High-capacity battery

Abstract

The utility model relates to a high-capacity battery which comprises a square shell, the bottom of the square shell is open, a cover plate is connected to the bottom of the square shell in a sealing fit mode, two expansion grooves are formed in the inner side of the top end of the square shell, and assembly holes are formed in the bottoms of the two expansion grooves; a positive terminal and a negative terminal are respectively assembled at the two assembly holes in an insulating and sealing manner, and the positive terminal and the negative terminal respectively extend into the two expansion slots; the pole core is arranged in the square shell, a positive pole lug and a negative pole lug are arranged at one end, close to the expansion slot, of the pole core, and the positive pole lug and the negative pole lug are electrically connected with the positive terminal and the negative terminal respectively. According to the utility model, the structure of the square shell is improved, and the two expansion slots are arranged at the top of the square shell and are respectively used for assembling the positive terminal and the negative terminal; meanwhile, a bottom support structure is omitted, so that the Z-direction space utilization rate of the square shell is effectively improved, the space utilization rate of the pole core in the square shell is improved, and the energy density of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a high-capacity battery. Background Art

[0002] With the continuous development of electric vehicles, people's requirements for electric vehicles are getting higher and higher. The industry is constantly challenging itself to have a longer driving range, and models with a range of 800km+ have appeared one after another.

[0003] The key to improving battery life is to improve the volume utilization of the battery. The current design concept of square shell batteries is mainly to set a cover structure on the top. The pole core tabs are connected to the cover plate poles. Space needs to be reserved on the top of the shell to accommodate the tabs. At the same time, due to the rounded corners at the bottom of the shell, interference will occur with the pole core. When the battery expands during a cycle, a dead zone will be generated at the interference point, thereby reducing the battery cycle life. Therefore, a bottom support needs to be set at the bottom to raise the pole core to avoid interference between the pole core and the rounded corners at the bottom of the shell. The current design of square shell batteries, on the one hand, requires space to be reserved at the top of the shell to accommodate the tabs, and on the other hand, a bottom support needs to be set at the bottom to raise the pole core, resulting in a very limited volume utilization of the square shell. Therefore, it is particularly important to improve the effective use of space for the tabs and to improve the effective utilization of stacked cores or rolled cores. Utility Model Content

[0004] Based on this, in order to solve the technical problem that the volume utilization rate of the current square shell battery is very limited, the utility model provides a high-capacity battery.

[0005] The utility model provides a high-capacity battery, which includes:

[0006] A square housing, the bottom end of which is open and sealed with a cover plate, the top inner side of which is formed with two expansion slots, the bottom of each expansion slot is provided with an assembly hole, the two assembly holes are respectively insulated and sealed with a positive terminal and a negative terminal, and the positive terminal and the negative terminal respectively extend into the two expansion slots; and

[0007] The pole core is arranged in a square shell and has a positive pole tab and a negative pole tab on its top. The positive pole tab and the negative pole tab respectively extend into the two expansion slots and are electrically connected to the positive terminal and the negative terminal respectively.

[0008] The utility model improves the square shell structure, sets two expansion slots on the top of the square shell, and the two expansion slots are used to assemble the positive terminal and the negative terminal respectively. At the same time, the two expansion slots can be used to expand the extension space of the positive electrode tab and the negative electrode tab respectively; an open opening is set at the bottom of the square shell and a cover plate is connected in a sealed manner at the bottom, thereby eliminating the rounded corner structure at the bottom of the square shell and causing no interference with the bottom of the pole core, thereby eliminating the bottom support structure, effectively improving the Z-direction space utilization of the square shell, thereby improving the space utilization of the pole core inside the square shell, and thus improving the energy density of the battery.

[0009] As a further improvement of the above solution of the present invention, two outwardly protruding protrusions are formed on the top of the square shell by stamping, and expansion grooves are formed inside the protrusions.

[0010] As a further improvement of the above solution of the present invention, the raised portion has an arc-shaped cross section or a square cross section.

[0011] As a further improvement of the above solution of the utility model, a sealing ring is provided outside the positive terminal and the negative terminal, and the positive terminal and the negative terminal are both insulated and sealed with the square shell through the sealing ring.

[0012] As a further improvement of the above solution of the present invention, the positive terminal and the negative terminal are both in an inverted T-shaped structure, and the transverse sections of the positive terminal and the negative terminal are welded to the positive electrode tab and the negative electrode tab respectively.

[0013] As a further improvement to the above-mentioned solution of the present invention, the positive electrode tab has a bent portion within the corresponding expansion slot, and the bent portion is arranged above the transverse section of the positive terminal, and the bent portion of the positive electrode tab is welded to the top surface of the transverse section of the positive terminal; the negative electrode tab has a bent portion within the corresponding expansion slot, and the bent portion is arranged above the transverse section of the negative terminal, and the bent portion of the negative electrode tab is welded to the top surface of the transverse section of the negative terminal; an insulating film is provided on the inner walls of the two expansion slots at positions corresponding to the bent portions of the positive and negative electrode tabs. The positive and negative electrode tabs are directly welded to the positive and negative terminals, respectively, eliminating the connecting piece, further saving space in the height direction of the square shell and improving the overall current capacity of the battery structure; an insulating film is provided near the tabs, which, on the one hand, provides insulation protection, and on the other hand, improves the thermal conductivity between the tabs and the square shell, thereby promptly transferring the temperature to the outside.

[0014] As a further improvement to the above-mentioned solution, both sealing rings extend to the outside of the square housing and fit closely to the outer side of the housing. A pressure plate is welded to the ends of the positive and negative terminals located outside the square housing, and the two pressure plates are respectively pressed against the two sealing rings. The provision of the pressure plates ensures the sealing performance of the positive and negative terminal positions.

[0015] As a further improvement of the above solution of the present invention, the cover plate and the open end of the square shell are sealed and connected by side welding or vertical welding to ensure the overall sealing and mechanical performance of the battery.

[0016] As a further improvement of the above solution of the present invention, the depth of the expansion slot is 1-3 mm. By setting the 1-3 mm expansion slot, the height space of the square housing can be further optimized by 1-3 mm.

[0017] As a further improvement of the above solution of the present invention, the distance between the edges of the positive terminal and the negative terminal and the inner wall of the expansion slot is 2-3 mm.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The utility model improves the square shell structure by setting two expansion slots on the top of the square shell to provide accommodation space for the positive pole tabs and negative pole tabs of the pole core respectively, so that the positive pole tabs and negative pole tabs no longer occupy the internal space of the square shell; at the same time, the bottom of the square shell is open and sealed with a cover plate at the bottom, eliminating the rounded corner structure at the bottom of the square shell, which will not interfere with the pole core, thereby eliminating the bottom support structure; in summary, the Z-direction space utilization of the square shell is effectively improved, and the space utilization of the pole core inside the square shell is improved, thereby improving the energy density of the battery.

[0020] 2. In the battery of the present invention, the bottom of the positive terminal and the negative terminal are directly welded to the positive electrode tab and the negative electrode tab in the two expansion slots respectively, so that the positive terminal and the negative terminal no longer occupy the internal space of the square shell. At the same time, the connecting piece is eliminated, which further saves the space occupied in the height direction of the square shell and improves the overall current capacity of the battery structure. At the same time, due to the thickness of the sealing ring, there is a certain gap in the outer periphery of the sealing ring located in the expansion slot. The present invention bypasses the bent parts of the positive electrode tab and the negative electrode tab by the outer edge of the terminal and enters the gap so that the bent parts of the positive electrode tab and the negative electrode tab are overlapped and welded with the top surface of the terminal, thereby saving a certain amount of space to improve the space utilization of the pole core inside the square shell. The height of the space saved by the present invention = the thickness of the eliminated connecting piece (0.4-1.5mm) + the thickness of the terminal transverse section (1-1.5mm) + the thickness of the tab. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of a high-capacity battery proposed in an embodiment of the present utility model;

[0022] Figure 2 for Figure 1 A top view of

[0023] Figure 3 for Figure 2 Cross-sectional view along the AA axis;

[0024] Figure 4 for Figure 2 A cross-sectional view in another direction;

[0025] Figure 5 for Figure 3 The enlarged schematic diagram of point B in the middle;

[0026] Figure 6 for Figure 4 The middle part is an enlarged schematic diagram;

[0027] Figure 7 for Figure 5 Partial enlarged image.

[0028] Figure numerals: 1. square shell; 2. cover plate; 3. expansion slot; 4. positive terminal; 5. negative terminal; 6. pole core; 7. positive pole ear; 8. raised portion; 9. sealing ring; 10. insulating film; 11. pressure plate; 12. explosion-proof valve; 13. liquid injection hole. DETAILED DESCRIPTION

[0029] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to facilitate a more thorough and comprehensive understanding of the disclosure of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] Reference Figures 1-4 This embodiment provides a high-capacity battery, including a square shell 1 and a pole core 6.

[0032] In this embodiment, the bottom end of the square shell 1 is open, and the bottom end of the square shell 1 is connected to a sealing cover plate 2 by side welding or vertical welding. Figure 4 、 Figure 5The top of the square housing 1 is formed by stamping with two outwardly protruding protrusions 8, each with an expansion slot 3 formed inside. In this embodiment, the protrusions 8 have a square cross-section. Of course, in other embodiments, the protrusions 8 can also have an arcuate cross-section. Both protrusions 8 have assembly holes extending through them, each housing a positive terminal 4 and a negative terminal 5. Each of the positive and negative terminals 4 and 5 is fitted with a sealing ring 9 extending from the outer side of the protrusions 8. The sealing ring 9 ensures a seal between the positive and negative terminals 4 and 5 and the square housing 1. In this embodiment, the positive and negative terminals 4 and 5 each have a T-shaped structure, with their transverse sections extending into the two expansion slots 3. A pressure plate 11 is welded to one end of each of the positive and negative terminals 4 and 5 located outside the square housing 1, and the two pressure plates 11 are respectively pressed against the two sealing rings 9.

[0033] The electrode core 6 is disposed within the rectangular housing 1. A positive electrode tab 7 and a negative electrode tab are formed at the top of the electrode core 6. The positive and negative electrode tabs 7 and 7 correspond to the two expansion slots 3, respectively. The positive and negative electrode tabs 7 and 7 extend into the two expansion slots 3, respectively, and their bent portions extend to the top surfaces of the transverse sections of the positive and negative terminals 4 and 5, respectively. The bent portions of the positive and negative electrode tabs 7 and 7 are welded to the top surfaces of the transverse sections of the positive and negative terminals 4 and 5, respectively. An insulating film 10 is provided between the weld locations and the inner walls of the expansion slots 3. In this embodiment, the electrode core 6 has a laminated structure. Of course, in other embodiments, the electrode core 6 can also have a wound structure. In this embodiment, to allow the positive and negative electrode tabs 7 to enter the expansion slots 3, the width and length of the expansion slots 3 must meet the following requirements: the distance between the inner wall of the expansion slot 3 and the edges of the positive and negative terminals 4 and 5 is 2-3 mm.

[0034] In this embodiment, the housing is provided with an explosion-proof valve 12 and a liquid injection hole 13 at a position between the two protrusions 8. Of course, in other embodiments, the explosion-proof valve 12 and the liquid injection hole 13 may also be provided on the cover plate 2.

[0035] With the above structure, when assembling the battery of this embodiment, firstly gather the positive pole tab 7 and the negative pole tab of the laminated pole core 6 in the middle, and then combine them. Figure 7, the bent parts of the positive electrode tab 7 and the negative electrode tab are respectively bypassed by the edges of the transverse sections of the positive terminal 4 and the negative terminal and respectively cover the top surfaces of the transverse sections of the positive terminal 4 and the negative terminal, and the bent parts of the positive electrode tab 7 and the negative electrode tab are respectively welded to the top surfaces of the transverse sections of the positive terminal 4 and the negative terminal by butterfly welding; then the open mouth of the square shell 1 is faced downward and installed upside down on the outside of the pole core 6, so that the positive terminal 4 and the negative terminal 5 respectively pass through the two assembly holes, and the compression amount of the sealing ring 9 is controlled by controlling the stroke, which can avoid the interference of the rounded corners of the square shell 1 with the corner positions of the pole core 6, thereby improving the cycle life; then the two pressing plates 11 are respectively welded to the top of the positive terminal 4 and the negative terminal 5, and the pressing plate 11 encapsulates the terminal, the sealing ring 9, the protrusion 8, etc. to ensure the sealing performance of the positive terminal 4 and the negative terminal 5; finally, the cover plate 2 is welded to the open end of the square shell 1 by side welding or vertical welding to ensure the overall sealing and mechanical properties of the battery.

[0036] In this embodiment, the structure of the square shell 1 is improved by setting two expansion slots 3 on the top of the square shell 1 to provide accommodation space for the positive electrode tab 7 and the negative electrode tab of the pole core 6 respectively, so that the positive electrode tab 7 and the negative electrode tab no longer occupy the internal space of the square shell 1; an open opening is set at the bottom of the square shell 1 and a cover plate 2 is sealed and connected at the bottom, thereby eliminating the rounded corner structure at the bottom of the square shell 1 and not interfering with the pole core 6, thereby eliminating the bottom support structure, effectively improving the Z-direction space utilization of the square shell 1, thereby improving the space utilization of the pole core 6 inside the square shell 1, and thus improving the energy density of the battery. In this embodiment, the bottom of the positive terminal 4 and the negative terminal 5 are directly welded to the positive electrode tab 7 and the negative electrode tab in the two expansion slots 3, respectively, so that the positive terminal 4 and the negative terminal 5 no longer occupy the internal space of the square shell 1. At the same time, the connecting piece is eliminated, which further saves the space occupied in the height direction of the square shell 1 and improves the overall current capacity of the battery structure. At the same time, due to the thickness of the sealing ring 9, there is a certain gap in the outer periphery of the sealing ring 9 located in the expansion slot 3. In this utility model, the bent parts of the positive electrode tab 4 and the negative electrode tab respectively bypass the outer edges of the corresponding terminals and enter the gap so that the bent parts of the positive electrode tab 4 and the negative electrode tab are respectively overlapped and welded with the top surfaces of the corresponding terminals, thereby saving a certain amount of space to improve the space utilization of the pole core 6 inside the square shell 1. The space height saved in this embodiment = the thickness of the eliminated connecting piece (0.4-1.5mm) + the thickness of the terminal transverse section (1-1.5mm) + the thickness of the tab.

[0037] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0038] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A high-capacity battery, characterized in that: It includes: A square housing (1) with an open bottom end and a cover plate (2) sealed thereon, two expansion slots (3) formed on the inner side of the top end, assembly holes formed at the bottoms of the two expansion slots (3), a positive terminal (4) and a negative terminal (5) respectively insulated and sealed at the two assembly holes, and the positive terminal (4) and the negative terminal (5) respectively extending into the two expansion slots (3); and The pole core (6) is arranged in the square shell (1) and has a positive pole tab (7) and a negative pole tab at its top. The positive pole tab (7) and the negative pole tab extend into the two expansion slots respectively and are electrically connected to the positive terminal (4) and the negative terminal (5) respectively.

2. The high-capacity battery according to claim 1, characterized in that Two outwardly protruding protrusions (8) are formed on the top of the square housing (1) by stamping, and expansion slots (3) are formed inside the protrusions (8).

3. The high-capacity battery according to claim 2, characterized in that The raised portion (8) has an arc-shaped cross section or a square cross section.

4. The high-capacity battery according to claim 1, characterized in that The positive terminal (4) and the negative terminal (5) are both sheathed with sealing rings (9), and the positive terminal (4) and the negative terminal (5) are both insulated and sealed with the square housing (1) through the sealing rings (9).

5. The high-capacity battery according to claim 1, characterized in that The positive terminal (4) and the negative terminal (5) both have an inverted T-shaped structure. The transverse sections of the positive terminal (4) and the negative terminal (5) extend into the two expansion slots (3) respectively. The transverse sections of the positive terminal (4) and the negative terminal (5) are respectively welded to the positive terminal (7) and the negative terminal.

6. The high-capacity battery according to claim 5, characterized in that The positive electrode tab (7) has a bent portion in the corresponding expansion slot (3), and the bent portion is arranged above the transverse section of the positive electrode terminal (4), and the bent portion of the positive electrode tab (7) is welded to the top surface of the transverse section of the positive electrode terminal (4); the negative electrode tab has a bent portion in the corresponding expansion slot (3), and the bent portion is arranged above the transverse section of the negative electrode terminal (5), and the bent portion of the negative electrode tab is welded to the top surface of the transverse section of the negative electrode terminal (5); and an insulating film (10) is provided on the inner walls of the two expansion slots (3) at positions corresponding to the bent portions of the positive electrode tab (7) and the negative electrode tab.

7. The high-capacity battery according to claim 4, characterized in that The two sealing rings (9) both extend to the outside of the square shell (1) and are in contact with the outer side surface of the square shell (1); the positive terminal (4) and the negative terminal (5) are both welded with a pressure plate (11) at one end located outside the square shell (1), and the two pressure plates (11) are respectively pressed against the two sealing rings (9).

8. The high-capacity battery according to claim 1, characterized in that The cover plate (2) and the open end of the square shell (1) are connected in a sealed fit by side welding or vertical welding.

9. The high-capacity battery according to claim 1, characterized in that The depth of the expansion slot (3) is 1-3 mm.

10. The high-capacity battery according to claim 1, characterized in that The distance between the edges of the positive terminal (4) and the negative terminal (5) and the inner side wall of the expansion slot (3) is 2-3 mm.

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