A large capacity battery

Abstract

The present invention relates to the field of battery technology, and discloses a large-capacity battery, including a cover plate and a shell, wherein a receiving cavity with one end open is defined in the shell, the cover plate is arranged at the open end of the shell, at least one battery cell is arranged in the receiving cavity, the cover plate includes at least two cover plate bodies, each of which is suitable for fixed connection with the shell, two adjacent cover plate bodies are welded and connected, each of the cover plate bodies is provided with a pole that can be electrically connected to the pole ear of at least one battery cell, and at least two cover plate bodies contain at least one positive cover plate and at least one negative cover plate. The cover plate of the large-capacity battery disclosed in the present invention includes at least two cover plate bodies, wherein the heat generated when one cover plate body is welded with other structures will not impact the other cover plate bodies, thereby reducing the damage to plastic parts such as seals, and improving the reliability of the connection between the cover plate and the shell.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a high-capacity battery. Background Technology

[0002] In the existing technology, the battery cover is a one-piece cover. When the one-piece cover is connected to other structures, it is mostly welded. This results in multiple welding positions on the cover. When welding inside one side of the cover, the heat generated by welding will also cause thermal shock to the other side of the cover, damaging plastic parts such as seals, thereby reducing the reliability of the connection between the cover and the shell. Summary of the Invention

[0003] Based on the above, the purpose of this invention is to provide a high-capacity battery that reduces damage to plastic parts such as seals during internal welding of the cover plate and improves the reliability of the connection between the cover plate and the shell.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A high-capacity battery includes a cover plate and a housing. The housing defines a receiving cavity with one end open. The cover plate is disposed at the open end of the housing. At least one battery cell is disposed in the receiving cavity. The cover plate includes at least two cover plate bodies. Each cover plate body is adapted to be fixedly connected to the housing. Adjacent cover plate bodies are welded together. Each cover plate body is provided with a terminal post that can be electrically connected to the electrode tab of at least one battery cell. The at least two cover plate bodies contain at least one positive cover plate and at least one negative cover plate.

[0006] As a preferred embodiment of a high-capacity battery, the terminals on the positive electrode cover are positive terminals, and each positive terminal is electrically connected to the positive tabs of at least two cells arranged face-to-face. The terminals on the negative electrode cover are negative terminals, and each negative terminal is electrically connected to the negative tabs of at least two cells arranged face-to-face.

[0007] As a preferred embodiment of a high-capacity battery, each of the cover plates is provided with a base plate electrically connected to the terminal post, and each base plate is electrically connected to the tabs of at least two cells that are sequentially electrically connected.

[0008] As a preferred embodiment of a high-capacity battery, each of the cover plates is provided with a base plate that is electrically connected to the terminal post, and the tabs of at least two of the battery cells are respectively fixed on the base plate.

[0009] As a preferred embodiment of a high-capacity battery, each of the cover plates is provided with a connecting piece and a base plate electrically connected to the electrode post. The base plate is disposed on the inner side of the cover plate body. The connecting piece includes a first connecting part and a second connecting part that are connected and stacked together. The first connecting part is electrically connected to the base plate, and the second connecting part is electrically connected to the electrode tab of the battery cell.

[0010] As a preferred embodiment of a high-capacity battery, the connection between the first connecting portion and the second connecting portion extends along the length direction of the housing, and at least two cells electrically connected to the same positive electrode cover are arranged in parallel.

[0011] As a preferred embodiment of a high-capacity battery, the connection between the first connection portion and the second connection portion extends along the width direction of the housing, and the path length from the pole of the second connection portion to the connection position of at least two of the battery cells to the same second connection portion is the same.

[0012] As a preferred embodiment of a high-capacity battery, the width of the second connection portion gradually increases along its own length direction and close to the direction of connection with the first connection portion.

[0013] As a preferred embodiment of a high-capacity battery, one of the two adjacent cover plates has a first step, and the other has a second step corresponding to the first step.

[0014] The beneficial effects of the present invention are as follows: The cover plate of the large-capacity battery disclosed in the present invention includes at least two cover plate bodies. The heat generated when one of the cover plate bodies is welded to other structures will not impact the other cover plate bodies, thereby reducing damage to plastic parts such as seals and improving the reliability of the connection between the cover plate and the shell. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a large-capacity battery not fully assembled according to a specific embodiment of the present invention;

[0017] Figure 2 yes Figure 1 A schematic diagram with the casing removed;

[0018] Figure 3This is a schematic diagram of a high-capacity battery provided in a specific embodiment of the present invention;

[0019] Figure 4 This is a cross-sectional view of a cover plate or the like provided in a specific embodiment of the present invention;

[0020] Figure 5 yes Figure 4 A magnified view of a portion at point A;

[0021] Figure 6 This is a schematic diagram of a high-capacity battery provided in the first other embodiment of the present invention;

[0022] Figure 7 This is a schematic diagram of a large-capacity battery provided in a second embodiment of the present invention;

[0023] Figure 8 This is a schematic diagram of a large-capacity battery provided in a third other embodiment of the present invention;

[0024] Figure 9 This is a schematic diagram of a large-capacity battery provided in a fourth other embodiment of the present invention;

[0025] Figure 10 This is a schematic diagram of a large-capacity battery provided in the fifth other embodiment of the present invention.

[0026] In the picture:

[0027] 11. Positive electrode cover; 110. Second step; 12. Negative electrode cover; 120. First step;

[0028] 21. Positive terminal; 22. Negative terminal;

[0029] 3. Connecting piece; 31. First connecting part; 32. Second connecting part;

[0030] 4. Base plate; 5. Housing; 6. Battery cell; 7. Explosion-proof valve; 8. Injection hole. Detailed Implementation

[0031] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0034] This embodiment provides a high-capacity battery, such as Figures 1 to 4 As shown, the high-capacity battery includes a cover plate and a housing 5. The housing 5 defines a receiving cavity with one open end. The cover plate is located at the open end of the housing 5. Four battery cells 6 are housed within the receiving cavity. The cover plate includes two cover plate bodies, each adapted to be fixedly connected to the housing 5. Adjacent cover plate bodies are welded together. Each cover plate body has a terminal post capable of electrically connecting to at least one electrode tab of a battery cell 6. The two cover plate bodies are a positive electrode cover plate 11 and a negative electrode cover plate 12, respectively. In other embodiments, the number of cover plate bodies is not limited to the two in this embodiment; it can also be three or more. These cover plate bodies are either positive electrode cover plates 11 or negative electrode cover plates 12, and there is at least one positive electrode cover plate 11 and at least one negative electrode cover plate 12. The specific number of cover plate bodies is set according to actual needs.

[0035] Specifically, in this embodiment, the weld formed by welding the positive electrode cover plate 11 and the negative electrode cover plate 12 is configured to crack when the pressure inside the casing 5 reaches a preset pressure. In other words, when welding the positive electrode cover plate 11 and the negative electrode cover plate 12 together, by weakening the welding strength, the weld can crack when the pressure inside the casing 5 reaches a preset pressure, thereby releasing pressure and improving the safety of the large-capacity battery.

[0036] Since the cover plate provided in this embodiment includes two cover plate bodies, the heat generated when one cover plate body is welded to other structures will not impact the other cover plate body, reducing damage to plastic parts such as seals and improving the reliability of the connection between the cover plate and the housing 5.

[0037] Specifically, such as Figure 2 As shown, in this embodiment, the four battery cells 6 are arranged face-to-face, and the positive and negative electrodes of each battery cell 6 are located at the same end of the housing 5. Figure 3 As shown, the terminals on the positive cover plate 11 are positive terminals 21, and each positive terminal 21 is electrically connected to the positive tabs of the four cells 6 arranged face-to-face. The terminals on the negative cover plate 12 are negative terminals 22, and each negative terminal 22 is electrically connected to the negative tabs of the four cells 6 arranged face-to-face. In other embodiments, the number of cells 6 can be one, two, three, or more than four, depending on actual needs.

[0038] During high-rate use, existing high-capacity batteries experience current concentrating at the connection point 3, which acts as a current collector. However, the short length of the connection point 3 results in a short current path and low impedance. Consequently, the current density is concentrated at the connection point between the connection point 3 and the base plate 4, leading to significant heat generation in this area. Furthermore, the relatively large current flowing into the connection point 3 causes uneven current distribution among the cells 6, resulting in different power outputs for different cells 6. Over time, this can cause some cells 6 to degrade too quickly, reducing the lifespan of the high-capacity battery.

[0039] like Figure 1 As shown, each cover plate body is provided with a connecting piece 3 and a base plate 4 electrically connected to the electrode post. The base plate 4 is located on the inner side of the cover plate body. The connecting piece 3 includes a first connecting part 31 and a second connecting part 32 that are connected and stacked. The first connecting part 31 is electrically connected to the base plate 4, and the second connecting part 32 is electrically connected to the electrode tab of the battery cell 6.

[0040] Specifically, in this embodiment, the connecting piece 3 is a long strip-shaped sheet structure. The first connecting part 31 and the second connecting part 32 are connected by a multi-layer flexible busbar, making it easier to bend the connecting piece 3. The connection between the first connecting part 31 and the second connecting part 32 extends along the length of the housing 5, and the four cells 6 electrically connected to the same positive electrode cover plate 11 are arranged in parallel. Along the direction from the end of the first connecting part 31 away from the second connecting part 32 to the second connecting part 32, the current on the first connecting part 31 is configured to gradually increase. When the high-capacity battery... Figure 1 When placed as shown, the current on the second connection portion 32 connected to the positive electrode cover plate 11 can gradually increase from bottom to top, and the current on the second connection portion 32 connected to the negative electrode cover plate 12 can gradually increase from top to bottom. Wherein, as... Figure 1 and Figure 2 As shown, the connection points of the first connecting part 31 and the second connecting part 32 of the two connecting pieces 3 are located on both sides of the housing 5 along the width direction, and the width direction of the housing 5 is the thickness direction of the battery cell 6.

[0041] Furthermore, this arrangement ensures that the lead-out directions of the connecting piece 3 connected to the positive electrode cover plate 11 and the connecting piece 3 connected to the negative electrode cover plate 12 are opposite, making the current flow paths almost equal. On the one hand, this reduces the uneven current distribution among the individual cells 6; on the other hand, since the root region of the connecting piece 3, where heat generation is more severe, is located on both sides of the casing 5 along the width direction, the temperature distribution of the cells 6 in the thickness direction is more uniform. This solves the problems of uneven current distribution and inconsistent heat generation and dissipation among the cells 6 inside the large-capacity battery, improving the consistency and service life of the large-capacity battery, and is conducive to the high-capacity configuration of large-capacity batteries.

[0042] To facilitate the assembly of the positive electrode cover 11 and the negative electrode cover 12, such as Figure 5 As shown, the negative electrode cover plate 12 is provided with a first step 120, and the positive electrode cover plate 11 is provided with a second step 110 corresponding to the first step 120. This allows the positive electrode cover plate 11 and the negative electrode cover plate 12 to be initially positioned when they are fastened to the housing 5, thereby facilitating their welding connection and achieving a sealed and fixed connection between the positive electrode cover plate 11 and the negative electrode cover plate 12.

[0043] Specifically, the assembly steps for assembling the cover plate and attaching it to the housing are as follows:

[0044] First, the first connecting part 31 of one connecting piece 3 is welded to the base plate 4 of the positive electrode cover plate 11, and the first connecting part 31 of the other connecting piece 3 is welded to the base plate 4 of the negative electrode cover plate 12.

[0045] Next, the four positive electrode tabs of the four battery cells 6 are respectively welded to the second connecting part 32 of the positive electrode cover plate 11, and the four negative electrode tabs of the four battery cells 6 are respectively welded to the second connecting part 32 of the negative electrode cover plate 12.

[0046] Then, fold the negative electrode cover 12 180° and then fold the positive electrode cover 11 180°.

[0047] Finally, the positive electrode cover plate 11 and the negative electrode cover plate 12 are welded onto the housing 5, and the positive electrode cover plate 11 and the negative electrode cover plate 12 are welded together.

[0048] It should be noted that when welding the positive electrode cover plate 11 and the negative electrode cover plate 12 to the housing 5, they are first fixed by spot welding, and then the perimeter of the cover plate is welded to the housing 5 to achieve a fixed connection between the cover plate and the housing 5. Similarly, when welding the positive electrode cover plate 11 and the negative electrode cover plate 12 together, spot welding can also be done first, and then the positive electrode cover plate 11 and the negative electrode cover plate 12 can be welded together to achieve a fixed connection between the cover plate and the housing 5.

[0049] In other embodiments, the connection points of the first connecting portion 31 and the second connecting portion 32 of the two connecting pieces 3 may also be located on the same side of the housing 5 along the width direction. That is, before the negative electrode cover plate 12 and the positive electrode cover plate 11 are folded over, the positive electrode cover plate 11 and the negative electrode cover plate 12 are located on the same side of the housing 5.

[0050] In other embodiments, such as Figure 6 As shown, there are six battery cells 6. The connection between the first connecting part 31 and the second connecting part 32 extends along the width direction of the housing 5, and the path length from the connection position of the four battery cells 6 to the terminal of the same second connecting part 32 is the same. Specifically, there are two cover plates, each corresponding to a connecting piece 3. The connection points of the first connecting part 31 and the second connecting part 32 of the two connecting pieces 3 are located on both sides of the housing 5 along its length. Specifically, this arrangement increases the uniformity of current distribution on the connecting pieces 3, making the temperature distribution of the large-capacity battery consistent along the thickness direction, and avoiding the phenomenon of excessively high local temperature reducing the service life of the battery cells 6.

[0051] like Figure 3 As shown, the cover plate of this embodiment is also provided with an explosion-proof valve 7 and an injection hole 8. The explosion-proof valve 7 can release pressure when the pressure in the accommodating cavity reaches the preset pressure. The injection hole 8 is connected to the accommodating cavity to inject electrolyte into the accommodating cavity.

[0052] In other embodiments, such as Figure 7 As shown, the second connecting portion 32 is not limited to the rectangular connecting piece of this embodiment. Along its length and close to the direction of connection with the first connecting portion 31, the width of the second connecting portion 32 gradually increases. Specifically, the second connecting portion 32 is a trapezoidal connecting piece. The trapezoidal connecting piece facilitates the distribution of the injection holes 8 on the cover plate, ensuring that the second connecting portion 32 does not obstruct the flow of electrolyte injected into the receiving cavity through the injection holes 8, thus accelerating the injection efficiency. Simultaneously, the trapezoidal connecting piece also facilitates the distribution of the explosion-proof valve 7 on the cover plate, preventing the second connecting portion 32 from directly facing the explosion-proof valve 7 and obstructing the pressure relief of the large-capacity battery, thereby improving the pressure relief capability of the large-capacity battery. Furthermore, the trapezoidal connecting piece used in the second connecting portion 32, compared to the rectangular connecting piece of this embodiment, uses less material, saving material costs for the second connecting portion 32.

[0053] Specifically, in other embodiments, such as Figure 8 As shown, when the second connecting part 32 is a trapezoidal connecting piece, the liquid injection hole 8 is located on the positive electrode cover plate 11 and is not directly opposite the second connecting part 32, the explosion-proof valve 7 is located on the negative electrode cover plate 12 and is not directly opposite the second connecting part 32, the positive electrode post 21 is located at the center of the positive electrode cover plate 11, and the negative electrode post 22 is located at the center of the negative electrode cover plate 12.

[0054] Specifically, each of the second connecting parts 32 in this embodiment is provided with four connecting slots, each connecting slot is provided with a corresponding tab, one end of the tab passes through the connecting slot and is folded to fit against the side of the second connecting part 32 away from the battery cell 6, and the tab is welded to the side of the transition piece 5 away from the battery cell 2.

[0055] Specifically, in other embodiments, such as Figure 9 As shown, when the second connecting part 32 is a trapezoidal connecting piece, the liquid injection hole 8 is located on the positive electrode cover plate 11, the explosion-proof valve 7 is located on the negative electrode cover plate 12 and on the lower side of the negative electrode cover plate 12, the positive electrode post 21 is eccentrically set on the positive electrode cover plate 11 and located on the upper left of the positive electrode cover plate 11, and the negative electrode post 22 is eccentrically set on the negative electrode cover plate 12 and located on the upper right of the negative electrode cover plate 12. The offset of the posts facilitates the connection of large-capacity batteries into a group, and the misalignment increases the width of the connecting busbar, thereby improving the heat dissipation capacity and insulation gap of the busbar.

[0056] Specifically, in other embodiments, such as Figure 10 As shown, when the second connecting part 32 is a trapezoidal connecting piece, the liquid injection hole 8 is located on the positive electrode cover plate 11, the explosion-proof valve 7 is located on the negative electrode cover plate 12 and on the upper side of the negative electrode cover plate 12, the positive electrode post 21 is eccentrically set on the positive electrode cover plate 11 and located on the upper left of the positive electrode cover plate 11, and the negative electrode post 22 is eccentrically set on the negative electrode cover plate 12 and located on the upper right of the negative electrode cover plate 12.

[0057] In other embodiments, the cover plate may not have a connecting piece 3. Each electrode on the cover plate body is electrically connected to the tabs of at least two sequentially electrically connected battery cells 6 through the base plate 4. Alternatively, each electrode on the cover plate body may be directly electrically connected to the tabs of at least two battery cells 6 through the base plate 4.

[0058] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A large capacity battery, characterized in that: The invention comprises a cover plate and a shell (5), wherein the shell (5) defines a receiving cavity with one end open, the cover plate is arranged at the open end of the shell (5), at least one battery cell (6) is arranged in the receiving cavity, the cover plate comprises at least two cover plate bodies, each of the cover plate bodies is suitable for being fixedly connected to the shell (5), two adjacent cover plate bodies are welded together, each of the cover plate bodies is provided with a pole capable of being electrically connected to a pole lug of at least one battery cell (6), and at least two of the cover plate bodies contain at least one positive electrode cover plate (11) and at least one negative electrode cover plate (12); The poles on the positive electrode cover plate (11) are positive poles (21), each of the positive poles (21) is electrically connected to the positive pole tabs of at least two battery cells (6) arranged face to face, and the poles on the negative electrode cover plate (12) are negative poles (22), each of the negative poles (22) is electrically connected to the negative pole tabs of at least two battery cells (6) arranged face to face; Each of the cover plate bodies is provided with a connecting piece (3) and a bottom plate (4) electrically connected to the pole, the bottom plate (4) being arranged on the inner side of the cover plate body, the connecting piece (3) comprising a first connecting portion (31) and a second connecting portion (32) which are connected and stacked, the first connecting portion (31) being electrically connected to the bottom plate (4), and the second connecting portion (32) being electrically connected to the pole lug of the battery cell (6); The connection point between the first connection part (31) and the second connection part (32) extends along the length direction of the shell (5); the connection points between the first connection part (31) and the second connection part (32) are respectively located on both sides of the shell (5) along the width direction, and are arranged in parallel with at least two of the battery cells (6) electrically connected to the same positive electrode cover plate (11).

2. The large-capacity battery according to claim 1, characterized in that: Each of the cover plate bodies is provided with a bottom plate (4) electrically connected to the pole, the bottom plate (4) being arranged on the inner side of the cover plate body, and each of the bottom plates (4) being electrically connected to the pole tabs of at least two of the battery cells (6) that are electrically connected in sequence.

3. The large-capacity battery according to claim 1, characterized in that: The width of the second connecting portion (32) gradually increases along its own length direction and close to the direction of connection with the first connecting portion (31).

4. The large-capacity battery according to claim 1, characterized in that: One of the two adjacent cover plate bodies is provided with a first step (120), and the other is provided with a second step (110) corresponding to the first step (120).

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