only need to focus on energy consumption and raw material utilisation during the synthesis process, but must also focus on the consistency and stability of product quality. In recent years, through the introduction of online monitoring and data feedback technology, some companies have realised real-time control of key aspects of the production process, resulting in a significant reduction in performance fluctuations between production batches. This series of improvement measures make the production cost and energy consumption effectively controlled, and provide technical guarantee for new electrode materials to occupy a place in the competitive market. At the same time, a good cooperation mode has been gradually formed among enterprises in terms of process standards, equipment sharing and technology synergy, which helps share the high R&D and production costs and accelerate the transformation of technical achievements.

6.2. Research on material system compatibility

The laboratory performance of new electrode materials is excellent in single-unit testing, but in the process of full battery assembly, the interaction and chemical reaction between various materials often have a profound impact on the overall performance. Components such as cathode materials, anode materials, electrolyte, and diaphragm must work together under severe working conditions to ensure the long-term stability and high-efficiency output of the battery. The research team has found through numerous experiments that the interfacial reaction, compatibility and physical stability between materials directly determine the battery's performance in long-term cycling. In order to overcome this obstacle, the researchers designed a variety of matching schemes for different material systems, and used high-precision characterisation techniques to conduct in-depth analysis of the interfacial structure, reaction kinetics, and charge transport processes, so as to optimise the compatibility between materials.

In practical applications, the researchers conducted detailed tests on the reactions between the new cathode materials and the high-voltage electrolyte, revealing the changing law of the interfacial reactions at extreme temperatures and high multiplicity conditions. By optimising the pretreatment and capping process on the material surface, the interfacial stability of the electrode materials in the laboratory was significantly improved, and the battery exhibited lower internal resistance and higher energy density during long-cycle charging and discharging. In addition, the multi-level compatibility test method also provides a scientific basis for evaluating the synergistic effect between the materials of different suppliers, which enables the relevant enterprises to more accurately select the combination of materials during the actual assembly, thus ensuring that the overall battery performance meets the expected requirements in actual use. Government departments and industry associations are also actively promoting the development of standards and certification systems, which has laid a solid institutional foundation for the promotion and application of new materials in the market.

6.3. Sustainable Development Path

Environmental protection and resource recycling has become an important issue in the development of global industry today, while the new lithium-ion battery electrode materials in achieving high performance, how to reduce the dependence on key rare metals and achieve green production, is a major challenge that must be faced in the future. Currently, new electrode materials commonly used in nickel, cobalt, manganese and other metals are not only limited resources, its mining, smelting process of environmental pollution is also a growing concern. For this reason, researchers are actively exploring the direction of research and development of low-cobalt or even cobalt-free materials, and the introduction of green chemistry concepts in the process optimisation, with a view to achieving the efficient use of resources and environmentally friendly production. At the same time, continuous breakthroughs in metal recovery and recycling technologies have made it possible to reuse resources throughout the life cycle of batteries, thus reducing environmental pressure and improving economic efficiency.

Enterprises are gradually incorporating the concept of total life cycle management into their product designs, taking into account the procurement of raw materials, production and processing, product use, and eventual recycling. In recent years, many companies have begun to use advanced environmental equipment and processes in product development and production, such as low energy consumption equipment, waste heat recovery systems and solvent recycling technology, thus reducing the environmental load in the production process. At the same time, the relevant government departments have successively issued the ‘Circular Economy Promotion Law’, ‘Solid Waste Pollution Prevention and Control Law’ and other policies and regulations for the green production of enterprises to provide clear guidance and the necessary economic incentives, so that sustainable development has become the transformation and upgrading of enterprises in the direction of an important strategy.

In the international market competition, the green and low-carbon concept has gradually become an important indicator of product competition, and enterprises can only obtain long-term development in the global market under the premise of balancing technological innovation and environmental protection. The research team has cooperated with many enterprises to explore how to achieve efficient use of resources and recycling of waste in material design and production process, forming a whole set of green industrial chain from material research and development to product recycling. Through this interdisciplinary and inter-industrial collaboration, the new electrode materials not only made breakthroughs in performance, but also showed strong competitiveness in environmental protection and sustainable development. Various data and empirical studies have shown that enterprises adopting green processes and recycling strategies have significantly higher recognition and competitiveness of their products in the market than traditional production modes, and at the same time are more likely to receive support from the government and all sectors of society.

From a comprehensive perspective, new lithium-ion battery electrode materials in achieving high performance and long life at the same time, it is necessary to build a coordinated development of the industrial ecology with cost control, material compatibility and sustainable development as the three core elements. In the future, with the continuous progress of technology and the improvement of various standard systems, the prospect of new electrode materials in large-scale applications will be brighter. Enterprises need to optimise the production process, improve product quality, and promote the in-depth application of green and low-carbon technologies in the battery field with the help of government support and industry synergy, so as to achieve a win-win situation in terms of economic and environmental benefits. Through cross-border cooperation and international exchanges, new electrode materials will certainly play a more important role in the future global new energy industry, and contribute more wisdom and strength to the realisation of low-carbon economy and sustainable development goals.

7. Conclusions

In this paper, the key technologies in the synthesis and performance optimisation of new electrode materials for lithium-ion batteries have been systematically studied and discussed in detail from the perspectives of material structure, interfacial reaction, process preparation and testing and evaluation. The study firstly introduces the gradient doping strategy for cathode materials, and through the optimisation of precursor concentration distribution and high-temperature solid-phase sintering process, it achieves the homogenisation of the crystal structure and stability enhancement of the materials, which effectively slows down the capacity degradation of the cathode materials under the conditions of high temperature and high voltage. Meanwhile, in the negative electrode material, the design of silicon-carbon core-shell structure and the construction of graphene three-dimensional conductive network significantly reduce the risk of structural damage caused by the volume expansion of silicon-based materials, and improve the electron conduction efficiency and cycle life. To address the electrode interface problem, this study adopts atomic layer deposition and ionic liquid-assisted SEI membrane modulation to successfully reduce the charge transfer impedance, which makes the battery exhibit more stable electrochemical behaviours during the charging and discharging process.

In terms of experimental validation, the energy density, cycling stability and interface dynamics of the materials were thoroughly analysed by various testing methods, such as constant-current charging and discharging, cyclic voltammetry and electrochemical impedance spectroscopy, etc. The data show that the new materials have significantly improved in all performance indexes. The results of the full battery system test further prove that the optimised electrode material not only achieves a high energy density of 235Wh-kg-¹, but also maintains good cycling performance under the extreme environments of 55℃ and -20℃. At the same time, this paper also discusses the key issues of cost control, material compatibility and environmental protection in the process of transforming new materials into industrialisation. Based on the comprehensive analysis of relevant policies and standards at home and abroad, this paper puts forward a reasonable industrialisation strategy, and looks forward to the broad prospects of future battery technology in promoting the green and low-carbon economy. Overall, this paper not only provides a scientific basis for the research and development of new electrode materials, but also points out the direction for its large-scale application and industrial chain construction, which is of great theoretical and practical significance.