Self-breathing self-protection module

Abstract

The utility model provides a kind of self-breathing self-protection module belongs to battery manufacturing technical field.The utility model discloses that ceramic fibre heat insulation pad is arranged between any two adjacent the battery module in the battery module The core between and end plate and the end of battery module between, two the end plate upper end is uniformly provided with insulating seat, and the outside of battery module and end plate is fixed by being tied with several steel bands, and the bottom of battery module and end plate is sequentially fixed with bottom insulating PC film and bottom epoxy plate from top to bottom;The top of battery module and end plate is sequentially fixed with CCS assembly and top insulating PC film from bottom to top, and the CCS assembly is provided with fuse aluminium row.The utility model can effectively eliminate the expansion force and the expansion thickness change of battery core, and anastomosis electrochemical reaction, and can be self-protected in overload, overload condition, improve product life, improve the safety and reliability of product, enhance the competitiveness of product in market.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, specifically to a self-breathing and self-protection module. Background Technology

[0002] A battery is a point-thermal-mechanical coupled system. In actual use, there will be issues of expansion and thickness changes. On the one hand, during charging and discharging, an SEI film is formed, generating gas and increasing the gas pressure inside the battery. As the cycle progresses, the thickness of the SEI film increases, causing the cell to expand. On the other hand, during charging and discharging, the insertion and extraction of Li+ between the positive and negative electrode materials will cause a phase transition in the structure, resulting in expansion. This is mainly reflected in the change of thickness in the negative electrode sheet.

[0003] The expansion and thickness changes of lithium-ion batteries are closely related to their reliability and safety. Laboratory studies typically use expansion force and expansion thickness as parameters to evaluate the changes in battery expansion behavior during charging and discharging. Irreversible stress within the battery also accumulates continuously during charging and discharging. Research indicates that the diffusion resistance of Li+ ions changes with increasing irreversible stress during charging and discharging. However, an appropriate increase in stress can reduce the loss of some active lithium, thereby reducing the rate of cell cycle capacity decay. This provides important guidance for selecting suitable response structures during cell assembly. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of expansion and thickness changes in batteries during charging and discharging in the prior art, and to provide a self-breathing and self-protection module.

[0005] This invention provides a self-breathing, self-protecting module that responds to the expansion force and thickness changes during battery charging and discharging. It provides sufficient rigidity and space to release and eliminate the expansion force and thickness of the battery and PACK pack. Furthermore, the breathing structure applies appropriate structural pressure to the cell, effectively shortening the Li+ migration path and reducing Li+ loss, thereby improving battery lifespan. This invention fully integrates the electrochemical mechanism of the cell, effectively eliminating potential expansion force hazards, significantly reducing after-sales maintenance costs, and improving product safety and reliability, thus enhancing market competitiveness. In addition, considering that high-rate discharge of the cell leads to insufficient ion migration speed in the electrodes, increased internal resistance, and a decreased voltage plateau, and that high-rate discharge causes a rapid increase in battery surface temperature, potentially leading to thermal runaway, and can cause the negative electrode graphite layer to crack, resulting in up to 30% capacity decay after 200 cycles, high-rate discharge shortens battery cycle life, and may cause battery overheating, lithium plating, SEI film growth, and other problems, increasing the risk of explosion and fire, this invention incorporates a high-rate discharge self-protection structure.

[0006] To solve the above problems, the technical solution provided by this utility model is as follows: A self-breathing and self-protecting module includes: an end plate and several battery cells. The battery cells are arranged side by side to form a battery module. End plates are respectively provided at both ends of the battery module. Heat insulation pads are provided between any two adjacent battery cells in the battery module and between the end plate and the end of the battery module. Insulating seats are fixedly provided at the upper ends of the two end plates. The battery module and the outer side of the end plates are bound together and fixed by several steel straps. A bottom insulating PC film and a bottom epoxy board are fixedly provided at the bottom of the battery module and the end plates from top to bottom. A CCS module and a top insulating PC film are fixedly provided at the top of the battery module and the end plates from bottom to top. A fused aluminum busbar is fixedly provided on the CCS module.

[0007] Preferably, the CCS assembly includes a CCS board, with positive and negative lead-out aluminum busbars respectively at both ends of the CCS board, a PCB and an FPC in the middle of the CCS board, series aluminum busbars on both sides of the CCS board, and a fusible aluminum busbar on one side of the CCS board. The positive lead-out aluminum busbar, negative lead-out aluminum busbar, series aluminum busbar, and fusible aluminum busbar are connected to the PCB through the FPC. The upper and lower surfaces of the CCS board are heat-sealed together by an upper hot-pressed PC film and a lower hot-pressed PC film.

[0008] Preferably, the positive electrode lead-out aluminum busbar, the negative electrode lead-out aluminum busbar, the series aluminum busbar and the fusible aluminum busbar are all corrugated arch bridges, and the fusible aluminum busbar is provided with a number of fusible grooves.

[0009] Preferably, the positive electrode lead-out aluminum busbar, negative electrode lead-out aluminum busbar, series aluminum busbar, and fused aluminum busbar are aligned with the terminals of the battery cells in the battery module.

[0010] Preferably, the lower hot-pressed PC film has several expansion joints between the positions of the corresponding positive electrode lead-out aluminum busbar, negative electrode lead-out aluminum busbar, series aluminum busbar and fused aluminum busbar; the upper hot-pressed PC film has several expansion joints between the positions of the corresponding positive electrode lead-out aluminum busbar, negative electrode lead-out aluminum busbar, series aluminum busbar and fused aluminum busbar.

[0011] Preferably, an insulating PC film for the module end face is also provided between the end plate and the battery module, and the insulating PC film for the module end face is disposed on the outside of the heat insulation pad.

[0012] Preferably, the heat insulation pad includes: aluminum-plastic film one, heat insulation material and aluminum-plastic film two arranged sequentially from top to bottom; aluminum-plastic film one and aluminum-plastic film two are formed by vacuum heat sealing around their perimeter to wrap the heat insulation material inside.

[0013] Preferably, double-sided adhesive tape or hot melt adhesive is applied to the outer surfaces of both aluminum-plastic film one and aluminum-plastic film two.

[0014] Preferably, the heat insulation material is ceramic fiber, aerogel, or mica sheet.

[0015] Preferably, the end plate is provided with a slot corresponding to the steel strip, and the steel strip is fixed by the slot.

[0016] Compared with the prior art, the technical solution provided by this utility model has the following advantages: 1. This invention employs a heat-insulating pad structure between the battery cells and between the battery module and the end plate to form a breathing structure. This structure responds to the expansion forces and thickness changes during battery charging and discharging, providing sufficient rigidity and space for expansion, thereby eliminating the expansion forces and thickness increases of the battery and PACK. The breathing structure also applies appropriate structural pressure to the cells, effectively shortening the Li+ migration path, reducing Li+ loss, and thus improving battery lifespan. This invention fully integrates the electrochemical mechanisms of the battery cells, effectively eliminating potential expansion forces, significantly reducing after-sales maintenance costs, improving product safety and reliability, and enhancing the product's market competitiveness.

[0017] 2. High-rate discharge can have the following adverse effects on the battery: (1) It will cause the battery surface temperature to rise rapidly, which may lead to the risk of thermal runaway; (2) It will cause the graphite layer of the negative electrode to crack, resulting in a capacity decay of up to 30% after 200 cycles; (3) It will shorten the cycle life of the battery; (4) May cause problems such as battery overheating, lithium plating, and SEI film growth, reducing the risk of explosion and fire.

[0018] In this invention, the CCS component is equipped with a fusible aluminum busbar, forming a high-rate discharge self-protection structure. During use, if the maximum value of the normal discharge rate is exceeded, the corrugated arch bridge of the fusible aluminum busbar melts, thereby disconnecting the battery cell and preventing insufficient ion migration speed in the electrodes, increased internal resistance, and a drop in voltage plateau caused by high-rate discharge. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a self-breathing and self-protection module proposed in an embodiment of the present invention.

[0020] Figure 2 This is an exploded view of a self-breathing and self-protection module proposed in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of a heat insulation pad for a self-breathing and self-protecting module proposed in an embodiment of this utility model.

[0022] Figure 4 This is a schematic diagram of the internal structure of a heat insulation pad for a self-breathing and self-protecting module proposed in an embodiment of this utility model.

[0023] Figure 5 This is a schematic diagram of the CCS structure of a self-breathing and self-protection module proposed in an embodiment of this utility model.

[0024] Figure 6 This is an exploded view of the CCS structure of a self-breathing and self-protecting module proposed in an embodiment of this utility model.

[0025] The attached diagram is labeled as follows: 1 is the top insulating PC film, 2 is the CCS assembly, 21 is the positive electrode lead-out aluminum busbar, 2101 is positioning hole one, 2102 is the first corrugated arch bridge, 2103 is the first CCS positioning hole, 22 is the negative electrode lead-out aluminum busbar, 2201 is the second positioning hole, 2202 is the second corrugated arch bridge, 2203 is the second CCS positioning hole, 23 is the PCB, 2301 is the PCB protrusion, 2302 is the acquisition terminal, 2303 is the waist hole, 2304 is the fifth positioning hole, 2305 is the thermistor, 24 is the lower heat-pressed PC film, 2401 is the first expansion joint, 25 is the upper heat-pressed PC film, 2501 is the printing label hole, 2502 is the second expansion joint, 26 is the series aluminum busbar, 2601 is the third positioning hole, 260... 2 is the third wave arch bridge, 2603 is the third CCS positioning hole, 27 is FPC, 2701 is the nickel sheet welded to the aluminum busbar side, 2702 is the nickel sheet of the wave arch bridge section, 2703 is the nickel sheet welded to the PCB side, 28 is the L-shaped hook, 29 is the fused aluminum busbar, 2901 is the fused groove, 2902 is the fourth wave arch bridge, 2903 is the fourth positioning hole, 2904 is the fourth CCS positioning hole, 3 is the battery cell, 4 is the insulating PC film on the module end face, 5 is the end plate, 6 is the insulating base, 7 is the steel strip, 71 is the thermoplastic sleeve, 8 is the bottom epoxy board, 9 is the bottom insulating PC film, 11 is the heat insulation pad, 1101 is the first aluminum-plastic film, 1102 is the heat insulation material, 1103 is the second aluminum-plastic film, 1104 is the double-sided adhesive, and 100 is the self-breathing and self-protecting module. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented based on the technical solution of the present invention and provides detailed implementation methods, but the protection scope of the present invention is not limited to the following embodiments.

[0027] like Figure 1 As shown, the self-breathing self-protection module 100 of this embodiment, as Figure 2 As shown, the battery module includes: an end plate 5 and several battery cells 3, wherein the battery cells 3 are electrochemical reaction carriers, and the several battery cells 3 are arranged side by side to form a battery module. The two ends of the battery module are respectively provided with end plates 5. Heat insulation pads 11 are provided between any two adjacent battery cells 3 in the battery module and between the end plate 5 and the end of the battery module. Insulating seats 6 are provided on the upper ends of the two end plates 5. The battery module and the outer side of the end plate 5 are bound and fixed by several steel straps 7. The bottom of the battery module and the end plate 5 are fixedly provided with a bottom insulating PC film 9 and a bottom epoxy board 8 from top to bottom. The top of the battery module and the end plate 5 are fixedly provided with a CCS module 2 and a top insulating PC film 1 from bottom to top. The top of the CCS module 2 is insulated by the top insulating PC film 1. The CCS module 2 is provided with a fusible aluminum busbar 29.

[0028] like Figure 4As shown, the internal structure of the heat insulation pad 11 includes: aluminum-plastic film one 1101, heat insulation material 1102, and aluminum-plastic film two 1103. The aluminum-plastic film one 1101 and aluminum-plastic film two 1103 are formed by vacuum heat sealing around their perimeter, thus heat-sealing the heat insulation material 1102 inside the aluminum-plastic film one 1101 and aluminum-plastic film two 1103. The thickness after forming is approximately 1-5mm, which can be adjusted as needed. The internal heat insulation material 1102 can be a flame-retardant, heat-insulating, and compressive-resistant elastic material such as ceramic fiber, aerogel, or mica sheets. Figure 3 As shown, after vacuum heat sealing, the outer surfaces of the heat insulation pad 11 on both sides need to be covered with double-sided adhesive 1104 or sprayed with hot melt adhesive to facilitate bonding of the battery cell 3 and the end plate 5. First, according to the series and parallel connection requirements, heat insulation pads 11 are placed between each battery cell 3. The battery cells 3 are bonded together by double-sided adhesive 1104 on both sides of the heat insulation pads 11. The outermost battery cells 3 at both ends of the battery module have heat insulation pads 11 placed on them first, and then the module end face insulating PC film 4 is placed on the surface of the heat insulation pads 11. This approach is mainly due to the fact that the end plate 5 is made of metal, and burrs and particles are easily formed on the surface, which may puncture the battery cell 3, causing insufficient withstand voltage and low insulation resistance of the battery cell 3, resulting in leakage, low withstand voltage, poor insulation, and even safety hazards. Finally, the end plates 5 are stacked along the thickness direction. The end plates 5 are provided with slots for fixing the steel strip 7. Since the heat insulation pads 11 have a certain degree of compressibility and rebound, a certain force is applied inward to the two end plates 5 by pre-tightening the tooling, i.e., the steel strip 7. The force is usually around 1000N, which can be adjusted according to the battery cells 3 and the outermost battery cells 3. After adjusting the space reserved in the heat insulation pad 11, the steel strip 7 is placed in. The steel strip 7 has thermoplastic sleeves 71 on both sides near the battery cell 3, which serve as insulation and protection. Multiple steel strips 7 can be placed at the same time according to structural needs to bind the battery cell 3, end plate 5, heat insulation pad 11 and the insulating PC film 4 on the end face of the module. The purpose is twofold: first, to provide sufficient space for the heat insulation pad 11, and for the steel strip 7 and end plate 5 to provide sufficient rigidity and strength to release and eliminate the expansion force and expansion thickness of the battery and PACK pack; second, to apply appropriate structural pressure to the battery cell 3 through the pre-tightening fixture, which can effectively shorten the migration path of Li+, reduce Li+ loss and thus improve the battery life. By fully combining the electrochemical mechanism of the battery cell, the potential hidden dangers of expansion force can be effectively eliminated, greatly saving after-sales maintenance costs, improving the safety and reliability of the product, and enhancing the product's competitiveness in the market.

[0029] Both end plates 5 are provided with slots that match the insulating base 6, fixing and limiting the insulating base 6. The insulating bases 6 at both ends are respectively provided with screw holes corresponding to the positive lead-out aluminum busbar 21 and the negative lead-out aluminum busbar 22 of the CCS component 2. Screws are threadedly connected to the insulating bases 6 at both ends, the positive lead-out aluminum busbar 21, and the negative lead-out aluminum busbar 22, thereby fixing and limiting the positive lead-out aluminum busbar 21, the negative lead-out aluminum busbar 22, and the external leads. For example... Figure 5As shown, the CCS assembly 2 includes a CCS board. Positive electrode lead-out aluminum busbars 21 and negative electrode lead-out aluminum busbars 22 are respectively disposed at both ends of the CCS board. A PCB 23 and an FPC 27 are disposed in the middle of the CCS board. Series aluminum busbars 26 are disposed on both sides of the CCS board, and a fusible aluminum busbar 29 is disposed on one side of the CCS board. The positive electrode lead-out aluminum busbars 21, negative electrode lead-out aluminum busbars 22, series aluminum busbars 26, and fusible aluminum busbars 29 are connected to the PCB 23 via the FPC 27. The upper and lower surfaces of the CCS board are heat-sealed together by an upper hot-pressed PC film 25 and a lower hot-pressed PC film 24. The positive electrode lead-out aluminum busbars 21, negative electrode lead-out aluminum busbars 22, series aluminum busbars 26, and fusible aluminum busbars 29 are directly opposite the terminals of the battery cell 3. Figure 6 As shown, the positive electrode lead-out aluminum busbar 21 is provided with a positioning hole 2101 corresponding to the terminal of the battery cell 3; the negative electrode lead-out aluminum busbar 22 is provided with a positioning hole 2201 corresponding to the terminal of the battery cell 3; the series aluminum busbar 26 is provided with a positioning hole 2601 corresponding to the terminal of the battery cell 3; and the fusible aluminum busbar 29 is provided with a positioning hole 2903 corresponding to the terminal of the battery cell 3. Positioning holes 2101, 2201, 2601, and 2903 are respectively laser-welded to the terminal of the corresponding battery cell 3. The laser welding is used to weld the integrated CCS module 2. The CCS module 2 is located on the corresponding positive electrode lead-out aluminum busbar 21, negative electrode lead-out aluminum busbar 22, and series aluminum busbar 26. Laser welding holes are reserved at the positions of the aluminum busbar 26 and the fused aluminum busbar 29. Ultimately, the positive electrode lead-out aluminum busbar 21, negative electrode lead-out aluminum busbar 22, series aluminum busbar 26, and fused aluminum busbar 29 are welded to the battery cell 3 of the battery module. In addition to positioning holes corresponding to the terminals of the battery cell 3, the positive electrode lead-out aluminum busbar 21, negative electrode lead-out aluminum busbar 22, series aluminum busbar 26, and fused aluminum busbar 29 also have wave-shaped arch bridges corresponding to the spaces between two adjacent battery cells 3. Wave-shaped arch bridge one 2102 is provided on the positive electrode lead-out aluminum busbar 21, wave-shaped arch bridge two 2202 is provided on the negative electrode lead-out aluminum busbar 22, wave-shaped arch bridge three 2602 is provided on the series aluminum busbar 26, and wave-shaped arch bridge four 2902 is provided on the fused aluminum busbar 29. The purpose is to prevent tensile forces between the aluminum busbar and the battery cell 3 due to the expansion of the battery cell 3 during charging and discharging and changes in electrode thickness. The wave-shaped arch bridges can eliminate the expansion of the battery cell 3 during charging and discharging and changes in electrode thickness.

[0030] In addition, the positive electrode lead-out aluminum busbar 21 is provided with a CCS positioning hole 1 2103, the negative electrode lead-out aluminum busbar 22 is provided with a CCS positioning hole 2203, the series aluminum busbar 26 is provided with a CCS positioning hole 3 2603, and the fusion aluminum busbar 29 is provided with a CCS positioning hole 4 2904. The upper hot-pressed PC film 25 and the lower hot-pressed PC film 24 are positioned by the CCS positioning holes 1 2103, 2 2203, 3 2603, and 4 2904. C-film 25 and lower hot-pressed PC film 24 are provided with positioning holes corresponding to CCS positioning hole 1 2103, CCS positioning hole 2203, CCS positioning hole 3 2603 and CCS positioning hole 4 2904, and laser welding holes corresponding to positive lead aluminum busbar 21, negative lead aluminum busbar 22, series aluminum busbar 26 and fused aluminum busbar 29. Positive lead aluminum busbar 21, negative lead aluminum busbar 22, series aluminum busbar 26 and fused aluminum busbar 29 are connected through FPC 27 and PCB 23. 27 is a flexible circuit board, and PCB23 is a printed circuit board. FPC27 integrates nickel sheets 2701 (aluminum busbar side soldered), 2702 (wave arch bridge section nickel sheet), 2703 (PCB side soldered nickel sheet), and a thermistor 2305. The nickel sheet 2701 on the aluminum busbar side is used to solder the positive electrode lead-out aluminum busbar 21, the negative electrode lead-out aluminum busbar 22, the series aluminum busbar 26, and the fused aluminum busbar 29. The wave arch bridge section nickel sheet 2702 addresses the microscopic deformation of the aluminum busbar caused by the expansion of the battery cell 3 during charging and discharging and changes in electrode thickness. The nickel sheet 2703 on the PCB side connects to the PCB acquisition circuit and transmits data to the acquisition terminal 2302. One end of PCB23 has a PCB protrusion 2301 that extends beyond the entire structure of PCB23. The acquisition terminal 2302 is fixedly mounted on the upper surface of the PCB protrusion 2301 to facilitate interface between the acquisition terminal 2302 and an external BMS. The PCB acquisition circuit is obtained through PCB printing technology, which is a current and very mature technology, and therefore will not be described in detail. The thermistor 2305 is located at the nickel strip 2703 soldered to the PCB side, and the two are bonded together by thermally conductive adhesive. The nickel strip 2703 has L-shaped hooks 28 on both sides of the thermistor 2305, which mainly serve to fix the thermally conductive adhesive. In addition, the nickel strip 2703 senses heat through the L-shaped hooks 28, bringing the heat closer to the thermistor 2305 for more accurate temperature acquisition. The thermistor 2305 senses the heat generated by the positive lead aluminum busbar 21, negative lead aluminum busbar 22, series aluminum busbar 26, fused aluminum busbar 29, and battery module through the nickel strips 2701 soldered to the aluminum busbar side, the corrugated arch bridge section nickel strip 2702, and the nickel strips 2703 soldered to the PCB side. This data is also transmitted to the acquisition terminal 2302 through the PCB acquisition circuit, and the acquisition terminal 2302 is connected to the external BMS.

[0031] In addition to the PCB acquisition circuit, PCB23 also has a waist hole 2303 and a positioning hole 2304 corresponding to the explosion-proof valve of cell 3. The upper hot-pressed PC film 25 and the lower hot-pressed PC film 24 also have corresponding waist holes and positioning holes. The upper hot-pressed PC film 25 and the lower hot-pressed PC film 24 are heat-sealed together by FPC27, PCB23, positive electrode lead-out aluminum busbar 21, negative electrode lead-out aluminum busbar 22, series aluminum busbar 26 and fusible aluminum busbar 29 through heat sealing equipment. After heat sealing, the positioning holes 2101, 2201, 2601 and 2903 of CCS component 2 are welded together with the pole of cell 3 by laser welding. In addition, the fusible aluminum busbar 29 has several fusible grooves 2901. At point 2902 of the wave arch bridge, the fuse groove 2901 is removed according to the maximum normal discharge rate of cell 3. An upper limit coefficient of 10-20% can also be reserved. Once the maximum value of the upper limit is exceeded, the wave arch bridge 2902 of the aluminum busbar 29 will melt and disconnect cell 3. This is to prevent high-rate discharge of cell 3 from causing insufficient ion migration speed in the electrode, increased internal resistance, and a drop in voltage plateau. It is also to prevent high-rate discharge from causing the battery surface temperature to rise rapidly, which may lead to thermal runaway risk. High-rate discharge can also cause the graphite layer of the negative electrode to crack, resulting in a capacity decay of up to 30% after 200 cycles. It can also shorten the cycle life of the battery and may cause problems such as battery overheating, lithium plating, and SEI film growth, thus reducing the risk of explosion and fire.

[0032] The upper hot-pressed PC film 25 has several expansion joints 2502 between the positions corresponding to the positive electrode lead-out aluminum busbar 21, the negative electrode lead-out aluminum busbar 22, the series aluminum busbar 26, and the fused aluminum busbar 29. The upper hot-pressed PC film 25 also has several printing label holes 2501. The purpose of the expansion joints 2502 is to prevent the micro-deformation of the aluminum busbars caused by the expansion of the battery cell 3 during charging and discharging and changes in electrode thickness, which would lead to stretching of the upper hot-pressed PC film 25. The printing label holes 2501 are intended to avoid obscuring the text printed on the PCB 23, facilitating production confirmation and identification. The lower hot-pressed PC film 24 has several expansion joints 2401 between the positions corresponding to the positive electrode lead-out aluminum busbar 21, the negative electrode lead-out aluminum busbar 22, the series aluminum busbar 26, and the fused aluminum busbar 29. The purpose of these expansion joints is also to prevent the expansion of the battery cell 3 during charging and discharging and changes in electrode thickness, which would lead to micro-deformation of the aluminum busbars and cause stretching of the upper hot-pressed PC film 25.

[0033] The CCS component 2 and the battery module are welded together. The top is insulated with a flame-retardant PC film 1, and the bottom is insulated with a flame-retardant PC film 9 and a bottom epoxy board 8. In addition to flame-retardant insulation, the bottom epoxy board 8 mainly serves to facilitate assembly line operations. The smooth surface of the bottom epoxy board 8 reduces friction on the assembly line and protects the battery cell 3. The top insulating PC film 1, bottom insulating PC film 9, and bottom epoxy board 8 prevent the battery cell 3 from contacting surrounding metal, avoiding safety hazards during charging and discharging. Furthermore, the charging and discharging of the battery cell 3 will come into contact with the charging and discharging wires, preventing short circuits and other safety risks.

[0034] After assembly, the self-breathing and self-protection module 100, under the excitation of the charging and discharging equipment, causes a phase change in the structure of the battery cell 3 due to electrochemical reactions and the insertion and extraction of Li+ between the positive and negative electrode materials. This results in the breathing expansion and thickness change of the battery cell 3. The so-called breathing expansion refers to the continuous expansion and thickening of the negative electrode and SEI film during the charging process due to the continuous insertion of Li+ into the negative electrode. The internal pressure and thickness gradually increase until the charging is completed. After discharging, Li+ continuously extracts from the negative electrode, and the internal pressure and thickness gradually decrease until the discharging is completed. According to relevant studies, although a phase change occurs during the charging and discharging process, resulting in certain fluctuations, the overall trend does not change significantly. The above describes the breathing expansion change of the battery cell 3. In this embodiment, a matching breathing structure heat insulation pad 11 is set between the battery cells 3. When the battery cell 3 expands, the heat insulation pad 11 has compressibility and rebound properties, which can not only provide a certain reaction force to the battery cell 3, but also absorb the expansion deformation of the battery cell 3. When the battery cell 3 discharges, the heat insulation pad 11 returns to its original shape as the thickness of the battery cell 3 decreases under the action of self-tension. Since the heat insulation pad 11 applies appropriate structural pressure, it can effectively shorten the migration path of Li+, reduce the loss of Li+, and thus improve the service life of the battery. By fully combining the electrochemical mechanism of the battery cell, the potential hidden dangers of expansion force can be effectively eliminated, greatly saving after-sales maintenance costs, improving the safety and reliability of the product, and enhancing the product's competitiveness in the market.

[0035] This embodiment incorporates multiple breathable thermal insulation pads 11 between the battery cells 3 of the battery module. By considering the strength of the external structure in advance, it prevents irreversible deformation and damage to the external fixing structure, avoids adverse effects on battery life, and prevents battery and fixing structure rupture or battery fire and explosion. Therefore, the thermal insulation pads 11 ensure the safety and stability of the battery cells under both normal use and abnormal conditions.

[0036] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A self-breathing and self-protection module, comprising: An end plate (5) and several battery cells (3) are arranged side by side to form a battery module. The two ends of the battery module are respectively provided with end plates (5). The battery module is characterized in that a heat insulation pad (11) is provided between any two adjacent battery cells (3) and between the end plate (5) and the end of the battery module. An insulating seat (6) is fixedly provided on the upper end of the two end plates (5). The battery module and the outer side of the end plate (5) are tied and fixed by several steel strips (7). The bottom of the battery module and the end plate (5) are fixedly provided with a bottom insulating PC film (9) and a bottom epoxy board (8) from top to bottom. The top of the battery module and the end plate (5) are fixedly provided with a CCS component (2) and a top insulating PC film (1) from bottom to top. A fused aluminum busbar (29) is fixedly provided on the CCS component (2).

2. The self-breathing and self-protection module according to claim 1, characterized in that, The CCS assembly (2) includes a CCS board. A positive lead-out aluminum busbar (21) and a negative lead-out aluminum busbar (22) are respectively provided at both ends of the CCS board. A PCB (23) and an FPC (27) are provided in the middle of the CCS board. A series aluminum busbar (26) is provided on both sides of the CCS board. A fusible aluminum busbar (29) is provided on one side of the CCS board. The positive lead-out aluminum busbar (21), the negative lead-out aluminum busbar (22), the series aluminum busbar (26) and the fusible aluminum busbar (29) are connected to the PCB (23) through the FPC (27). The upper and lower surfaces of the CCS board are heat-sealed together by the upper hot-pressed PC film (25) and the lower hot-pressed PC film (24).

3. The self-breathing and self-protection module according to claim 2, characterized in that, The positive lead-out aluminum busbar (21), negative lead-out aluminum busbar (22), series aluminum busbar (26) and fuse aluminum busbar (29) are all wavy arch bridge shaped, and the fuse aluminum busbar (29) is provided with several fuse grooves (2901).

4. The self-breathing and self-protection module according to claim 2, characterized in that, The positive lead-out aluminum busbar (21), negative lead-out aluminum busbar (22), series aluminum busbar (26) and fused aluminum busbar (29) are directly opposite the terminals of the battery cell (3) in the battery module.

5. A self-breathing self-protection module according to claim 2, characterized in that, The lower hot-pressed PC film (24) has several expansion joints (2401) between the positions of the corresponding positive electrode lead-out aluminum busbar (21), negative electrode lead-out aluminum busbar (22), series aluminum busbar (26) and fused aluminum busbar (29); the upper hot-pressed PC film (25) has several expansion joints (2502) between the positions of the corresponding positive electrode lead-out aluminum busbar (21), negative electrode lead-out aluminum busbar (22), series aluminum busbar (26) and fused aluminum busbar (29).

6. A self-breathing self-protection module according to claim 1, characterized in that, An insulating PC film (4) is also provided between the end plate (5) and the battery module, and the insulating PC film (4) is provided on the outside of the heat insulation pad (11).

7. A self-breathing self-protection module according to claim 1, characterized in that, The heat insulation pad (11) includes: aluminum-plastic film one (1101), heat insulation material (1102) and aluminum-plastic film two (1103) arranged sequentially from top to bottom; the aluminum-plastic film one (1101) and aluminum-plastic film two (1103) are formed by vacuum heat sealing around their perimeter, and the heat insulation material (1102) is wrapped inside.

8. A self-breathing self-protection module according to claim 7, characterized in that, Double-sided adhesive tape (1104) or hot melt adhesive is applied to the outer surfaces of both aluminum-plastic film one (1101) and aluminum-plastic film two (1103).

9. A self-breathing self-protection module according to claim 7, characterized in that, The heat insulation material (1102) is ceramic fiber, aerogel or mica sheet.

10. A self-breathing and self-protection module according to claim 1, characterized in that, The end plate (5) is provided with a slot corresponding to the steel strip (7), and the steel strip (7) is fixed by the slot.

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