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, the battery cell comprises a shell, a pair of pole columns are arranged on the shell, and a pair of through grooves are formed in the shell and positioned between the pair of pole columns; one end of each connecting piece is connected with the corresponding pole, and the other end of each connecting piece extends to the position of the corresponding through groove; the pole group is arranged in the shell, the pole group comprises two pole cores, the connecting piece is arranged in the middle of the width direction of the top sides of the two pole cores, a plurality of pole lugs are arranged on the upper sides of the pole cores, the plurality of pole lugs are folded towards the middle parts of the pole cores to form lug pieces, the lug pieces are bent towards the direction of the connecting piece, the total height H of the folded parts of the pole lugs and the bent parts of the lug pieces is greater than or equal to 1.5 mm and less than or equal to 5mm, and H is greater than or equal to 1.5 mm and less than or equal to 5mm. The thickness of the lug is t, and t is more than or equal to 0.1 mm and less than or equal to 2.5 mm; according to the utility model, the problems that the connection structure of the pole lug and the pole column occupies a large longitudinal space of the shell, and the performance of the battery cell is influenced are solved.

Description

Technical Field

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

[0002] Power batteries are the main power source for new energy vehicles, responsible for providing continuous and stable electric energy for vehicles. Power batteries are composed of multiple connected battery cells, each of which includes an internal pole group and a shell. The pole group is provided with positive and negative pole ears for drawing out the current of the pole group, and the shell is provided with poles, which are connected to the corresponding pole ears through connecting sheets, thereby connecting the battery cell to the circuit.

[0003] In the related art, the pole group is composed of at least one pole core. The pole ears of the pole core are led out and gathered together to form ear pieces. After the ear pieces are bent, they are connected to the lower parallel plate of the U-shaped connecting piece on the upper side, and then connected to the pole column by the upper parallel plate of the connecting piece, thereby realizing the connection between the pole ears and the pole column.

[0004] However, in the above-mentioned related technologies, since the connecting piece is U-shaped and arranged on the upper side of the pole ear, the bending space after the pole ear is folded to form the ear is very limited. After bending, the pole ear and the formed ear are relatively high. In addition, since the connecting piece is U-shaped, the structure connecting the entire pole ear and the pole column occupies a large amount of longitudinal space in the shell, affecting the space utilization rate in the shell, thereby resulting in a reduction in the space and volume that can be set for the pole core, affecting the performance of the battery cell. Utility Model Content

[0005] In view of this, the utility model provides a battery cell and a battery pack to solve the problem that the structure for connecting the pole tabs and poles occupies a large longitudinal space of the shell and affects the performance of the battery cell.

[0006] In the first aspect, the utility model provides a battery cell, comprising: a shell, a pair of poles are installed on the top wall of the shell, the poles penetrate the top wall of the shell, and a pair of through slots are provided on the shell between the pair of poles; a pair of connecting pieces are provided on the inner side of the shell, one end of each connecting piece is connected to the corresponding pole, and the other end extends to the corresponding through slot position; a pole group is provided in the shell, the pole group includes two pole cores, the connecting piece is provided in the middle of the width direction of the top side of the two pole cores, and the pole A plurality of pole ears are provided on the upper side of the core, and the plurality of pole ears are gathered toward the middle of the pole core to form an ear piece, and the ear piece extends toward the through slot and is bent toward the connecting piece, and the bent portion of the ear piece abuts against the upper surface of the connecting piece, and the total height of the gathered portion of the pole ear and the bent portion of the ear piece is H, and satisfies 1.5mm≤H≤5mm, and the thickness of the ear piece is t, and satisfies 0.1mm≤t≤2.5mm; a pair of sealing plates, whose circumferential side contours are respectively adapted to the corresponding through slots, and are welded to the slot walls of the through slots.

[0007] Beneficial effects: By setting the shell and the pole in an integrated manner, a welding process of the cover plate is reduced during the assembly process compared to the method of setting the cover plate, making the assembly operation faster, and making the integrity of the upper structure of the battery cell better and having higher pressure resistance. A through groove is provided on the top wall of the shell, so that the pole ear of the pole group is led out from the through groove position, and the pole ear is gathered to form an ear piece, which is convenient for the staff to operate the pole ear after the battery is assembled. A connecting piece is arranged on the inner surface of the top wall of the shell, one end of the connecting piece is located at the lower end of the corresponding pole and connected to the pole, and the other end extends laterally to a position opposite to the through slot, so as to be connected to the ear piece, so that the staff can conveniently perform welding operations on the ear piece and the connecting piece through the through slot position, and finally, a sealing plate is installed at the through slot to close the internal space of the shell, so as to protect the connecting piece, the pole ear and other structures, because the ear piece led out from the pole group is arranged opposite to the corresponding through slot and is located on the side of the corresponding pole, when the ear piece is electrically connected to the pole, the connecting piece can be arranged into a structure approximately in the shape of a plate, thereby saving the longitudinal space in the shell, and in addition, because the connecting piece is arranged into a structure approximately in the shape of a plate, when the pole ear is connected to the connecting piece, the ear piece has more sufficient bending space, which is convenient for controlling the bending angle of the ear piece, thereby improving the connection stability between the ear piece and the connecting piece, and can also further reduce the occupation of the longitudinal space in the shell. In addition, by limiting the thickness t of the ear piece, it is ensured that the various pole ears that are gathered to form the ear piece are compacted with each other to improve the welding quality of the ear piece and the connecting piece, reduce the possibility of the pole ear disintegrating when the ear piece is disturbed, and also avoid the excessive compaction of the pole ear, resulting in a large internal stress on the pole ear during the bending process, resulting in the risk of the pole ear tearing. At the same time, limiting the thickness of the ear piece is also convenient for controlling the total height H of the gathered part of the pole ear and the bent ear piece, further improving the utilization rate of the longitudinal space in the shell. The entire battery cell structure greatly improves the space utilization rate in the shell, which is equivalent to increasing the volume of the pole group that can be set in the shell of the same volume, which can effectively improve the battery performance. In addition, since the pole ears, connecting pieces and poles 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 production efficiency.

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

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

[0010] In an alternative embodiment, the width of the electrode core is W, and 6 mm ≤ W ≤ 30 mm is satisfied.

[0011] Advantageous effects: The thickness of the electrode core is selected according to the required battery capacity. By restricting the range of the width of the electrode core, during the process of the tabs of the electrode core being folded to form ear pieces, it is avoided that due to the excessive difference in the distances between the tabs at the edge and the middle part of the electrode core and the ear pieces, the flatness of the end face of the ear piece is relatively low and the possibility of subsequent welding between the ear piece and the connecting piece is affected, or it is avoided that the flatness of the end face of the ear piece is too poor and an additional ear piece die-cutting process is required to improve the flatness of the end face of the ear piece.

[0012] In an alternative embodiment, the distance between the unbent part of the ear piece and the side wall of the electrode core on the side away from the connecting piece is the offset W1, and W1 ≤ 0.5W, 1 mm ≤ W1 ≤ 15 mm is satisfied.

[0013] Advantageous effects: By controlling the folding offset W1 of the tabs, the staff can indirectly control the distance between the ear piece before bending and the connecting piece, avoiding the situation that the tabs are too close and difficult to bend, or the tabs are torn during the bending process. In addition, by controlling the maximum value of the folding offset W1, it is avoided that the ear piece is too close to the side of the electrode core facing the connecting piece, so that the situation that the tabs at the end of the ear piece are uneven can be avoided as much as possible. In addition, by making the ratio of the offset W1 to the width W of the electrode core, the situation that the tabs are uneven during the process of the tabs being folded to form the ear piece and during the bending process of the ear piece is further reduced. The staff can adjust the folding position of the tabs away from the connecting piece according to the actual situation, so as to further keep the end of the ear piece flat. Thus, the end of the ear piece does not need to go through the die-cutting process, saving costs and improving processing efficiency.

[0014] In an alternative embodiment, the bending angle of the ear piece towards the connecting piece is 90°, and the bending part is a rounded corner, and the radius R of the rounded corner satisfies 0.1 mm ≤ R ≤ 3 mm.

[0015] Advantageous effects: By controlling the radius of the rounded corner at the bending part of the ear piece, it is avoided that when the radius of the rounded corner is too large, the required bending space for the tabs is large, affecting the space utilization rate inside the housing, and at the same time, when the radius is too small, the tabs are torn after bending, affecting the welding quality and the power connection quality.

[0016] 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 is satisfied.

[0017] Beneficial effects: By ensuring that the distance between the connecting piece and the part of the lug before bending is greater than 0.2 mm, the pole ear and the connecting piece are prevented from being too close, and interference occurs during the bending process of the lug, resulting in the pole ear squeezing the pole ear and tearing the pole ear, which affects the subsequent welding quality and the quality of the node.

[0018] In an alternative embodiment, a connection hole is provided at a position on the top wall of the housing corresponding to the pole column. The pole column passes through the connection hole and is connected to the housing. 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 inner surface of the top wall of the housing and separates the connecting piece from the inner surface of the top wall of the housing.

[0019] Beneficial effects: By providing a sealing ring and a first insulating plate, the sealing ring is arranged around the pole column, improving the sealing performance at the connection hole, 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 inner surface of the top wall of the housing to avoid short circuit. The first insulating plate is arranged above the connecting piece, separating the connecting piece from the inner surface of the top wall of the housing and the sealing plate, avoiding short circuit between the connecting piece and the inner surface of the top wall of the housing and the sealing plate, resulting in the leakage of the housing, and improving the reliability of the battery core.

[0020] In an alternative embodiment, a second insulating plate is provided on the inner surface of the top wall of the housing. The second insulating plate is located between a pair of the through grooves. The second insulating plate extends in the direction of the two through grooves and separates the connecting piece from the inner surface of the top wall of the housing.

[0021] Beneficial effects: By providing a second insulating plate at a position between the two through grooves on the inner surface of the top wall of the housing, the part of the inner surface of the top wall of the housing between the two through grooves is separated from the end of the connecting piece extending to the middle of the inner surface of the top wall of the housing, enabling the connecting piece to extend to one side of the through groove close to the middle of the inner surface of the top wall of the housing, so that it has sufficient length without short circuiting with the inner surface of the top wall of the housing, effectively avoiding the situation of housing leakage. In addition, since the connecting piece has sufficient length, it also provides sufficient space for the connection between the connecting piece and the lug, reducing the situation that the contact between the lug and the connecting piece is poor and affects the performance of the battery core.

[0022] In an alternative embodiment, an explosion-proof valve is provided on the top wall of the housing. The explosion-proof valve is arranged between the two through grooves.

[0023] Beneficial effects: The explosion-proof valve is used to release the internal pressure of the battery core when the battery core is out of control thermally, preventing the battery from exploding.

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

[0025] Beneficial effects: 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 enhancing the production efficiency of the battery pack. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

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

[0028] Figure 2 It is a schematic structural diagram of the internal electrode group of a battery cell according to an embodiment of the present invention;

[0029] Figure 3 It is Figure 2 a schematic diagram of another perspective in

[0030] Figure 4 It is Figure 3 a schematic cross-sectional structure diagram at A-A in

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

[0032] Figure 6 It is a schematic cross-sectional structure diagram of a battery cell according to an embodiment of the present invention for showing the internal structure;

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

[0034] Figure 8 It is a schematic diagram of a battery cell according to an embodiment of the present invention for showing the state before the tab is bent.

[0035] Description of the reference numerals:

[0036] 100, housing; 101, pole; 102, through groove; 103, connection hole; 200, connection piece; 300, electrode group; 301, electrode core; 302, tab; 400, sealing plate; 501, sealing ring; 502, first insulating plate; 503, second insulating plate; 600, explosion-proof valve. Specific Embodiments

[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. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model 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 will be 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, a pair of pole columns 101 are installed on the top wall of the housing 100, the pole columns 101 penetrate through the top wall of the housing 100, and a pair of through slots 102 are provided on the housing 100 between the pair of pole columns 101; a pair of connecting pieces 200 are arranged inside the housing 100, one end of each connecting piece 200 is connected to the corresponding pole column 101, and the other end extends to the position of the corresponding through slot 102; a pole group 300 is arranged inside the housing 100, the pole group 300 includes two pole cores 301, the connecting pieces 200 are arranged in the middle of the top side width direction of the two pole cores 301, a plurality of pole tabs are provided on the upper side of the pole core 301, the plurality of pole tabs converge towards the middle of the pole core 301 to form an ear piece 302, the ear piece 302 extends towards the through slot 102 and bends towards the connecting piece 200, the bent part of the ear piece 302 abuts against the upper surface of the connecting piece 200, the total height of the converged part of the pole tabs and the bent part of the ear piece 302 is H, and 1.5 mm ≤ H ≤ 5 mm is satisfied, the thickness of the ear piece 302 is t, and 0.1 mm ≤ t ≤ 2.5 mm is satisfied; a pair of sealing plates 400, the peripheral contours of which are respectively adapted to the corresponding through slots 102 and are welded to the slot walls of the through slots 102.

[0040] In this embodiment, the housing 100 and the pole 101 are integrally arranged, and a welding process of the cover plate is reduced during the assembly process compared to the method of setting the cover plate, so that the assembly operation is faster, and the integrity of the upper structure of the battery cell is better, and it has a higher pressure resistance. A through groove 102 is provided on the top wall of the housing 100, so that the pole ear of the pole group 300 is led out from the position of the through groove 102, and the pole ear is gathered to form an ear piece 302, which is convenient for the staff to operate the pole ear after the battery is assembled. A connecting piece 200 is provided on the inner surface of the top wall of the housing 100. One end of the connecting piece 200 is located at the lower end of the corresponding pole 101 and connected to the pole 101, and the other end extends laterally to a position opposite to the through slot 102, so as to be connected to the ear piece 302. The staff can conveniently perform welding operation on the ear piece 302 and the connecting piece 200 through the through slot 102. Finally, a sealing plate 400 is installed at the through slot 102 to close the internal space of the housing 100 and protect the connecting piece 200, the pole ear and other structures. Because the ear piece 302 led out from the pole group 300 is connected to the corresponding The through slots 102 are arranged opposite to each other and are located on the side of the corresponding pole 101. When the ear piece 302 is electrically connected to the pole 101, the connecting piece 200 can be arranged into a structure approximately in the shape of a plate, thereby saving the longitudinal space in the shell 100. In addition, since the connecting piece 200 is arranged into a structure approximately in the shape of a plate, when the pole ear is connected to the connecting piece 200, the ear piece 302 has more sufficient bending space, which makes it easy to control the bending angle of the ear piece 302, thereby improving the connection stability between the ear piece 302 and the connecting piece 200, and can also further reduce the occupation of the longitudinal space in the shell 100. In addition, by limiting the thickness t of the ear piece 302, it is ensured that the various pole ears that are gathered to form the ear piece 302 are compacted to improve the welding quality of the ear piece 302 and the connecting piece 200, and reduce the possibility of the pole ear disintegrating when the ear piece 302 is disturbed. At the same time, it also avoids the excessive compaction of the pole ear, resulting in a large internal stress on the pole ear during the bending process, resulting in the risk of the pole ear tearing. At the same time, limiting the thickness of the ear piece 302 is also convenient for controlling the total height H of the gathered part of the pole ear and the bent ear piece 302, further improving the utilization rate of the longitudinal space in the housing 100. 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 300 that can be set in the housing 100 of the same volume, which can effectively improve the battery performance. In addition, due to the horizontal dislocation of the pole ear, the connecting piece 200 and the pole 101, the components are not easy to interfere with each other, which reduces the difficulty of assembling and welding of the components and improves the production efficiency.

[0041] In the above embodiments, specifically, a pair of pole columns 201 are respectively arranged at two ends of the top wall of the housing 100 in the length direction, and are respectively connected to the positive and negative electrodes of the pole group 300. A pair of through grooves 202 are located between the two pole columns 201, and are respectively arranged on one side of the corresponding pole column 201 facing the middle of the top wall of the housing 100. The connecting piece 200 is arranged in a sheet shape similar to a flat plate, and the connecting piece 200 includes a pole column connecting portion and an ear piece connecting portion which are connected to each other. The pole column connecting portion and the ear piece connecting portion can be integrally arranged, or can be separately arranged and connected into a whole by welding or other means. Among them, the pole column connecting portion is located at the lower end of the pole column 201 and is welded to the pole column 201, and the ear piece connecting portion extends to the through groove 202 adjacent to the pole column 201.

[0042] In addition, specifically, the pole core 401 is composed of multiple layers of pole pieces stacked together, and pole tabs are led out from the upper side of the pole pieces. The pole tabs converge and concentrate towards the middle of the width direction of the pole core 401, and are stacked together to form an ear piece 402. The ear piece 402 is connected to the connecting piece 200 to realize the power connection between the pole core 401 and the connecting piece 200.

[0043] In one embodiment, please refer to Figures 1 to 5 , the height of the converged part of the pole tab is h, and it satisfies 0.2 mm ≤ h ≤ 3.5 mm.

[0044] Specifically, the converged part of the pole tab refers to the distance in the height direction of the pole core 301 from the position where the pole tab is led out from the upper side of the pole core 301 to the position where the ear piece 302 is formed after convergence, or it can also be understood as the distance between the lower side of the ear piece 302 and the upper side of the pole core 301 in the height direction of the pole core 301.

[0045] In this embodiment, by controlling the height of the converged part of the pole tab, the total height of the pole tab and the ear piece 302 can be compressed to improve the space utilization rate. At the same time, it can also ensure that the pole tab is fully compacted during the convergence process, improve the structural strength of the pole group 300, and improve the anti-disturbance ability of the structures of the pole tab and the ear piece 302.

[0046] In one embodiment, please refer to Figures 1 to 5 , the width of the pole core 301 is W, and it satisfies 6 mm ≤ W ≤ 30 mm.

[0047] It should be noted that the width of the pole core 301 is the total thickness of the multiple layers of pole pieces, diaphragms, packaging films, tapes, etc. that make up the pole core 301.

[0048] In this embodiment, the thickness of the pole core is selected according to the required battery capacity. By limiting the range of the width of the pole core 301, when the pole ears of the pole core 301 are gathered to form the ear pieces 302, it is avoided that the end face of the ear piece 302 has a low degree of flatness due to the large difference in distance between the pole ears at the edge and the middle part of the pole core 301 and the ear piece 302, which affects the subsequent welding of the ear piece 302 with the connecting piece 200. Or it is avoided that the end face of the ear piece 302 has a poor degree of flatness, and an additional die-cutting process of the ear piece 302 is required to improve the flatness of the end face of the ear piece 302.

[0049] In one embodiment, see Figures 1 to 5 The distance between the unbent portion of the ear piece 302 and the side wall of the pole core 301 away from the connecting piece 200 is an offset distance W1, and satisfies W1≤0.5W, 1mm≤W1≤15mm.

[0050] It should be noted that since the ear 302 is formed by stacking multiple ears, the ears have basically the same length before they are gathered together to form the ear 302. During the gathering process, due to the different distances between the positions of different ear pieces 302, after they are gathered to the position of the ear piece 302, the distances between the ends of the ear piece 302 are different. In addition, since the ear piece 302 is bent toward the connecting piece 200, the bending may also cause slight misalignment of the multi-layer ears of the ear piece 302. The staff can adjust the position of the ear piece 302 formed by gathering, combined with the angle and direction of the bending of the ear piece 302, so as to keep the end of the bent ear piece 302 as flat as possible. This embodiment guides and restricts the staff in adjusting the position of the ear piece 302 by adjusting the proportional relationship between W1 and W.

[0051] In this embodiment, please refer to Figures 1 to 5 By controlling the closing offset W1 of the pole ear, the staff can indirectly control the distance between the ear piece 302 and the connecting piece 200 before bending, so as to avoid the difficulty of bending the pole ear due to the distance being too close, or the pole ear tearing during the bending process. In addition, by controlling the maximum value of the closing offset W1, the ear piece 302 is prevented from being too close to the side of the pole core 301 facing the connecting piece 200, so as to avoid the unevenness of the pole ears at the end of the ear piece 302 as much as possible. In addition, by making the ratio of the offset W1 to the width W of the pole core 301, the unevenness of the end of the ear piece 302 during the process of the pole ear closing to form the ear piece 302 and the process of the ear piece 302 bending is further reduced. The staff can adjust the closing position of the pole ear in the direction away from the connecting piece 200 according to the actual situation, so as to further keep the end of the ear piece 302 flush. As a result, the end of the ear piece 302 does not need to go through the die-cutting process, saving costs and improving processing efficiency.

[0052] In one embodiment, see Figures 1 to 5, the lug 302 is bent at a 90° angle towards the connecting piece 200, and the bent part is a rounded corner with a radius R of the rounded corner satisfying 0.1 mm ≤ R ≤ 3 mm.

[0053] In this embodiment, by controlling the radius of the rounded corner at the bent part of the lug 302, it is possible to avoid a situation where the required bending space for the tab is too large due to an overly large radius of the rounded corner, which affects the space utilization rate inside the housing 100. At the same time, it also avoids the situation where the tab tears after bending when the radius is too small, which affects the welding quality and the power connection quality.

[0054] In one embodiment, please refer to Figures 1 to 5 , the minimum distance between the part of the lug 302 before bending and the side wall of the connecting piece 200 is a, and it satisfies 0.2 mm ≤ a.

[0055] In this embodiment, by ensuring that the distance between the connecting piece 200 and the part of the lug 302 before bending is greater than 0.2 mm, it is possible to avoid the tab being too close to the connecting piece 200 and interference occurring during the process of bending the lug 302, which may cause the tab to squeeze the tab and tear the tab, affecting the subsequent welding quality and the joint quality.

[0056] In one embodiment, please refer to Figures 6 to 8 , at the position on the top wall of the housing 100 corresponding to the pole 101, a connection hole 103 is provided. The pole 101 passes through the connection hole 103 and is connected to the housing 100. Inside the connection hole 103, a sealing ring 501 and a first insulating plate 502 are provided. The sealing ring 501 surrounds the circumference of the pole 101. The first insulating plate 502 extends in the direction of the through groove 102 parallel to the inner surface of the top wall of the housing 100, and separates the connecting piece 200 from the inner surface of the top wall of the housing 100.

[0057] In this embodiment, by providing the sealing ring 501 and the first insulating plate 502, with the sealing ring 501 arranged around the pole 101, the sealing performance at the connection hole 103 is improved, avoiding the situation of electrolyte leakage from the battery cell and external liquid entering the battery cell. At the same time, it also separates the pole 101 from the inner surface of the top wall of the housing 100 to avoid short - circuiting. The first insulating plate 502 is arranged on the upper side of the connecting piece 200, separating the connecting piece 200 from the inner surface of the top wall of the housing 100 and the sealing plate 400, avoiding short - circuiting between the connecting piece 200 and the inner surface of the top wall of the housing 100 and the sealing plate 400, which may cause the housing 100 to leak electricity, and improving the reliability of the battery cell.

[0058] In one embodiment, please refer to Figures 6 to 8 , on the inner surface of the top wall of the housing 100, a second insulating plate 503 is provided. The second insulating plate 503 is located between a pair of through grooves 102 and extends in the direction of the two through grooves 102 and separates the connecting piece 200 from the inner surface of the top wall of the housing 100.

[0059] In this embodiment, by providing a second insulating plate 503 at a position between two through slots 102 on the inner surface of the top wall of the housing 100, the part of the inner surface of the top wall of the housing 100 between the two through slots 102 is separated from one end of the connecting piece 200 extending towards the middle of the inner surface of the top wall of the housing 100, enabling the connecting piece 200 to extend to one side of the through slot 102 close to the middle of the inner surface of the top wall of the housing 100. Thus, while having sufficient length, it will not be short-circuited with the inner surface of the top wall of the housing 100, effectively avoiding the situation of electric leakage of the housing 100. Additionally, since the connecting piece 200 has sufficient length, it also provides sufficient space for the connection between the connecting piece 200 and the lug 302, reducing the situation that the poor contact between the lug 302 and the connecting piece 200 affects the performance of the battery cell.

[0060] In one embodiment, please refer to Figures 6 to 8 , an explosion-proof valve 600 is provided on the top wall of the housing 100, and the explosion-proof valve 600 is arranged between the two through slots 102.

[0061] In this embodiment, the explosion-proof valve 600 is used to release the internal pressure of the battery cell when the battery cell is in thermal runaway, preventing the battery from exploding.

[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 cells.

[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 enhancing the production efficiency of the battery pack.

[0064] 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 all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing, on the top wall of which a pair of pole columns are installed, the pole columns penetrate through the top wall of the housing, and a pair of through grooves are provided on the housing between the pair of pole columns; A pair of connecting pieces, arranged inside the housing, 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, arranged inside 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, and the plurality of pole tabs converge towards the middle of the pole cores to form ear pieces, the ear pieces extend towards the through grooves and bend towards the connecting pieces, the bent part of the ear pieces abuts against the upper surface of the connecting pieces, the total height of the converged part of the pole tabs and the bent part of the ear pieces is H, and 1.5 mm ≤ H ≤ 5 mm is satisfied, the thickness of the ear pieces is t, and 0.1 mm ≤ t ≤ 2.5 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, characterized in that, The width of the pole core is W, and 6 mm ≤ W ≤ 30 mm is satisfied.

4. The cell according to claim 3, wherein, The distance between the unbent part of the ear piece and the side wall of the pole core away from the connecting piece is the offset W1, and W1 ≤ 0.5W, 1 mm ≤ W1 ≤ 15 mm is satisfied.

5. The cell according to claim 1, wherein The bending angle of the ear piece towards the connecting piece is 90°, and the bending part is a fillet, and the radius R of the fillet satisfies 0.1 mm ≤ R ≤ 3 mm.

6. The cell according to claim 1, wherein 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.

7. The battery cell according to any one of claims 1 to 6, characterized in that, At the positions corresponding to the pole columns on the top wall of the housing, connection holes are provided, the pole columns pass through the connection holes and are connected to the housing, a sealing ring and a first insulating plate are provided inside the connection holes, the sealing ring surrounds the periphery of the pole columns, and the first insulating plate extends towards the through grooves parallel to the inner surface of the top wall of the housing and separates the connecting piece from the inner surface of the top wall of the housing.

8. The battery cell according to claim 1, characterized in that, A second insulating plate is provided on the inner surface of the top wall of the housing, the second insulating plate is located between the pair of through grooves, and the second insulating plate extends towards the two through grooves and separates the connecting piece from the inner surface of the top wall of the housing.

9. The battery cell according to claim 1, characterized in that, An explosion-proof valve is provided on the top wall of the housing, and the explosion-proof valve is arranged between the two through grooves.

10. A battery pack, characterized in that, Comprising: A plurality of electric cores according to any one of claims 1 to 9.

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