High-temperature resistant lithium iron phosphate battery with aluminum casing

Abstract

High-temperature resistant lithium iron phosphate battery with an aluminum casing, including: a housing, wherein the aluminium housing has an internal receiving chamber; and An electrode arrangement housed in the receiving space, wherein the electrode arrangement comprises a first electrode plate, a second electrode plate, and a composite separator arranged between the first electrode plate and the second electrode plate, wherein the first electrode plate comprises a first current collector and a first active material layer arranged on one side of the first current collector, and wherein the second electrode plate comprises a second current collector and a second active material layer arranged on one side of the second current collector, wherein the first current collector has multiple microgrooves uniformly distributed on a surface of the first current collector, and wherein the composite separator consists of a ceramic-coated separator layer, a high-temperature-resistant polymer separator layer, and a hydrophobic, breathable separator layer.

Description

TECHNICAL AREA

[0001] The present utility model relates to the technical field of batteries, in particular to a high-temperature resistant lithium iron phosphate battery with an aluminum casing. STATE OF THE ART

[0002] Lithium-ion batteries occupy an important position in existing battery technologies due to their advantages such as energy density and charging and discharging performance. The assembly process of electrode components (such as stacking or winding) in square lithium-ion batteries plays a crucial role in achieving a compact battery structure and highly efficient performance.

[0003] In actual operation, however, the electrode assembly is subject to a continuous temperature increase due to factors such as heat generated by internal electrochemical reactions and heat transfer from the external environment. This not only accelerates the aging of the internal battery materials and triggers side reactions such as electrolyte decomposition, leading to increased capacity loss and a shortened operating life, but can also cause potential safety risks such as short circuits and fires due to thermal runaway. DISCLOSURE OF THE USE PATTERN

[0004] In view of the shortcomings of the prior art, the present utility model provides for a high-temperature-resistant lithium iron phosphate battery with an aluminum casing. A specific technical solution is as follows.

[0005] The high-temperature-resistant lithium iron phosphate battery with the aluminum casing comprises: a casing, the aluminum casing having an internal receiving chamber; and an electrode assembly housed within the receiving chamber. The electrode assembly comprises a first electrode plate, a second electrode plate, and a composite separator located between the first and second electrode plates. The first electrode plate includes a first current collector and a first active material layer located on one side of the first current collector. The second electrode plate includes a second current collector and a second active material layer located on one side of the second current collector. The first current collector has multiple microgrooves uniformly distributed across its surface.The composite separator consists of a ceramic-coated separator layer, a high-temperature resistant polymer separator layer, and a hydrophobic, breathable separator layer.

[0006] As an improvement on the technical solution described above, the ceramic-coated separator layer has a coating thickness in the range of 1 µm to 5 µm and faces the first electrode plate. The high-temperature-resistant polymer separator layer consists of polyimide material with a thickness in the range of 10 µm to 30 µm and is located between the ceramic-coated separator layer and the hydrophobic, breathable separator layer. The hydrophobic, breathable separator layer consists of polytetrafluoroethylene material with a thickness in the range of 5 µm to 20 µm and faces the second electrode plate.

[0007] As an improvement on the technical solution described above, the housing is provided with several heat dissipation fins that are evenly distributed on an inner wall of the housing.

[0008] As an improvement on the technical solution described above, lithium iron phosphate is used as the main material of the first active layer and graphite as the main material of the second active layer. The first active layer has a lower gram capacity than the second active layer.

[0009] As an improvement on the technical solution described above, vinylene carbonate is added to the electrolyte inside the housing to form a solid electrolyte interface film on the surfaces of the first electrode plate and the second electrode plate.

[0010] As an improvement on the technical solution described above, the first current collector consists of an aluminum foil with a thickness ranging from 8 µm to 16 µm. A second current collector consists of a copper foil with a thickness of 6 µm to 12 µm and a nickel layer with a thickness of 1 µm to 3 µm, which is applied to the surface of the copper foil.

[0011] As an improvement on the technical solution described above, a first battery tab is arranged on the first active material layer. A second battery tab is arranged on the second active material layer.

[0012] The present utility model has the following advantageous effects.

[0013] 1. In the present disclosure, a multilayer composite separator structure is used. The ceramic-coated separator layer facing the positive electrode exhibits excellent thermal stability and ionic conductivity, thus preventing short circuits between the positive and negative electrodes at high temperatures. The high-temperature-resistant polymer separator layer located in the middle is able to withstand high temperatures without shrinking or cracking. The hydrophobic, breathable separator layer facing the negative electrode prevents short circuits caused by excessive electrolyte penetration and dissipates high-temperature gases. This maintains pressure equilibrium and ensures battery safety.

[0014] 2. The addition of vinylene carbonate to the electrolyte synergistically improves cycle performance, ensures stable operation at high temperatures, inhibits iron ion deposition, prevents problems such as increased self-discharge and capacity loss, and promotes the formation of a stable SEI film to protect the electrodes. A special aging process further stabilizes the SEI film and improves the battery's high-temperature tolerance, offering significant advantages over conventional batteries in high-temperature environments.

[0015] 3. The aluminum casing is characterized by excellent mechanical strength, low weight, and outstanding heat dissipation. This provides physical protection for the battery core and facilitates heat dissipation. Numerous heat-dissipation fins on the inner wall of the casing further enhance the heat dissipation effect. This increases the battery's stability and safety in high-temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a schematic representation of the overall structure of the present utility model. Fig. Figure 2 shows a schematic structural view of an electrode arrangement in the present utility model. Fig. Figure 3 shows a schematic structural view of a first electrode plate in the present utility model. Fig. Figure 4 shows a schematic structural view of a composite separator in the present utility model.

[0016] Reference numerals of the accompanying drawings: 1, Housing; 2, Electrode arrangement; 21, First electrode plate; 211, First current collector; 210, Microgroove; 212, First active material layer; 22, Composite separator; 221, Ceramic-coated separator layer; 222, High-temperature resistant polymer separator layer; 223, Hydrophobic, breathable separator layer; 23, Second electrode plate; 3, Heat dissipation fin. EXECUTION FORMS OF THE USE PATTERN

[0017] To clarify the objectives, technical solutions, and advantages of this utility model, it is described in detail with reference to the accompanying drawings and examples. It is understood that the examples described here serve only to illustrate, and not to limit, the scope of this utility model. Example

[0018] As in Fig. 1, Fig. 2, Fig. 3 to Fig. As shown in Figure 4, the core components of a high-temperature-resistant lithium iron phosphate battery with an aluminum housing according to the present utility model comprise a housing 1 and an electrode assembly 2. The housing is the aluminum housing 1 and serves as the outer packaging structure of the battery. The recess provided within the aluminum housing offers a stable installation space for the electrode assembly 2 and ensures that all components are effectively protected with regard to mechanical protection and insulation from the chemical environment. In this way, external contaminants, moisture, and the like are prevented from affecting the internal electrochemical system of the battery. Furthermore, a specific path for heat transfer and dissipation is provided.

[0019] In particular, a first current collector 211 has several microgrooves 210 distributed evenly on a surface of the first current collector.

[0020] The formed microgroove structure can have a controlled depth between 0.2 µm and 2 µm and a controlled width between 0.2 µm and 3 µm.

[0021] From the perspective of increasing the contact area, these microgrooves significantly increase the surface roughness of the aluminum foil. Compared to an untreated, smooth aluminum foil surface, the active material can be more effectively filled into the grooves if the surface of the aluminum foil is coated with a first positive electrode active material (such as lithium iron phosphate that has undergone a special doping and coating treatment), resulting in a significant increase in the actual contact area between the aluminum foil and the active material.

[0022] With regard to relieving thermal stress, the positive electrode active material and other associated components undergo volume changes due to thermal expansion during battery operation in a high-temperature environment. This, in turn, exerts stress on the current collector aluminum foil. These uniformly distributed microgroove structures act like tiny "buffer spaces" that can absorb some of the material deformation caused by thermal expansion. This disperses the stress and prevents excessive local concentration, which could lead to damage to the aluminum foil, such as warping or cracking. In this way, the overall structural stability of the positive electrode is improved at high temperatures, ensuring that the battery can still perform stable and reliable charging and discharging operations under high-temperature operating conditions.This extends the battery's lifespan.

[0023] In particular, the electrode assembly 2, as the core component for the battery's energy conversion, consists of a first electrode plate 21, a second electrode plate 23, and a composite separator 22 located between the first electrode plate 21 and the second electrode plate 23. In the structural design of the first electrode plate 21, the first current collector 211 is made of an aluminum foil with a specific thickness (8 µm to 16 µm). Its excellent electrical conductivity and adequate mechanical strength provide stable support for electron transport and a physical base for the first active material layer 212. The first active material layer 212 consists mainly of lithium iron phosphate.By finely regulating microscopic parameters of the lithium iron phosphate, such as the crystal structure and particle size distribution, the kinetics of lithium ion insertion and removal during a charging and discharging process are optimized. Furthermore, the gram capacity of the first active material layer 212 is designed to be smaller than that of a second active material layer in order to achieve a capacity-matching equilibrium and efficient interaction between the electrodes.

[0024] In particular, a second current collector of the second electrode plate 23 consists of a copper foil with a thickness of 6 µm to 12 µm and a nickel layer with a thickness of 1 µm to 3 µm, which is applied to the surface of the copper foil. The high conductivity of the copper foil enables rapid electron conduction, while the nickel layer plays an important role in increasing the corrosion resistance of the current collector and improving the interfacial bonding performance with the active material layer, thereby ensuring the stability and continuity of electron transfer during an electrode reaction process. The second active material layer consists of graphite.The unique layered crystal structure of graphite gives it abundant lithium-ion storage sites, and its characteristic high gram capacity allows for excellent capacity matching to the positive electrode material during charge and discharge cycles, ensuring high efficiency of the overall energy output and input of the battery.

[0025] In particular, the composite separator 22 represents a crucial line of defense to ensure safe and stable operation of the battery and is formed by the ordered combination of a ceramic-coated separator layer 221, a high-temperature-resistant polymer separator layer 222 and a hydrophobic, breathable separator layer 223.

[0026] The ceramic-coated separator layer 221 (with aluminum oxide as the typical ceramic material and a precisely controlled coating thickness between 1 µm and 5 µm) is closely adjacent to the first electrode plate 21 (positive electrode). Thanks to its excellent thermal stability, the ceramic-coated separator layer 221 effectively maintains the structural integrity of the separator in high-temperature environments and prevents direct contact and short circuits between the positive and negative electrodes caused by softening and deformation of the separator due to temperature increases. Furthermore, the excellent ionic conductivity of the ceramic-coated separator layer ensures the smooth transport of lithium ions between the positive and negative electrodes and maintains the normal operation of the battery during charging and discharging.In this way, the safety of the battery is ensured without negatively affecting the electrochemical properties of the battery.

[0027] The high-temperature resistant polymer separator layer 222 consists of a high-performance polyimide material and has a thickness ranging from 10 µm to 30 µm. This polyimide material exhibits excellent high-temperature resistance and can withstand temperatures of up to several hundred degrees Celsius without showing obvious signs of failure such as thermal shrinkage or cracking. It thus provides a reliable physical insulation barrier for the electrode assembly 2 under the high-temperature operating conditions of the battery. This effectively prevents the risk of internal short circuits caused by contact between the positive and negative electrodes, ensuring the structural stability and safety of the battery in high-temperature environments.The high-temperature resistant polymer separator layer 222 acts as one of the core support layers to achieve the high-temperature resistant performance of the battery.

[0028] The hydrophobic, breathable separator layer 223 consists of polytetrafluoroethylene (PTFE) with a thickness of 5 µm to 20 µm and faces the second electrode plate 23 (negative electrode). The hydrophobic property of the hydrophobic, breathable separator layer 223 effectively prevents excessive electrolyte penetration into the separator, thus avoiding short-circuit problems caused by the formation of a continuous electrolyte film when the electrolyte is located in the separator's pores. Furthermore, the breathability of the hydrophobic, breathable separator layer plays an important role when gas is generated within the battery due to high temperatures; the gas can be discharged in a controlled manner to precisely maintain the pressure equilibrium within the battery.This prevents safety risks such as battery swelling or cracking due to gas accumulation, thus ensuring the stability and reliability of the battery during high-temperature operation.

[0029] Preferably, the housing 1 is provided with multiple heat dissipation fins 3, which are innovatively and uniformly distributed on an inner wall of the housing 1. These heat dissipation fins 3 significantly increase the heat dissipation efficiency of the battery by increasing the contact area between the housing 1 and the external environment. During battery operation, the heat generated by the electrode arrangement 2 can be rapidly transferred to the housing 1. The multiple heat dissipation fins 3 efficiently dissipate the heat to the environment via heat dissipation processes such as natural convection or forced air cooling, thereby effectively reducing the temperature inside the battery and mitigating the negative effects of high temperatures on battery performance. Furthermore, the battery's continuous operation capability and stability in high-temperature environments are improved.

[0030] Important additives such as ODFB and vinylene carbonate (VC) are precisely added to the electrolyte within housing 1. To improve battery cycle performance, the chemical reactions involved in the formation of an SEI film on the electrode surface optimize the composition and structure of the SEI film, making it denser and more stable. The migration resistance of lithium ions at the electrode / electrolyte interface is effectively reduced, thereby decreasing electrode polarization. This ensures that the battery maintains a high capacity retention rate even after multiple charge and discharge cycles, significantly extending its service life.

[0031] With regard to improving high-temperature performance, the vinylene carbonate additive effectively inhibits the deposition of iron ions from the positive electrode material (lithium iron phosphate). In high-temperature environments, iron ion deposition can lead to serious problems such as increased battery self-discharge and rapid capacity loss. These two additives, however, alter the dissolution-sedimentation equilibrium of iron ions and, by interacting with the active sites on the surface of the lithium iron phosphate, prevent the iron ions from entering the electrolyte. This ensures stable battery operation in a high-temperature range of 35°C to 60°C. The stability and reliability of battery performance are maintained, and strong support is provided for safe and efficient operation in high-temperature application scenarios.

[0032] Furthermore, a first battery tab is located on the first active material layer 212, and a second battery tab is located on the second active material layer. As a critical component of the connection between the electrodes inside the battery and the external circuit, the battery tab must be designed and manufactured with excellent conductivity, mechanical stability, and sealing performance. Optimizing the material, structure, and connection process of the battery tab ensures smooth current transfer during charging and discharging. This results in efficient energy interaction between the battery and external devices. Moreover, it prevents battery performance degradation and safety risks caused by problems such as poor contact and corrosion of the battery tab.

[0033] In particular, lithium iron phosphate is used as the main material of the first electrode plate 21 (positive electrode) in the electrode arrangement 2, and the gram capacity of the positive electrode material is more than 150 mAh / g. Graphite is used as the main material of the second negative electrode, and the gram capacity of the negative electrode material is more than 350 mAh / g.

[0034] In particular, the optimization of parameters such as the crystal structure and particle size of the lithium iron phosphate material ensures efficient storage and release of lithium ions during charging and discharging, resulting in a high energy density for the battery. The unique layered structure of the graphite provides ample space for lithium ion storage, and its high gram capacity better adapts to the charging and discharging processes of the positive electrode, thereby improving the overall charging and discharging performance of the battery.

[0035] To improve the battery's cycle performance, the present disclosure further focuses on optimizing and adjusting the proportion of the conductive agent in a positive electrode ratio, controlling the proportion of the conductive agent in the positive electrode material within a range of 0.5% to 2%. A suitable proportion of the conductive agent can significantly increase the electronic conductivity of the positive electrode material and reduce electrode polarization, resulting in smoother lithium ion transport during repeated charging and discharging cycles. This further increases the overall battery lifespan.

[0036] In a manufacturing process for the electrode material of the present disclosure:

[0037] 1. Manufacturing process of the first positive electrode plate: First, lithium iron phosphate powder, the main material for the positive electrode, was weighed according to a stoichiometric ratio using a high-precision electronic balance. This ensured that the material purity and chemical composition met the design requirements. Subsequently, a suitable conductive material (such as highly conductive carbon black, carbon nanotubes with a unique microstructure, or a mixture of both in a specific ratio) was selected according to a predetermined proportion range (0.5% to 2%), and the corresponding mass was accurately weighed.

[0038] Next, a suitable amount of the binder, i.e., polyvinylidene fluoride (PVDF), was added. Subsequently, the materials described above were placed together in the organic solvent N-methylpyrrolidone (NMP) and thoroughly stirred and mixed under specific rate and time conditions using a high-speed stirrer to disperse them uniformly and form the preliminary mixed slurry.

[0039] The mixed slurry was then transferred to a ball mill and subjected to fine ball milling under optimized ball milling process parameters (such as the ball-to-material ratio, the ball milling time, and the ball milling speed) to further refine the particle size, improve material uniformity, and obtain a uniform and fine positive electrode slurry. Finally, the positive electrode slurry was uniformly applied to the aluminum foil current collector to a thickness of 8 µm to 16 µm using a high-precision coating device, and the coating thickness and uniformity were checked. The organic solvent was removed by a rigorous drying process (such as vacuum drying and hot air drying under controlled drying temperature, time, and atmosphere).Subsequently, the thickness and porosity of the electrode plate were adjusted by a precise rolling process to ensure that the gram capacity of the positive electrode plate was greater than 150 mAh / g and that the comprehensive battery performance requirements regarding the physical and electrochemical properties of the positive electrode plate were met.

[0040] 2. Manufacturing Process of the Secondary Negative Electrode Plate: High-quality graphite was selected as the main material for the negative electrode. It underwent rigorous screening to ensure the integrity of the crystal structure and the purity of the graphite. After weighing out a suitable quantity of graphite, a binder consisting of sodium carboxymethylcellulose (CMC) and polymerized styrene-butadiene rubber (SBR) in a specific ratio, as well as additives, such as dispersants, in appropriate quantities, were added. All these materials were combined in a suitable organic solvent and dispersed and mixed using a high-speed stirrer to form the negative electrode slurry.Using a coating process similar to that used for the positive electrode plate, the negative electrode slurry was uniformly applied to the copper foil current collector with a thickness of 6 µm to 12 µm. The copper foil surface was pre-coated with a nickel layer 1 µm to 3 µm thick to improve interfacial bonding and corrosion resistance. After coating, processes such as drying and rolling were performed to produce the negative electrode plate with a gram capacity of more than 350 mAh / g. This ensures that the negative electrode plate exhibits excellent lithium-ion storage and release performance, high mechanical strength, and good electrical conductivity, thus meeting the requirements for synergistic operation with the positive electrode plate.

[0041] (2) Method for preparing the electrolyte: Lithium hexafluorophosphate (LiPF6) was precisely weighed, slowly dissolved in an organic solvent system formed by mixing ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), etc., in a specific ratio, and continuously stirred using a magnetic stirrer or a circulating stirrer at a specific temperature and stirring speed to ensure that the lithium salt was completely dissolved and the specified concentration was achieved. Subsequently, ODFB and vinylene carbonate (VC) additives were added to the electrolyte in strict proportions and stirred for a specific period to ensure that the additives were uniformly dispersed in the electrolyte. This resulted in the formation of the optimized electrolyte.During the manufacturing process, ambient humidity, temperature, and cleanliness had to be strictly controlled to prevent impurities from mixing and impairing the electrolyte's performance. This ensured that the electrolyte exhibited excellent ionic conductivity, chemical stability, and thermal stability. In this way, a stable electrochemical environment was created for the battery.

[0042] In particular, during the battery assembly processes and aging procedures described in the present disclosure: 1. Assembly Process: In a glovebox or dry room environment that meets cleanliness standards, the manufactured positive electrode plate, the negative electrode plate, and the separator (e.g., a porous separator made of polyethylene or polypropylene with excellent chemical stability and pore structure) were stacked or wound according to a precisely defined sequence. During the assembly process, it was ensured that the layers were tightly pressed together without creases or misalignment to guarantee the structural integrity and consistency of the electrode assembly 2. The assembled electrode assembly 2 was carefully inserted into the aluminum housing, and the manufactured electrolyte was injected into the housing 1 using a high-precision injection device.The injection volume and speed were controlled to ensure that the electrolyte completely wetted the electrode assembly 2 without any risk of leakage. Finally, the aluminum casing was sealed using an advanced packaging process (such as laser welding and heat sealing) to complete the production of the long-lasting finished battery and to ensure that the battery meets design standards regarding mechanical structure and chemical sealing. This prevents corrosion and interference from the external environment from penetrating the battery's interior. 2. Aging Treatment Process: After capacity assessment, the battery was placed in a temperature-controlled chamber where the temperature could be precisely regulated between 35°C and 60°C. The battery's state of charge (SOC) was then precisely set to 100% SOC using a professional charging and discharging device. Under these conditions, an aging treatment lasting 24 to 72 hours was performed. During the aging process, a series of complex physical and chemical changes occurred between the electrodes within the battery and the electrolyte. These included the further growth, stabilization, and optimization of the SEI film, as well as the fine-tuning of the crystal structure of the electrode material. The strict control of parameters such as aging temperature, time, and SOC promoted the synergistic effect between the various components within the battery, resulting in a more stable and dense SEI film.This effectively improves its ability to protect the electrodes in high-temperature environments and reduces lithium ion consumption and side reactions at the electrode / electrolyte interface. In this way, the overall high-temperature resistance and cycle performance of the battery are optimized, and the reliability and durability of the battery are ensured in high-temperature application scenarios.

[0043] The assembly and aging of the battery in the present disclosure can be carried out according to the following steps. 1. The manufactured positive electrode plate, the negative electrode plate and the separator (e.g. a porous separator made of polyethylene or polypropylene) were stacked or wound in a specific sequence, placed in the aluminum casing, injected with the manufactured electrolyte and subjected to packaging and other processes to produce the non-obsolete finished battery. 2. After capacity assessment, the battery was placed in a temperature-controlled chamber at 35°C to 60°C, and its state of charge (SOC) was set to 100% for a specific period – for example, 24 to 72 hours. Upon completion of the aging process, the battery was a lithium iron phosphate battery with an aluminum casing, characterized by excellent high-temperature resistance.

[0044] The following effective results can therefore be achieved with the present disclosure: 1. The battery of the present utility model successfully achieves a high energy density by finely controlling the microstructure of the lithium iron phosphate material of the positive electrode and fully utilizing the high capacity of the graphite material of the negative electrode. When used as a power source for electric vehicles, the vehicle's range can be significantly improved compared to conventional batteries of the same type, thus meeting the demand for long-distance travel. With regard to energy storage systems, more electrical energy can be stored in a limited space, improving energy storage efficiency and economic benefits, and providing a more efficient solution for energy storage and supply. This effectively mitigates the energy density limitation that has previously hindered the expansion of battery applications. 2. By precisely controlling the proportion of conductive medium in the positive electrode, the electron conduction path within the electrode is effectively optimized, significantly reducing electrode polarization and ensuring efficient lithium-ion transport during charging and discharging. Multiple charge-discharge cycle tests have confirmed that this battery exhibits excellent performance in terms of operating time, with a capacity retention rate significantly higher than that of conventional batteries. Long-term use allows for the maintenance of stable energy output and supply, reducing costs and resource waste associated with frequent battery replacements and improving the economic viability and sustainability of battery use. This enhances the battery's competitiveness in various cyclic charge-discharge application scenarios. 3. The addition of vinylene carbonate to the electrolyte and the implementation of a specific aging process have resulted in a significant improvement in the battery's high-temperature performance. Therefore, the battery can operate stably in high-temperature environments ranging from 35°C to 60°C, effectively inhibiting a number of adverse problems caused by iron ion deposition. This maintains the electrochemical equilibrium and structural stability within the battery. Compared to conventional batteries, the battery in this utility model exhibits a lower capacity degradation rate and greater safety under high-temperature operating conditions, making it suitable for widespread use in industrial energy storage, electric vehicle fast charging, and other applications with harsh high-temperature environments.This expands the applicable temperature range of the lithium-ion battery, thereby improving its reliability and adaptability in complex environments. This opens up a new avenue for the development of battery technology in high-temperature applications.

[0045] Thanks to the aforementioned multifaceted innovative design and process optimization, the present utility model comprehensively solves the main problems of existing lithium-ion batteries in high-temperature environments and offers a technological solution for a high-temperature-resistant lithium iron phosphate battery with an aluminum casing, which has high practical value and broad application prospects for the further development of battery technology. It is of great importance in promoting the development of the battery industry in the field of high-temperature applications.

[0046] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments. Any modification, equivalent replacement, improvement, etc., made in accordance with the principles of the present disclosure falls within the scope of protection of the present disclosure.

Claims

[1] High-temperature resistant lithium iron phosphate battery with an aluminum casing, comprising: a housing, wherein the aluminium housing has an internal receiving chamber; and An electrode arrangement housed in the receiving space, wherein the electrode arrangement comprises a first electrode plate, a second electrode plate and a composite separator arranged between the first electrode plate and the second electrode plate, wherein the first electrode plate comprises a first current collector and a first active material layer arranged on one side of the first current collector, and wherein the second electrode plate comprises a second current collector and a second active material layer arranged on one side of the second current collector, wherein the first current collector has several microgrooves uniformly distributed on a surface of the first current collector, and wherein the composite separator consists of a ceramic-coated separator layer, a high-temperature-resistant polymer separator layer and a hydrophobic, breathable separator layer. [2] High-temperature resistant lithium iron phosphate battery with an aluminum casing according to claim 1, wherein: the ceramic-coated separator layer has a coating thickness in the range of 1 µm to 5 µm and faces the first electrode plate; the high-temperature resistant polymer separator layer consists of polyimide material with a thickness in the range of 10 µm to 30 µm and is located between the ceramic-coated separator layer and the hydrophobic, breathable separator layer; and The hydrophobic, breathable separator layer consists of polytetrafluoroethylene material with a thickness in the range of 5 µm to 20 µm and faces the second electrode plate. [3] High-temperature resistant lithium iron phosphate battery with an aluminum housing according to claim 1, wherein the housing is provided with several heat dissipation fins that are evenly distributed on an inner wall of the housing. [4] High-temperature resistant lithium iron phosphate battery with an aluminum casing according to claim 1, wherein: Lithium iron phosphate is used as the main material of the first active material layer; Graphite is used as the main material of the second active material layer; and The first active material layer has a lower gram capacity than the second active material layer. [5] High-temperature resistant lithium iron phosphate battery with an aluminum casing according to claim 1, wherein vinylene carbonate is added to the electrolyte in the casing to form a solid electrolyte interface film on the surfaces of the first electrode plate and the second electrode plate. [6] High-temperature resistant lithium iron phosphate battery with an aluminum casing according to claim 1, wherein: the first current collector consists of an aluminum foil with a thickness in the range of 8 µm to 16 µm; and the second current collector consists of a copper foil with a thickness of 6 µm to 12 µm and a nickel layer with a thickness of 1 µm to 3 µm, which is applied to the surface of the copper foil. [7] High-temperature resistant lithium iron phosphate battery with an aluminum casing according to claim 1, wherein: a first battery tab is arranged on the first active material layer; and a second battery tab is arranged on the second active material layer.

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