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 and a pole group, a pole mounting hole and an operation hole are formed in the cover plate; a reinforcing part is arranged on the second conductive part; the pole group is arranged in the shell; tabs are arranged at the end parts of the pole groups; and the tabs are bent towards the outer wall surfaces of the second conductive parts to form bent parts. According to the battery cell with the structure, the tabs extend out of the cover plate from the operation holes, and the second conductive part is subjected to a force facing the pole group in the process of bending the tabs through the operation holes and bending the tabs towards the second conductive part. The reinforcing part is arranged on the second conductive part, so that the overall strength of the connecting piece can be effectively improved, the second conductive part can be prevented from being deformed in the process of bending the tab towards the outer wall surface of the second conductive part, the bending part is ensured to be tightly attached to the second conductive part, and then the bending part is welded on the second conductive part through the operation of the operation hole; the welding effect and the welding yield of the bending part and the second conductive part can be improved.

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, and a cover plate. The electrode assembly is arranged inside the housing. An electrode tab is provided at the end of the electrode assembly, and the cover plate is arranged on the opening of the housing. When assembling the battery cell, one side of the connecting piece is first welded to the bottom plate of the electrode post, and the other side of the connecting piece is welded to the electrode tab. For the battery cell with such a structure, the electrode tab and the connecting piece cannot be closely attached, which affects the welding effect of the two. 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 electrode tab and the connecting piece cannot be closely attached, which affects the welding effect of the two.

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

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

[0006] A cover plate arranged on the open end, and the cover plate is provided with an electrode post mounting hole and an operation hole; an electrode post is arranged in the electrode post hole;

[0007] A connecting piece, including a first conductive part and a second conductive part. The first conductive part is electrically connected to the inner end face of the electrode post. One side of the second conductive part is connected to the first conductive part, and the other side extends towards the lower side of the operation hole; a reinforcing part is arranged on the second conductive part;

[0008] An electrode assembly arranged inside the housing; an electrode tab is provided at the end of the electrode assembly, and the electrode tab is bent towards the outer wall surface of the second conductive part to form a bent part, and the bent part is welded to the second conductive part.

[0009] Beneficial effects: For the battery cell with such a structure, the electrode tab extends out of the cover plate through the operation hole. By bending the electrode tab through the operation hole, during the process of bending the electrode tab towards the second conductive part, the second conductive part receives a force towards the electrode assembly. By arranging a reinforcing part on the second conductive part, the overall strength of the connecting piece can be effectively improved. During the process of bending the electrode tab towards the outer wall surface of the second conductive part, the deformation of the second conductive part can be prevented, so as to ensure that the bent part is closely attached to the second conductive part. Then, by operating through the operation hole to weld the bent part to the second conductive part, the welding effect and the welding yield rate of the bent part and the second conductive part can be improved.

[0010] In an optional embodiment, the reinforcing part includes a reinforcing rib arranged on the outer wall surface of the second conductive part.

[0011] Beneficial effects: The reinforcing rib is provided on the outer wall surface of the second conductive part, which can effectively improve the overall strength of the connecting piece, prevent the connecting piece from deforming, ensure the close fit between the second conductive part and the bent part, and ensure the welding effect of the two. After the battery cell is assembled, the connecting piece is located on the top surface of the electrode group, and the reinforcing rib is provided on the outer wall surface of the second conductive part. While increasing the strength of the connecting piece, it can avoid interference between the reinforcing rib and the electrode group, making the overall structure more compact and improving the utilization rate of the internal space of the battery cell.

[0012] In an alternative embodiment, the reinforcing rib extends along a first direction; a relief hole is provided on the second conductive part, and there are multiple groups of the electrode groups. Along a second direction perpendicular to the first direction, the tabs at the ends of the electrode groups located inside and outside extend through the relief hole and are bent towards the outer wall surface of the second conductive part.

[0013] Beneficial effects: The tabs at the ends of the inner electrode groups extend through the relief holes and are bent towards the outer wall surface of the second conductive part, so that multiple groups of electrode groups can be arranged inside the housing, and different numbers of electrode groups can be designed according to the required battery cell capacity.

[0014] In an alternative embodiment, the relief hole extends in the same direction as the reinforcing rib, and the distance between the reinforcing rib and the end of the relief hole on the same side along the first direction is L, and L≥0.5mm.

[0015] Beneficial effects: Such a setting can keep an appropriate distance between the end of the relief hole and the reinforcing rib. By increasing the overall strength of the connecting piece through the reinforcing rib, the influence of opening the relief hole on the strength of the connecting piece can be compensated.

[0016] In an alternative embodiment, the width of the reinforcing rib extending along the second direction is W, and the thickness of the second conductive part extending along a third direction is T, and W≥T.

[0017] Beneficial effects: The width of the reinforcing rib is greater than or equal to the thickness of the second conductive part. Such a setting can effectively ensure the strength of the reinforcing rib and the connecting piece, and ensure the welding strength between the second conductive part and the bent part.

[0018] In an alternative embodiment, W≤2.5T.

[0019] Beneficial effects: By restricting the width of the reinforcing rib, it is avoided that the reinforcing rib occupies too much space on the outer wall surface of the second conductive part, ensuring that the second conductive part can have enough area to be welded to the bent part, thereby ensuring the welding area between the second conductive part and the tab, and ensuring the over-current capacity of the battery cell.

[0020] In an alternative embodiment, a stamping groove is provided on the inner wall surface of the second conductive part opposite to the reinforcing rib. The width of the stamping groove extending in the second direction is W1, where 0.5T ≤ W1 ≤ 1.2T, and W1 < W.

[0021] Beneficial effects: By controlling the size of the stamping groove and making the width of the stamping groove smaller than the width of the reinforcing rib, the overall strength of the connecting piece can be further ensured.

[0022] In an alternative embodiment, the height of the reinforcing rib extending in the third direction is H, where H ≥ 0.35T.

[0023] Beneficial effects: By controlling the thickness of the reinforcing rib, the strength of the reinforcing rib and the connecting piece can be further ensured, preventing the connecting piece from deforming.

[0024] In an alternative embodiment, the reinforcing ribs are provided on both the second conductive parts on both sides of the avoidance hole along the second direction, and the second conductive parts on both sides of the avoidance hole along the second direction are symmetrically arranged.

[0025] Beneficial effects: Such an arrangement can make the connecting piece symmetrically arranged in the width direction, and the reinforcing ribs on both sides of the avoidance hole are also symmetrically arranged, which can improve the overall strength of the connecting piece and facilitate the setting of bending parts on the outer wall surfaces of the second conductive parts on both sides in the width direction of the reinforcing rib.

[0026] In a second aspect, the present invention further provides a battery pack, including the battery cell described in any one of the above. The battery pack includes a battery cell and has the same technical effects as the battery cell, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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 for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a three-dimensional structure schematic diagram of a battery cell according to an embodiment of the present invention;

[0029] Figure 2 It is a three-dimensional structure schematic diagram of a connecting piece in a battery cell according to an embodiment of the present invention;

[0030] Figure 3 It is a top view of a connecting piece in a battery cell according to an embodiment of the present invention;

[0031] Figure 4 For Figure 3Cross-sectional view taken along line A-A;

[0032] Figure 5 Schematic diagram during the cell assembly process of an embodiment of the present invention;

[0033] Figure 6 Schematic diagram showing the bending part welded to the second conductive part during the cell assembly process of an embodiment of the present invention;

[0034] Figure 7 Schematic diagram of the cooperation between the electrode group and the tab connecting piece;

[0035] Figure 8 Schematic diagram of the cooperation between the tab and the electrode group and the connecting piece after the tab is bent.

[0036] Explanation of reference numerals:

[0037] 1. Housing; 2. Cover plate; 201. Operation hole; 3. Terminal; 4. Connecting piece; 401. First conductive part; 402. Second conductive part; 403. Reinforcing part; 404. Avoidance hole; 5. Electrode group; 6. Tab; 601. Bending part; 7. Sealing plate. Detailed implementation manners

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0039] The side of each component of the cell facing the outside of the housing 1 is called the outside, and the side of each component facing the inside of the housing 1 is called the inside. The upper part refers to the upper part in the z direction when the cell is in Figure 1 the state, and the lower part refers to the lower part in the z direction when the cell is in Figure 1 the state. When the cell is in Figure 1 the state, the x direction refers to the length direction of the cell, the y direction refers to the thickness direction of the cell, and the z direction refers to the height direction of the cell.

[0040] Next, in conjunction with Figures 1 to 8 , the embodiments of the present invention will be described.

[0041] According to an embodiment of the present invention, on the one hand, a cell is provided, which includes a housing 1, a cover plate 2, a connecting piece 4, and an electrode group 5.

[0042] Wherein, one side of the housing 1 is provided with an open end; a cover plate 2 is arranged on the open end, and a pole post mounting hole and an operation hole 201 are provided on the cover plate 2; a pole post 3 is arranged in the pole post mounting hole; the connecting piece 4 includes a first conductive part 401 and a second conductive part 402, the first conductive part 401 is electrically connected to the inner end face of the pole post 3, one side of the second conductive part 402 is connected to the first conductive part 401, and the other side extends towards the lower side of the operation hole 201; a reinforcing part 403 is arranged on the second conductive part 402; a pole group 5 is arranged in the housing 1; a pole tab 6 is arranged at the end of the pole group 5, the pole tab 6 is bent towards the outer wall surface of the second conductive part 402 to form a bent part 601, and the bent part 601 is welded to the second conductive part 402.

[0043] For the battery cell with this structure, the pole tab 6 extends out of the cover plate 2 through the operation hole 201. When the pole tab 6 is bent through the operation hole 201 and towards the second conductive part 402, the second conductive part 402 is subjected to a force towards the pole group 5. By arranging the reinforcing part 403 on the second conductive part 402, the overall strength of the connecting piece 4 can be effectively improved. During the process of bending the pole tab 6 towards the outer wall surface of the second conductive part 402, deformation of the second conductive part 402 can be prevented, so as to ensure that the bent part 601 is closely attached to the second conductive part 402. Then, by operating through the operation hole 201 to weld the bent part 601 to the second conductive part 402, the welding effect and the welding yield rate of the bent part 601 and the second conductive part 402 can be improved.

[0044] Optionally, in some embodiments, as Figures 2 to 4 shown, the reinforcing part 403 includes a reinforcing rib arranged on the outer wall surface of the second conductive part 402. The reinforcing rib is arranged on the outer wall surface of the second conductive part 402, which can effectively improve the overall strength of the connecting piece 4, prevent the connecting piece 4 from deforming, ensure that the second conductive part 402 is closely attached to the bent part 601, and ensure the welding effect between the two. After the battery cell is assembled, the connecting piece 4 is located on the top surface of the pole group 5. The reinforcing rib is arranged on the outer wall surface of the second conductive part 402. While increasing the strength of the connecting piece 4, interference between the reinforcing rib and the pole group 5 can be avoided, which can make the overall structure more compact and improve the utilization rate of the internal space of the battery cell.

[0045] As Figure 2 and Figure 3As shown, in some embodiments, the reinforcing rib extends in the first direction (x-direction, i.e., the length direction of the battery cell); an avoidance hole 404 is provided on the second conductive part 402, and there are multiple groups of pole groups 5. Along the second direction (y-direction, i.e., the thickness direction of the battery cell) perpendicular to the first direction, the tab 6 at the end of the inner pole group 5 extends out through the avoidance hole 404 and bends towards the outer wall surface of the second conductive part 402, so that multiple groups of pole groups 5 can be arranged inside the housing 1, and different numbers of pole groups 5 can be designed according to the required battery cell capacity. The tab 6 of the inner pole group 5 extends out from the avoidance hole 404, then extends out of the cover plate 2 through the operation hole 201 and bends to the outer wall surface of the second conductive part 402. The bent part 601 of each tab 6 is welded to the second conductive part 402, and the first conductive part 401 is welded to the pole post 3, thereby realizing the electrical connection of all the pole groups 5 and the pole post 3.

[0046] In some embodiments, as Figure 3 shown, the avoidance hole 404 extends in the same direction as the reinforcing rib, and the distance between the reinforcing rib and the end of the avoidance hole 404 on the same side in the first direction is L, L≥0.5mm, that is Figure 3 the distance between the left end of the avoidance hole 404 and the left end of the reinforcing rib, and the distance between the right end of the avoidance hole 404 and the right end of the reinforcing rib in Figure 3 are both greater than 0.5mm, so as to keep an appropriate distance between the end of the avoidance hole 404 and the reinforcing rib. By increasing the overall strength of the connecting piece 4 through the reinforcing rib, the influence of opening the avoidance hole 404 on the strength of the connecting piece 4 can be compensated.

[0047] In some embodiments, as Figure 4 shown, the width of the reinforcing rib extending in the second direction is W, and the thickness of the second conductive part 402 extending in the third direction (z-direction) is T, W≥T, that is, the width of the reinforcing rib is greater than or equal to the thickness of the second conductive part 402. Such a setting can effectively ensure the strength of the reinforcing rib and the connecting piece 4, and ensure the welding strength between the second conductive part 402 and the bent part 601.

[0048] In some embodiments, W≤2.5T, that is, the width of the reinforcing rib is not too wide. By restricting the width of the reinforcing rib, it is avoided that the reinforcing rib occupies too much space on the outer wall surface of the second conductive part 402, ensuring that the second conductive part 402 can have enough area to be welded to the bent part 601, thereby ensuring the welding area between the second conductive part 402 and the tab 6 and ensuring the over-current capacity of the battery cell.

[0049] In some embodiments, as Figure 4As shown, a stamping groove is provided on the inner wall surface of the second conductive part 402 opposite to the reinforcing rib. The width of the stamping groove extending in the second direction is W1, where 0.5T ≤ W1 ≤ 1.2T, and W1 < W. The reinforcing rib is formed by stamping, which is convenient and fast to manufacture. The width W1 of the stamping groove formed on the inner wall surface of the second conductive part 402 after stamping satisfies 0.5T ≤ W1 ≤ 1.2T, and W1 < W. By controlling the size of the stamping groove and making the width of the stamping groove smaller than the width of the reinforcing rib, the overall strength of the connecting piece 4 can be further ensured.

[0050] In some embodiments, as Figure 4 shown, the height of the reinforcing rib extending in the third direction is H, where H ≥ 0.35T. By controlling the thickness of the reinforcing rib, the strength of the reinforcing rib and the connecting piece 4 can be further ensured, and the deformation of the connecting piece 4 can be prevented.

[0051] As Figures 2 to 4 shown, reinforcing ribs are provided on the second conductive parts 402 on both sides of the avoiding hole 404 along the second direction, and the second conductive parts 402 on both sides of the avoiding hole 404 along the second direction are symmetrically arranged. Figure 3 In , the x direction is the length direction of the connecting piece 4, and the y direction is the width direction of the connecting piece 4. The connecting piece 4 is symmetrically arranged in the width direction, and the reinforcing ribs on both sides of the avoiding hole 404 are also symmetrically arranged, which can improve the overall strength of the connecting piece 4 and facilitate the setting of the bending part 601 on the outer wall surfaces of the second conductive parts 402 on both sides in the width direction of the reinforcing rib.

[0052] As Figure 3 shown, in some embodiments, the width of the second conductive part is greater than the width of the first conductive part, which can further improve the strength of the second conductive part. Such a setting can improve the anti-deformation ability of the second conductive part. When a downward pressure is applied to the second conductive part during the bending of the tab 6, the deformation of the second conductive part 402 can be prevented, ensuring that the bending part 601 is in close contact with the second conductive part, thereby improving the welding effect between the two.

[0053] As Figure 7 and Figure 8 shown, in some embodiments, there are four sets of pole groups 5, and the tabs 6 of each set of pole groups 5 include a positive tab and a negative tab. Along the second direction (y direction, i.e., the thickness direction of the battery cell), the positive tabs of all the pole groups 5 are aligned, and the negative tabs of all the pole groups 5 are aligned; the tabs 6 of the pole groups 5 located inside extend out of the cover plate 2 through the avoiding hole 404 and the operation hole 201, and the tabs 6 of the two sets of pole groups 5 located outside are arranged at both ends of the second conductive part 402 extending in the second direction, and the adjacent two tabs 6 in the second direction are bent towards each other.

[0054] Optionally, in some embodiments, the terminal post 3 includes a positive terminal post and a negative terminal post. There are two terminal post mounting holes and an operation hole 201 on the cover plate 2. The battery cell further includes a sealing plate 7, and the sealing plate 7 is sealingly arranged on the operation hole 201 to form a sealed structure for the whole battery cell. The positive terminal post 3 and the negative terminal post 3 are respectively arranged in the two terminal post mounting holes.

[0055] The connecting piece 4 includes a positive connecting piece and a negative connecting piece. The two sides of the positive connecting piece are respectively welded to the positive terminal post and the negative electrode tab, and the two sides of the negative connecting piece are respectively welded to the negative terminal post and the negative electrode tab.

[0056] In some embodiments, the battery cell further includes a first insulating member, a second insulating member and a sealing member. The first insulating member is arranged on the outer wall surface of the cover plate 2; the second insulating member is arranged on the inner wall surface of the cover plate 2, the outer end surface of the terminal post 3 is crimped on the first insulating member, and the conductive connecting piece 4 is located inside the second insulating member. The sealing member is sleeved on the terminal post 3.

[0057] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including the battery cell described in any one of the above.

[0058] For the battery pack with this structure, by arranging the reinforcing portion 403 on the second conductive portion 402 of the battery cell therein, the overall strength of the connecting piece 4 can be effectively improved. During the process of bending the electrode tab 6 towards the outer wall surface of the second conductive portion 402, deformation of the second conductive portion 402 can be prevented, so as to ensure that the bent portion 601 is closely attached to the second conductive portion 402, and the welding effect and welding yield rate of the bent portion 601 and the second conductive portion 402 can be improved.

[0059] Although the embodiments of the present invention are described with reference to 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 is arranged on the open end, and a pole mounting hole and an operation hole are arranged on the cover plate; a pole is arranged in the pole mounting hole; A connecting piece, comprising a first conductive part and a second conductive part, wherein the first conductive part is electrically connected to the inner end surface of the pole, and one side of the second conductive part is connected to the first conductive part and the other side extends toward the lower side of the operation hole; a reinforcing part is provided on the second conductive part; A pole group is arranged in the shell; a pole ear is arranged at the end of the pole group, the pole ear is bent toward the outer wall surface of the second conductive part to form a bent part, and the bent part is welded to the second conductive part.

2. The battery cell according to claim 1, characterized in that: The reinforcement portion includes reinforcement ribs arranged on the outer wall surface of the second conductive portion.

3. The battery cell according to claim 2, characterized in that: The reinforcing rib extends along a first direction; an avoidance hole is provided on the second conductive part, and the pole group is provided with multiple groups. Along a second direction perpendicular to the first direction, the pole ear at the end of the pole group located inside extends out through the avoidance hole and bends toward the outer wall surface of the second conductive part.

4. The battery cell according to claim 3, characterized in that: The avoidance hole and the reinforcing rib extend in the same direction, and a distance between the reinforcing rib and an end of the avoidance hole on the same side along the first direction is L, where L is ≥ 0.5 mm.

5. The battery cell according to any one of claims 2 to 4, characterized in that: The width of the reinforcing rib extending along the second direction is W, the thickness of the second conductive portion extending along the third direction is T, and W≥T.

6. The battery cell according to claim 5, characterized in that: W≤2.5T.

7. The battery cell according to claim 5, characterized in that: A punching groove is provided on the inner wall surface of the second conductive portion opposite to the reinforcing rib, and the width of the punching groove extending along the second direction is W1, 0.5T≤W1≤1.2T, and W1<W.

8. The battery cell according to claim 5, characterized in that: The height of the reinforcing rib extending along the third direction is H, and H≥0.35T.

9. The battery cell according to claim 3 or 4, characterized in that: The reinforcing ribs are provided on the second conductive parts on both sides of the avoidance hole along the second direction, and the second conductive parts on both sides of the avoidance hole along the second direction are symmetrically arranged.

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

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