16340 battery

Development of positive electrode material technology for 16340 battery

This paper reviews the development history of production and preparation technology of positive electrode materials for lithium-ion batteries and analyzes the development direction of positive electrode materials for lithium-ion batteries. At the end of the last century, from the perspective of processing performance and battery performance of positive electrode materials for lithium-ion batteries, the research team of Tsinghua University proposed a technology for preparing high-density spherical precursors by controlling crystallization. Combined with the subsequent solid-phase sintering process, an industrial technology for preparing lithium-containing electrode materials was proposed. Among them, the controlled crystallization method for preparing precursors can regulate and optimize the performance of materials at four levels: unit cell structure, primary particle composition and morphology, secondary particle size and morphology, and particle surface chemistry. The materials produced by this technology process have the characteristics of easy control of particle size and morphology, good uniformity, batch consistency and stability, and can simultaneously meet the comprehensive requirements of batteries for material electrochemical performance and processing performance. Due to the high packing density of the material, it is particularly suitable for high specific energy batteries. This technology process is applicable to a variety of positive electrode materials and is suitable for large-scale production. As time goes by, it has gradually been proven to be the best production technology process for positive electrode materials for lithium-ion batteries, and has been widely accepted and recognized by the current industry. This is also one of the important contributions made by Chinese scientists to the international lithium-ion battery industry. Lithium-ion batteries have the advantages of high specific energy, high energy storage efficiency and long life. In recent years, they have gradually occupied the main market share of electric vehicles, energy storage systems and mobile electronic devices. Since Sony Corporation of Japan took the lead in commercializing lithium-ion batteries in 1990, the negative electrode material has always been carbon-based material, while the positive electrode material has made great progress and is the most critical material to promote the performance of lithium-ion batteries. The research and development of positive electrode materials for lithium-ion batteries are mainly carried out in three aspects: 1) At the basic science level, it is mainly to discover new materials, or to calculate, design and synthesize the composition, crystal structure and defect structure of materials, in order to discover new positive electrode materials with excellent electrochemical performance; 2) At the material chemistry level, it is mainly to explore the synthesis technology, in order to optimize the material structure factors such as the crystal structure, orientation, particle morphology, interface, etc. of the material, to obtain the best match between the electrochemical performance, processing performance and battery performance, with the purpose of developing the material structure and its synthesis method that can achieve the best comprehensive performance of positive electrode materials; 3) At the material engineering technology level, it is mainly to develop large-scale, low-cost and stable equipment and processes, in order to develop reasonable engineering technology to meet market demand. In order for the positive electrode materials of lithium-ion batteries to play the best performance in the whole battery, it is necessary to further optimize the physical and chemical properties of the materials such as crystal structure, particle structure and morphology, particle surface chemistry, material packing density and compaction density on the premise of optimizing the material composition, and at the same time, it is necessary to strictly prevent the introduction of trace metal impurities in the process. Of course, stable and high-quality large-scale production is an important guarantee for the stable performance of materials in battery manufacturing. As lithium battery technology improves and the lithium battery market matures, the application fields of different cathode materials are gradually divided, that is, the performance requirements of lithium-ion batteries for various cathode materials are also different. Therefore, the mainstream synthesis technology and process of cathode materials have also experienced different development paths. This article reviews the industrial application history of the main cathode materials of lithium-ion batteries, focuses on the industrial technology development process of the materials, and looks forward to the development direction of cathode material manufacturing technology. 1. Performance requirements of lithium-ion batteries for cathode materials (1) Industry performance requirements for lithium-ion batteries To understand the technical indicators of cathode materials, we need to start with the technical indicators of batteries. In the early days of the lithium-ion battery industry, it mainly served the development of mobile electronic products, such as laptops, tablets, mobile smart terminals (mobile phones), etc. In recent years, the new energy industry and the electric vehicle industry have risen rapidly, and the demand for lithium-ion batteries has grown rapidly, stimulating the lithium battery industry to accelerate its development. Therefore, lithium-ion batteries need to meet many technical performance indicators before they can be recognized by the industry and further developed. Among these technical indicators, the most basic ones are specific energy, cycle stability, specific power, cost, safety and reliability, durability, manufacturing efficiency, sustainability, etc. The indicators are interrelated, and different application fields have different priorities for lithium-ion battery indicators. Compared with lithium-ion batteries in portable electronic products, the biggest difference between lithium-ion batteries used in energy storage and electric vehicle industries is that the capacity of single cells has increased by ten times or even dozens of times, and the complexity of the functions, structures and applications of battery modules has increased significantly, which has put forward higher requirements for the consistency and reliability of lithium-ion batteries. The most important technical indicators of lithium-ion batteries are specific energy and cycle performance, followed by performance indicators such as specific power, safety, reliability, cost and consistency. The higher the specific energy, the lower the material cost per unit energy (Wh); the longer the cycle life, the lower the actual cost of the battery. At present, lithium-ion batteries for mobile smart terminals need to meet the requirements of specific energy of more than 700Wh/L and cycle performance of more than 200 times, while lithium-ion batteries for electric vehicles need to meet the requirements of specific energy of more than 140Wh/kg (lithium iron phosphate or lithium manganese oxide positive electrode materials) or 200Wh/kg (layered oxide positive electrode materials) and cycle performance of more than 1,500 times. Lithium-ion battery positive electrode materials must meet the above battery indicators before they can be accepted by the mainstream battery market. At present, the specific energy and cycle performance of lithium-ion batteries mainly depend on the positive electrode materials, so the main research and development goals of lithium-ion battery positive electrode materials are high specific energy and long cycle life. For lithium-ion batteries for electric vehicles, although their requirements for volume specific energy are not as stringent as those for portable electronic product batteries, after all, the space of passenger cars is limited, and the weight of the car body will affect the mileage of electric vehicles, so the mass specific energy and volume specific energy of the battery are still very important. In addition, the requirements for almost all other performance of automotive lithium-ion batteries are almost stringent, far higher than the performance requirements of portable electronic product batteries. There are three biggest differences between it and portable electronic product batteries: First, electric vehicle power requires higher voltage and current, and requires a large number of single cells to be connected in series and parallel. This makes the specific energy that can be actually used by the battery pack not only depend on the specific energy of the single cell, but also depend on the consistency of the single cell, especially the dynamic consistency. The consistency of 16340 battery has gradually attracted people's attention in recent years. Second, the scale of single cells has increased significantly, which makes the price of single cells higher, and the harm caused by thermal runaway is more serious. Therefore, the market is more sensitive to the safety and reliability of batteries. Third, since electric vehicles need a service life of 10-15 years, the requirements for cycle performance are very high, generally requiring more than 1,500 times. In addition, since electric vehicles need to start and accelerate, there are certain requirements for the specific power of 16340 battery. With the rapid development of the electric vehicle industry, power lithium-ion batteries will become the mainstream products of the lithium battery industry together with portable electronic product batteries in the future. Specific energy and cycle performance are the most important performance indicators that are always pursued in the development of lithium-ion battery technology. With the increasing attention paid to safety, reliability, specific power and consistency, the technology in this area is expected to develop rapidly. It should be noted that as lithium-ion batteries gradually penetrate into various fields of the national economy, there will be more and more non-mainstream lithium-ion battery market segments, which have special requirements for battery performance indicators and are beyond the scope of this article. (2) Positive electrode materials that meet the needs of the mainstream lithium-ion battery industry. At present, the positive electrode materials that meet the battery performance requirements of the mainstream lithium-ion battery market mainly include layered lithium cobalt oxide LiCoO2 materials (LCO), spinel lithium manganese oxide LiMn2O4 materials (LMO), olivine lithium iron phosphate LiFePO4 materials (LFP), olivine lithium manganese iron phosphate LiMn0.8Fe0.2PO4 materials (LMFP), layered ternary materials LiNi1/3Mn1/3Co1/3O2 materials (NMC333), Layered ternary materials include LiNi0.4Mn0.4Co0.2O2 (NMC442), LiNi0.5Mn0.3Co0.2O2 (NMC532), LiNi0.6Mn0.2Co0.2O2 (NMC622), LiNi0.7Mn0.2Co0.1O2 (NMC721), LiNi0.8Mn0.1Co0.1O2 (NMC811) and layered high-nickel materials LiNi0.8Co0.15Al0.05O2 (NCA), etc. From the perspective of industrial application, the above materials have different physical and chemical characteristics and are suitable for lithium-ion batteries in different application fields, so the key performance indicators of material products are also different. Lithium cobalt oxide LiCoO2 (LCO) material is the positive electrode material with the highest compaction density at present, so the prepared lithium-ion battery has the highest volume energy ratio, making it the main positive electrode material for lithium-ion batteries for tablets and mobile smart terminals. Its main disadvantages are limited cobalt resources and high costs, which limit its widespread application in the field of electric vehicles. The structure and reaction characteristics of this material are that as the charging voltage gradually increases, the amount of lithium released gradually increases, and the available capacity of LCO gradually increases, but when the amount of lithium released exceeds 55% (that is, the charging potential relative to metallic lithium is 4.25V, and the charging voltage relative to the graphite|LCO full battery is 4.2V), the structural stability of the material decreases rapidly, and the life and safety deteriorate rapidly. Therefore, LCO positive electrode materials that can withstand higher charging voltages and meet the chemical stability requirements of battery applications are the main development direction of current material preparation technology. LCO has a stable structure and is relatively easy to synthesize. Its preparation technology is simple and relatively mature. Before 2000, LCO was mainly produced by solid-phase sintering technology of cobalt oxide/lithium carbonate mixtures. With people's extreme pursuit of product bulk density, specific surface modification, etc., the method of controlling crystallization to prepare lithium cobalt oxide precursors has gradually become the main industrial preparation technology due to its advantages in material morphology control. The main advantages of spinel lithium manganese oxide LiMn2O4 (LMO) materials are abundant raw material resources, low cost, and good battery safety; its recognized main disadvantages are low battery specific energy and poor cycle stability. Since the 1990s, people have explored the application of LMO in electric buses, passenger cars, special vehicles, power tools and other fields, attracted by its low raw material and process costs and good safety. The traditional solid-phase sintering preparation technology cannot achieve the regulation of material structure. In order to improve its cycle stability and material tap density, the author's team introduced the liquid phase process to prepare the precursor in 2004, and further improved the material performance through surface coating, lattice doping, surface gradient and other technologies. However, due to the high solubility of the material, the cycle stability of the battery has not been well met. Only by further cooperating with the electrolyte can the battery life meet the demand. At present, although LMO is rarely used in automotive 16340 battery, it has been widely used in small power battery industries such as electric bicycles that are more cost-sensitive. In addition, with people's attention to the safety of large-scale 16340 battery for vehicles, blending with ternary materials has also become one of the main uses of LMO materials. The main advantages of olivine lithium iron phosphate LiFePO4 (LFP) materials are abundant raw material resources, low cost, good battery safety and cycle performance, and its main disadvantage is low battery specific energy. This material has been widely used not only in electric bicycles, electric buses, electric buses, and special vehicles, but also in large-scale energy storage industries. Since lithium ions in this material are transmitted along a one-dimensional channel, the material has significant anisotropy and is extremely sensitive to defective structures. The preparation process needs to ensure the high uniformity of the synthesis reaction and the precise Fe:P ratio in order to obtain better capacity and rate performance. Based on the complexity of the material structure and the synthesis reaction, there are two main difficulties in the preparation of this material: first, the process requires a reducing atmosphere. The reaction raw materials have different requirements for the reducing atmosphere due to different types and particle sizes. Local reducibility that is too high or too low will cause impurities to remain in the product; second, the material needs to be carbon-coated on the surface or compounded with other types of conductive agents, which makes it difficult to control the impurities and compaction density of the material. In 2005, the author's research group proposed to use controlled crystallization technology to prepare high-performance iron phosphate precursor (FP), and then prepare LFP through carbon thermal reduction with lithium source and carbon source. The above process route has been further improved and has become the mainstream lithium iron phosphate material preparation technology. In order to meet people's continuous pursuit of LFP battery performance, high uniformity and high batch stability have become the most concerned product indicators of LFP positive electrode materials. On the one hand, traditional solid-phase sintering technology is difficult to achieve efficient consistency control in principle, and on the other hand, consistency control will lead to a significant increase in process costs. Compared with the solid-phase process, the precursor prepared by the liquid phase process or the positive electrode material prepared by hydrothermal/solvothermal has better structural adjustability and controllability, and good batch stability and reaction uniformity. Similar to large chemical plants, continuous solvothermal processes are easy to achieve ultra-large-scale production. Therefore, liquid phase technology has gradually become the development trend of the next generation of high-quality LFP positive electrode material preparation technology. Olivine lithium manganese iron phosphate LiMn0.8Fe0.2PO4 (LMFP) material is an upgraded version of LFP material, with a specific energy 10% higher than LFP; due to the differences in the reaction kinetics of Mn and Fe raw materials and the requirements for reducing atmosphere, the main disadvantage of this material is that it is difficult to prepare. At present, the industrial preparation process based on the solid phase method is still immature and has not yet been widely used. If the liquid phase preparation technology of LFP is industrially applied, the preparation problem of this type of material is expected to be solved. The development of ternary materials began at the beginning of this century. In the late 1990s, with the large-scale application of LCO, due to the limitation of cobalt resources, people hoped to replace cobalt with nickel, which is more abundant in resources. Compared with LCO, LiNiO2 material (LNO) was once considered the most promising lithium-ion battery material because of its abundant resources, low price and higher capacity. However, as a positive electrode material, LNO also has difficult problems such as difficult preparation, unstable material structure and poor battery cycle performance. In order to solve the problems of structural stability and thermal stability of LNO, people doped cobalt and manganese into the bulk phase of LNO, and the earliest nickel-cobalt-manganese ternary material NCM came into being. In order to improve the tap density of the material, in 2005, the author's research group proposed to use controlled crystallization technology to prepare high-density spherical nickel-cobalt-manganese hydroxide precursors, and then mixed and sintered them with lithium sources to prepare NCM333. On this basis, the material performance was further improved through surface coating, lattice doping, surface gradient and other technologies. The layered ternary material LiNi1/3Mn1/3Co1/3O2 (NMC333) has the best comprehensive performance among all layered oxide positive electrode materials composed of Ni, Co, and Mn transition metal elements, and is currently the main positive electrode material for passenger car 16340 battery. NMC333 also has a high specific capacity when charged to 4.5V. Its main disadvantage is the high cobalt content, which poses problems of resources and cost. In order to reduce costs and increase capacity, people have continuously increased the nickel content on the basis of NMC333, and developed a series of layered ternary materials with different nickel contents. NMC442 is a derivative of NMC333 to NMC532 and NMC622 is a transitional product developed. Since its comprehensive performance is not as good as NMC333, NMC532 and NMC622, the scale of production and application is relatively limited. NMC532 is one of the most widely used ternary materials. When the nickel ratio in the ternary transition metal is less than or equal to 50%, the sintering atmosphere of the material is air, and the production cost is relatively low; when the nickel ratio is greater than or equal to 60%, the sintering atmosphere requires oxygen or oxygen/air mixed gas, and the production cost is relatively high. Therefore, among the ternary series of positive electrode materials sintered in air atmosphere, NMC532 has the highest nickel content, the highest capacity, and good cost performance. It currently has a certain market share. NMC622 is a positive electrode material with good comprehensive performance, but its disadvantage is that it is difficult to prepare. With the increasing maturity of its preparation process, the application ratio of NMC622 in passenger car 16340 battery has steadily increased, and it is also one of the most widely used ternary materials. The comprehensive performance of NMC721 is not as good as that of NMC811 and NMC622. It is a transitional product in the development process of ternary materials from NMC622 to NMC811 and has not been greatly developed. The main advantages of NMC811 and NCA are high specific capacity. At the same time, nickel resources are more abundant than cobalt, the cost is lower than cobalt, and the problem of limited raw material resources is relatively small. The disadvantages are that the material preparation is difficult, it is very sensitive to moisture, and the conditions and technical thresholds for battery preparation are high. NCA has begun to be used on a large scale in the electric vehicle industry, while NMC811 is recognized as one of the main choices for lithium-ion batteries with a specific energy of more than 300Wh/kg. The various performance indicators of the above materials can meet the performance requirements of automotive lithium-ion batteries for positive electrode materials and the basic requirements of battery manufacturing technology for material processing performance. They are the main lithium-ion battery positive electrode materials that have been or are expected to be used in the industry. 2. Requirements for the preparation of high-performance positive electrode materials With the continuous deepening of people's research on the physical and chemical aspects of materials and the continuous development of material preparation technology, people have found that high-performance positive electrode materials need to be tailored from four aspects: the unit cell structure, primary particle crystal structure, secondary particle structure, and material surface chemistry, as well as the process optimization of the large-scale production process technology of materials, so that the materials can show more excellent performance and better meet the various requirements of the lithium-ion battery industry for positive electrode materials. The Lithium Ion Battery Laboratory of the Institute of Nuclear and New Energy Technology of Tsinghua University began the research and development of high-performance electrode materials for secondary batteries in the early 1990s. In the process of research and development of high-activity, high-density spherical nickel hydroxide Ni(OH)2 positive electrode materials for nickel-hydrogen batteries and their preparation technology, a new technology process for the preparation of electrode materials featuring controlled crystallization has been formed. This technology process can easily achieve structural regulation at four levels: unit cell structure, primary particle crystal structure, secondary particle structure, and material surface chemistry, and optimize the various properties of positive electrode materials to meet the requirements of electrodes and batteries for positive electrode materials. The above four levels contribute differently to the material performance: the first level, the unit cell structure, that is, the basic unit cell structure of the crystal, is mainly regulated by doping to achieve the purpose of optimizing the energy level structure/ion transmission channel of the material, thereby improving the electronic conductivity/ionic conductivity or structural stability of the material, and then improving the rate performance and cycle performance of the material. The second level, the crystal morphology of the primary particles. By controlling the synthesis conditions, the dominant growth direction, grain size, and grain stacking mode of the crystal can be changed. The optimization at this level can optimize the area of the electrochemically active/inert interface, the stress release path, and the lithium ion diffusion path, thereby improving the rate performance, cycle stability, and energy density of the battery. The third level, the secondary particle structure. Secondary particles are particles formed by the mutual fusion and stacking of primary particles. The stacking density of primary particles, the morphology of secondary particles, the size and distribution of secondary particles can be changed by synthesis conditions. The optimization at this level can obtain the best material processing performance, pole piece compaction density, and particle mechanical strength, thereby improving the energy density of the battery. The fourth level, the surface chemistry of the material. Mainly refers to the gradient of surface coating and surface element concentration. Optimization of material surface chemistry can greatly improve the performance of materials. In practice, the above four levels are interrelated and influence each other. For example, good morphology control is very conducive to the improvement of surface chemistry. The academic achievements formed by our laboratory in the 1990s when systematically developing spherical nickel hydroxide, a positive electrode material for nickel-hydrogen batteries, laid a solid theoretical and practical foundation for the subsequent development of high-performance lithium-ion battery electrode materials and opened up a new research field. In the field of electric vehicles and energy storage, batteries are required to have good consistency and reliability. Based on this, new requirements are put forward for the stability of large-scale production of positive electrode materials, and the positive electrode material industry urgently needs advanced material scale preparation technology. 3. Controlled crystallization/solid phase reaction process to prepare high-performance positive electrode materials Before 2006, the only lithium cobalt oxide LiCoO2 and lithium manganese oxide LiMn2O4 positive electrode materials that have been mass-produced for lithium-ion batteries were using mature ceramic industry synthesis technology-high temperature solid phase method. The basic process is to mix the reactants and then sinter them. The advantages of this technology are mature equipment and simple technology. The biggest disadvantage is that the particle size distribution of the product is difficult to control, and the uniformity, consistency and reproducibility are poor. Based on the technical achievements of high-density spherical nickel hydroxide, our laboratory has developed a unique controlled crystallization/solid phase reaction new process since the late 1990s. This new process takes the controlled crystallization preparation of precursors as the technical core and optimizes the material structure and its performance from four levels. Since the materials prepared by this process technology have spherical or quasi-spherical morphology, high packing density, good processing performance, and can improve the energy density of the battery, it shows excellent comprehensive performance. The controlled crystallization/solid phase reaction process is widely accepted by the industry today. In 1999, our laboratory first reported the preparation of spherical LiCoO2 positive electrode materials using Co(OH)2 as a precursor. Since the structures of Co(OH)2 and LiCoO2 are similar, the solid phase reaction temperature is low and the sintering time is short, and LiCoO2 powder with a uniform NaFeO2 layered structure without impurities can be obtained. At the same time, the process technology for optimizing Ni(OH)2 can be used to optimize the Co(OH)2 precursor, so as to obtain LiCoO2 powder with good fluidity, good dispersibility and high packing density. Subsequently, these academic ideas were used to prepare a series of positive electrode materials, which gradually developed into the main production process route of positive electrode materials for lithium batteries today, namely the controlled crystallization/solid phase reaction process. In 2001, our laboratory first published an article on the preparation of high-nickel positive electrode material LiNi0.8Co0.2O2 using spherical Ni0.8Co0.2(OH)2 as a precursor, and simultaneously carried out surface modification and Al doping modification. Al doping evolved into today's NCA material. In 2003, our laboratory first published the process technology for preparing spinel lithium manganese oxide using controlled crystallization technology, and then first proposed to improve the high-temperature cycle stability of spinel lithium manganese oxide by using "gradient materials" with rich cobalt on the surface, and further modified spinel lithium manganese oxide based on controlled crystallization technology. These studies show that controlled crystallization technology not only has good controllability in the preparation of homogeneous materials, but also has the advantages of simple process and easy control in material surface coating, especially gradient coating. Because of the low intrinsic electronic and ionic conductivity of lithium iron phosphate, it can only obtain usable electrochemical properties after nano-sizing, but the stacking and compaction density of nanoparticles is low, which seriously affects the energy density of lithium iron phosphate batteries. In 2005, our laboratory proposed a synthetic route of preparing spherical FePO4 precursors by controlled crystallization technology, then mixing lithium source and carbon source, and synthesizing high-performance and high-density LiFePO4 by carbon thermal reduction. Among them, the liquid phase method can well control the Fe:P ratio of the precursor, and can simultaneously achieve the regulation of nano primary particles and high-density spherical secondary particles, and simultaneously achieve the uniform compounding of conductive carbon in the secondary particles. Although the final lithium iron phosphate product is still obtained by solid phase sintering, the uniform, high-density, batch-stable, controllable particle size, and precisely controllable composition of the precursor greatly improves the uniformity and batch stability of lithium iron phosphate positive electrode materials and significantly reduces the impurity content. The above academic ideas have gradually been recognized by the industry and have become the basic process route for large-scale production of LFP today. Since 2005, our laboratory has reported the preparation of high-performance NMC333 positive electrode materials using controlled crystallization/solid phase reaction technology. Further modification studies on coating and doping of NMC333 cathode materials were conducted. At present, the mainstream cathode materials required by the power lithium-ion battery industry are all produced by controlled crystallization/solid phase reaction process. Especially for the synthesis of lithium iron phosphate materials and various ternary materials for large-scale energy storage and electric vehicle batteries, the controlled crystallization/solid phase reaction process has irreplaceable advantages. It can modify and regulate the precursor in a targeted manner according to the needs of different batteries. At the same time, the product is also easy to achieve good uniformity and consistency, which is crucial for the stable production of 16340 battery, especially the consistency of 16340 battery. After more than ten years of development, controlled crystallization/solid phase reaction technology has become the mainstream production technology and process in the international cathode material industry. This is an important contribution made by Chinese scientists to the lithium-ion battery industry. 4. Large-scale production technology of lithium-ion battery materials With the rapid development of large-scale energy storage and electric vehicles, more and more stringent requirements are put forward for the product quality of lithium-ion battery cathode materials. In order to meet the market's high-quality requirements for cathode materials, automated and intelligent large-scale production technology and equipment technology have become increasingly important. In the past fifteen years, the controlled crystallization/solid phase reaction technology has been improved day by day. However, my country is still a developing country, and a large number of obsolete equipment and rigid production processes are common, especially in small and medium-sized enterprises. The overall level of national industrialization is still at the stage of Industry 2.0 and Industry 3.0, and there is still a distance from the information-based and intelligent industrial production technology level of Industry 4.0 in developed countries. This has become the main problem that hinders the further improvement of the efficiency and quality of my country's manufacturing industry. This phenomenon also exists in lithium-ion battery positive electrode material production enterprises. Therefore, the production process and equipment management level of lithium-ion battery positive electrode materials in my country urgently need to be transformed and upgraded, and information technology should be used to improve, improve and reconstruct production factors, improve the level of enterprise organization and management, innovate production methods, improve asset quality and service functions, and adapt to the rapid development and changes of the market. Around 2000, new projects for lithium-ion battery positive electrode materials generally had a production capacity of 200-500 tons. Around 2010, it was generally a production capacity of 2,000 tons. At present, new projects are generally 5,000-2,000 tons in the first phase, and more than 50,000 tons are planned. With the continuous expansion of production capacity, new challenges have been raised to the design layout and operation management of the factory. In order to meet the high-quality and large-scale demand for electrode materials in the electric vehicle and energy storage industries, information-based, automated and intelligent large-scale production technologies based on automatic powder delivery have been gradually developed. At present, some domestic enterprises have begun to gradually adopt advanced large-scale production technologies. It mainly includes automatic powder delivery, automatic metering, automated production and intelligent control, information-based remote real-time monitoring, and advanced manufacturing execution systems. 5. Conclusion The lithium iron phosphate preparation process based on controlled crystallization preparation of iron phosphate precursor/carbon thermal reduction solid-phase reaction has been gradually accepted by the industry and has become the current mainstream process route. The next step is to prepare high-performance lithium iron phosphate by solvent thermal method. It is likely to become a new ultra-large-scale production method to meet the needs of large-scale fixed energy storage in the future. Among the ternary materials, NMC333 has the best comprehensive performance, NMC532 has a good price-performance ratio, and NMC811/NCA has the highest specific capacity at 4.2V. Therefore, these materials will be greatly developed in a certain period of time to meet the needs of large-scale mobile energy storage (such as electric vehicles) in the future. After more than 20 years of development, the production technology of lithium-ion battery positive electrode materials has gradually concentrated on the technical route based on controlled crystallization/solid-phase reaction process. This technical route takes the controlled crystallization preparation of precursors as the technical core, and can optimize the performance of materials at four levels. The materials prepared by this technical route have the characteristics of easy control of particle morphology, good uniformity, consistency and reproducibility. And the material has a high packing density, which can improve the energy density of the battery. Since the materials prepared by this technical route have relatively the best comprehensive performance, the controlled crystallization/solid phase reaction technical route is widely accepted by the industry today. In order to meet the high-quality and large-scale demand for electrode materials in the electric vehicle and energy storage industries, based on the concept of Industry 4.0, my country has developed large-scale production technologies including information, automation and intelligence for automatic powder transportation. The rapid development of fixed energy storage and mobile energy storage industries has driven the technological progress of lithium-ion battery positive electrode materials. In the development of positive electrode material preparation technology, the focus used to be on the research and development of unit technology and process, mainly optimizing the material processing performance and electrochemical performance through the structural regulation of materials. In the future, large-scale intelligent manufacturing still needs to focus on the scalability of unit technology and process, and more attention needs to be paid to the feedback and linkage efficiency between unit technology and process, so as to improve the energy efficiency of large-scale manufacturing processes and improve product stability. In the early stages of this technology development, Chinese researchers have made indispensable innovative contributions. At present, my country has become the largest producer of positive electrode materials for lithium-ion batteries, accounting for more than 50%. The scale of R&D is also the largest in the world. We believe that in the future large-scale intelligent manufacturing stage, Chinese scientists will also make important contributions in new processes, new equipment, and intelligence.

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