Large-size ultra-thin square polymer power battery

Abstract

The application relates to a large-size ultra-thin square polymer power battery, which comprises a battery shell, battery cover plates arranged on the two sides of the battery shell, and a battery core installed in the battery shell. The battery shell comprises two symmetrically arranged shell units, the shell unit comprises a bottom plate, vertical plates fixedly connected to the two sides of the bottom plate, and extension plates fixedly connected to the ends of the vertical plates away from the bottom plate, the two shell units are combined to form a cavity for accommodating the battery core, and the extension plates between the two shell units abut and are fixedly welded. The battery cover plate is provided with two cover plate bodies embedded in the cavity and located at the two ends of the cavity, the cover plate body comprises a welding ring arranged on the outer wall of the cover plate body in the circumferential direction, the welding ring is used for abutting against the inner wall of the cavity, and the welding ring is fixedly connected to the shell unit through welding. Through the above technical scheme, a large-size battery in any direction can be prepared, the single capacity of the battery is improved, and various use requirements can be met.

Description

[Technical Field]

[0001] This application relates to a large-size, ultra-thin, square-shaped polymer power battery, belonging to the field of power battery technology. [Background Technology]

[0002] Currently, there are three common types of power batteries: pouch batteries, prismatic batteries, and cylindrical batteries. Pouch batteries can be made quite thin, with thicknesses ranging from 5mm to 12mm. Unconventional batteries, such as blade batteries, use traditional aluminum casings, are approximately 1000mm long, 120mm wide, and 10mm thick, with a long, blade-like shape. Due to their high energy density, excellent heat dissipation, and high space utilization, blade batteries are increasingly finding a market in high-energy-density, high-rate discharge modes.

[0003] Although blade batteries are designed to be as thin and large as possible, current blade batteries cannot actually be made to any size in the width direction. Other traditional batteries, on the other hand, are at most the size of an A4 sheet of paper, with a thickness typically between 9mm and 15mm. This is because traditional battery casings are made using a stamping and stretching process, which involves directly stamping and stretching a sheet of material until it becomes a box structure with an opening at one end. Figure 1 As shown.

[0004] Generally, 1.5mm manganese-aluminum plates are used for stamping, and the stamping depth can only reach 288mm-300mm. If the battery size is too large, the required stamping depth would be too great, making the process impossible to complete smoothly. This limitation in battery size leads to a limited battery capacity. Currently, the largest single-cell capacity of a battery can reach 350Ah. If the required battery capacity for specific applications, such as large-scale photovoltaic energy storage power stations, is 1000Ah-2000Ah, then these battery capacities are too small.

[0005] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects. [Summary of the Invention]

[0006] The purpose of this application is to provide a large-size battery to meet subsequent usage needs.

[0007] The purpose of this application is to achieve the following technical solution: a large-size ultra-thin square-shaped polymer power battery, including a battery shell, battery cover plates disposed on both sides of the battery shell, and battery cells installed inside the battery shell;

[0008] The battery casing includes two symmetrically arranged casing units. Each casing unit includes a base plate, vertical plates fixedly connected to both sides of the base plate, and an extension plate fixedly connected to the end of the vertical plate away from the base plate. The two casing units are combined to form a cavity for accommodating the battery cell. The extension plates between the two casing units abut against each other and are welded together.

[0009] The battery cover plate has two parts, which are respectively located at the two ends of the cavity. The battery cover plate includes a cover plate body embedded in the cavity. The cover plate body has a welding ring circumferentially disposed on the outer wall of the cover plate body. The welding ring is used to abut against the inner wall of the cavity. The welding ring is fixedly connected to the housing unit by welding.

[0010] Furthermore, the corresponding extension plates are reinforced by a two-pass welding-deep penetration welding, with the welding depth of the two-pass welding-deep penetration welding being 1 / 3 to 2 / 3 of the thickness of the extension plate.

[0011] Furthermore, the welding ring and the shell unit are reinforced by a two-pass welding-deep penetration welding, and the welding depth of the two-pass welding-deep penetration welding is 1 / 3 to 2 / 3 of the thickness of the shell unit.

[0012] Furthermore, the width of the extension plate is not less than 1.5 mm.

[0013] Furthermore: the welding ring has abutment plates on both sides for abutting against the end wall of the battery casing, the abutment plates cover the extension plate, and the abutment plates are welded and fixed to the outside of the extension plate.

[0014] Furthermore: at least one of the base plates is provided with a limiting ring on its inward side, and the battery cell is installed inside the limiting ring and limited by the limiting ring.

[0015] Furthermore, the base plate is provided with an insulating sheet on the side facing the battery cell to isolate the battery cell from the base plate.

[0016] Further: The battery cell includes several positive electrode units and several negative electrode units, which are arranged alternately. The positive electrode unit includes a positive electrode sheet and a positive electrode polymer interface management layer film located on both sides of the positive electrode sheet (26). The negative electrode unit includes a negative electrode sheet and a negative electrode polymer interface management layer film located on both sides of the negative electrode sheet.

[0017] Furthermore, the negative electrode is shorter than the positive electrode and the negative electrode is wider than the positive electrode.

[0018] Furthermore: the positive electrode polymer interface management layer membrane includes a first non-polar membrane and a first positive electrode conductive polymer interface management layer membrane located on both sides of the first non-polar membrane, and the negative electrode polymer interface management layer membrane includes a second non-polar membrane and a second negative electrode conductive polymer interface management layer membrane located on both sides of the second non-polar membrane.

[0019] Compared with existing technologies, this application has the following advantages: By adopting the above-mentioned technical solution, the battery casing is divided into two parts, which are spliced ​​and welded together to form a complete battery casing. Since the overall structure of the casing unit is nearly flat and the stamping depth is small, the operating range during die casting is large, allowing for the production of casing units with large planar dimensions in any direction. The welding between the two extension plates and the welding between the extension plates and the cover plate body ensures the airtightness of the entire battery, making the battery safer overall. This allows for more stable and safer encapsulation of large-sized cells in any direction within the cavity. Thus, large-sized batteries in any direction can be manufactured, increasing the single-cell capacity of the battery and meeting various application requirements. [Attached Image Description]

[0020] Figure 1 This is a schematic diagram of the structure of a battery casing in the prior art.

[0021] Figure 2 This is a schematic diagram of the structure of Example 1.

[0022] Figure 3 This is an exploded view of the battery casing and battery cell in Example 1.

[0023] Figure 4 This is a cross-sectional view of the battery casing in Example 1.

[0024] Figure 5 This is a partial schematic diagram of the battery casing in Example 1.

[0025] Figure 6 This is a schematic diagram of the battery cover at the terminal post in Example 1.

[0026] Figure 7 This is a schematic diagram of the battery cover in Example 1.

[0027] Figure 8 This is a partial structural diagram of the battery cover in Example 1.

[0028] Figure 9 This is a schematic diagram of the structure of the second insulating layer in Example 1.

[0029] Figure 10 This is a schematic diagram of the shell unit in Embodiment 1.

[0030] Figure 11 yes Figure 10 Enlarged view of point A in the middle.

[0031] Figure 12 This is a partial schematic diagram of the contact between the limiting plate and the battery cover in Example 1.

[0032] Figure 13 This is a schematic diagram of the battery cover at the glue injection port in Example 1.

[0033] Figure 14 This is a schematic diagram of the battery cell structure in Example 1.

[0034] Figure 15 This is a schematic diagram of the positive electrode unit in Example 1.

[0035] Figure 16 This is a schematic diagram of the structure of the positive electrode polymer interface management layer membrane in Example 1.

[0036] Figure 17 This is a schematic diagram of the negative electrode unit in Example 1.

[0037] Figure 18 This is a schematic diagram of the structure of the negative electrode polymer interface management layer membrane in Example 1.

[0038] Figure 19 This is a process flow diagram of the positive electrode unit fabrication in Example 1.

[0039] Figure 20 This is a schematic diagram of the membrane thermal composite process of the positive electrode polymer interface management layer in Example 1.

[0040] Figure 21 This is a flowchart of the fabrication of the negative electrode unit in Example 1.

[0041] Figure 22 This is a process flow diagram of the fabrication of the negative electrode unit in Example 1.

[0042] Figure 23 This is a schematic diagram of the membrane thermal composite process of the negative electrode polymer interface management layer in Example 1.

[0043] Figure 24 This is a schematic diagram of the manufacturing process of the battery cell in Example 1.

[0044] Figure 25 This is a partial schematic diagram of the contact plate in Embodiment 2.

[0045] Explanation of reference numerals in the attached drawings: 1. Battery casing; 2. Battery cover; 3. Battery cell; 4. Casing unit; 5. Base plate; 6. Vertical plate; 7. Extension plate; 8. Edge clamp; 9. Slot; 10. Sealing layer; 11. Limiting plate; 12. Limiting ring; 13. Insulating sheet; 14. Cover body; 15. Terminal post; 16. Current plate; 17. Welding ring; 18. Through groove; 19. Sealing assembly; 20. Explosion-proof valve; 21. Injection port; 22. Rubber gasket; 23. Sealing cap; 24. Positive electrode unit; 25. Negative electrode unit; 26. Positive electrode sheet; 27. Positive electrode polymer interface management layer film; 28. First non-polar separator; 29. ​​First positive electrode conductive polymer interface management layer film; 30. Negative electrode sheet; 31. Negative electrode polymer interface management layer film; 32. Second non-polar separator; 33. Second negative electrode conductive polymer interface management layer film; 34. Positive electrode tab; 35. Positive electrode roll; 36. Positive electrode unit roll; 37. First heating zone; 38. Second heating zone; 39. Third heating zone; 40. Positive electrode pressure roller; 41. Negative electrode tab; 42. Negative electrode roll; 43. Negative electrode unit roll; 44. Fourth heating zone; 45. Fifth heating zone; 46. Sixth heating zone; 47. Negative electrode pressure roller; 48. Seventh heating zone; 49. Eighth heating zone; 50. Ninth heating zone; 51. Abutment plate; 61. PP sleeve; 62. First insulating layer; 63. Second insulating layer; 63. Copper foil layer or aluminum foil layer; 64. Third insulating layer; 65. First fixing plate; 66. Fourth insulating layer; 67. Fifth insulating layer; 68. Sixth insulating layer.

Detailed Implementation Methods

[0046] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0047] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] Please see Figures 1 to 7 As shown, a preferred embodiment of this application presents a large-size, ultra-thin, square-shaped polymer power battery. The single-cell capacity can reach 500AH-2000AH, with a maximum of 3000AH. (Refer to...) Figure 2 and Figure 3 The large-size ultra-thin square-shaped polymer power battery includes a battery casing 1, battery cover plates 2 located on both sides of the battery casing 1, and battery cells 3 installed inside the battery casing 1.

[0050] Reference Figure 4 and Figure 5 The battery casing 1 comprises two casing units 4. Each casing unit 4 is U-shaped and flat, thin. Each casing unit 4 includes a base plate 5, vertical plates 6 fixedly connected to both ends of the base plate 5, and an extension plate 7 fixedly connected to one end of the vertical plates 6 and parallel to the base plate 5. The dimensions of the base plate 5, vertical plates 6, and extension plate 7 can be customized according to actual requirements. The casing unit 4 is die-cast from a 1-1.5mm thick manganese-aluminum sheet. In this embodiment, the base plate 5 measures 505.5mm x 740mm, the vertical plate 6 measures 12.75mm x 740mm, and the extension plate 7 measures 3mm x 740mm.

[0051] During assembly, the two housing units 4 are placed symmetrically so that the extension plates 7 between the two housing units 4 abut against each other. The sides of the two abutting extension plates 7 are welded together by laser welding. Then, a second welding—a deep penetration weld—is performed in the middle of the extension plates 7, with the welding depth reaching half the depth of the base plate 5. This results in better sealing of the battery casing 1 formed by the two housing units 41, making it less prone to air leakage.

[0052] Reference Figure 5To further improve the sealing performance of the battery casing 1 and reduce the possibility of air leakage between the two casing units 4, the battery casing 1 also includes two retaining edges 8. Two extension plates welded together form an extension plate assembly. One retaining edge 8 corresponds to one extension plate assembly. A retaining groove 9 is formed along the length of the retaining edge 8, into which the extension plate assembly is inserted. A sealing layer 10, which can be made of resin, is provided between the retaining edge 8 and the vertical plate 6. The retaining edge 8 stably connects the two casing units 41 together, and the sealing adhesive improves the sealing performance between the retaining edge 8 and the casing unit 4. This ultimately improves the sealing performance of the battery casing 1. When the retaining edge 8 is installed on the extension plate assembly, the end face of the retaining edge 8 is on the same plane as the bottom plate 5, meaning the thickness of the retaining edge 8 is equal to the total thickness of the two casing units 4 welded together.

[0053] Using the above method, battery casings 1 for thin batteries of any size can be manufactured. To enlarge the battery casing 1, simply enlarge the base plate 5. The stamping depth of the casing unit 4 does not need to be very deep, as the stamping process can fully achieve this, and the processing difficulty and cost are low.

[0054] Meanwhile, the existing battery casing 1 has uneven thickness of its base plate 5 and side plates due to its large stamping depth. In this case, the stamping depth required when processing the casing unit 4 is not large, which can ensure that the thickness of the casing unit 4 is as uniform as possible, and better adapt to the various performance requirements of the subsequent battery casing 1, such as heat dissipation performance.

[0055] Reference Figures 6 to 9 The battery cover 2 includes a cover body 14, terminal posts 15 connected to the cover body 14, a current-carrying plate 16, and a welding ring 17 disposed along the cover body 14. A through groove 18 is formed on the cover body 14 for the terminal posts 15 to pass through. The terminal posts 15 and the current-carrying plate 16 are located on opposite sides of the cover body 14, with the terminal posts 15 passing through the through groove 18 and connected to the current-carrying plate 16. The terminal posts 15 are fixedly installed on the cover body 14, and a gap exists between the two sides of the terminal posts 15 and the welding ring 17 along the width direction of the cover body 14.

[0056] The pole post 15 is also provided with a sealing component 19, which is connected to the pole post 15 by a hot melt welding process to fill the gap between the two sides of the sealing pole post 15 and the welding ring 17.

[0057] The sealing assembly 19 includes a PP sleeve 61, a first insulating layer 62, a second insulating layer 63, a third insulating layer 64, and a first fixing plate 65. The PP sleeve 61 is fitted onto the electrode post 15. The first insulating layer 62 is fitted onto the side of the PP sleeve 61 away from the electrode plate 16. The second insulating layer 63 is fitted onto the PP sleeve 61 and connected to the first insulating layer 62, so that the first insulating layer 62 is partially molten and connected to the second insulating layer 63, thereby fixing the connection between the first insulating layer 62 and the second insulating layer 63 after the first insulating layer 62 is completely cured. Similarly, the third insulating layer 64 is fitted onto the PP sleeve 61 and connected to the second insulating layer 63, so that the third insulating layer 64 is partially molten and connected to the second insulating layer 63, thereby fixing the connection between the third insulating layer 64 and the second insulating layer 63 after the third insulating layer 64 is completely cured. The first fixing plate 65 is disposed between the pole post 15 and the cover plate body 14. The first fixing plate 65 and the pole post 15 are interference-fitted to fill the gap. Simultaneously, the first fixing plate 65 and the pole post 15 are laser-welded together, making the connection between the first fixing plate 65 and the third insulating layer 64 more robust. Furthermore, the first fixing plate 65 and the third insulating layer 64 are thermally fused together. In this embodiment, the PP sleeve 61 is made of polypropylene (modified PP), the first insulating layer 62 and the third insulating layer 64 are both made of polypropylene (modified PP), and the second insulating layer 63 is made of insulating ceramic. Polypropylene is a semi-crystalline material that is harder and has a higher melting point than PE (polyethylene). Modified PP does not suffer from environmental stress cracking. Typically, PP is modified by adding glass fibers, metal additives, or thermoplastic rubber.

[0058] The insulating ceramic includes a main body and a copper foil layer 631 or an aluminum foil layer 631 coated on the outer surface of the main body. That is, the insulating ceramic can be covered with copper foil or aluminum foil on both sides. The purpose of this design is to achieve a fixed connection between the insulating ceramic and the polypropylene through a hot-melt welding process, while ensuring that there are no gaps between the insulating ceramic and the polypropylene, thereby ensuring the sealing performance of the power battery cover.

[0059] The sealing assembly 19 also includes a fourth insulating layer 66 sleeved on the side of the PP sleeve 61 near the electrode plate 16, a fifth insulating layer 67 sleeved on the PP sleeve 61 and connected to the fourth insulating layer 66, and a sixth insulating layer 68 sleeved on the PP sleeve 61 and connected to the fifth insulating layer 67. Similarly, to further enhance the overall sealing performance of the power battery cover, the electrode post 15, PP sleeve 61, fourth insulating layer 66, fifth insulating layer 67, and sixth insulating layer 68 are connected by a hot-melt welding process.

[0060] In this embodiment, the fourth insulating layer 66 and the sixth insulating layer 68 are made of polypropylene, and the fifth insulating layer 67 is made of insulating ceramic. That is, in this embodiment, the fourth insulating layer 66 and the sixth insulating layer 68 have the same structure as the first insulating layer 62 and the third insulating layer 64 described above, and the fifth insulating layer 67 has the same structure as the third insulating layer 64 described above, which will not be described again here. Furthermore, the connection method between the fourth insulating layer 66, the fifth insulating layer 67, and the sixth insulating layer 68 is the same as the connection method between the first insulating layer 62, the second insulating layer 63, and the third insulating layer 64, which will not be described again here.

[0061] Reference Figure 6 The width of welding ring 17 can be designed according to actual welding requirements; in this embodiment, the width of welding ring 17 is 2.5mm. (Refer to...) Figure 10 and Figure 11 To facilitate the installation of the cover plate body 14, a limiting plate 11 is provided on the inward side of the base plate 5. The limiting plate 11 and the base plate 5 are integrally die-cast. (Refer to...) Figure 12 When the cover plate body 14 is embedded in the battery casing 1, the cover plate body 14 abuts against the limiting plate 11. At this time, the outer end face of the welding ring 17 and the end wall of the battery casing 1 are on the same horizontal plane.

[0062] Reference Figure 6 The cover plate body 14 is provided with an injection port 21 and an explosion-proof valve 20, which are located on both sides of the pole post 15, respectively. (Refer to...) Figure 13 The injection port 21 is equipped with a rubber gasket 22 to seal the injection port 21. A sealing cap 23 is also threaded onto the injection port 21.

[0063] When assembling the cover plate and battery casing 1, two battery cover plates 2 are respectively embedded into both ends of the battery casing 1 until the cover plate body 14 abuts against the limiting plate 11. At this time, the welding ring 17 is located on the outward side of the cover plate body 141. The welding ring 17 and the corresponding end face of the battery casing 1 are fixed by laser welding. Then, a second welding-deep penetration welding is performed at 1 / 2 of the welding ring 17, with the penetration welding depth reaching 1 / 2 of the bottom plate depth. This improves the sealing between the battery cover plate 2 and the battery casing 1 and reduces the occurrence of air leakage. During installation, the terminal post 15 passes through the through groove 18, and the terminal post 15 and the current plate 16 are welded together in one go by ultrasonic roll welding.

[0064] Reference Figure 3 To facilitate the subsequent installation of the battery cell 3 and improve safety, at least one of the base plates 5 has a limiting ring 12 on its inward side. The limiting ring 12 is used to define the position of the battery cell 3 inside the battery casing. An insulating sheet 13 is provided on the inward side of the base plate 5, and the insulating sheet 13 is located inside the limiting ring 12.

[0065] Reference Figure 14The battery cell 3 includes several positive electrode units 24 and several negative electrode units 25, which are arranged alternately. The length difference between the negative electrode unit 25 and the positive electrode unit 24 is 0.5-1.5mm, and the length difference between the width of the negative electrode unit 25 and the width of the positive electrode unit 24 is 0.5-1.5mm, thereby reducing the possibility of short circuit.

[0066] Refer to 15 and Figure 16 The positive electrode unit 24 includes a positive electrode plate 26, a positive electrode polymer interface management layer film 27 located on both sides of the positive electrode plate 26, and a positive electrode active material 69 located between the positive electrode plate 26 and the positive electrode polymer interface management layer film 27. The positive electrode polymer interface management layer film 27 includes a first non-polar membrane 28 and a first positive electrode conductive polymer interface management layer film 29 located on both sides of the first non-polar membrane 28.

[0067] Reference Figure 17 and Figure 18 The negative electrode unit 25 includes a negative electrode sheet 30, a negative electrode polymer interface management layer film 31 located on both sides of the negative electrode sheet 30, and a negative electrode active material 70 located between the negative electrode sheet 30 and the negative electrode polymer interface management layer film 31. The negative electrode polymer interface management layer film 31 includes a second non-polar separator 32 and a second negative electrode conductive polymer interface management layer film 33 located on both sides of the second non-polar separator 32.

[0068] The thicknesses of the first non-polar separator 28, the second non-polar separator 32, the first positive conductive polymer interface management layer film 29, and the second negative conductive polymer interface management layer film 33 are set according to the actual materials and requirements. In this embodiment, the first non-polar separator 28 and the second non-polar separator 32 are both 5 μm thick, and the first positive conductive polymer interface management layer film 29 and the second negative conductive polymer interface management layer film 33 are both 1-1.5 μm thick. Therefore, the thicknesses of the positive polymer interface management layer film 27 and the negative polymer interface management layer film 31 are both 7-8 μm. (Refer to...) Figure 1 The total thickness of the positive electrode polymer interface management layer film 27 and the negative electrode polymer interface management layer film 31 between the positive electrode 26 and the negative electrode 30 is 14-16 μm.

[0069] The first nonpolar membrane 28 and the second nonpolar membrane 32 can be made of materials such as PE, PP, PET, PEO, PAN, PA, PI, and aramid. The micropore size of the first nonpolar membrane 28 and the second nonpolar membrane 32 is between 0.03 and 1 micrometer, and the microporosity of the membranes is between 40% and 60%. The first nonpolar membrane 28 and the second nonpolar membrane 32 are nonpolar polymer framework phases, and their porosity structure allows for the passage of ions and electrons.

[0070] The first positive electrode conductive polymer interface management layer membrane 29 is composed of PVDF-HFP, a solid electrolyte, a binder, a conductive agent, and nano-oxides. The binder is PVDF, a polar polymer framework phase. PVDF-HFP is a polar amorphous conductive polymer group, existing in a continuous state on the surface of the first non-polar membrane 285 and within the micropores of the binder. The solid electrolyte includes, but is not limited to, boehmite, LLZO, PIM-1 embedded with lithium fluoride, and Li0.33La0.56TiO3. The solid electrolyte exists in a continuous state on the surface of the first non-polar membrane 285 and within its micropores.

[0071] The conductive agents include, but are not limited to, any one of VFCF, SPUER-Li, S-O, KS-6, KS-15, SFG-6, SFG-15, 350G, acetylene black (AB), Ketjen black (KB), vapor-grown carbon fiber (VGCF), and carbon nanotubes (CNT). VFCF can be modified or other ions can be introduced, such as introducing fluoride ions onto the VGCF surface, to improve its compatibility with the active material and current collector through chemical reactions. SPUER-Li can be replaced with conductive agents such as Ketjen black ECP, acetylene black, carbon nanotubes, KS-6, etc.; or it can be used without replacement, selecting more than two of the conductive agents (conductive agent models include SPUER-Li, S-O, KS-6, KS-15, SFG-6, SFG-15, 350G, acetylene black (AB), Ketjen black (KB), vapor-grown carbon fiber (VGCF), and carbon nanotubes (CNT).

[0072] The second negative electrode conductive polymer interface management layer film 33 is composed of a binder, a conductive agent, and nano-oxides. The conductive agent includes, but is not limited to, any one of VFCF, SPUER-Li, conductive carbon black SP, Ketjen black ECP, acetylene black, carbon nanotubes, and SFG-6.

[0073] The processing steps for cell 3 are as follows:

[0074] 1. Reference Figure 19 Prepare 0.012mm thick aluminum foil as the substrate for the positive electrode 26.

[0075] 2. Reference Figure 19 A positive electrode tab 34 is cut out on the positive electrode plate 26 to form a positive electrode roll 35;

[0076] 3. Reference Figure 15 and Figure 19 Prepare a first non-polar diaphragm 28. The first non-polar diaphragm 28 is made of at least one component selected from PE, PP, PET, PEO, PAN, PA, PI, and aramid. In this embodiment, the first non-polar diaphragm 28 is made of PE. Add positive electrode active material, adhesive, and an appropriate amount of conductive agent to make cathode paste.

[0077] 4. Reference Figure 15 and Figure 19 The cathode slurry is coated on both sides of the first non-polar membrane 28 to form the first positive electrode conductive polymer interface management layer film 29, leaving space for the positive electrode tab 34. Specifically, the positive electrode active material is lithium iron phosphate (LFP), the conductive agent is conductive carbon black, and the binder is PVDF. The LFP, conductive agent, and binder are mixed in a ratio of 94:4:2 in NMP (N-methylpyrrolidone) to form a slurry. The slurry is then uniformly coated onto the first non-polar membrane 28 by roller coating, vacuum dried at 120 degrees Celsius for 16 hours, and then rolled to form the positive electrode polymer interface management layer film 27.

[0078] 5. Reference Figure 20 Prepare two rolls of positive electrode polymer interface management layer film 27 and one roll of positive electrode roll 35. Press the positive electrode polymer interface management layer film 27, positive electrode roll 35 and positive electrode polymer interface management layer film 27 in the order of process requirements on the thermal composite machine to form a three-in-one positive electrode roll 35 containing polymer interface management layer, namely positive electrode unit roll 36.

[0079] Specifically, during hot pressing, the positive electrode polymer interface management layer film 27, the positive electrode roll 35, and the positive electrode polymer interface management layer film 27 sequentially pass through the first heating zone 37, the second heating zone 38, and the third heating zone 39. The temperature of the first heating zone 37 is 60℃~90℃, the temperature of the second heating zone 38 is 90℃~110℃, and the temperature of the third heating zone 39 is 110℃~120℃. The third heating zone 39 is provided with a positive electrode pressure roller 40. There are two positive electrode pressure rollers 40, and a gap is formed between the two positive electrode pressure rollers 40 for the positive electrode unit roll 36 to pass through. The temperature of the positive electrode pressure roller 40 is 110℃~120℃.

[0080] 6. Reference Figure 19 The positive electrode unit 36 ​​is cut into positive electrode units 24;

[0081] 7. Reference Figure 21 Prepare a 0.006mm thick copper foil as the substrate for the negative electrode 30;

[0082] 8. Reference Figure 21 A negative electrode tab 41 is cut out on the negative electrode sheet 30 to form a negative electrode roll 42;

[0083] 9. Reference Figure 17 and Figure 21 Prepare a second non-polar diaphragm 32. The second non-polar diaphragm 32 is made of at least one component selected from PE, PP, PET, PEO, PAN, PA, PI, and aramid. In this embodiment, the second non-polar diaphragm 32 is made of PE. Add the negative electrode active material, adhesive, and an appropriate amount of conductive agent to make the anode slurry.

[0084] 10. Reference Figure 17 and Figure 21 The anode slurry is coated on both sides of the second non-polar membrane 32 to form the second negative electrode conductive polymer interface management layer film 33, leaving space for the negative electrode tab 41. Specifically, the negative electrode active material is mesophase carbon microspheres (MCMB), the conductive agent is conductive carbon black, and the binder is PVDF. The MCMB, conductive agent, and binder are mixed in a ratio of 95:3:2 in NMP (N-methylpyrrolidone) to form a slurry. The slurry is then uniformly coated onto the second non-polar membrane 32 by roller coating, vacuum dried at 120 degrees Celsius for 16 hours, and then rolled to form the negative electrode polymer interface management layer film 31.

[0085] 11. Reference Figure 22 Prepare two rolls of negative electrode polymer interface management layer film 31 and one roll of negative electrode roll 42. Press the negative electrode polymer interface management layer film 31, negative electrode roll 42 and negative electrode polymer interface management layer film 31 in the order of process requirements on the thermal composite machine to form a three-in-one negative electrode roll 42 containing polymer interface management layer, namely negative electrode unit roll 43.

[0086] Specifically, during the hot pressing of the negative electrode polymer interface management layer film 31, the negative electrode roll 42, and the negative electrode polymer interface management layer film 31, they sequentially pass through the fourth heating zone 44, the fifth heating zone 45, and the sixth heating zone 46. The temperature of the fourth heating zone 44 is 90℃~110℃, the temperature of the fifth heating zone 45 is 110℃~125℃, and the temperature of the sixth heating zone 46 is 125℃~130℃. The sixth heating zone 46 is provided with a negative electrode pressure roller 47. There are two negative electrode pressure rollers 47, and a gap is formed between the two negative electrode pressure rollers 47 for the negative electrode unit roll 43 to pass through. The temperature of the negative electrode pressure roller 47 is 125℃~130℃.

[0087] 12. Reference Figure 21 The negative electrode unit 43 is cut into negative electrode units 25;

[0088] 13. Reference Figure 14 and Figure 23 The negative electrode unit 25 and the positive electrode unit 24 are stacked together in an alternating and opposite manner by the robotic arm of the stacking machine to form the battery cell 3 according to the process requirements;

[0089] 14. Reference Figure 24 The stacked battery cell 3 is then coated with adhesive and hot-pressed. Specifically, during the hot-pressing of the battery cell 3, it passes through the seventh heating zone 48, the eighth heating zone 49, and the ninth heating zone 50 in sequence. The temperature of the seventh heating zone 48 is 80℃~100℃, the temperature of the eighth heating zone 49 is 100℃~120℃, and the temperature of the ninth heating zone 50 is 120℃~140℃.

[0090] 15. After hot pressing, the battery undergoes primary activation, is dried, and then placed in an aluminum-plastic composite bag or battery casing 1 for secondary activation and sealing.

[0091] The manufacturing process of a large-size ultra-thin square-shaped polymer power battery according to an embodiment of this application includes the following steps:

[0092] 1. Manufacturing battery cell 3;

[0093] 2. Place the battery cell 3 in the limiting ring 12 of a housing unit 4, and then cover the battery cell 3 with another housing unit 4 so that the two housing units 4 abut against each other; then fix the two housing units 4 together stably by means of multi-pass welding, edge clamping structure, etc.

[0094] 3. Install the battery cover 2 onto the battery casing 1, and then use multiple welding processes to secure the battery cover 2 and the battery casing 1 together stably, forming a closed and well-sealed battery assembly.

[0095] 4. Glue is injected into the cavity through the glue injection port 21 on the battery cover plate 2, thereby sealing the battery in one step. The whole installation process is convenient, and the battery cell 3 can also be put into the battery casing relatively stably and conveniently, which improves the installation efficiency.

[0096] Example 2

[0097] The difference between Example 2 and Example 1 is that, referring to Figure 25 The welding ring 17 has abutment plates 51 extending outward on both sides. The abutment plates 51 are used to cover the joint of the extension plate assembly and are welded and fixed to the extension plate 7 and the clamping edge 8, thereby making the battery as a whole have better airtightness.

[0098] The above are only two specific embodiments of this application. Any other improvements made based on the concept of this application shall be considered within the scope of protection of this application.

Claims

1. A large-size, ultra-thin, square-shaped polymer power battery, characterized in that: Includes a battery casing (1), battery cover plates (2) located on both sides of the battery casing (1), and battery cells (3) installed inside the battery casing (1); The battery casing (1) includes two symmetrically arranged casing units (4). Each casing unit (4) includes a base plate (5), vertical plates (6) fixedly connected to both sides of the base plate (5), and an extension plate (7) fixedly connected to one end of the vertical plate (6) away from the base plate (5). The two casing units (4) are combined to form a cavity for accommodating the battery cell (3). The extension plates (7) between the two casing units (4) are abutted and welded together. The battery cover (2) has two parts and is located at the two ends of the cavity. The battery cover (2) includes a cover body (14) embedded in the cavity and a welding ring (17) arranged along the cover body (14). The welding ring (17) is used to abut against the inner wall of the cavity. The welding ring (17) is fixedly connected to the housing unit (4) by welding. The battery cell (3) includes a plurality of positive electrode units (24) and a plurality of negative electrode units (25), the positive electrode units (24) and the negative electrode units (25) are arranged alternately, the positive electrode unit (24) includes a positive electrode plate (26) and a positive electrode polymer interface management layer film (27) located on both sides of the positive electrode plate (26), and the negative electrode unit (25) includes a negative electrode plate (30) and a negative electrode polymer interface management layer film (31) located on both sides of the negative electrode plate (30); The positive electrode polymer interface management layer membrane (27) includes a first non-polar membrane (28) and a first positive electrode conductive polymer interface management layer membrane (29) located on both sides of the first non-polar membrane (28). The negative electrode polymer interface management layer membrane (31) includes a second non-polar membrane (32) and a second negative electrode conductive polymer interface management layer membrane (33) located on both sides of the second non-polar membrane (32). The first positive electrode conductive polymer interface management layer film (29) is composed of PVDF-HFP, solid electrolyte, binder, conductive agent and nano oxide; the second negative electrode conductive polymer interface management layer film (33) is composed of binder, conductive agent and nano oxide.

2. The large-size ultra-thin square-shaped polymer power battery according to claim 1, characterized in that: The corresponding extension plates (7) are reinforced by two-pass welding-deep penetration welding, and the welding depth of the two-pass welding-deep penetration welding is 1 / 3-2 / 3 of the thickness of the extension plate (7).

3. The large-size ultra-thin square-shaped polymer power battery according to claim 1, characterized in that: The welding ring (17) and the shell unit (4) are reinforced by a two-pass welding-deep penetration welding, and the welding depth of the two-pass welding-deep penetration welding is 1 / 3 to 2 / 3 of the thickness of the shell unit (4).

4. A large-size ultra-thin square-shaped polymer power battery according to claim 2, characterized in that: The width of the extension plate (7) is not less than 1.5 mm.

5. A large-size ultra-thin square-shaped polymer power battery according to claim 3, characterized in that: The welding ring (17) has abutment plates (51) on both sides for abutting against the end wall of the battery casing (1). The abutment plates (51) cover the extension plate (7) and are welded and fixed to the outside of the extension plate (7).

6. A large-size ultra-thin square-shaped polymer power battery according to claim 1, characterized in that: At least one of the base plates (5) has a limiting ring (12) on its inward side, and the battery cell (3) is installed in the limiting ring (12) and limited by the limiting ring (12).

7. A large-size ultra-thin square-shaped polymer power battery according to claim 1, characterized in that: The base plate (5) has an insulating sheet (13) on the side facing the battery cell (3) to isolate the battery cell (3) from the base plate (5).

8. A large-size ultra-thin square-shaped polymer power battery according to claim 1, characterized in that: The length of the negative electrode (30) is shorter than the length of the positive electrode (26), and the width of the negative electrode (30) is shorter than the width of the positive electrode (26).

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