Battery cell and battery pack

Abstract

The utility model relates to the technical field of power batteries, and discloses a battery cell and a battery pack, and the battery comprises a shell, one side of which is provided with an opening; the cover plate is provided with a pair of pole columns, and a pair of through grooves are formed in the cover plate and located between the pair of pole columns; a pair of connecting sheets; the pole group is arranged in the shell and comprises two pole cores, a plurality of pole lugs are arranged on the upper sides of the pole cores, the pole lugs are folded towards the middle parts of the pole cores to form lug pieces, the lug pieces extend towards the direction of the through grooves and are bent towards the direction of the connecting pieces, the bent parts of the lug pieces abut against the upper surfaces of the connecting pieces, and the total height of the folded parts of the pole lugs and the bent parts of the lug pieces is H, 1.5 mm < = H < = 5mm; according to the utility model, the problems that the longitudinal space occupied by the tab connecting piece and the pole in the shell is relatively large, the structures of all parts are easy to interfere, and the assembly and the welding are hindered are solved.

Description

Technical Field

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

[0002] The power battery is the main power source of new energy vehicles and is responsible for providing continuous and stable electric energy for the vehicle. The power battery is composed of multiple battery cell units connected in series. Each battery cell structure includes a pole group inside and a housing. Positive and negative pole tabs are provided on the pole group for leading out the current of the pole group, and a pole post is provided on the housing. The pole post is connected to the corresponding pole tab through a connecting piece, thereby connecting the battery cell to the circuit.

[0003] In the related art, the pole tab led out from the pole group is arranged on the lower side of the pole post. A connecting piece is arranged on the lower side of the pole post. The connecting piece is arranged in a U shape with two parallel connecting parts. The two connecting parts of the connecting piece are arranged up and down relatively. One connecting part is connected to the bottom end of the pole post, and the other is connected to the pole tab, thereby realizing the connection between the pole post and the pole group.

[0004] However, in the above-mentioned related art, the sequential arrangement of the pole tab, the connecting piece and the pole post in the longitudinal direction occupies a relatively large internal space of the housing. At the same time, the structures of each part interfere with each other, causing certain obstacles to the bending of the pole tab and the welding of the pole tab and the connecting piece, and affecting the production efficiency. Summary of the Utility Model

[0005] In view of this, the utility model provides a battery cell and a battery pack to solve the problems that the pole tab connecting piece and the pole post occupy a relatively large longitudinal space in the housing, and the structures of each part are prone to interference, causing obstacles to assembly and welding.

[0006] In a first aspect, the utility model provides a battery cell, comprising: a housing with an opening on one side; a cover plate, the peripheral contour of which is adapted to the shape of the opening of the housing. A pair of pole posts are installed on the cover plate, and the pole posts penetrate through the cover plate. A pair of through slots are arranged between the pair of pole posts on the cover plate; a pair of connecting pieces, one end of each connecting piece is connected to the corresponding pole post, and the other end extends to the position of the corresponding through slot; a pole group, arranged in the housing, the pole group includes two pole cores. The connecting pieces are arranged in the middle of the width direction on the top sides of the two pole cores. A plurality of pole tabs are arranged on the upper sides of the pole cores. The plurality of pole tabs converge towards the middle of the pole core to form an ear piece. The ear piece extends towards the through slot and bends towards the connecting piece. The bent part of the ear piece abuts against the upper surface of the connecting piece. The total height of the converged part of the pole tab and the bent part of the ear piece is H, and 1.5 mm ≤ H ≤ 5 mm; a pair of sealing plates, the peripheral contours of which are respectively adapted to the corresponding through slots and are welded to the slot walls of the through slots.

[0007] Beneficial effects: The split assembly design of the housing and the cover plate facilitates the insertion of the electrode group into the housing. The cover plate is provided to close the top opening of the housing, achieving the limitation and protection of the electrode group. A through groove is opened on the cover plate, and the tab of the electrode group is led out from the position of the through groove, and the tabs are gathered to form an ear piece. After the battery is assembled, it is convenient for the staff to operate on the tabs. A connecting piece is arranged below the cover plate. One end of the connecting piece is located at the lower end of the corresponding electrode post and is connected to the electrode post, while the other end extends laterally to a position opposite to the through groove, facilitating connection with the ear piece, so that the staff can conveniently perform welding operations on the ear piece and the connecting piece through the position of the through groove. Finally, by installing a sealing plate at the through groove, the internal space of the housing is closed to protect structures such as the connecting piece and the tabs. Since the ear piece led out from the electrode group is arranged opposite to the corresponding through groove and is located laterally of the corresponding electrode post, when electrically connecting the tab to the electrode post, the connecting piece can be set into an approximately flat plate-like structure, thereby saving the longitudinal space inside the housing. In addition, since the connecting piece is set into an approximately flat plate-like structure, when the tab is connected to the connecting piece, the tab has more sufficient bending space, facilitating the control of the bending angle of the tab to improve the connection stability between the tab and the connecting piece, and also being able to further reduce the occupation of the longitudinal space inside the housing. In addition, by restricting the total height of the bent part of the ear piece, the utilization rate of the longitudinal space inside the housing is further improved. The entire battery cell structure greatly improves the utilization rate of the space inside the housing, which is equivalent to increasing the volume of the electrode group that can be arranged in the housing of the same volume, and can effectively improve the battery performance. At the same time, since the tabs, the connecting piece, and the electrode post are arranged in a staggered manner in the horizontal direction, each component is not prone to interference, reducing the difficulty of assembling and welding each component and improving the production efficiency.

[0008] In an optional embodiment, the height of the gathered part of the tab is h, and it satisfies 0.2 mm ≤ h ≤ 3.5 mm.

[0009] Beneficial effects: By controlling the height of the gathered part of the tab, the staff can compress the total height of the tab and the ear piece to improve the space utilization rate. At the same time, it can also ensure that the tab is fully compacted during the gathering process, improve the structural strength of the electrode group, and enhance the anti-disturbance ability of the tab and ear piece structures.

[0010] In an optional embodiment, the width of the electrode core is W. After the tab is gathered to the middle of the electrode core, the distance between the tab and the side wall of the electrode core away from the connecting piece is the offset W1, which satisfies 6 mm ≤ W ≤ 30 mm and 1 mm ≤ W1 ≤ 15 mm.

[0011] Beneficial effects: The thickness of the pole core is selected according to the required battery capacity. By controlling the convergence offset W1 of the pole ear, the staff can indirectly control the distance between the pole ear before bending and the connecting piece, avoiding the situation that the distance is too close, which makes it difficult to bend the pole ear or causes the pole ear to tear during the bending process. In addition, by controlling the maximum value of the convergence offset W1, it is possible to avoid the ear piece getting too close to the side of the pole core facing the connecting piece, thus minimizing the unevenness of each pole ear at the end of the ear piece. As a result, the end of the ear piece does not require die-cutting, saving costs and improving processing efficiency.

[0012] In an alternative embodiment, the offset W1 satisfies W1 ≤ 0.5W.

[0013] Beneficial effects: By setting the ratio of the offset W1 to the width W of the pole core, the unevenness of the end of the ear piece during the formation of the ear piece by converging the pole ear and during the bending of the ear piece is further reduced. The staff can adjust the convergence position of the pole ear away from the connecting piece according to the actual situation, thereby further keeping the end of the ear piece flush.

[0014] In an alternative embodiment, the thickness of the ear piece is t, and 0.1 mm ≤ t ≤ 2.5 mm.

[0015] Beneficial effects: By controlling the thickness of the ear piece, it is ensured that each pole ear forming the ear piece by convergence is compacted against each other to improve the welding quality between the ear piece and the connecting piece, reduce the possibility of the pole ear disintegrating when the ear piece is disturbed, and at the same time avoid the situation where the pole ear is overly compacted, resulting in a large internal stress on the pole ear during the bending process and increasing the risk of the pole ear tearing.

[0016] In an alternative embodiment, the angle at which the ear piece is bent towards the connecting piece is 90°, and the bend is a rounded corner, and the radius R of the rounded corner satisfies 0.1 mm ≤ R ≤ 3 mm.

[0017] Beneficial effects: By controlling the radius of the rounded corner at the bend of the ear piece, it is possible to avoid the situation where the required bending space for the pole ear is too large due to an overly large radius of the rounded corner, which affects the utilization rate of the space inside the housing, and at the same time avoid the situation where the pole ear tears after bending and the welding quality and power connection quality are affected when the radius is too small.

[0018] In an alternative embodiment, the minimum distance between the part of the ear piece before bending and the side wall of the connecting piece is a, and 0.2 mm ≤ a.

[0019] Beneficial effects: By ensuring that the distance between the connecting piece and the part of the ear piece before bending is greater than 0.2 mm, it is possible to avoid the pole ear being too close to the connecting piece, resulting in interference during the bending of the ear piece, which causes the ear piece to squeeze the ear piece and tear the pole ear, affecting the subsequent welding quality and connection quality.

[0020] In an alternative embodiment, a connection hole is provided at a position on the cover plate corresponding to the pole column. The pole column passes through the connection hole and is connected to the cover plate. A sealing ring and a first insulating plate are provided inside the connection hole. The sealing ring surrounds the circumference of the pole column. The first insulating plate extends in the direction of the through groove parallel to the plate surface of the cover plate and separates the connection piece from the cover plate.

[0021] Advantageous effects: By providing the sealing ring and the first insulating plate, with the sealing ring arranged around the pole column, the sealing performance at the connection hole is improved, preventing the leakage of the battery core liquid and the entry of external liquid into the battery core. At the same time, the pole column is separated from the cover plate to avoid short circuit. The first insulating plate is arranged on the upper side of the connection piece, separating the connection piece from the cover plate and the sealing plate, avoiding the short circuit between the connection piece and the cover plate and the sealing plate, preventing the leakage of electricity from the housing, and improving the reliability of the battery core.

[0022] In an alternative embodiment, a second insulating plate is provided on the side of the cover plate facing the inside of the housing. The second insulating plate is located between a pair of the through grooves and extends in the direction of the two through grooves and separates the connection piece from the cover plate.

[0023] Advantageous effects: By providing the second insulating plate at the position between the two through grooves on the cover plate, the part of the cover plate between the two through grooves is separated from the end of the connection piece extending towards the middle of the cover plate, enabling the connection piece to extend to the side of the through groove close to the middle of the cover plate. Thus, it has sufficient length without short circuiting with the cover plate, effectively preventing the leakage of electricity from the housing. In addition, since the connection piece has sufficient length, it also provides sufficient space for the connection between the connection piece and the ear piece, reducing the situation that the poor contact between the ear piece and the connection piece affects the performance of the battery core.

[0024] In a second aspect, the present utility model also provides a battery pack, comprising: a plurality of the above-mentioned battery cores.

[0025] Advantageous effects: The battery core group in the battery pack is composed of the above-mentioned battery cores, thereby improving the reliability of the battery pack and the production efficiency of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present utility model 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 utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is an overall schematic diagram of a battery core according to an embodiment of the present utility model;

[0028] Figure 2 Schematic diagram of the internal electrode group and tab structure of a battery cell housing according to an embodiment of the present utility model;

[0029] Figure 3 is Figure 2 a schematic diagram from another perspective;

[0030] Figure 4 is Figure 3 a schematic cross-sectional view taken along line A-A in

[0031] Figure 5 is Figure 4 an enlarged schematic view of B in

[0032] Figure 6 Schematic diagram of a battery cell according to an embodiment of the present utility model for showing the positional structure of various components inside the housing;

[0033] Figure 7 is Figure 6 an enlarged schematic view of C in

[0034] Figure 8 Schematic diagram of a battery cell according to an embodiment of the present utility model for showing the tab before bending.

[0035] Explanation of reference numerals:

[0036] 100, housing; 200, cover plate; 201, pole; 202, through groove; 203, connection hole; 300, connection piece; 400, electrode group; 401, electrode core; 402, tab; 500, sealing plate; 601, first insulating plate; 602, second insulating plate; 603, sealing ring. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0038] The following will describe the embodiments of the present utility model in conjunction with Figures 1 to 8 , the embodiments of the present utility model are described.

[0039] According to an embodiment of the present utility model, on the one hand, a battery cell is provided. Please refer to Figures 1 to 5, including a housing 100 with an opening on one side; a cover plate 200, the peripheral contour of which is adapted to the shape of the opening of the housing 100, a pair of pole columns 201 are installed on the cover plate 200, the pole columns 201 penetrate through the cover plate 200, and a pair of through grooves 202 are provided on the cover plate 200 between the pair of pole columns 201; a pair of connecting pieces 300, one end of each connecting piece 300 is connected to the corresponding pole column 201, and the other end extends to the position of the corresponding through groove 202; a pole group 400, arranged in the housing 100, the pole group 400 includes two pole cores 401, the connecting piece 300 is arranged in the middle of the top side width direction of the two pole cores 401, a plurality of pole ears are provided on the upper side of the pole core 401, the plurality of pole ears converge towards the middle of the pole core 401 to form an ear piece 402, the ear piece 402 extends towards the through groove 202 and bends towards the connecting piece 300, the bent part of the ear piece 402 abuts against the upper surface of the connecting piece 300, the total height of the converged part of the pole ears and the bent part of the ear piece 402 is H, and 1.5mm ≤ H ≤ 5mm is satisfied; a pair of sealing plates 500, the peripheral contours of which are respectively adapted to the corresponding through grooves 202 and are welded to the groove walls of the through grooves 202.

[0040] In this embodiment, the housing 100 and the cover plate 200 are designed to be assembled separately, so that the electrode group 400 can be easily loaded into the housing 100. The cover plate 200 is used to close the top opening of the housing 100 to limit and protect the electrode group 400. A through slot 202 is provided on the cover plate 200, and the pole ear of the electrode group 400 is led out from the through slot 202, and the pole ear is gathered to form an ear piece 402, so that the staff can operate the pole ear easily after the battery is assembled. A connecting piece 300 is arranged below the cover plate 200. One end of the connecting piece 300 is located at the lower end of the corresponding pole 201 and connected to the pole 201, and the other end extends laterally to a position opposite to the through slot 202, so as to be connected to the ear piece 402. The staff can conveniently perform welding operations on the ear piece 402 and the connecting piece 300 through the through slot 202. Finally, the sealing plate 500 is installed at the through slot 202 to close the internal space of the housing 100, so as to protect the connecting piece 300, the pole ear and other structures. Because the ear piece 402 led out from the pole group 400 is arranged opposite to the corresponding through slot 202 and is located at the corresponding pole 2 01, when the pole ear is electrically connected to the pole column 201, the connecting piece 300 can be set to a structure similar to a flat plate, thereby saving the longitudinal space in the housing 100. In addition, since the connecting piece 300 is set to a structure similar to a flat plate, when the pole ear is connected to the connecting piece 300, the pole ear has more sufficient bending space, which is convenient for controlling the bending angle of the pole ear, thereby improving the connection stability of the pole ear and the connecting piece 300, and can further reduce the occupation of the longitudinal space in the housing 100. In addition, by limiting the total height of the bent part of the ear piece 402, the utilization rate of the longitudinal space in the housing 100 is further improved. The entire battery cell structure greatly improves the space utilization rate in the housing 100, which is equivalent to increasing the volume of the pole group 400 that can be set in the housing 100 of the same volume, which can effectively improve the battery performance. At the same time, since the pole ear, the connecting piece 300 and the pole column 201 are staggered in the horizontal direction, the components are not easy to interfere with each other, which reduces the difficulty of assembling and welding the components and improves the production efficiency.

[0041] In the above embodiment, specifically, a pair of poles 201 are disposed at both ends of the length direction of the cover plate 200, and are respectively connected to the positive electrode and the negative electrode of the pole group 400, and a pair of through slots 202 are located between the two poles 201, and are correspondingly disposed on one side of the corresponding pole 201 toward the middle of the cover plate 200. The connecting piece 300 is configured to be a sheet-like sheet that is approximately flat, and the connecting piece 300 includes a pole connecting portion and an ear connecting portion that are connected to each other, and the pole connecting portion and the ear connecting portion may be integrally disposed, or may be separately disposed and connected to form a whole by welding or the like, wherein the pole connecting portion is located at the lower end of the pole 201 and is welded to the pole 201, and the ear 402 connecting portion extends to the through slot 202 adjacent to the pole 201.

[0042] In addition, specifically, the pole core 401 is composed of multiple layers of stacked pole sheets, and pole ears are led out from the upper side of the pole sheets. The pole ears are gathered and concentrated toward the middle of the width direction of the pole core 401, and are stacked together to form ear pieces 402. The ear pieces 402 are connected to the connecting pieces 300 to achieve electrical connection between the pole core 401 and the connecting pieces 300.

[0043] In one embodiment, see Figures 1 to 5 The height of the gathered part of the tab is h, and satisfies 0.2mm≤h≤3.5mm.

[0044] Specifically, the gathered portion of the pole ear refers to the distance in the height direction of the pole core 401 from the position where the pole ear is led out from the upper side of the pole core 401 to the position where it is gathered to form the ear piece 402. It can also be understood as the distance between the lower side of the ear piece 402 and the upper side of the pole core 401 in the height direction of the pole core 401.

[0045] In this embodiment, the staff can control the height of the retracted part of the pole ear to compress the total height of the pole ear and the ear piece 402, thereby improving the space utilization rate. At the same time, it can also ensure that the pole ear is fully compacted during the retracting process, thereby improving the structural strength of the pole group 400 and improving the anti-disturbance ability of the pole ear and the ear piece 402 structure.

[0046] In one embodiment, see Figures 1 to 5 The width of the pole core 401 is W. After the pole ear is gathered to the middle of the pole core 401, the distance between the pole ear and the side wall of the pole core 401 away from the connecting piece 300 is the offset distance W1, which satisfies 6mm≤W≤30mm and 1mm≤W1≤15mm.

[0047] It should be noted that the width of the pole core 401 is the total thickness of the multiple layers of pole pieces constituting the pole core 401 and the tapes for fixing the pole pieces.

[0048] In this embodiment, the thickness of the pole core is selected according to the required battery capacity, and the staff can indirectly control the distance between the ear 402 and the connecting plate 300 before bending by controlling the closing offset W1 of the pole ear, so as to avoid the difficulty of bending the pole ear due to the close distance, or the pole ear tearing during the bending process. In addition, by controlling the maximum value of the closing offset W1, the ear 402 is prevented from being too close to the side of the pole core 401 facing the connecting plate 300, so as to minimize the unevenness of the pole ears at the end of the ear 402, so that the end of the ear 402 does not need to undergo a die-cutting process, saving costs and improving processing efficiency.

[0049] In one embodiment, see Figures 1 to 5 , the offset W1 satisfies W1≤0.5W.

[0050] In the present embodiment, it should be noted that since the ear piece 402 is formed by stacking a plurality of pole ears, the pole ears have substantially the same length before they are gathered together to form the ear piece 402. During the gathering process, due to the different distances between the positions of different ear pieces 402, after the ear piece 402 is gathered together, the distances between the ends of the ear piece 402 are different. Furthermore, since the ear piece 402 is bent toward the connecting piece 300, the bending may also cause slight misalignment of the multi-layer pole ears of the ear piece 402. The staff may adjust the position of the ear piece 402 formed by the gathering, combined with the angle and direction of the bending of the ear piece 402, so as to keep the end of the bent ear piece 402 as flush as possible. The present embodiment guides and restricts the staff in adjusting the position of the ear piece 402 by adjusting the proportional relationship between W1 and W.

[0051] In this embodiment, by making the ratio of the offset W1 to the width W of the pole core 401, it is further explained that when the pole ear is gathered to form the ear piece 402, and during the bending process of the ear piece 402, the end of the ear piece 402 becomes uneven. The staff can adjust the gathering position of the pole ear in the direction away from the connecting piece 300 according to the actual situation, so as to further keep the end of the ear piece 402 flush.

[0052] In one embodiment, see Figures 1 to 5 , the thickness of the ear piece 402 is t, and satisfies 0.1mm≤t≤2.5mm.

[0053] In this embodiment, by controlling the thickness of the ear piece 402, it is ensured that the various ears that are gathered to form the ear piece 402 are compacted against each other to improve the welding quality between the ear piece 402 and the connecting piece 300, thereby reducing the possibility of the ear piece 402 disintegrating when the ear piece 402 is disturbed. At the same time, it also avoids excessive compaction of the ear piece, which results in greater internal stress on the ear piece during the bending process, leading to the risk of the ear piece tearing.

[0054] In one embodiment, see Figures 1 to 5 The ear piece 402 is bent toward the connecting piece 300 at an angle of 90°, and the bending position is rounded, and the radius R of the rounded corner satisfies 0.1mm≤R≤3mm.

[0055] In this embodiment, by controlling the radius of the fillet at the bending point of the ear piece 402, it is possible to avoid the situation where the fillet radius is too large, resulting in a large bending space required for the pole ear, affecting the space utilization rate in the shell 100. At the same time, it is also possible to avoid the situation where the radius is too small, resulting in the pole ear tearing after bending, affecting the welding quality and the power connection quality.

[0056] In one embodiment, see Figures 1 to 5 The minimum distance between the portion of the ear piece 402 before being bent and the side wall of the connecting piece 300 is a, and satisfies 0.2 mm ≤ a.

[0057] In this embodiment, by ensuring that the distance between the connecting piece 300 and the part of the lug 402 before bending is greater than 0.2 mm, the pole ear and the connecting piece 300 are prevented from being too close, and interference occurs during the bending of the lug 402, resulting in the pole ear being squeezed by the lug 402 and the pole ear being torn, affecting the subsequent welding quality and the node quality.

[0058] In one embodiment, please refer to Figures 6 to 8 , a connection hole 203 is provided at a position on the cover plate 200 corresponding to the pole post 201. The pole post 201 passes through the connection hole 203 and is connected to the cover plate 200. A sealing ring 603 and a first insulating plate 601 are provided inside the connection hole 203. The sealing ring 603 surrounds the circumference of the pole post 201. The first insulating plate 601 extends in the direction of the through groove 202 parallel to the plate surface of the cover plate 200, and separates the connecting piece 300 from the cover plate 200.

[0059] In this embodiment, by providing the sealing ring 603 and the first insulating plate 601, the sealing ring 603 is arranged around the pole post 201, improving the sealing performance at the connection hole 203, preventing the leakage of the battery core liquid and the entry of external liquid into the battery core. At the same time, the pole post 201 is separated from the cover plate 200 to prevent short circuit. The first insulating plate 601 is arranged on the upper side of the connecting piece 300, separating the connecting piece 300 from the cover plate 200 and the sealing plate 500, preventing the connecting piece 300 from being short-circuited with the cover plate 200 and the sealing plate 500, resulting in the leakage of the housing 100, and improving the reliability of the battery core.

[0060] In one embodiment, please refer to Figures 6 to 8 , a second insulating plate 602 is provided on the side of the cover plate 200 facing the inside of the housing 100. The second insulating plate 602 is located between a pair of through grooves 202. The second insulating plate 602 extends in the direction of the two through grooves 202 and separates the connecting piece 300 from the cover plate 200.

[0061] In this embodiment, by providing the second insulating plate 602 located at the position between the two through grooves 202 on the cover plate 200, the part of the cover plate 200 between the two through grooves 202 is separated from the end of the connecting piece 300 extending towards the middle of the cover plate 200, enabling the connecting piece 300 to extend to the side of the through groove 202 close to the middle of the cover plate 200. Thus, while having sufficient length, it will not be short-circuited with the cover plate 200, effectively preventing the leakage of the housing 100. In addition, since the connecting piece 300 has sufficient length, it also provides sufficient space for the connection between the connecting piece 300 and the lug 402, reducing the situation that the contact between the lug 402 and the connecting piece 300 is poor and affecting the performance of the battery core.

[0062] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including a plurality of the above-mentioned battery cores.

[0063] In this embodiment, the battery cell group in the battery pack is composed of the above-mentioned battery cells, thereby improving the reliability of the battery pack and the production efficiency of the battery pack.

[0064] In addition, specifically, in some of the above embodiments, a liquid injection hole is provided on the cover plate 200. The liquid injection hole is located between the two through grooves 202 and is used to inject liquid electrolyte to infiltrate the battery cells and improve the performance of the battery cells.

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

Claims

1. A battery cell, characterized in that, Comprising: A housing having an opening on one side; A cover plate, the peripheral contour of which is adapted to the shape of the opening of the housing. A pair of pole columns are installed on the cover plate, the pole columns penetrate through the cover plate, and a pair of through grooves are provided on the cover plate between the pair of pole columns; A pair of connecting pieces, one end of each connecting piece is connected to the corresponding pole column, and the other end extends to the position of the corresponding through groove; A pole group is arranged in the housing. The pole group includes two pole cores. The connecting pieces are arranged in the middle of the width direction on the top sides of the two pole cores. A plurality of pole tabs are provided on the upper sides of the pole cores. The plurality of pole tabs converge towards the middle of the pole core to form ear pieces. The ear pieces extend towards the through grooves and bend towards the connecting pieces. The bent part of the ear piece abuts against the upper surface of the connecting piece. The total height of the converged part of the pole tabs and the bent part of the ear piece is H, and 1.5 mm ≤ H ≤ 5 mm is satisfied; A pair of sealing plates, the peripheral contours of which are respectively adapted to the corresponding through grooves and are welded to the groove walls of the through grooves.

2. The battery cell according to claim 1, wherein The height of the converged part of the pole tabs is h, and 0.2 mm ≤ h ≤ 3.5 mm is satisfied.

3. The battery cell according to claim 1, wherein The width of the pole core is W. After the pole tabs converge to the middle of the pole core, the distance between the pole core and the side wall on the side away from the connecting piece is the offset W1, and 6 mm ≤ W ≤ 30 mm and 1 mm ≤ W1 ≤ 15 mm are satisfied.

4. The battery cell according to claim 3, wherein The offset W1 satisfies W1 ≤ 0.5W.

5. The battery cell according to claim 1, characterized in that, The thickness of the ear piece is t, and 0.1 mm ≤ t ≤ 2.5 mm is satisfied.

6. The battery cell according to claim 1, wherein, The angle at which the ear piece bends towards the connecting piece is 90°, and the bent part is a rounded corner. The radius R of the rounded corner satisfies 0.1 mm ≤ R ≤ 3 mm.

7. The battery cell according to claim 1, characterized in that The minimum distance between the part of the ear piece before bending and the side wall of the connecting piece is a, and 0.2 mm ≤ a is satisfied.

8. The battery cell according to any one of claims 1 to 7, characterized in that, At the position on the cover plate corresponding to the pole column, a connection hole is provided. The pole column passes through the connection hole and is connected to the cover plate. A sealing ring and a first insulating plate are provided inside the connection hole. The sealing ring surrounds the periphery of the pole column. The first insulating plate extends in the direction of the through groove parallel to the plane of the cover plate and separates the connecting piece from the cover plate.

9. The battery cell according to claim 8, wherein, On the side of the cover plate facing the inside of the housing, a second insulating plate is provided. The second insulating plate is located between the pair of through grooves. The second insulating plate extends in the direction of the two through grooves and separates the connecting piece from the cover plate.

10. A battery pack, characterized in that, Comprising: A plurality of battery cells as described in any one of claims 1 to 9.

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