Battery cover plate, battery and battery assembly method

Abstract

The invention relates to the technical field of battery production, in particular to a battery cover plate, a battery and a battery assembly method.The battery cover plate comprises an end cover and an even number of connecting pieces, the inner side of the end cover is provided with an even number of containing grooves in one-to-one correspondence with the connecting pieces, and one ends of the connecting pieces are rotationally connected into the containing grooves; wherein the rotation directions of half of the connecting pieces and the other half of the connecting pieces are opposite in the process from the initial state to entering the containing groove. According to the invention, the even number of connecting sheets are arranged, and then the connecting sheets are divided into two equal parts which are respectively used for being connected with the tabs and are bent in opposite directions, so that the acting force of the tabs on the end cover can be counteracted in one direction, the stress of the end cover in the direction is zero, and finally, the end cover and the shell are pressed together; and the phenomenon that the end cover and the shell cannot be pressed due to stress resilience caused by bending of the tab is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of battery production, and more particularly, to a battery cover, a battery, and a battery assembly method. Background Art

[0002] The battery cell is the core energy storage unit of the battery, and is currently divided into laminated cells and wound cells. The laminated cell is a structure formed by stacking the positive electrode sheet, negative electrode sheet and separator layer by layer to form a current collector, and then leading the positive and negative electrode ears from the current collector. Figure 1 The figure shows a conventional laminated battery during assembly. In the conventional battery assembly process, the multiple electrode sheets on one side of the bare cell 2 are pressed together to form a tab 201, which is then bent 90° and directly welded to the end cap 1.

[0003] However, due to the excessive number of lamination layers, the tab 201 will have yield stress after bending and stress rebound will occur. The tab 201 will generate an oblique outward pressure on the end cap 1, thereby driving the end cap 1 to move in the y-axis direction, resulting in the end cap 1 and the end cap 1 being in contact. Figure 2 The shell 7 shown cannot be pressed together, which eventually leads to defects such as gaps or cold welds in the peripheral welds between the end cover 1 and the shell 7 . Summary of the Invention

[0004] In order to address the problem in the above-mentioned prior art that the stress rebound caused by the bending of the tab leads to the end cover and the shell being unable to be pressed together, which ultimately leads to gaps or cold welds in the peripheral welds between the end cover and the shell, the present invention provides a battery cover, a battery and a battery assembly method, which can press the end cover and the shell together, avoiding defects such as gaps or cold welds in the peripheral welds between the end cover and the shell.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] A battery cover plate includes an end cap and an even number of connecting tabs for connecting to tabs. The inner side of the end cap is provided with an even number of receiving slots corresponding one-to-one to the connecting tabs. One end of each connecting tab is rotatably connected to the receiving slots. The receiving slots are used to accommodate the connecting tabs and the tabs connected to the connecting tabs. Half of the connecting tabs and the other half rotate in opposite directions from an initial state to entering the receiving slots. It is understood that the inner side of the end cap is the side of the end cap that is connected to the housing, and the outer side of the end cap is the side exposed to the outside after the end cap is connected to the housing.

[0007] In the above technical solution, the connecting piece is used to connect one by one with the tabs at the end of the bare battery cell, and the tabs are bent by rotating the connecting piece. Since half of the connecting pieces have the opposite rotation direction to the other half of the connecting pieces, the bending direction of half of the tabs is opposite to the bending direction of the other half of the tabs. The forces applied to the end cover in the y-axis direction cancel each other out, making the force on the end cover in the y-axis direction zero, thereby avoiding the movement of the end cover in the y-axis direction, and ultimately avoiding defects such as gaps or cold welds in the peripheral welds between the end cover and the shell. In addition, since the tabs can be stored in the storage slot after bending without occupying the internal space of the shell, the effective volume of the shell can be saved, thereby improving the energy density of the entire battery.

[0008] Furthermore, the connecting piece is connected to a locking assembly, and the end cap is provided with a mating structure for mating with the locking assembly. When the tab is bent into position, the locking assembly engages with the mating structure, thereby locking the shaft. As can be appreciated, because the shaft is locked and cannot slide back, the tab cannot rotate around its bend to reset, and the end cap cannot move away from the x-axis of the housing. This allows for a smoother and more secure connection between the end cap and the housing.

[0009] Furthermore, one end of each connecting piece is provided with a rotating shaft, and the end of each rotating shaft is provided with the locking assembly, and each locking assembly includes a spring and a clamping block, with the two ends of the spring respectively connected to the end of the rotating shaft and the clamping block; a sliding groove is provided on the inner wall of each receiving groove, and the inner wall of each sliding groove is provided with the matching structure; the locking assembly and the end of each rotating shaft are slidably arranged in the sliding groove, and the matching structure is used for the clamping block to extend into and engage with the clamping block. It is understandable that during the bending process of the tab, the spring is in a compressed state, and the rotating shaft rotates while sliding along the sliding groove until the clamping block slides to the matching structure and is pushed into the matching structure by the spring, thereby locking the rotating shaft.

[0010] Of course, in addition to the above methods, the locking assembly and the mating structure can also be connected by magnetic connection or slider-bevel wedge connection. In the case of magnetic connection, a slot is provided on the inner wall of the chute, and a magnet is placed in the slot. The locking assembly is made of an iron / nickel alloy and automatically attracts and locks when it approaches the magnet. In the case of slider-bevel wedge connection, a tapered slope is provided on the inner wall of the chute, and the locking assembly is a wedge-shaped block that is squeezed and wedged when it slides onto the slope.

[0011] Furthermore, an anti-reversal feature is provided on the outer circumferential surface of the shaft. When the connecting piece is perpendicular to the end cap, the anti-reversal feature abuts against the bottom of the receiving slot. The anti-reversal feature prevents the shaft from rotating in the opposite direction, forcing the shaft to rotate only in the direction that drives the tab to bend, thereby preventing tab bending failure.

[0012] Preferably, the end cap includes a pole and a cover body connected in sequence, and the edge of the cover body is connected to the edge of one end of the shell; the cover body is provided with an injection hole, and the injection hole is connected to the inner cavity of the shell; the side of the cover body close to the bare battery cell is provided with a first insulating layer, and the side of the connecting piece away from the pole ear is provided with a second insulating layer; the storage grooves are all opened on the side of the cover body away from the pole. It can be understood that the insulating layer can avoid the contact between the side of the cover body and the connecting piece and the bare battery cell, and avoid the conduction short circuit caused by the positive and negative pole pieces contacting the side of the cover body and the connecting piece at the same time. By applying an insulating coating, the process of covering the weld with traditional insulating tape can be replaced, thereby eliminating the gluing process, eliminating multiple processes such as tape cutting, positioning, bonding and rolling, and shortening the process flow. Moreover, compared with the traditional gluing process, applying an insulating coating can achieve more reliable insulation and sealing, and is more suitable for batteries with high energy density.

[0013] The present invention also provides a battery, comprising a bare cell and a shell, wherein the shell is sleeved on the outside of the bare cell, and further comprising the above-mentioned battery cover, wherein one end of the bare cell is provided with an even number of tabs corresponding one-to-one with the connecting tabs; the tabs are connected one-to-one with the connecting tabs, wherein half of the tabs are bent in the opposite direction to the other half of the tabs, and the tabs and the connecting tabs are both located in the corresponding receiving slots and the tabs abut against the inner walls of the receiving slots; and one end of the battery cover is connected to one end of the shell. The tabs at one end of the bare cell may all be positive tabs, may all be negative tabs, or may include both positive and negative tabs.

[0014] It should be noted that the bare cell can be a stacked cell formed by alternating stacking of positive electrode sheets, separators and negative electrode sheets, or a wound cell formed by stacking positive electrode sheets, separators and negative electrode sheets in sequence and then winding them.

[0015] The beneficial effects of the above-mentioned battery are similar to the beneficial effects of the aforementioned battery cover, so they are not described in detail.

[0016] Preferably, two battery covers are provided, one connected to each end of the housing; both ends of the bare cell are provided with an even number of tabs, each connected to the connecting piece in a one-to-one correspondence; the tabs at one end of the bare cell are both positive tabs, and the tabs at the other end are both negative tabs. In this technical solution, the positive tab of the battery is provided at one end of the bare cell, and the negative tab is provided at the other end of the bare cell.

[0017] The present invention also provides a battery assembly method, which is applied to the above-mentioned battery and comprises the following steps:

[0018] S1: Prepare the above-mentioned end caps and bare cells;

[0019] S2: attaching and welding one side surface of the tab to one side surface of the corresponding connecting piece;

[0020] S3: Push the end cover toward the bare cell, so that the tabs are bent one by one and enter the receiving grooves to abut against the receiving grooves.

[0021] Preferably, in step S3, before pushing the end cap toward the bare cell, the connecting piece is first pushed to pre-bend the tab, and then the end cap is pushed toward the bare cell. This can reduce the resistance of pushing the end cap and ensure that the tab can be bent smoothly.

[0022] Preferably, in step S1, an insulating coating is applied to both the side of the end cap where the receiving slot is provided and the side of the connecting piece not used for connection to the tab. As previously mentioned, applying an insulating coating replaces the traditional process of covering weld marks with insulating tape, thereby eliminating the taping process and omitting multiple steps such as tape cutting, positioning, taping, and rolling, shortening the process. Furthermore, compared to the traditional taping process, applying an insulating coating provides more reliable insulation and sealing, making it more suitable for high-energy-density batteries.

[0023] Preferably, two end caps are provided, each connected to one end of the housing. The other end of the bare cell is also provided with multiple tabs, with the tabs at each end of the bare cell having opposite polarities and connected to the two end caps, respectively. It should be noted that the two end caps are connected to the tabs at each end of the bare cell in the same manner, so that neither end cap will be offset.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) An even number of connecting pieces are provided on the end cover, and the connecting pieces are then divided into two equal parts and used to connect with the tabs and bent in opposite directions, respectively. This allows the force exerted by the tabs on the end cover to be offset in the y-axis direction, so that the force on the end cover in the y-axis direction is zero, and ultimately allows the end cover and the shell to be pressed together, thereby avoiding peripheral welding defects between the end cover and the shell. In addition, the receiving groove provided on the end cover can accommodate the bent tabs and connecting pieces, which can save the effective volume of the shell, thereby improving the energy density of the entire battery.

[0026] (2) An insulating coating is applied to both the side of the end cap where the receiving groove is provided and the side of the connecting piece not connected to the tab. By applying the insulating coating, the traditional insulating tape covering the weld print is replaced, thereby eliminating the gluing process, omitting multiple steps such as tape cutting, positioning, laminating, and rolling, and shortening the process. Moreover, the insulating coating can achieve more reliable insulation and sealing compared to the traditional gluing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a state diagram of the connection process between the bare cell and the end cap in the prior art;

[0028] Figure 2 is a structural schematic diagram of the shell;

[0029] Figure 3 Schematic diagram of the structure of the end cover;

[0030] Figure 4 is a cross-sectional view of the end cover in one direction;

[0031] Figure 5 It is a cross-sectional view of the end cover in another cross-sectional direction;

[0032] Figure 6 is a cross-sectional view of the rotating shaft and the anti-reversal member;

[0033] Figure 7 is a structural schematic diagram of the connecting piece from one viewing angle;

[0034] Figure 8 is a structural diagram of the connecting piece from another perspective;

[0035] Figure 9 A schematic diagram of the connection process between a bare cell and an end cap in a battery assembly method;

[0036] Figure 10 A schematic diagram of a battery assembly method showing a state before the tab is bent;

[0037] Figure 11 A schematic diagram of the bent tab state in a battery assembly method.

[0038] In the accompanying drawings: 1-end cover; 101-pole; 102-cover body; 1021-storage slot; 1022-slide slot; 1023-matching structure; 1024-liquid injection hole; 2-bare battery cell; 201 pole ear; 3-connecting piece; 4-rotating shaft; 5-locking assembly; 501-spring; 502-block; 6-anti-reversal part; 7-housing. DETAILED DESCRIPTION

[0039] The drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate the embodiments, some components in the drawings may be omitted, enlarged, or reduced in size, and do not represent actual product dimensions. Those skilled in the art will understand that some well-known structures and their descriptions may be omitted from the drawings. The positional relationships depicted in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0040] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "long", "short", etc. indicating the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0041] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0042] Example 1

[0043] This embodiment is the first embodiment of a battery cover. Figures 2 to 11 As shown, it includes an end cap 1 and two connecting pieces 3 for connecting to the tabs 201. The inner side of the end cap 1 is provided with two receiving grooves 1021 corresponding to the connecting pieces 3. One end of the connecting piece 3 is rotatably connected to the receiving groove 1021. The receiving groove 1021 is used to accommodate the connecting piece 3 and the tab 201 connected to the connecting piece 3. One of the connecting pieces 3 and the other connecting piece 3 rotate in opposite directions from the initial state to the other connecting piece 3 in the process of entering the receiving groove 1021, and both connecting pieces 3 are gradually retracted inward, and finally the rotating end of the connecting piece 3 is farther from the horizontal center line of the end cap 1 than the other end of the connecting piece 3. It can be understood that the inner side of the end cap 1 is the side of the end cap 1 used to connect to the shell 7, and the outer side of the end cap 1 is the side exposed to the outside after the end cap 1 is connected to the shell 7.

[0044] Furthermore, the two receiving slots 1021 are staggered.

[0045] Furthermore, the connecting piece 3 is connected to a locking assembly 5, and the end cap 1 is provided with a mating structure 1023 for mating with the locking assembly 5. When the tab 201 is bent into position, the locking assembly 5 engages with the mating structure 1023, thereby locking the rotating shaft 4. It can be understood that because the rotating shaft 4 is locked and cannot slide back, the tab 201 cannot rotate around its own bend to reset, and the end cap 1 cannot move in the x-axis direction away from the housing 7. This makes the connection between the end cap 1 and the housing 7 smoother and more secure.

[0046] Furthermore, one end of each connecting piece 3 is provided with a rotating shaft 4, and the end of each rotating shaft 4 is provided with a locking assembly 5. Each locking assembly 5 includes a spring 501 and a clamping block 502. The two ends of the spring 501 are respectively connected to the end of the rotating shaft 4 and the clamping block 502. Both sides of the inner wall of the receiving groove 1021 are provided with a sliding groove 1022, that is, one receiving groove 1021 has two sliding grooves 1022. The ends of the sliding grooves 1022 are provided with a matching structure 1023 in the form of a clamping groove. The locking assembly 5 and the end of the rotating shaft 4 are both slidably arranged in the sliding groove 1022, and the matching structure 1023 is used for the clamping block 502 to extend into and engage with the clamping block 502. It can be understood that during the bending process of the tab 201, the spring 501 is in a compressed state, and the rotating shaft 4 rotates while sliding along the sliding groove 1022 until the clamping block 502 slides to the matching structure 1023 and is pushed into the matching structure 1023 by the spring 501, thereby locking the rotating shaft 4. Of course, the sliding groove 1022 may not be provided, as long as the rotating shaft 4 can slide. However, providing the sliding groove 1022 can make the sliding of the rotating shaft 4 more stable.

[0047] The locking assembly 5 and the mating structure 1023 can also be connected by magnetic attraction or by a slider-type wedge-type connection. For a magnetic connection, a slot is provided on the inner wall of the chute 1022, and a magnet is positioned within the slot. The locking assembly 5 is made of an iron / nickel alloy and automatically locks when it is in contact with the magnet. For a slider-type wedge-type connection, a tapered surface is provided on the inner wall of the chute 1022, and the locking assembly 5 is a wedge-shaped block that is squeezed and wedged when it slides onto the surface.

[0048] Furthermore, an anti-reversal feature 6 is provided on the outer circumferential surface of the rotating shaft 4. Specifically, the anti-reversal feature 6 includes a connecting portion 601 and an abutting portion 602, which are interconnected and perpendicular to each other. The connecting portion 601 is connected to the rotating shaft 4. When the connecting piece 3 is perpendicular to the end cap 1, the abutting portion 601 abuts the bottom of the receiving groove 1021. The anti-reversal feature 6 prevents the rotating shaft 4 from rotating in the opposite direction, forcing the rotating shaft 4 to rotate only in the direction that drives the tab 201 to bend, thereby preventing the tab 201 from failing to bend.

[0049] Furthermore, the end cap 1 includes a pole 101 and a cover body 102, which are connected in sequence. The edge of the cover body 102 is connected to the edge of one end of the shell 7. The cover body 102 is provided with an injection hole 1024, which is connected to the inner cavity of the shell 7 to facilitate the injection of electrolyte into the shell 7. A first insulating layer is provided on the side of the cover body 102 close to the bare cell 2, and a second insulating layer is provided on the side of the connecting piece 3 away from the tab 201. The receiving grooves 1021 are both provided on the side of the cover body 102 away from the pole 101. It can be understood that the insulating layer can prevent the side of the cover body 102 and the connecting piece 3 from contacting the bare cell 2, thereby preventing the positive and negative electrodes from contacting the side of the cover body 102 and the connecting piece 3 at the same time, thereby preventing a short circuit caused by the conductive connection. By applying an insulating coating, the traditional process of covering the weld with insulating tape can be replaced, thereby eliminating the adhesive application process, omitting multiple processes such as tape cutting, positioning, laminating, and rolling, and shortening the process flow. Moreover, compared with the traditional gluing process, applying an insulating coating can achieve more reliable insulation and sealing, and is more suitable for high-energy-density batteries.

[0050] The working principle or workflow of this embodiment is as follows: the connecting piece 3 is used to be welded one by one with the tabs 201 at the end of the bare cell 2, and the tabs 201 are bent by rotating the connecting piece 3. Since the rotation direction of one of the connecting pieces 3 is opposite to that of the other connecting piece 3, the bending directions of the two tabs 201 are opposite, and the forces applied to the end cover 1 in the y-axis direction cancel each other out, so that the force on the end cover 1 in the y-axis direction is zero, thereby avoiding the movement of the end cover 1 in the y-axis direction, and ultimately avoiding defects such as gaps or cold welds in the peripheral welding between the end cover 1 and the shell 7. In addition, since the tabs 201 can be accommodated in the storage groove 1021 after being bent without occupying the internal space of the shell 7, the effective volume of the shell 7 can be saved, thereby improving the energy density of the entire battery.

[0051] Example 2

[0052] This embodiment is a second embodiment of a battery cover. This embodiment is similar to the first embodiment, except that four receiving slots 1021 are provided in this embodiment, and four connecting plates 3 are provided correspondingly.

[0053] Other features and beneficial effects of this embodiment are consistent with those of embodiment 1.

[0054] Example 3

[0055] This embodiment is the third embodiment of a battery cover. This embodiment is similar to embodiment 1, except that, in the process from an initial state to entering the storage groove 1021, the two connecting pieces 3 are gradually expanded outward, and finally the rotating end of the connecting piece 3 is closer to the horizontal center line of the end cover 1 than the other end of the connecting piece 3.

[0056] Other features and beneficial effects of this embodiment are consistent with those of embodiment 1.

[0057] Example 4

[0058] This embodiment is the first embodiment of a battery. Figures 2 to 11 As shown, it includes a bare cell 2 and a housing 7, which is sleeved on the outside of the bare cell 2 and also includes the battery cover described in Example 1. One end of the bare cell 2 is provided with two tabs 201 corresponding one-to-one with the connecting piece 3; the tabs 201 are connected one-to-one with the connecting piece 3, wherein the bending direction of half of the tabs 201 is opposite to the bending direction of the other half of the tabs 201, and the tabs 201 and the connecting piece 3 are both located in the corresponding receiving groove 1021, and the tabs 201 abut against the inner wall of the receiving groove 1021; one end of the battery cover is connected to one end of the housing 7. Among them, the tabs 201 at one end of the bare cell 2 can be all positive tabs, all negative tabs, or both positive and negative tabs.

[0059] Specifically, the battery targeted by this embodiment is a laminated battery, and the bare cell 2 is a laminated cell formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet in sequence.

[0060] In this embodiment, two battery cover plates are provided, and the two battery cover plates are respectively connected to the two ends of the housing 7; two tabs 201 are provided at both ends of the bare cell 2, and the tabs 201 are connected to the connecting piece 3 in a one-to-one correspondence; the tabs 201 at one end of the bare cell 2 are both positive tabs 201, and the tabs 201 at the other end are both negative tabs 201. The positive tab 201 of the battery is provided at one end of the bare cell 2, and the negative tab 201 is provided at the other end of the bare cell 2.

[0061] Other features and beneficial effects of this embodiment are consistent with those of embodiment 1.

[0062] Example 5

[0063] This embodiment is similar to embodiment 4, except that the battery targeted by this embodiment is a wound battery, and the bare cell 2 is a wound cell formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet in sequence and then winding them.

[0064] Other features and beneficial effects of this embodiment are consistent with those of Example 2.

[0065] Example 6

[0066] This embodiment is the first embodiment of a battery assembly method. Figures 2 to 11 As shown, it includes the following steps:

[0067] S1: Prepare the above-mentioned end cap 1 and bare cell 2;

[0068] S2: attaching and welding one side surface of the tab 201 to one side surface of the corresponding connecting piece 3;

[0069] S3: Push the end cap 1 toward the bare cell 2, causing the tabs 201 to bend one by one and enter the receiving groove 1021 to abut against the receiving groove 1021. During the bending process of the tab 201, the spring 501 is in a compressed state, and the shaft 4 slides and rotates until the block 502 of the locking assembly 5 slides to the mating structure 1023. The spring 501 pushes the block 502 into the mating structure 1023 and engages with the mating structure 1023, thereby locking the shaft 4 at the mating structure 1023. At this time, the tab 201 is just bent into place.

[0070] Furthermore, in step S3, before pushing the end cap 1 toward the bare cell 2, the connecting piece 3 is first pushed to pre-bend the tab 201, and then the end cap 1 is pushed toward the bare cell 2. This can reduce the resistance of pushing the end cap 1 and ensure that the tab 201 can be bent smoothly.

[0071] Furthermore, in step S1, an insulating coating is applied to both the side of the end cap 1 where the receiving groove 1021 is provided and the side of the connecting piece 3 not used for connection to the tab 201. As previously described, applying an insulating coating replaces the traditional process of covering the weld mark with insulating tape, thereby eliminating the adhesive application process and omitting multiple steps such as tape cutting, positioning, laminating, and rolling, thus shortening the process flow. Furthermore, compared to the traditional adhesive application process, applying an insulating coating achieves more reliable insulation and sealing, making it more suitable for high-energy-density batteries.

[0072] Furthermore, two end caps 1 are provided, and the two end caps 1 are respectively connected to the two ends of the housing 7; the other end of the bare cell 2 is also provided with multiple tabs 201, and the tabs 201 at the two ends of the bare cell 2 have opposite polarities and are respectively connected to the two end caps 1. It should be noted that the connection method between the two end caps 1 and the tabs 201 at the two ends of the bare cell 2 is the same, so neither end cap 1 will be offset.

[0073] Other features and beneficial effects of this embodiment are consistent with those of Example 4 or Example 5.

[0074] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A battery cover, comprising an end cover (1), characterized in that: The invention also includes an even number of connecting pieces (3) for connecting with the tabs (201); an even number of receiving grooves (1021) corresponding one to one with the connecting pieces (3) are provided on the inner side of the end cover (1); one end of the connecting piece (3) is rotatably connected to the receiving groove (1021); the receiving groove (1021) is used to accommodate the connecting piece (3) and the tabs (201) connected to the connecting piece (3); wherein half of the connecting pieces (3) and the other half of the connecting pieces (3) rotate in opposite directions from the initial state to the direction of rotation when entering the receiving groove (1021).

2. A battery cover according to claim 1, characterized in that: The connecting piece (3) is connected to a locking assembly (5), and the end cover (1) is provided with a matching structure (1023) for matching and connecting with the locking assembly (5).

3. A battery cover according to claim 2, characterized in that: One end of each connecting piece (3) is provided with a rotating shaft (4), and the end of each rotating shaft (4) is provided with the locking assembly (5), and each locking assembly (5) includes a spring (501) and a clamping block (502), and the two ends of each spring (501) are respectively connected to the end of each rotating shaft (4) and the clamping block (502); a sliding groove (1022) is provided on the inner wall of each receiving groove (1021), and a matching structure (1023) is provided on the inner wall of each sliding groove (1022); the ends of each locking assembly (5) and each rotating shaft (4) are slidably arranged in the sliding groove (1022), and the matching structure (1023) is used for the clamping block (502) to extend into and be clamped with the clamping block (502).

4. A battery cover according to claim 3, characterized in that: An anti-reversal member (6) is provided on the outer circumferential surface of the rotating shaft (4); when the connecting piece (3) is perpendicular to the end cover (1), the anti-reversal member (6) abuts against the bottom of the receiving groove (1021).

5. The battery cover according to claim 1, characterized in that: The end cover (1) comprises a pole (101) and a cover body (102) connected in sequence, the edge of the cover body (102) being connected to an edge of one end of the shell (7); a liquid injection hole (1024) being provided on the cover body (102), the liquid injection hole (1024) being communicated with the inner cavity of the shell (7); a first insulating layer being provided on a side of the cover body (102) close to the bare battery cell (2), and a second insulating layer being provided on a side of the connecting piece (3) away from the pole lug (201); and the receiving grooves (1021) being provided on a side of the cover body (102) away from the pole (101).

6. A battery comprising a bare cell (2) and a shell (7), wherein the shell (7) is sleeved on the outside of the bare cell (2), characterized in that: It also includes a battery cover according to any one of claims 1 to 5, wherein one end of the bare battery cell (2) is provided with an even number of pole ears (201) corresponding one-to-one to the connecting piece (3); the pole ears (201) are connected one-to-one to the connecting piece (3), wherein the bending direction of half of the pole ears (201) is opposite to the bending direction of the other half of the pole ears (201), the pole ears (201) and the connecting piece (3) are both located in the corresponding receiving groove (1021) and the pole ears (201) are in contact with the inner wall of the receiving groove (1021); one end of the battery cover is connected to one end of the shell (7).

7. A battery according to claim 6, characterized in that: Two battery covers are provided, and the two battery covers are respectively connected to the two ends of the shell (7); both ends of the bare battery cell (2) are provided with an even number of pole tabs (201), and the pole tabs (201) are connected to the connecting piece (3) in a one-to-one correspondence; the pole tabs (201) at one end of the bare battery cell (2) are all positive pole tabs (201), and the pole tabs (201) at the other end are all negative pole tabs (201).

8. A battery assembly method, applied to the battery according to claim 7, characterized in that: The following steps are involved: S1: preparing the end cap (1) and the bare cell (2); S2: attaching and welding one side surface of the tab (201) to one side surface of the corresponding connecting piece (3); S3: Pushing the end cover (1) toward the bare battery cell (2) causes the tabs (201) to bend one by one and enter the receiving groove (1021) to abut against the receiving groove (1021).

9. A battery assembly method according to claim 8, characterized in that: In step S3, before pushing the end cover (1) toward the bare battery core (2), the connecting piece (3) is first pushed to pre-bend the tab (201), and then the end cover (1) is pushed toward the bare battery core (2).

10. A battery assembly method according to claim 8, characterized in that: In step S1, an insulating coating is applied to both the side of the end cover (1) where the receiving groove (1021) is provided and the side of the connecting piece (3) not used for connection with the tab (201).

Images