High-temperature-resistant lithium iron phosphate aluminum shell battery
By combining a multi-layer composite membrane structure and lithium iron phosphate material with vinylene carbonate electrolyte, the safety and lifespan issues of lithium-ion batteries under high-temperature environments have been solved, achieving improved stability and safety at high temperatures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-05
- Publication Date
- 2026-03-27
AI Technical Summary
Existing lithium-ion batteries are prone to safety hazards due to thermal runaway in high-temperature environments, and their cycle life is shortened and capacity decay is accelerated.
It adopts a multi-layer composite membrane structure, including a ceramic-coated membrane layer, a high-temperature resistant polymer membrane layer, and a hydrophobic and breathable membrane layer, combined with lithium iron phosphate as the positive electrode material, and adds vinylene carbonate electrolyte inside the shell, and uses heat dissipation fins to improve heat dissipation efficiency.
It effectively prevents short circuits between the positive and negative electrodes at high temperatures, improves the safety and stability of the battery at high temperatures, extends cycle life, inhibits iron ion precipitation, and ensures stable operation of the battery in high-temperature environments.
Smart Images
Figure CN224053339U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field especially relates to high temperature resistance performance lithium iron phosphate aluminum shell battery. BACKGROUND
[0002] In the prior art of battery technology, lithium ion batteries occupy an important position due to their energy density, charge and discharge performance and other advantages. Among them, the electrode assembly assembly process (such as lamination or winding) of square lithium ion battery plays a key role in realizing compact structure and high efficiency of battery.
[0003] But in actual operation, the electrode assembly is easily caused to continuously climb in temperature due to internal heat generation by electrochemical reaction and external environmental heat transfer and other factors. This not only accelerates the aging of the internal materials of the battery, causes electrolyte decomposition and other side reactions, causes the capacity attenuation of the battery to intensify and the cycle life to shorten, but also may cause safety hazards such as short circuit, fire and the like due to thermal runaway. SUMMARY
[0004] The utility model provides high temperature resistance performance lithium iron phosphate aluminum shell battery in view of the prior art, and the specific technical scheme is as follows:
[0005] The shell has a receiving cavity in the interior of the aluminum shell body;
[0006] The electrode assembly is received in the receiving cavity, and the electrode assembly includes a first electrode sheet, a second electrode sheet, and a composite separation film arranged between the first electrode sheet and the second electrode sheet. The first electrode sheet includes a first current collector and a first active material layer arranged on the side of the first current collector. The second electrode sheet includes a second current collector and a second active material layer arranged on the side of the second current collector. The surface of the first current collector is provided with a plurality of micro grooves distributed uniformly. The composite separation film is composed of a ceramic coating separation film layer, a high-temperature-resistant polymer separation film layer, and a hydrophobic and air-permeable separation film layer.
[0007] As an improvement of the above technical solution, the coating thickness of the ceramic coating separation film layer is 1-5 microns, and the ceramic coating separation film layer faces the first electrode sheet. The high-temperature-resistant polymer separation film layer is made of polyimide material, and the thickness is 10-30 microns. The high-temperature-resistant polymer separation film layer is located between the ceramic coating separation film layer and the hydrophobic and air-permeable separation film layer. The hydrophobic and air-permeable separation film layer is made of polytetrafluoroethylene material, and the thickness is 5-20 microns. The hydrophobic and air-permeable separation film layer faces the second electrode sheet.
[0008] As an improvement of the above technical solution, the inner wall of the shell is uniformly provided with a plurality of heat dissipation fins.
[0009] As an improvement of the above technical solution, the first active material layer uses lithium iron phosphate as the main material, the second active material layer uses graphite as the main material, and the gram capacity of the first active material layer is less than that of the second active material layer.
[0010] As the improvement of the above technical scheme: the carbonic acid ethylene ester is added in the electrolyte in the shell, so that the surface of the first pole piece and the second pole piece is formed with a solid electrolyte interface film.
[0011] As the improvement of the above technical scheme: the first current collector is selected from an aluminum foil with a thickness of 8-16 microns, the second current collector is selected from a copper foil with a thickness of 6-12 microns, and a nickel layer with a thickness of 1-3 microns is plated on the surface of the copper foil.
[0012] As the improvement of the above technical scheme: the first active material layer is provided with a first tab, and the second active material layer is provided with a second tab.
[0013] The beneficial effects of the present application are as follows:
[0014] 1. The application adopts a multi-layer composite diaphragm structure, the ceramic coating diaphragm layer faces the positive electrode, has good thermal stability and ion conductivity, prevents short circuit under high temperature of the positive and negative electrodes, the high-temperature-resistant polymer diaphragm layer is in the middle and can withstand high temperature without shrinking and breaking, the hydrophobic and breathable diaphragm layer faces the negative electrode, prevents short circuit caused by excessive soaking of electrolyte and can discharge high-temperature gas to maintain pressure balance, and ensures the safety of the battery.
[0015] 2. The addition of carbonic acid ethylene ester in the electrolyte cooperates to improve the cycle performance, ensures stable work under high temperature, inhibits the precipitation of iron ions, avoids problems such as increase of self-discharge and capacity attenuation, promotes the formation of a stable SEI film to protect the electrode, a specific aging process further stabilizes the SEI film, strengthens the high-temperature resistance of the battery, and the battery has outstanding advantages in a high-temperature environment compared with a traditional battery.
[0016] 3. The aluminum shell has good mechanical strength, light weight and heat dissipation performance, provides physical protection for the battery core and helps heat dissipation, the heat dissipation fins on the inner wall of the shell further enhance the heat dissipation effect and improve the stability and safety of the battery under high-temperature environment. BRIEF DESCRIPTION OF DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of the whole utility model;
[0018] Figure 2 It is a structural schematic diagram of the electrode assembly in the utility model;
[0019] Figure 3 It is a structural schematic diagram of the first pole piece in the utility model;
[0020] Figure 4 It is a structural schematic diagram of the composite isolation film in the utility model.
[0021] Reference signs: 1, shell; 2, electrode assembly; 21, first pole piece; 211, first current collector; 210, micro groove; 212, first active material layer; 22, composite separator; 221, ceramic coating separator layer; 222, high-temperature-resistant polymer separator layer; 223, hydrophobic and air-permeable separator layer; 23, second pole piece; 4, second pole piece; 3, heat dissipation fin. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical scheme and advantages of the utility model clearer, the utility model will be described in further detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.
[0023] Embodiment
[0024] Please refer to Figures 1-4 The high-temperature-resistant lithium iron phosphate aluminum shell battery core assembly of the utility model comprises a shell 1 and an electrode assembly 2. The shell is made of aluminum, the aluminum shell 1 serves as a battery external packaging structure, the accommodating cavity designed inside the shell provides a stable installation space for the electrode assembly 2, ensures that each component is effectively protected in terms of mechanical protection and chemical environment isolation, prevents external impurities, moisture and the like from interfering with the battery internal electrochemical system, and provides a certain path for heat transfer and dissipation.
[0025] Specifically, the surface of the first current collector 211 is provided with a plurality of micro grooves 210 uniformly distributed.
[0026] The micro groove structure formed has a depth controllable between 0.2-2 microns and a width controllable between 0.2-3 microns.
[0027] From the perspective of increasing the contact area, these small grooves greatly increase the roughness of the aluminum foil surface. Compared with the smooth aluminum foil surface without treatment, when the first positive active material (such as lithium iron phosphate subjected to special doping and coating treatment) is coated thereon, the active material can better fill into the grooves, so that the actual contact area between the aluminum foil and the active material is significantly increased.
[0028] From the aspect of relieving thermal stress, when the battery works in a high-temperature environment, the positive active material and other related components will change in volume due to thermal expansion, thereby exerting stress on the current collector aluminum foil. These uniformly distributed small grooves act as a micro "buffer space" and can accommodate part of the material deformation caused by thermal expansion, so that the stress is dispersed, avoiding excessive concentration of stress in a local area and causing the aluminum foil to warp, break or be damaged, thereby enhancing the stability of the positive electrode overall structure at high temperatures and ensuring that the battery can still stably and reliably charge and discharge under high-temperature working conditions, thereby prolonging the service life of the battery.
[0029] Specifically, the electrode assembly 2 is the core part of the battery energy conversion, which is tightly composed of the first pole piece 21, the second pole piece 4 and the composite separator 22 sandwiched between the two. In the structural design of the first pole piece 21, the first current collector 211 is selected as an aluminum foil with a specific thickness (8-16 microns), which provides stable electronic transmission support and physical adhesion basis for the first active material layer 212 due to its good electrical conductivity and suitable mechanical strength. The first active material layer 212 is mainly composed of lithium iron phosphate, and by fine control of its crystal structure, particle size distribution and other micro parameters, the embedding and de-embedding dynamics of lithium ions in the charging and discharging process are optimized, and the specific capacity is designed to be less than that of the second active material layer, so as to realize the capacity matching balance and efficient cooperative work between the electrodes.
[0030] Specifically, the second current collector of the second pole piece 4 is a copper foil with a thickness of 6-12 microns, and a 1-3 micron thick nickel layer is plated on its surface. The high electrical conductivity of the copper foil helps to conduct electrons quickly, and the nickel layer plays a key role in enhancing the corrosion resistance of the current collector and improving the interface bonding performance with the active material layer, ensuring the stability and continuity of electron transmission in the electrode reaction process. The second active material layer is selected from graphite, which has a unique layered crystal structure that provides it with abundant lithium ion storage sites. The large specific capacity characteristics enable it to achieve good capacity matching with the positive electrode material in the charging and discharging cycle, ensuring the efficiency of the overall energy output and input of the battery.
[0031] Specifically, the composite separator 22 is the key defense line to ensure the safe and stable operation of the battery, which is composed of a ceramic coating separator layer 221, a high-temperature resistant polymer separator layer 222 and a hydrophobic and breathable separator layer 223 in order.
[0032] The ceramic coating separator layer 221 (with aluminum oxide as a typical ceramic material, the coating thickness is precisely controlled at 1-5 microns) is closely faced to the first pole piece 21 (positive electrode). In a high temperature environment, it effectively maintains the integrity of the separator structure due to its excellent thermal stability, preventing the direct contact short circuit of the positive and negative electrodes caused by the softening and deformation of the separator due to temperature rise; at the same time, its good ion conduction performance ensures the smooth transmission of lithium ions between the positive and negative electrodes, maintaining the normal progress of the battery charging and discharging process, ensuring the safety of the battery while not affecting the performance of the battery.
[0033] The high-temperature-resistant polymer diaphragm layer 222 is made of high-performance polyimide material, and the thickness is designed to be in the range of 10-30 microns. The polyimide material has outstanding high-temperature resistance and can withstand high temperatures of hundreds of degrees without significant thermal shrinkage, rupture, or other failure behaviors. It provides a reliable physical isolation barrier for the electrode assembly 2 under high-temperature conditions, effectively preventing internal short circuit risks caused by the contact between the positive and negative electrodes, and ensuring the structural stability and safety of the battery under high-temperature environments. It is one of the core support layers for the high-temperature resistance of the battery.
[0034] The hydrophobic and gas-permeable diaphragm layer 223 is made of polytetrafluoroethylene material with a thickness of 5-20 microns, facing the second pole piece 23 (negative electrode). Its hydrophobic property effectively prevents excessive infiltration of electrolyte into the diaphragm, avoiding short circuit problems caused by the formation of a continuous liquid film of electrolyte in the diaphragm pores. At the same time, its gas permeability plays a key role in the case of gas generation inside the battery due to high temperature, allowing the gas to be discharged moderately and accurately maintaining the internal pressure balance of the battery, preventing safety hazards such as battery swelling and rupture caused by gas accumulation, and ensuring the stability and reliability of the battery during high-temperature operation.
[0035] Preferably, the inner wall of the shell 1 is innovatively uniformly distributed with multiple heat dissipation fins 3. These heat dissipation fins 3 significantly improve the battery's heat dissipation efficiency by increasing the contact area between the shell 1 and the external environment. During battery operation, the heat generated by the electrode assembly 2 can be quickly transferred to the shell 1, and the heat dissipation fins 3 can efficiently dissipate heat to the surrounding environment through natural convection or forced air cooling, effectively reducing the internal temperature of the battery and alleviating the negative impact of high temperature on battery performance, further enhancing the battery's continuous working ability and stability in high-temperature environments.
[0036] Precise addition of ODFB and VC (vinyl carbonate) key additives in the electrolyte inside the shell 1. In terms of battery cycle performance improvement, these additives participate in the chemical reactions during the formation of the SEI film on the electrode surface, optimizing the composition and structure of the SEI film, making it more dense and stable, effectively reducing the migration resistance of lithium ions at the electrode / electrolyte interface, and reducing electrode polarization, thereby ensuring that the battery can maintain a high capacity retention rate after multiple charge and discharge cycles, significantly extending the battery's service life.
[0037] In terms of high-temperature performance enhancement, the vinyl carbonate additive can effectively inhibit the precipitation of iron ions from the positive electrode material (lithium iron phosphate). In high-temperature environments, the precipitation of iron ions can easily cause increased self-discharge of the battery and rapid capacity decay, among other serious problems. However, these two additives interact with the active sites on the surface of lithium iron phosphate, changing the dissolution-deposition balance of iron ions and preventing them from entering the electrolyte, ensuring stable operation of the battery within the temperature range of 35°C-60°C, maintaining the stability and reliability of the battery's performance, and providing strong protection for the safe and efficient operation of the battery in high-temperature application scenarios.
[0038] In addition, the first active material layer 212 is provided with a first tab, and the second active material layer is equipped with a second tab. The tab is a key part of connecting the internal electrode of the battery to the external circuit, and its design and manufacture need to ensure good electrical conductivity, mechanical stability and sealing. By optimizing the tab material, structure and connection process, the smooth transmission of current during the charging and discharging process of the battery is ensured, and efficient energy interaction between the battery and external devices is realized, while avoiding performance degradation or safety hazards caused by poor contact, corrosion and other problems at the tab site.
[0039] Specifically, the first tab 21 (positive electrode) in the electrode assembly 2 uses lithium iron phosphate as the main material, and the specific capacity of the positive electrode material is > 150 mAh / g, and the second negative electrode graphite is used as the main material, and the specific capacity of the negative electrode material is > 350 mAh / g.
[0040] Specifically, by optimizing the crystal structure and particle size of the lithium iron phosphate material itself, it is ensured that it can efficiently embed and extract lithium ions during the charging and discharging process, thereby providing a higher energy density for the battery. The unique layered structure of graphite provides a rich site for lithium ion storage, and the large specific capacity can better match the charging and discharging process of the positive electrode, improving the charging and discharging performance of the entire battery.
[0041] Further, in order to improve the cycle performance of the battery, the present application focuses on optimizing and adjusting the proportion of the conductive agent in the positive electrode ratio, and controlling the proportion of the conductive agent in the positive electrode material within the range of 0.5%-2%. The appropriate proportion of conductive agent can significantly improve the electronic conductivity of the positive electrode material, reduce electrode polarization, so that the transmission of lithium ions is smoother during repeated charging and discharging, thereby improving the overall cycle life of the battery.
[0042] In the electrode material preparation process of the present application:
[0043] 1. First positive electrode tab preparation process: First, according to the stoichiometric ratio, lithium iron phosphate powder is used as the main material of the positive electrode by using a high-precision electronic balance to ensure that the material purity and chemical composition meet the design requirements. Then, according to the set conductive agent proportion (0.5%-2%), select the appropriate conductive agent (such as high-conductivity conductive carbon black, carbon nanotubes with unique microstructure, or a combination of the two in a specific ratio), and accurately weigh the corresponding mass.
[0044] Next, an appropriate amount of adhesive polyvinylidene fluoride (PVDF) is added, and the above materials are placed together in an organic solvent N-methyl pyrrolidone (NMP), and a high-speed stirring device is used to stir and mix under specific speed and time conditions to ensure uniform dispersion of all components, forming a preliminary mixed slurry.
[0045] Afterwards, the mixed slurry is transferred to a ball milling device for fine ball milling treatment under optimized ball milling process parameters (such as ball-to-material ratio, ball milling time, ball milling speed, etc.) to further refine the particle size and improve the material uniformity, thereby obtaining a uniform and fine positive electrode slurry. Finally, the positive electrode slurry is uniformly coated on an aluminum foil current collector with a thickness of 8-16 microns using a high-precision coating device, the coating thickness and uniformity are controlled, a strict drying process (such as vacuum drying, hot air drying, etc. with controlled drying temperature, time and atmosphere) is performed to remove the organic solvent, and then an accurate rolling process is performed to adjust the thickness and porosity of the electrode sheet, thereby ensuring that the positive electrode sheet has a specific capacity > 150 mAh / g and meets the comprehensive requirements of the battery performance on the physical and electrochemical properties of the positive electrode sheet.
[0046] 2. Second negative electrode sheet preparation step: high-quality graphite material is selected as the negative electrode main material, and the integrity and purity of the graphite crystal structure are strictly ensured. After a proper amount of graphite is weighed, a binder composed of carboxymethyl cellulose sodium (CMC) and styrene-butadiene rubber (SBR) in a specific ratio and a proper amount of dispersant and other additives are added, and they are placed together in a suitable organic solvent. A strong stirring device is used for dispersion and mixing to form a negative electrode slurry. A similar coating process as the positive electrode sheet is used to uniformly coat the negative electrode slurry on a copper foil current collector with a thickness of 6-12 microns. A 1-3 micron thick nickel layer is pre-coated on the surface of the copper foil to enhance the interface bonding and corrosion resistance. After coating, drying, rolling and other processes, a negative electrode sheet with a specific capacity > 350 mAh / g is prepared, which ensures that the negative electrode sheet has good lithium ion storage and release performance, mechanical strength and electrical conductivity, and meets the requirements of working with the positive electrode sheet.
[0047] (II) Electrolyte preparation method: lithium salt lithium hexafluorophosphate (LiPF6) is accurately weighed and slowly dissolved in an organic solvent system composed of ethylene carbonate (EC), dimethyl carbonate (DMC), methyl ethyl carbonate (EMC), etc. in a specific ratio. A magnetic stirrer or a circulating stirring device is used for continuous stirring at a specific temperature and stirring speed to ensure that the lithium salt is fully dissolved and reaches the specified concentration. Then, according to strict addition amount standards, ODFB and VC vinylene carbonate additives are added to the electrolyte respectively, and the stirring is continued for a certain period of time to ensure that the additives are uniformly dispersed in the electrolyte, thereby forming an optimized electrolyte. During the preparation process, the environmental humidity, temperature and cleanliness need to be strictly controlled to prevent impurities from being mixed in and affecting the performance of the electrolyte, thereby ensuring that the electrolyte has good ionic conductivity, chemical stability and thermal stability, and provides a stable electrochemical environment for the battery.
[0048] The present application is particularly in the battery assembly and aging process:
[0049] 1. Assembly process: In a clean glove box or dry room environment, the prepared positive electrode sheet, negative electrode sheet, and separator (such as a polyethylene or polypropylene porous separator with good chemical stability and pore structure) are stacked or wound according to the precise design sequence. During assembly, ensure that each layer is tightly attached, without wrinkles or deviation, to maintain the structural integrity and consistency of the electrode assembly 2. Carefully place the assembled electrode assembly 2 into the aluminum shell, and use high-precision liquid injection equipment to inject the prepared electrolyte into the shell 1, controlling the injection amount and speed to ensure that the electrolyte fully infiltrates the electrode assembly 2 without leakage risk. Finally, seal the aluminum shell through advanced packaging processes (such as laser welding, heat sealing, etc.), complete the preparation of the unaged battery product, and ensure that the battery meets the design standards in terms of mechanical structure and chemical sealing, preventing external environmental erosion and interference.
[0050] 2. Aging process: Place the assembled battery in a thermostat that can accurately control the temperature between 35°C and 60°C, and use professional charging and discharging equipment to accurately adjust the battery state of charge to 100% SOC. Under these conditions, perform 24-72 hours of aging treatment. During the aging process, a series of complex physical and chemical changes occur between the electrodes and electrolyte inside the battery, such as further growth, stabilization, and optimization of the SEI film, fine-tuning of the electrode material crystal structure, etc. By strictly controlling the aging temperature, time, and state of charge, etc., the synergistic effect between the various components inside the battery is promoted, making the SEI film more stable and dense, effectively improving its protection ability for the electrodes in high-temperature environments, reducing lithium ion consumption and side reactions at the electrode / electrolyte interface, and thus optimizing the overall high-temperature performance and cycle performance of the battery, ensuring the reliability and durability of the battery in high-temperature application scenarios.
[0051] For the battery assembly and aging of the present application, the following steps can be followed:
[0052] I. The prepared positive electrode sheet, negative electrode sheet, and separator (such as a polyethylene or polypropylene porous separator) are stacked or wound according to a certain sequence, placed in an aluminum shell, injected with prepared electrolyte, and subjected to packaging and other processes to produce unaged battery products.
[0053] II. Place the assembled battery in a thermostat that can accurately control the temperature between 35°C and 60°C, adjust the battery state of charge to 100% SOC, and perform specific time length, such as 24-72 hours of aging treatment. The battery after aging is a lithium iron phosphate aluminum shell battery with excellent high-temperature performance.
[0054] Thus, the following effective effects can be achieved in the present application:
[0055] 1、Through fine control of the microstructure of the positive lithium iron phosphate material and full use of the large capacity characteristics of the negative graphite material, the utility model discloses a battery successfully realizes higher energy density.In the application of electric vehicle power supply, compared with the traditional similar battery, the vehicle endurance mileage can be significantly improved, the long-distance travel demand can be met, in the energy storage system aspect, more electric energy can be stored in the limited space, the energy storage efficiency and economic benefit are improved, a more efficient solution is provided for energy storage and supply, and the restriction of the energy density bottleneck on the expansion of the battery application field is effectively alleviated.
[0056] 2、Precise control of the proportion of positive conductive agent, effective optimization of the electrode internal electron conduction path, greatly reduce the electrode polarization phenomenon, ensure the efficient transmission of lithium ion in the charging and discharging process.After multiple charging and discharging cycle test verification, the battery has excellent performance in cycle life, and the capacity retention rate is significantly higher than that of the traditional battery.In the long-term use process, stable energy output and input performance can be maintained, the cost and resource waste caused by frequent battery replacement are reduced, the economy and sustainability of battery use are improved, and the competitiveness of the battery in various cyclic charging and discharging application scenarios is enhanced.
[0057] 3、The role of adding vinylene carbonate in the electrolyte and the implementation of the specific aging process bring qualitative leap to the high temperature performance of the battery.In the high temperature environment of 35 DEG C-60 DEG C, the battery can work stably, effectively inhibits a series of adverse problems caused by iron ion precipitation, maintains the internal electrochemical balance and structural stability of the battery.Compared with the traditional battery, it has lower capacity decay rate and higher safety in high temperature working condition, and can be widely used in industrial energy storage, electric vehicle fast charging and other fields with severe high temperature environment, expands the application temperature range of lithium ion battery, improves the reliability and adaptability of the battery in complex environment, and opens up a new path for the development of battery technology in high temperature field.
[0058] The utility model discloses a kind of lithium ion batteries with high temperature resistance, which is provided by the above-mentioned multiple innovative designs and process optimization, and comprehensively solves the key problems of existing lithium ion batteries in high temperature environment, provides a high practical value and wide application prospect of high-temperature-resistant lithium iron phosphate aluminum shell battery technical scheme for battery technology progress, and has important significance for promoting the development of battery industry in high temperature application field.
[0059] The above is only the preferred embodiment of the utility model, and does not limit the utility model, and any modification, equivalent replacement and improvement, etc. within the spirit and principles of the utility model should be included in the protection scope of the utility model.
Claims
1. A high temperature resistant lithium iron phosphate aluminum can battery characterized in that, The application relates to a lithium ion battery, which comprises the following parts: a shell, the inside of which is provided with a containing cavity; an electrode assembly contained in the containing cavity, the electrode assembly comprising a first pole piece, a second pole piece and a composite separation film arranged between the first pole piece and the second pole piece, the first pole piece comprising a first current collector and a first active material layer arranged on the side of the first current collector, the second pole piece comprising a second current collector and a second active material layer arranged on the side of the second current collector, the surface of the first current collector being provided with a plurality of uniformly distributed micro-grooves, and the composite separation film being composed of a ceramic coating separation film layer, a high-temperature-resistant polymer separation film layer and a hydrophobic and air-permeable separation film layer.
2. The high-temperature performance lithium iron phosphate aluminum can cell of claim 1, wherein: The coating thickness of the ceramic coating separation film layer is 1-5 microns, and the ceramic coating separation film layer faces the first pole piece, the high-temperature-resistant polymer separation film layer is made of polyimide material and has a thickness of 10-30 microns, the high-temperature-resistant polymer separation film layer is arranged between the ceramic coating separation film layer and the hydrophobic and air-permeable separation film layer, the hydrophobic and air-permeable separation film layer is made of polytetrafluoroethylene material and has a thickness of 5-20 microns, and the hydrophobic and air-permeable separation film layer faces the second pole piece.
3. The high-temperature performance lithium iron phosphate aluminum can cell of claim 1, wherein: The inner wall of the shell is uniformly provided with a plurality of heat dissipation fins.
4. The high temperature performance lithium iron phosphate aluminum can cell of claim 1, wherein: The first active material layer is made of lithium iron phosphate as a main material, the second active material layer is made of graphite as a main material, and the gram capacity of the first active material layer is smaller than that of the second active material layer.
5. The high temperature performance lithium iron phosphate aluminum can cell of claim 1, wherein: Vinylene carbonate liquid is added to the electrolyte in the shell to form a solid electrolyte interface film on the surface of the first pole piece and the second pole piece.
6. The high-temperature performance lithium iron phosphate aluminum can cell of claim 1, wherein: The first current collector is made of aluminum foil with a thickness of 8-16 microns, and the second current collector is made of copper foil with a thickness of 6-12 microns, and a nickel layer with a thickness of 1-3 microns is plated on the surface of the copper foil.
7. The high-temperature performance lithium iron phosphate aluminum can cell of claim 1, wherein: The first active material layer is provided with a first tab, and the second active material layer is provided with a second tab.