Battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery pack, and the battery cell comprises a shell, a cover plate, a connecting sheet, a pole group, an insulating protection piece and a pole lug, the connecting sheet comprises a first conductive part and a second conductive part; the insulating protection piece is arranged between one end, facing the cover plate, of the pole group and the connecting sheet, and an avoiding hole is formed in the insulating protection piece; the tab is arranged at the end part of one side of the pole group; and the tab extends out of the insulating protection piece through the avoiding hole and is bent towards the outer wall surface of the second conductive part to form a bent part. According to the battery cell with the structure, the insulation protection piece is arranged between the pole group and the connecting piece, and the insulation protection piece can prevent the connecting piece from being stressed and deformed to damage a diaphragm of the pole group and prevent short circuit in the pole group, so that the safety performance of the battery cell is improved. The first conductive part of the connecting piece is suitable for being welded with the pole to realize the electric connection between the pole and the connecting piece, and the second conductive part of the connecting piece is welded with the bending part to realize the electric connection between the connecting piece and the tab, so that the electric connection between the pole group and the pole is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery cell and a battery pack. Background Art

[0002] The battery cell includes structures such as a housing, an electrode assembly, a cover plate, a terminal post, and a connecting piece, etc. The electrode assembly is arranged inside the housing, electrode tabs are provided at the ends of the electrode assembly, the terminal post is arranged on the cover plate, the cover plate is arranged on the opening of the housing, one end of the connecting piece is welded to the inner end face of the terminal post, and the other end of the connecting piece is welded to the electrode tab. The connecting piece is arranged on the top of the electrode assembly. When the connecting piece is deformed by force, the connecting piece is likely to damage the separator, resulting in an internal short circuit phenomenon in the battery cell, affecting the safety performance of the battery cell. Summary of the Utility Model

[0003] In view of this, the utility model provides a battery cell and a battery pack to solve the problem that the connecting piece in the battery cell is likely to damage the separator.

[0004] In a first aspect, the utility model provides a battery, comprising:

[0005] A housing with an open end on one side;

[0006] A cover plate arranged on the open end;

[0007] A connecting piece including a first conductive part and a second conductive part;

[0008] An electrode assembly arranged inside the housing;

[0009] An insulating protection member arranged between one end of the electrode assembly facing the cover plate and the connecting piece, and an avoidance hole is provided on the insulating protection member;

[0010] An electrode tab arranged at one side end of the electrode assembly; the electrode tab extends out of the insulating protection member through the avoidance hole and is bent towards the outer wall surface of the second conductive part to form a bent part.

[0011] Advantageous Effects: For the battery cell with this structure, an insulating protection member is arranged between the electrode assembly and the connecting piece. The insulating protection member can prevent the connecting piece from being deformed by force and damaging the separator of the electrode assembly, prevent internal short circuit of the electrode assembly, and thus improve the safety performance of the battery cell. The first conductive part of the connecting piece is suitable for being welded to the terminal post to realize the electrical connection between the terminal post and the connecting piece. The second conductive part of the connecting piece is welded to the bent part to realize the electrical connection between the connecting piece and the electrode tab, and thus realize the electrical connection between the electrode assembly and the terminal post.

[0012] In an optional embodiment, an upwardly protruding flanging part is provided at the outer edge of the avoidance hole below the bent part.

[0013] Beneficial effects: The flanging portion wraps around the side of the connecting piece, preventing the tab from protruding from the avoidance hole and preventing the tab from contacting the side wall of the connecting piece during the process of bending the tab, thereby avoiding tearing damage to the tab.

[0014] In an alternative embodiment, the height of the flanging portion is h, and h≥1.2 mm.

[0015] Beneficial effects: The height of the flanging portion is appropriate, which can effectively protect the tab. At the same time, the height of the flanging portion can be made smaller than the thickness of the connecting piece, preventing the flanging portion from exceeding the top surface of the second conductive portion, ensuring that the bending portion can be attached to the top surface of the second conductive portion, thereby ensuring the welding effect between the two.

[0016] In an alternative embodiment, the tab gathering surface on the top surface of the electrode group is inclined, and an inclined portion is provided on the insulating protection member above the tab gathering surface. The inclined portion inclines downward toward the outside of the electrode group with respect to the tab gathering surface.

[0017] Beneficial effects: The inclined portion inclines downward toward the outside of the electrode group with respect to the tab gathering surface. The inclined portion is attached to the tab gathering surface. During the welding process of the bending portion and the second conductive portion, the welding slag generated can slide down along the inclined portion, preventing the welding slag from falling onto the tab gathering surface. At the same time, the thickness of the tab gathering surface near the vertical portion of the tab is relatively thick. The inclined portion above the tab gathering surface of the present invention inclines in the same direction as the tab gathering surface, and the inclination angles of the two are the same, which can prevent the inclined portion from pressing and damaging the tab gathering surface.

[0018] In an alternative embodiment, the inclined portion is provided above the avoidance hole, and the edge of the inclined portion extending in the first direction extends beyond the edge of the avoidance hole.

[0019] Beneficial effects: Such a setting can strengthen the strength of the inclined portion and the insulating protection member, ensuring that the insulating protection member is effectively held between the electrode group and the connecting piece.

[0020] In an alternative embodiment, the distance between the edge of the inclined portion and the edge of the avoidance hole is d1, and d1≥0.5 mm.

[0021] Beneficial effects: Such a setting can ensure that the inclined portion is stably provided on the insulating protection member on both sides of the avoidance hole, ensuring the stability and strength of the inclined portion itself. At the same time, it can avoid waste of space and materials due to the excessive distance of the inclined portion extending in the x direction, which is beneficial to improving the space utilization rate of the battery cell and saving the manufacturing cost of the battery cell.

[0022] In an alternative embodiment, the distance between the inner wall of the inclined portion facing the tab and the tab is d, and d≥0.5 mm.

[0023] Beneficial effects: Such a setting can keep an appropriate distance between the inclined part and the tab, preventing the inclined part from contacting the tab during the assembly process or use and damaging the tab.

[0024] In an alternative embodiment, the thickness of the insulation protection member is t, where 0.2 mm ≤ t ≤ 1.2 mm.

[0025] Beneficial effects: The thickness of the insulation protection member is moderate, which can prevent it from being punctured by the connecting piece, thereby preventing the connecting piece from puncturing the diaphragm, preventing internal short circuit of the battery cell, and improving the safety of the battery cell; at the same time, it can avoid the thickness of the insulation protection member being too thick, reducing the occupied space of the insulation protection member in the height direction of the battery cell and improving the space utilization rate of the battery cell.

[0026] In an alternative embodiment, multiple groups of the pole groups are provided, and the bent portions of the tabs at the ends of adjacent two groups of the pole groups are bent towards each other.

[0027] Beneficial effects: Such a setting can set different numbers of pole groups according to the capacity requirements of the battery cell, improving the flexibility of the battery cell capacity design.

[0028] In a second aspect, the present invention also provides a battery pack, including the battery cell described in any one of the above.

[0029] Beneficial effects: For the battery pack with such a structure, an insulation protection member is provided between the pole group and the connecting piece in the battery cell. The insulation protection member can prevent the connecting piece from being deformed by force and damaging the diaphragm of the pole group, preventing internal short circuit of the pole group, thereby improving the safety performance of the battery cell and the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required to be used in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic internal structure diagram of a battery cell according to an embodiment of the present invention;

[0032] Figure 2 is Figure 1 a top view of;

[0033] Figure 3 is Figure 2 a sectional view taken along the A-A direction of;

[0034] Figure 4 is Figure 3 a partial enlarged view of part A in;

[0035] Figure 5 is Figure 1 A three-dimensional structural schematic diagram of the middle insulating protection part;

[0036] Figure 6 is Figure 5 The top view of;

[0037] Figure 7 A schematic diagram of the cooperation between the insulating protection part and the tab;

[0038] Figure 8 A schematic diagram of the cooperation between the insulating protection part, the tab and the connecting piece.

[0039] Explanation of reference numerals:

[0040] 1. Connecting piece; 11. First conductive part; 12. Second conductive part; 2. Electrode group; 3. Insulating protection part; 31. Avoidance hole; 32. Flanging part; 33. Tilted part; 4. Tab; 41. Bent part; 42. Tab converging surface. Detailed implementation manners

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0042] Below in conjunction with Figures 1 to 8 , describe the embodiments of the present utility model.

[0043] According to an embodiment of the present utility model, on the one hand, a battery is provided, which includes a housing, a cover plate, a connecting piece 1, an electrode group 2, an insulating protection part 3 and a tab 4.

[0044] Among them, one side of the housing is provided with an open end; the cover plate is arranged on the open end; the connecting piece 1 includes a first conductive part 11 and a second conductive part 12; the electrode group 2 is arranged inside the housing; the insulating protection part 3 is arranged between one end of the electrode group 2 facing the cover plate and the connecting piece 1, and an avoidance hole 31 is provided on the insulating protection part 3; the tab 4 is arranged at one side end of the electrode group 2; the tab 4 passes through the avoidance hole 31 and extends out of the insulating protection part and bends towards the outer wall surface of the second conductive part 12 to form a bent part 41.

[0045] For the battery cell of this structure, an insulating protection member 3 is provided between the electrode assembly 2 and the connecting piece 1. The insulating protection member 3 can prevent the connecting piece 1 from being deformed by force and damaging the separator of the electrode assembly 2, and prevent internal short circuit of the electrode assembly 2, thereby improving the safety performance of the battery cell. The first conductive portion 11 of the connecting piece 1 is adapted to be welded to the electrode post to achieve electrical connection between the electrode post and the connecting piece 1. The second conductive portion 12 of the connecting piece 1 is welded to the bending portion 41 to achieve electrical connection between the connecting piece 1 and the electrode tab 4, thereby achieving electrical connection between the electrode assembly 2 and the electrode post.

[0046] In some embodiments, two mounting holes and an operation hole are provided on the cover plate. The electrode post includes a positive electrode post and a negative electrode post. The positive electrode post and the negative electrode post are respectively arranged in the two mounting holes, and the operation hole is located between the positive electrode post and the negative electrode post. The electrode tab 4 extends out of the insulating protection member 3 through the avoidance hole 31, and then extends out of the cover plate through the operation hole. The electrode tab 4 is bent through the operation hole to form a bending portion 41, so that the bending portion 41 closely adheres to the second conductive portion 12, and then the bending portion 41 is welded to the second conductive portion 12 through the operation hole. The electrode tab 4 can be bent and welded conveniently and quickly through the operation hole.

[0047] In some embodiments, such as Figure 3 and Figure 4 shown, a flanging portion 32 protruding upward is provided on the outer edge of the avoidance hole 31 on the lower side of the bending portion 41. As Figure 7 and Figure 8 shown, the folded electrode tab 4 extends upward to the upper part of the electrode assembly 2. After the electrode tab 4 is bent, a vertical section and a bending portion 41 are formed. The flanging portion 32 is arranged opposite to the vertical section, and the flanging portion 32 wraps around the side surface of the connecting piece 1, preventing the electrode tab 4 from contacting the side wall of the connecting piece 1 during the process of the electrode tab 4 extending out of the avoidance hole 31 and bending the electrode tab 4, resulting in tearing damage of the electrode tab 4.

[0048] In some embodiments, the battery cell includes a square shell battery cell. The Figure 1 x direction in Figure 1 is called the length direction of the battery cell, Figure 1 the y direction in is called the thickness direction of the battery cell,

[0049] the z direction in Figure 4 is called the height direction of the battery cell.

[0050] Figure 1 、 Figure 3 、 Figure 4 and Figure 5As shown, the electrode group 2 is formed by laminating multiple electrode plates. The tab 4 is arranged on the top of the electrode plate. After lamination, multiple tabs 4 converge towards the middle in the thickness direction of the electrode group 2, forming a tab convergence surface 42 on the end face of the electrode group 2. Since the tabs 4 all converge in the middle of the electrode group 2, the tab convergence surface 42 on the top surface of the electrode group 2 is inclined. Along the thickness direction of the electrode group 2, the height inside the tab convergence surface 42 is high and the height outside is low. If the bottom surface of the insulation protection part 3 is all flat, and the flat structure is pressed against the top surface of the tab convergence surface 42, when pressure is applied to the tab convergence surface 42 by the insulation protection part 3 after the battery cell is assembled, it is easy to cause damage to the tab convergence surface 42; the welding slag formed after the tab 4 is welded to the second conductive part 12 is also easy to fall onto the tab 4. To solve this problem, the present utility model is provided with an inclined part 33 on the insulation protection part 3 above the tab convergence surface 42. The inclined part 33 is inclined downward towards the outside of the electrode group 2 with the tab convergence surface 42. The inclined part 33 is attached to the tab convergence surface 42. The welding slag generated during the process of welding the bending part 41 and the second conductive part 12 can slide down along the inclined part 33, preventing the welding slag from falling onto the tab convergence surface 42. At the same time, the thickness of the tab convergence surface 42 near the vertical part of the tab 4 is relatively thick. The inclined part 33 above the tab convergence surface 42 of the present utility model is inclined in the same direction as the tab convergence surface 42, and the inclination angles of the two are the same, which can prevent the inclined part 33 from pressing and damaging the tab convergence surface 42.

[0051] In some embodiments, as Figure 5 and Figure 6 shown, the inclined part 33 is arranged above the avoidance hole 31. The edge of the inclined part 33 extending along the first direction (x-direction, i.e., the length direction of the battery cell) extends beyond the edge of the avoidance hole 31. Such a setting can strengthen the strength of the inclined part 33 and the strength of the insulation protection part 3, ensuring that the insulation protection part 3 is effectively held between the electrode group 2 and the connection piece 1.

[0052] In some embodiments, the distance between the edge of the inclined part 33 and the edge of the avoidance hole 31 is d1, and d1≥0.5mm. Such a setting can ensure that the inclined part 33 is stably arranged on the insulation protection part 3 on both sides of the avoidance hole 31, ensuring the stability and strength of the inclined part 33 itself. At the same time, it can avoid waste of space and materials due to the excessive extension distance of the inclined part 33 along the x-direction, which is beneficial to improving the space utilization rate of the battery cell and saving the manufacturing cost of the battery cell.

[0053] In some embodiments, as Figure 4 shown, the distance between the inner wall of the inclined part 33 facing the tab 4 and the tab 4 is d, and d≥0.5mm. Such a setting can keep an appropriate distance between the inclined part 33 and the tab 4, preventing the inclined part 33 from contacting the tab 4 and damaging the tab 4 during the assembly process or the use process.

[0054] In some embodiments, the thickness of the insulating protection member 3 is t, where 0.2 mm ≤ t ≤ 1.2 mm. The thickness of the insulating protection member 3 is appropriate, which can prevent the connecting piece 1 from puncturing it, thereby preventing the connecting piece 1 from puncturing the diaphragm, preventing internal short circuit of the battery cell, and improving the safety of the battery cell. At the same time, it can avoid the thickness of the insulating protection member 3 being too thick, reduce the occupied space of the insulating protection member 3 in the height direction of the battery cell, and improve the space utilization rate of the battery cell.

[0055] In some embodiments, the distance between the edge of the avoidance hole 31 extending in the y direction and the edge of the insulating protection member 3 is greater than or equal to 1.5 mm. Such a setting can ensure that there is enough solid part of the insulating protection member 3 on the side of the avoidance hole 31, ensure the overall structural strength of the insulating protection member 3, and prevent the connecting piece 1 from damaging the insulating protection member 3.

[0056] In some embodiments, the width of the insulating protection member 3 extending in the y direction is the same as the thickness of the electrode assembly 2. In other embodiments, the width of the insulating protection member 3 can also be smaller than the thickness of the electrode assembly 2.

[0057] In some embodiments, there are multiple sets of electrode assemblies 2, and the bent portions 41 of the electrode tabs 4 at the ends of adjacent two sets of electrode assemblies 2 are bent towards each other. Such a setting can set different numbers of electrode assemblies 2 according to the capacity requirements of the battery cell, improving the flexibility of the battery cell capacity design.

[0058] For example, in some embodiments, there are two sets of electrode assemblies 2, and the electrode tabs 4 at the ends of the two sets of electrode assemblies 2 are arranged oppositely; a groove is provided in the middle area of the second conductive portion 12, and the bent portions 41 of the two electrode tabs 4 are bent towards each other and are respectively attached to the second conductive portion 12 on both sides of the groove.

[0059] The two sets of electrode assemblies 2 are attached to each other, and the insulating protection member 3 is arranged on the top surfaces of the two sets of electrode assemblies 2. Positive electrode tabs and negative electrode tabs are arranged at intervals along the x direction at the top of each set of electrode assemblies 2. The positive electrode tabs of the two sets of electrode assemblies 2 are opposite to each other and are arranged at intervals along the length direction of the battery cell, and the negative electrode tabs of the two sets of electrode assemblies 2 are opposite to each other and are arranged at intervals along the length direction of the battery cell. When assembling the battery cell, first weld and fix the first conductive portion 11 of the connecting piece 1 on the pole column. During the assembly process of the battery cell, the insulating protection member 3 is arranged on the top surface of the electrode assembly 2, the electrode tab 4 extends out from the avoidance hole 31, the electrode assembly 2 is placed into the shell, so that the second conductive portion 12 is located between the two oppositely arranged electrode tabs 4, the electrode tab 4 extends out of the cover plate through the operation hole, the bent portion 41 is formed by operating the electrode tab 4 through the operation hole, and then the bent portion 41 is welded to the second conductive portion 12 through the operation hole, and then the cover plate is welded to the shell.

[0060] In some embodiments, the cross-section of the insulation protection member 3 is rectangular. Four avoidance holes 31 are provided on the insulation protection member 3. The four avoidance holes 31 are arranged in pairs and aligned. Four tab ears 4 of two groups of electrode groups 2 respectively extend out through the four avoidance holes 31. Inclined portions 33 are provided on both sides of each avoidance hole 31 along the y direction. A flanging portion 32 is provided at the edge of the inclined portion 33 located on the inner side along the y direction.

[0061] The connecting piece 1 includes a positive connecting piece and a negative connecting piece. The first conductive portion 11 of the positive connecting piece is welded to the positive electrode post, and the second conductive portion 12 of the positive connecting piece is welded to the positive tab ear. The first conductive portion 11 of the negative connecting piece is welded to the negative electrode post, and the second conductive portion 12 of the negative connecting piece is welded to the negative tab ear. The structure of the positive connecting piece is the same as that of the negative connecting piece, and the positive connecting piece and the negative connecting piece are arranged oppositely.

[0062] In some embodiments, the battery cell further includes an upper insulation member, a sealing ring, a lower insulation member and a sealing plate. The upper insulation member is arranged on the outer wall surface of the cover plate. The sealing ring is arranged between the electrode post and the cover plate. The lower insulation member is arranged on the inner wall surface of the cover plate. The connecting piece 1 is located inside the lower insulation member. The sealing plate is hermetically arranged on the operation hole so that the battery cell forms a sealed structure as a whole. Optionally, in some embodiments, the sealing plate is welded to the cover plate.

[0063] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including the above-mentioned battery cell.

[0064] For the battery pack with this structure, an insulation protection member 3 is arranged between the electrode group 2 and the connecting piece 1 in the battery cell. The insulation protection member 3 can prevent the connecting piece 1 from being deformed by force and damaging the separator of the electrode group 2, and prevent internal short circuit of the electrode group 2, thereby improving the safety performance of the battery cell and the battery pack.

[0065] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that: include: A housing having an open end on one side; A cover plate, disposed on the opening end; A connecting piece, comprising a first conductive portion and a second conductive portion; A pole group, disposed in the housing; An insulating protective member, arranged between one end of the pole group facing the cover plate and the connecting piece, and an escape hole is provided on the insulating protective member; A pole ear is arranged at one end of the pole group; the pole ear extends out of the insulating protective member through the avoidance hole and is bent toward the outer wall surface of the second conductive part to form a bent portion.

2. The battery cell according to claim 1, characterized in that: An outer edge of the avoidance hole at the lower side of the bending portion is provided with a flange portion protruding upward.

3. The battery cell according to claim 2, characterized in that: The height of the flange portion is h, and h≥1.2 mm.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The tab gathering surface on the top surface of the pole group is inclined, and the insulating protection member on the upper side of the tab gathering surface is provided with an inclined portion, and the inclined portion and the tab gathering surface are inclined downward toward the outer side of the pole group.

5. The battery cell according to claim 4, characterized in that: The inclined portion is disposed above the avoidance hole, and an edge of the inclined portion extending along the first direction exceeds an edge of the avoidance hole.

6. The battery cell according to claim 5, characterized in that: The distance between the edge of the inclined portion and the edge of the avoidance hole is d1, and d1≥0.5 mm.

7. The battery cell according to claim 4, characterized in that: The distance between the inner wall of the inclined portion facing the pole lug and the pole lug is d, and d≥0.5 mm.

8. The battery cell according to any one of claims 1 to 3, characterized in that: The thickness of the insulating protective member is t, 0.2 mm≤t≤1.2 mm.

9. The battery cell according to any one of claims 1 to 3, characterized in that: There are multiple pole groups, and the bending portions of the pole ears at the ends of two adjacent pole groups are bent toward each other.

10. A battery pack, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 9.

Images