Battery monomer, battery pack and battery pack

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery monomer, a battery pack and a battery pack, the battery monomer comprises an electrode assembly and a battery shell, the electrode assembly is roll-shaped, the electrode assembly comprises a hot-pressing section and two non-hot-pressing sections, the two non-hot-pressing sections are respectively positioned on two sides of the hot-pressing section, the electrode assembly is arranged in the battery shell, and the battery shell is arranged in the battery shell. At least one of the multiple wall bodies of the battery shell is a pressure relief wall, the pressure relief wall is perpendicular to the axis direction of the electrode assembly, the pressure relief wall is provided with nicks and a pressure relief area, the nicks are located on the edge of the pressure relief area and extend in the circumferential direction of the pressure relief area, and at least part of the orthographic projection of the non-hot-pressing section on the pressure relief wall is located in the pressure relief area. And thus, the use safety of the battery monomer can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a battery monomer, battery pack and battery package. BACKGROUND

[0002] The safety of battery has been an important issue of the battery manufacturers and users, and various manufacturers and related research institutions have also carried out a lot of work in this regard. In order to reduce the probability of explosion due to short circuit of battery, an explosion-proof valve is usually provided on the battery cover. When the internal environment of the battery shell reaches a certain pressure, the valve plate on the explosion-proof valve opens to discharge the high-pressure gas in the battery shell.

[0003] The explosion-proof valve is usually arranged at the middle position of the battery cover. For the winding electrode assembly, it is usually oval or track-shaped, having a flat section and arc-shaped sections at both ends of the flat section. In the assembly process, the flat section area in the middle usually needs to be hot-pressed to form a hot-pressed section, while the arc-shaped sections at both ends are non-hot-pressed sections. The explosion-proof valve arranged at the middle position of the battery cover is arranged opposite to the hot-pressed section of the electrode assembly. Since the pole pieces of the hot-pressed section are closely attached to each other, it is not conducive to the flow of gas in the battery shell between the pole pieces. After the valve plate of the explosion-proof valve is opened, rapid exhaust cannot be achieved.

[0004] Therefore, it is urgent to provide a battery monomer, battery pack and battery package to solve the above technical problems. UTILITY MODEL CONTENTS

[0005] The first purpose of the utility model is to provide a battery monomer with high safety in use.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The battery monomer comprises:

[0008] The electrode assembly is in a winding shape and comprises a hot-pressed section and two non-hot-pressed sections, and the two non-hot-pressed sections are respectively located at both sides of the hot-pressed section.

[0009] The battery shell, the electrode assembly is arranged in the battery shell, at least one of the plurality of walls of the battery shell is a pressure relief wall, the pressure relief wall is perpendicular to the axis direction of the electrode assembly, the pressure relief wall is provided with a score and a pressure relief area, the score is located at the edge of the pressure relief area and extends along the circumferential direction of the pressure relief area, and the orthographic projection of the non-hot-pressed section on the pressure relief wall is at least partially located in the pressure relief area.

[0010] Optionally, the starting point of the score is arranged in a spaced manner with the end point of the score.

[0011] Optionally, the non-pressure relief wall adjacent to the pressure relief wall in the plurality of walls of the battery shell is an adjacent wall, the pressure relief wall and the adjacent wall are arranged at an included angle and are connected through a connecting edge, and the start point of the score and the end point of the score are located at the connecting edge.

[0012] Optionally, the orthographic projection of the non-heat pressing section on the pressure relief wall is entirely located within the pressure relief area.

[0013] Optionally, the orthographic projection of the heat pressing section on the pressure relief wall is partially located within the pressure relief area, the heat pressing section and the non-heat pressing section are connected through a connecting part, the spacing between the orthographic projection of the connecting part on the pressure relief wall and the orthographic projection of the end of the score close to the heat pressing section on the pressure relief wall is a, and 0.5mm

[0014] Optionally, the score and the pressure relief area form a pressure relief structure, and each non-heat pressing section corresponds to one pressure relief structure.

[0015] Optionally, the number of pressure relief structures is two, the number of electrode assemblies is at least two, the at least two electrode assemblies are arranged along the thickness direction of the heat pressing section, and the non-heat pressing sections located on the same side of the at least two electrode assemblies correspond to the same pressure relief structure.

[0016] Optionally, the score is formed on the side of the pressure relief wall facing the electrode assembly;

[0017] and / or, the score is arc-shaped;

[0018] and / or, the wall located at the bottom of the battery shell is the pressure relief wall.

[0019] The second object of the utility model is to provide a battery pack, which has high use safety.

[0020] To achieve the object, the utility model adopts the following technical scheme:

[0021] The battery pack comprises at least two battery monomers.

[0022] The third object of the utility model is to provide a battery pack, which has high use safety.

[0023] To achieve the object, the utility model adopts the following technical scheme:

[0024] The battery pack comprises a battery box and the battery pack, and the battery pack is arranged in the battery box.

[0025] The utility model has the beneficial effects of:

[0026] The battery monomer provided by the utility model has at least one of the plurality of walls of the battery shell being a pressure relief wall, the pressure relief wall is provided with a pressure relief area and a notch, the notch is located at the edge of the pressure relief area and extends along the circumference of the pressure relief area, when the pressure in the battery shell reaches the fracture pressure value of the notch, the notch is broken, the pressure relief area flies out or is folded in the direction away from the electrode assembly to form an exhaust hole on the pressure relief wall; the pressure relief wall is perpendicular to the axis direction of the electrode assembly, and the orthographic projection of the non-hot pressing section of the electrode assembly on the pressure relief wall is at least partially located in the pressure relief area, since the non-hot pressing section of the roll-shaped electrode assembly is not subjected to hot pressing treatment, the non-hot pressing section of the electrode assembly is relatively loose (that is, there is a large gap between the pole pieces of the non-hot pressing section), which is beneficial to the circulation of the gas in the battery shell through the gap between the pole pieces after the notch is broken, and then the gas is discharged from the battery shell through the exhaust hole, the effect of rapid exhaust is realized, and the explosion-proof performance of the battery monomer is improved.

[0027] On the other hand, since the non-hot pressing section of the electrode assembly is relatively loose, the electrolyte in the battery shell is easily gathered at the gap between the pole pieces, when the notch is broken and the high-pressure gas in the battery shell circulates through the gap between the pole pieces, the electrolyte gathered between the pole pieces can flow together with the high-pressure gas and be discharged from the battery shell through the exhaust hole, and the effect of further improving the explosion-proof performance of the battery monomer is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a structural schematic view of the electrode assembly provided by the utility model;

[0029] Figure 2 is a perspective view of the battery shell when the notch is not broken;

[0030] Figure 3 is a perspective view of the battery shell after the notch is broken;

[0031] Figure 4 is a perspective view of the battery monomer provided by the utility model;

[0032] Figure 5 is a sectional view of the battery monomer provided by the utility model.

[0033] In the drawings:

[0034] 100, electrode assembly; 110, hot pressing section; 120, non-hot pressing section; 130, connecting part; 200, battery shell; 210, pressure relief wall; 211, notch; 212, pressure relief area; 213, pressure relief structure; 220, adjacent wall; 230, connecting edge. DETAILED DESCRIPTION

[0035] The utility model will be made further detailed description in combination with the drawings and examples. It can be understood that the specific examples described here are only used to explain the utility model, and not limited to the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.

[0036] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0037] In the utility model, unless otherwise explicitly specified and limited, the first feature is "on" or "below" the second feature, which can include direct contact between the first and second features, or indirect contact between the first and second features through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0038] In the description of the embodiment, the terms "up", "down", "right", "left" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, therefore, it cannot be understood as a limitation of the utility model. In addition, the terms "first", "second" are only used to distinguish in description, and have no special meaning.

[0039] The embodiment provides a battery monomer, which has higher use safety.

[0040] Specifically, as Figures 1 to 5As shown, the battery cell includes an electrode assembly 100 and a battery case 200, wherein the electrode assembly 100 is in a roll shape, the electrode assembly 100 includes a hot-pressing section 110 and two non-hot-pressing sections 120, the two non-hot-pressing sections 120 are respectively located on two sides of the hot-pressing section 110, the electrode assembly 100 is arranged in the battery case 200, at least one of a plurality of wall bodies of the battery case 200 is a pressure relief wall 210, the pressure relief wall 210 is perpendicular to an axis direction of the electrode assembly 100, the pressure relief wall 210 is provided with a score line 211 and a pressure relief area 212, the score line 211 is located at an edge of the pressure relief area 212 and extends along a circumferential direction of the pressure relief area 212, and a normal projection of the non-hot-pressing section 120 on the pressure relief wall 210 is at least partially located in the pressure relief area 212.

[0041] Based on the above design, at least one of a plurality of wall bodies of the battery case 200 is the pressure relief wall 210, the pressure relief wall 210 is provided with the pressure relief area 212 and the score line 211, the score line 211 is located at an edge of the pressure relief area 212 and extends along a circumferential direction of the pressure relief area 212, when the pressure in the battery case 200 reaches a fracture pressure value of the score line 211, the score line 211 is broken, the pressure relief area 212 flies out or is folded in a direction away from the electrode assembly 100 to form an exhaust hole on the pressure relief wall 210; the pressure relief wall 210 is perpendicular to the axis direction of the electrode assembly 100, and a normal projection of the non-hot-pressing section 120 of the electrode assembly 100 on the pressure relief wall 210 is at least partially located in the pressure relief area 212, since the non-hot-pressing section 120 of the roll-shaped electrode assembly 100 is not subjected to hot-pressing treatment, the non-hot-pressing section 120 of the electrode assembly 100 is relatively loose (i.e., there is a large gap between the pole pieces of the non-hot-pressing section 120), which is beneficial to the flow of the gas in the battery case 200 through the gap between the pole pieces after the score line 211 is broken, and then the gas is discharged out of the battery case 200 through the exhaust hole, thereby achieving the effect of rapid exhaust and improving the explosion-proof performance of the battery cell.

[0042] On the other hand, since the non-hot-pressing section 120 of the electrode assembly 100 is relatively loose, the electrolyte in the battery case 200 is easily accumulated in the gap between the pole pieces, when the score line 211 is broken and the high-pressure gas in the battery case 200 flows through the gap between the pole pieces, the electrolyte accumulated between the pole pieces can flow together with the high-pressure gas and be discharged out of the battery case 200 through the exhaust hole, thereby further improving the explosion-proof performance of the battery cell.

[0043] When the score line 211 extends along the circumferential direction of the pressure relief area 212 and is connected end to end (i.e., the starting point and the ending point of the score line 211 overlap), after the score line 211 is broken, the pressure relief area 212 will fly out in one piece under the action of the high-pressure gas, which reduces the use safety of the battery cell. To solve this problem, as shown in Figures 1 to 5As shown, the starting point of the score 211 is spaced apart from the ending point of the score 211, so that a connecting area is formed between the starting point and the ending point of the score 211. After the score 211 is broken, the pressure relief area 212 is folded in a direction away from the electrode assembly 100, and the connecting area keeps the pressure relief area 212 connected with the pressure relief wall 210, avoiding the pressure relief area 212 from being blown out in one piece, and improving the safety of the battery cell.

[0044] Further, as shown in the drawings, Figures 1 to 5 As shown, the adjacent wall 220 adjacent to the pressure relief wall 210 among the plurality of wall bodies of the battery shell 200 is arranged at an angle with the pressure relief wall 210 and connected through the connecting edge 230. The starting point of the score 211 and the ending point of the score 211 are both located at the connecting edge 230. In this embodiment, the angle between the pressure relief wall 210 and the adjacent wall 220 is 90°. In other embodiments, the angle between the pressure relief wall 210 and the adjacent wall 220 can also be other angles, such as 60° or 100°, etc. The connecting edge 230 has a lower structural strength compared with the pressure relief wall 210. Therefore, the starting point and the ending point of the score 211 are both arranged at the connecting edge 230, so that the connecting area is located at the connecting edge 230. After the score 211 is broken, the connecting area with a lower structural strength can be quickly deformed to make the pressure relief area 212 fold in a direction away from the electrode assembly 100, and can also expand the folding angle of the pressure relief area 212, achieving the effect of quickly and massively exhausting gas and liquid. In addition, after the pressure relief area 212 is folded in a direction away from the electrode assembly 100, the heat in the battery shell 200 can also be exhausted out of the battery shell 200 through the exhaust hole. Expanding the folding angle of the pressure relief area 212 is conducive to improving the heat exhaust efficiency and achieving the effect of quickly dissipating heat, thereby reducing the probability of thermal runaway of the battery cell.

[0045] Optionally, as shown in the drawings, Figures 1 to 5 The orthogonal projection of the non-heat pressing section 120 on the pressure relief wall 210 is entirely located in the pressure relief area 212, which is conducive to quickly exhausting the gas and electrolyte gathered in the non-heat pressing section 120 out of the battery shell 200 through the exhaust hole after the score 211 is broken.

[0046] Further, as shown in the drawings, Figures 1 to 5As shown, the orthographic projection of the hot-pressing section 110 on the pressure relief wall 210 is located within the pressure relief area 212, the hot-pressing section 110 is connected with the non-hot-pressing section 120 through the connecting part 130, the spacing between the orthographic projection of the connecting part 130 on the pressure relief wall 210 and the orthographic projection of the end of the score 211 on the pressure relief wall 210 is a, 0.5mm < a < 6mm, for example, a can be 0.5mm, 1mm, 3mm, 5mm or 6mm, etc., the area of the pressure relief area 212 is as large as possible, and the area of the exhaust hole is as large as possible, so as to ensure the exhaust efficiency, the liquid discharge efficiency and the heat dissipation efficiency after the score 211 is broken, and the pressure relief wall 210 also has a certain structural strength. The connecting part 130 can be the connecting interface between the hot-pressing section 110 and the non-hot-pressing section 120.

[0047] Optionally, as shown in Figures 1 to 5 The score 211 and the pressure relief area 212 form a pressure relief structure 213, and each non-hot-pressing section 120 corresponds to an exhaust hole after the score 211 is broken. It can be seen that this structure design has the effect of improving the exhaust efficiency, the liquid discharge efficiency and the heat dissipation efficiency after the score 211 is broken. It is particularly pointed out that each non-hot-pressing section 120 corresponds to an exhaust hole, which is not limited to that the number of non-hot-pressing sections 120 and the number of exhaust holes are the same and one-to-one correspondence; a plurality of non-hot-pressing sections 120 can correspond to the same exhaust hole, or one hot-pressing section 120 can correspond to one exhaust hole.

[0048] Further, as shown in Figures 1 to 5 The number of pressure relief structures 213 is two, and the number of electrode assemblies 100 is at least two, for example, the number of electrode assemblies 100 can be two, three or five, etc. At least two electrode assemblies 100 are arranged in the thickness direction of the hot-pressing section 110, and the non-hot-pressing sections 120 on the same side of the at least two electrode assemblies 100 correspond to the same pressure relief structure 213, so as to ensure that the pressure relief wall 210 has a certain structural strength.

[0049] Optionally, as shown in Figures 1 to 5 The score 211 is arc-shaped, so as to simplify the process of forming the score 211 on the pressure relief wall 210. Of course, in other embodiments, the score 211 can also have other shapes, such as square or sharp angle, etc.

[0050] Optionally, the score 211 is formed on the side of the pressure relief wall 210 facing the electrode assembly 100, i.e., the score 211 is formed on the inner surface of the pressure relief wall 210, so as to avoid damaging the plating layer on the outer surface of the pressure relief wall 210 (i.e., the surface of the side of the pressure relief wall 210 facing away from the electrode assembly 100), reduce the probability of rusting on the outer surface of the pressure relief wall 210, and form the score 211 on the inner surface of the pressure relief wall 210, so that the score 211 is easier to break when the pressure in the battery case 200 rises to the breaking pressure of the score 211, further improving the exhaust and drainage efficiency.

[0051] Optionally, as shown in FIG. 2, the wall at the bottom of the battery case 200 is the pressure relief wall 210. When the score 211 breaks, the electrolyte in the battery case 200 is quickly discharged through the exhaust hole under the double effects of the driving action of the high-pressure gas and the gravity, further improving the drainage efficiency of the battery case 200. Figures 1 to 5

[0052] In this embodiment, the number of pressure relief walls 210 is one, and in other embodiments, the number of pressure relief walls 210 can also be two, three or even more. For example, when the number of pressure relief walls 210 is two, one of the two pressure relief walls 210 is the wall at the bottom of the battery case 200, and the other is the wall at the top of the battery case 200; when the number of pressure relief walls 210 is three, the three pressure relief walls 210 are all walls at the bottom of the battery case 200, and the three pressure relief walls 210 are combined to form the bottom wall of the battery case 200, which provides support for the electrode assembly 100.

[0053] This embodiment also provides a battery pack including at least two battery monomers described above. For example, the number of battery monomers described above can be two, four or five, etc. The battery monomers in the battery pack are electrically connected. The battery pack uses the battery monomers described above. When the internal pressure of the battery monomer rises sharply, the score 211 breaks, and the gas and electrolyte accumulated in the non-hot pressing section 120 of the electrode assembly 100 are quickly discharged from the battery case 200 through the exhaust hole, so that the battery monomer has high explosion-proof performance, and the use safety of the battery pack is improved.

[0054] This embodiment also provides a battery pack including a battery box and the battery pack described above. The battery pack is arranged in the battery box. When the pressure of the battery monomer rises sharply, the score 211 of the battery case 200 breaks, so that the gas and electrolyte accumulated in the non-hot pressing section 120 of the electrode assembly 100 are quickly discharged from the battery case 200 through the exhaust hole, and the use safety of the battery pack is improved.

[0055] ​Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, various obvious changes, re-adjustments and replacements can be made without departing from the protection scope of the present application. Here, it is not necessary and also impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application claim.

Claims

1. A battery cell, characterized by The application relates to a battery cell, comprising: an electrode assembly (100) in a roll shape, the electrode assembly (100) comprising a hot-pressing section (110) and two non-hot-pressing sections (120) respectively located on both sides of the hot-pressing section (110); a battery shell (200) in which the electrode assembly (100) is arranged, at least one of the walls of the battery shell (200) being a pressure relief wall (210) perpendicular to the axis direction of the electrode assembly (100), the pressure relief wall (210) being provided with a score line (211) and a pressure relief area (212), the score line (211) being located at the edge of the pressure relief area (212) and extending along the circumferential direction of the pressure relief area (212), and the non-hot-pressing section (120) being at least partially located in the pressure relief area (212) in the orthographic projection on the pressure relief wall (210).

2. The battery cell of claim 1, wherein, The starting point of the score line (211) is spaced apart from the ending point of the score line (211).

3. The battery cell of claim 2, wherein, Among the walls of the battery shell (200), the non-pressure relief wall adjacent to the pressure relief wall (210) is an adjacent wall (220), the pressure relief wall (210) and the adjacent wall (220) are arranged at an angle and are connected through a connecting edge (230), and the starting point of the score line (211) and the ending point of the score line (211) are both located at the connecting edge (230).

4. The battery cell according to any one of claims 1 to 3, characterized in that, The non-hot-pressing section (120) is entirely located in the pressure relief area (212) in the orthographic projection on the pressure relief wall (210).

5. The battery cell of claim 4, wherein, The hot-pressing section (110) is partially located in the pressure relief area (212) in the orthographic projection on the pressure relief wall (210), the hot-pressing section (110) and the non-hot-pressing section (120) are connected through a connecting part (130), the spacing between the orthographic projection of the connecting part (130) on the pressure relief wall (210) and the orthographic projection of the end of the score line (211) close to the hot-pressing section (110) on the pressure relief wall (210) is a, and 0.5mm 6. The battery cell of any one of claims 1-3, wherein, The score line (211) and the pressure relief area (212) constitute a pressure relief structure (213), and each non-hot-pressing section (120) corresponds to one pressure relief structure (213).

7. The battery cell of claim 6, wherein, The number of the pressure relief structures (213) is two, the number of the electrode assemblies (100) is at least two, the at least two electrode assemblies (100) are arranged along the thickness direction of the hot-pressing section (110), and the non-hot-pressing sections (120) on the same side of the at least two electrode assemblies (100) correspond to the same pressure relief structure (213).

8. The battery cell of any one of claims 1-3, wherein, The score line (211) is arranged on the side of the pressure relief wall (210) facing the electrode assembly (100); The score line (211) is arc-shaped; The wall at the bottom of the battery shell (200) is the pressure relief wall (210).

9. A battery pack characterized by The application further relates to a battery comprising at least two battery cells according to any one of claims 1-8.

10. A battery pack, characterized by, The battery pack of claim 9 is disposed in the battery case.

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