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 top wall of the shell, and a pair of through grooves are formed in the top wall of the shell; the connecting piece is arranged on the lower side of the inner surface of the top wall of the shell, and one end of the connecting piece extends to the lower side of the through groove; the pole group is arranged in the shell, two groups of tabs are arranged at one end of the pole group, and the bent parts of the tabs abut against the upper surface of the connecting piece; the peripheral contours of the sealing plates are matched with the corresponding through grooves respectively, the sealing plates are welded to the groove walls of the through grooves, at least one combination groove is formed in the lower side plate face of each sealing plate, and the size of a groove opening of each combination groove is larger than that of the groove bottom; the pair of insulation pads are arranged on the lower sides of the corresponding sealing plates, the insulation pads and the corresponding sealing plates are integrally arranged through injection molding, the insulation pads are provided with a plurality of combination parts which are integrally formed with the insulation pads through injection molding, the combination parts are matched with the combination grooves, and the problem that the insulation pads are disengaged from the original positions due to disturbance, and consequently electric leakage of the shell is caused is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, and particularly relates 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, since the pole post is provided on the housing, after the pole group is installed in the housing, the staff needs to perform an electrifying operation between the pole tab and the pole post. To facilitate the operation of the staff, a channel needs to be reserved on the housing to provide space for the operation of the staff. After the welding is completed, the staff seals the channel with a sealing plate to protect the pole tab and related components. An insulating pad is also provided on the side of the sealing plate facing the pole tab to separate the sealing plate from the live components.

[0004] However, in the above-mentioned related art, after the connection between the pole tab and the pole post is completed, in order to improve the performance of the battery cell, it is necessary to evacuate the inside of the housing and then inject liquid electrolyte through the liquid injection hole reserved on the housing. During the injection and evacuation operations of the liquid electrolyte, structures such as the insulating pad near the liquid injection hole inside the housing will be disturbed due to the impact of air flow or electrolyte liquid flow. If the disturbance causes structures such as the insulating pad to deviate from their original positions, it is easy to cause a short circuit between the housing and the live components, resulting in the leakage of the housing. Summary of the Utility Model

[0005] In view of this, the utility model provides a battery cell and a battery pack to solve the problem that the insulating pad is disturbed and deviates from its original position during the injection of liquid electrolyte or the evacuation operation, resulting in the leakage of the housing.

[0006] In a first aspect, the utility model provides a battery cell, comprising:

[0007] A housing, on the top wall of which there are a pair of terminal posts, and a pair of through grooves are formed on the top wall of the housing between the pair of terminal posts; a pair of connecting pieces, arranged on the lower side of the top wall of the housing, one end of the connecting piece extends to the lower side of the through groove and is arranged opposite to the through groove; a pole group, arranged inside the housing, two sets of pole tabs are provided at one end of the pole group, and the two sets of pole tabs are respectively arranged in one-to-one correspondence with the pair of through grooves, the pole tabs extend along the direction of the top wall of the housing and are bent towards the corresponding connecting piece, and the bent part of the pole tab abuts against the upper surface of the connecting piece; 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, at least one engaging groove is provided on the lower side plate surface of the sealing plate, and the notch size of the engaging groove is smaller than the bottom size; a pair of insulating pads, arranged on the lower side of the corresponding sealing plates, the insulating pads are integrally provided with the corresponding sealing plates by injection molding, and a plurality of engaging parts integrally injection molded with the insulating pads are provided on the insulating pads, and the engaging parts are adapted to the engaging grooves.

[0008] Advantages: By arranging the terminal posts on the top wall of the housing and providing through grooves on the housing for connecting the pole tabs and the connecting pieces, compared with the method of closing the housing with a cover plate, the possibility of the error in the welding size of the cover plate affecting the subsequent welding precision of the pole tabs and the connecting pieces, the sealing plates and the through grooves during the assembly process is reduced. The two through grooves provided on the housing provide an operating space for the staff to weld the pole tabs and the connecting pieces. At the same time, compared with the method of providing a large through groove corresponding to two sets of pole tabs, the overall structural strength of the housing is better, and the compressive capacity of the battery cell is improved. The sealing plates are provided to seal the through grooves and protect the structures such as the pole tabs and the connecting pieces below. An insulating pad is arranged on the lower side of the sealing plate, and the insulating pad is integrally provided with the sealing plate by injection molding, so that all parts of the insulating pad can be closely combined with the sealing plate. In the assembly operations such as vacuum pumping and liquid injection of the battery, which may disturb the insulating pad, the situation that the insulating pad is locally separated from the sealing plate at the edge position or the included angle position of the sealing plate due to being disturbed is greatly reduced, thereby providing a reliable insulating effect for the sealing plate and the charged components on the lower side of the sealing plate. At the same time, the engaging groove provided on the sealing plate is combined with the engaging part injection molded on the insulating pad, which increases the contact area between the insulating pad and the sealing plate, thereby enhancing the bonding strength between the insulating pad and the sealing plate, and further reducing the situation of the insulating pad separating from its original position and causing the housing to leak electricity.

[0009] In an alternative embodiment, the engaging groove is a frustum-shaped groove, the diameter of the notch of the engaging groove is d, and 0.5mm ≤ d ≤ 6mm is satisfied.

[0010] Beneficial effects: By controlling the diameter of the notch of the engaging groove, the staff can prevent the notch diameter from being too small, which may cause the injection molding material to be difficult to enter during the injection molding process and thus fail to form an engaging part. It can also avoid the situation where the contact area between the engaging part and the groove wall of the engaging groove is too small, making it difficult to effectively improve the bonding strength between the insulating pad and the sealing plate. At the same time, it can avoid the situation where the notch diameter is too large, which may affect the structural strength of the sealing plate itself.

[0011] In an alternative embodiment, the diameter of the bottom of the upper side of the engaging groove is D, and it satisfies D = d + 0.3 mm.

[0012] Beneficial effects: Since the notch diameter of the engaging groove is smaller than the bottom diameter of the groove, and the bottom diameter is at least 0.3 mm larger than the notch diameter, it can prevent the size difference between the notch and the bottom from being too small, which may cause the engaging part to easily come out of the engaging groove and the insulating pad to easily separate from the sealing plate. At the same time, it can also prevent the size difference between the notch and the bottom from being too large, which may cause the injection molding material forming the engaging part to be difficult to fill the engaging groove during the injection molding process, thereby reducing the bonding area between the engaging part and the groove wall of the engaging groove and weakening the bonding strength, making the insulating pad easy to separate from the sealing plate.

[0013] In an alternative embodiment, the distance between the upper side plate surface of the sealing plate and the bottom of the engaging groove is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0014] Beneficial effects: By controlling the distance between the bottom of the engaging groove and the upper side plate surface of the sealing plate, the staff can reserve enough depth for the engaging groove, thereby enabling the sealing plate and the insulating pad to have sufficient bonding strength. At the same time, it can also avoid the situation where the thickness of the sealing plate at the position of the engaging groove is too small, resulting in weak structural strength, easy breakage, and leakage of the battery core liquid, etc., which affect the battery quality, and improve the reliability of the battery core.

[0015] In an alternative embodiment, the depth of the engaging groove is H, and 0.3 mm ≤ H ≤ 1.2 mm.

[0016] Beneficial effects: By controlling the depth of the engaging groove, the staff can avoid the situation where the connection strength between the sealing plate and the insulating pad is weak due to the too small depth of the engaging groove. At the same time, it can also avoid the situation where when the sealing plate and the insulating pad are heat-melt connected, the molten material cannot fully fill the engaging groove, affecting the connection strength, due to the too large depth of the engaging groove. In addition, it can also avoid the situation where the depth of the engaging groove is set too large, resulting in too thin thickness of the sealing plate at the position of the engaging groove, affecting the structural strength of the sealing plate.

[0017] In an alternative embodiment, a connection hole is provided at the position on the top wall of the housing corresponding to the pole. The pole passes through the connection hole and is connected to the top wall of the housing. A sealing ring is provided inside the connection hole. The sealing ring surrounds the circumference of the pole and separates the pole from the inner surface of the top wall of the housing.

[0018] Beneficial effects: By providing a sealing ring on the housing structure and arranging the sealing ring around the pole column, the sealing performance at the connection hole is improved, avoiding 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, avoiding short - circuit.

[0019] In an optional implementation manner, an upper insulating member is provided on the lower side of the top wall of the housing. The upper insulating member is arranged parallel to the top wall of the housing and extends towards the direction of the through - slot, separating the connecting piece from the inner surface of the top wall of the housing.

[0020] Beneficial effects: By arranging the upper insulating member on the upper side of the connecting piece on the housing structure, the connecting piece is separated from the inner surface of the top wall of the housing and the sealing plate, avoiding the short - circuit between the connecting piece and the inner surface of the top wall of the housing and the sealing plate, which may cause the leakage of the housing, and improving the reliability of the battery core.

[0021] In an optional implementation manner, a lower insulating member is provided on the lower side of the top wall of the housing. The lower insulating member is located between a pair of the through - slots, and the lower insulating member extends towards the two through - slots and separates the connecting piece from the inner surface of the top wall of the housing.

[0022] Beneficial effects: By providing the lower insulating member located at the position between the two through - slots on the top wall of the housing, the part of the top wall of the housing between the two through - slots is separated from the end of the connecting piece extending towards the middle of the top wall of the housing, enabling the connecting piece to extend to the side of the through - slot close to the middle of the top wall of the housing. Thus, while having sufficient length, it will not be short - circuited with the inner surface of the top wall of the housing, effectively avoiding the leakage of the housing. In addition, since the connecting piece has sufficient length, it also provides sufficient space for the connection between the connecting piece and the pole ear, reducing the situation that the poor contact between the pole ear and the connecting piece affects the performance of the battery core.

[0023] In an optional implementation manner, an explosion - proof valve is provided on the top wall of the housing between a pair of the through - slots.

[0024] Beneficial effects: The explosion - proof valve is used to release the internal pressure of the battery core during the thermal runaway of the battery core, preventing the battery from exploding.

[0025] In the second aspect, the present utility model also provides a battery pack, including: a plurality of the above - mentioned battery cores.

[0026] Beneficial 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. At the same time, the sealing plate and the insulating pad have reliable connection strength, greatly reducing the leakage situation after the assembly of the battery cores is completed, improving the product reliability, and enhancing the production efficiency of the battery pack. Description of the Drawings

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

[0028] Figure 1 It is a schematic diagram of the overall structure of a battery cell according to an embodiment of the present utility model;

[0029] Figure 2 It is a schematic cross-sectional view of a battery cell according to an embodiment of the present utility model for showing the internal structure;

[0030] Figure 3 It is a schematic cross-sectional view of a battery cell according to an embodiment of the present utility model for showing the combined structure of the sealing plate and the insulating pad;

[0031] Figure 4 is Figure 3 an enlarged schematic view of A in;

[0032] Figure 5 It is a schematic diagram of a battery cell according to an embodiment of the present utility model for showing the insulating pad and the combined structure on the insulating pad;

[0033] Figure 6 It is a schematic diagram of a battery cell according to an embodiment of the present utility model before the sealing plate is assembled onto the housing;

[0034] Figure 7 It is a schematic cross-sectional view of the internal structure of a battery cell according to an embodiment of the present utility model before the sealing plate is assembled onto the housing;

[0035] Figure 8 is Figure 7 an enlarged schematic view of B in;

[0036] Figure 9 It is a schematic diagram of a battery cell according to an embodiment of the present utility model before the tab is bent and attached to the connecting piece;

[0037] Figure 10 It is a schematic diagram of a battery cell according to an embodiment of the present utility model after the tab is bent and attached to the connecting piece.

[0038] Explanation of reference numerals:

[0039] 100, housing; 101, terminal post; 102, through slot; 103, connection hole; 104, explosion-proof valve; 200, connecting piece; 300, electrode group; 301, tab; 400, sealing plate; 401, engaging groove; 500, insulating pad; 501, engaging portion; 601, sealing ring; 602, upper insulating member; 603, lower insulating member. Detailed implementation manners

[0040] 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. Obviously, 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.

[0041] The following combines Figures 1 to 10 , and describes the embodiments of the present utility model.

[0042] According to an embodiment of the present utility model, on the one hand, a battery cell is provided. Please refer to Figure 1 , Figure 2 , Figure 9 and Figure 10 , which includes a housing 100, a pair of terminal posts 101 provided on the top wall, a pair of through slots 102 opened between the pair of terminal posts 101 on the top wall of the housing 100; a pair of connecting pieces 200 provided on the lower side of the inner surface of the top wall of the housing 100, one end of the connecting piece 200 extending to the lower side of the through slot 102 and being disposed opposite to the through slot 102; an electrode group 300 disposed in the housing 100, two sets of tabs 301 provided at one end of the electrode group 300, the two sets of tabs 301 being respectively in one-to-one correspondence with the pair of through slots 102, the tabs 301 extending along the inner surface direction of the top wall of the housing 100 and bending towards the corresponding connecting piece 200, and the bent part of the tab 301 abutting against the upper surface of the connecting piece 200; a pair of sealing plates 400, the peripheral contours of which are respectively adapted to the corresponding through slots 102 and welded to the slot walls of the through slots 102, at least one engaging groove 401 being provided on the lower side plate surface of the sealing plate 400, the notch size of the engaging groove 401 being smaller than the bottom size; a pair of insulating pads 500 disposed under the corresponding sealing plates 400, the insulating pads 500 being integrally provided with the corresponding sealing plates 400 by injection molding, a plurality of engaging portions 501 integrally injection molded with the insulating pads 500 being provided on the insulating pads 500, the engaging portions 501 being adapted to the engaging grooves 401.

[0043] In this embodiment, by arranging the terminal post 101 on the top wall of the housing 100 and providing a through groove 102 in the housing 100 for connecting the tab 301 and the connecting piece 200, compared with the method of closing the housing 100 through the inner surface of the top wall of the housing 100, the possibility that the error of the welding dimension of the inner surface of the top wall of the housing 100 affects the welding precision of the subsequent tab 301 and connecting piece 200, the sealing plate 400 and the through groove 102, etc. during the assembly process is reduced. The two through grooves 102 provided on the housing 100 provide an operating space for the staff to weld the tab 301 and the connecting piece 200. At the same time, by adopting the method that the two through grooves 102 respectively correspond to two groups of tabs 301, compared with the method of setting a large through groove 102 corresponding to two groups of tabs 301 at the same time, the overall structural strength of the housing 100 is better, and the compressive capacity of the battery cell is improved. The sealing plate 400 is provided to seal the through groove 102 and protect the structures such as the lower tab 301 and the connecting piece 200. An insulating pad 500 is arranged below the sealing plate 400, and the insulating pad 500 is integrally provided with the sealing plate 400 by injection molding, so that all parts of the insulating pad 500 can be closely combined with the sealing plate 400. During the assembly operations such as vacuum pumping and liquid injection of the battery, which may disturb the insulating pad 500, the situation that the insulating pad 500 causes local detachment of the edge position or the included angle position of the sealing plate 400 due to being disturbed is greatly reduced, thereby providing a reliable insulating effect for the sealing plate 400 and the charged components below the sealing plate 400. At the same time, the engaging groove 401 provided on the sealing plate 400 is combined with the engaging portion 501 formed by injection molding on the insulating pad 500, which increases the contact area between the insulating pad 500 and the sealing plate 400, and further improves the bonding strength between the insulating pad 500 and the sealing plate 400, further reducing the situation that the insulating pad 500 detaches from its original position and causes the housing 100 to leak electricity.

[0044] In the above embodiment, specifically, a pair of terminal posts 101 on the housing 100 are symmetrically arranged about the longitudinal central axis of the housing 100, and a pair of through grooves 102 are also symmetrically arranged about the longitudinal central axis of the housing 100. The sizes and shapes of the pair of through grooves 102 are the same, which is convenient for adapting to the same sealing plate 400. It should be noted that the size and shape of the through groove 102 are not limited in this embodiment, as long as it is convenient for the staff to bend the tab 301, and the through groove 102 exposes the positions where the tab 301 and the connecting piece 200 need to be welded for welding. The shape and size of the sealing plate 400 match the shape and size of the through groove 102.

[0045] Specifically, the insulating pad 500 disposed on the lower side of the sealing plate 400 is dimensionally adapted to the sealing plate 400. It should be noted that the cross-section of the engaging groove 401 for enhancing the bonding force between the insulating pad 500 and the sealing plate 400 can be circular, square, rectangular or other shapes, and this embodiment does not make any limitations.

[0046] In addition, specifically, the electrode group 300 includes at least one electrode core. The tab 301 of the electrode core extends from a position close to the through groove 102, and is attached to the tab 301 connecting portion of the connecting piece 200 by bending and welding to achieve electrical connection with the connecting piece 200. Also, since the tab 101 connecting portion of the connecting piece is electrically connected to the tab 101, electrical connection between the tab 301 and the tab 101 is thus achieved. Exemplarily, the electrode group 300 includes two electrode cores arranged side by side. The tabs 301 of the two electrode cores extend from the corresponding electrode cores on the opposite sides along the width direction of the electrode group 300 and extend towards the connecting piece 200. After the tabs 301 contact the side wall of the connecting piece 200, they are bent upward and then bent in the horizontal direction, so as to abut against and be welded to the upper side of the electrode plate.

[0047] In one embodiment, please refer to Figures 3 to 5 , the engaging groove 401 is a frustum-shaped groove. The diameter of the groove opening of the engaging groove 401 is d, and 0.5 mm ≤ d ≤ 6 mm is satisfied.

[0048] Specifically, the groove opening of the engaging groove 401 refers to the opening of the engaging groove 401 facing the lower side. When the engaging groove 401 is arranged in a frustum shape, both the groove opening and the groove bottom of the engaging groove 401 are circular.

[0049] In this embodiment, the staff controls the diameter of the groove opening of the engaging groove 401 to prevent the groove opening diameter from being too small, which may cause the injection molding material to be difficult to enter during the injection molding process and thus unable to form the engaging portion 501, and also to avoid the situation where the contact area between the engaging portion 501 and the groove wall of the engaging groove 401 is too small, making it difficult to effectively improve the bonding strength between the insulating pad 500 and the sealing plate 400. It also avoids the situation where the groove opening diameter is too large, which may affect the structural strength of the sealing plate 400 itself.

[0050] In one embodiment, please refer to Figures 3 to 5 , the diameter of the groove bottom of the engaging groove 401 is D, and D = d + 0.3 mm is satisfied.

[0051] In this embodiment, since the notch diameter of the engaging groove 401 is smaller than the bottom diameter of the groove, and the bottom diameter is at least 0.3 mm larger than the notch diameter, it can prevent the size difference between the notch and the bottom from being too small, resulting in the engaging portion 501 being easily disengaged from the engaging groove 401, causing the insulating pad 500 to be easily detached from the sealing plate 400. At the same time, it also prevents the size difference between the notch and the bottom from being too large, resulting in the injection molding material forming the engaging portion 501 during the injection molding process being difficult to fill the engaging groove 401 completely, thereby reducing the bonding area between the engaging portion 501 and the groove wall of the engaging groove 401, weakening the bonding strength, and making the insulating pad 500 easily detached from the sealing plate 400.

[0052] In one embodiment, please refer to Figures 3 to 5 , the distance between the upper side plate surface of the sealing plate 400 and the bottom of the engaging groove 401 is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0053] Specifically, the distance between the upper side plate surface of the sealing plate 400 and the bottom of the engaging groove 401 is the thickness of the sealing plate 400 at the position of the engaging groove 401, and this thickness affects the structural strength of the sealing plate 400.

[0054] In this embodiment, the staff controls the distance between the bottom of the engaging groove 401 and the upper side plate surface of the sealing plate 400, so as to reserve enough depth for the engaging groove 401, and then enable the sealing plate 400 and the insulating pad 500 to have sufficient bonding strength. At the same time, it also avoids the situation that the thickness of the sealing plate 400 at the position of the engaging groove 401 is too small, resulting in weak structural strength, easy breakage, and liquid leakage of the battery cell, etc., which affect the battery quality, and improves the reliability of the battery cell.

[0055] In one embodiment, please refer to Figures 3 to 5 , the depth of the engaging groove 401 is H, and 0.3 mm ≤ H ≤ 1.2 mm.

[0056] Specifically, the depth of the engaging groove 401 refers to the distance between the notch of the engaging groove 401 and the bottom of the engaging groove 401 in the thickness direction of the sealing plate 400.

[0057] In this embodiment, the staff controls the depth of the engaging groove 401 to avoid the situation that the connection strength between the sealing plate 400 and the insulating pad 500 is weak due to the too small depth of the engaging groove 401. At the same time, it also avoids the situation that when the sealing plate 400 and the insulating pad 500 are heat-melt connected, the molten material cannot fully fill the engaging groove 401 and affect the connection strength due to the too large depth of the engaging groove 401. In addition, it also avoids the situation that the depth of the engaging groove 401 is set too large, resulting in the thickness of the sealing plate 400 at the position of the engaging groove 401 being too thin and affecting the structural strength of the sealing plate 400.

[0058] In one embodiment, please refer to Figures 6 to 8, at the position corresponding to the pole column 101 on the inner surface of the top wall of the housing 100, a connection hole 103 is provided. The pole column 101 passes through the connection hole 103 and is connected to the inner surface of the top wall of the housing 100. A sealing ring 601 is provided inside the connection hole 103. The sealing ring 601 surrounds the circumference of the pole column 101 and separates the pole column 101 from the inner surface of the top wall of the housing 100.

[0059] In this embodiment, structurally, by providing the sealing ring 601 and arranging the sealing ring 601 around the pole column 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, the pole column 101 is also separated from the inner surface of the top wall of the housing 100 to avoid short - circuiting.

[0060] In one embodiment, please refer to Figures 6 to 8 , a top insulating member 602 is provided on the lower side of the inner surface of the top wall of the housing 100. The top insulating member 602 extends in the direction of the through - slot 102 parallel to the plane of the inner surface of the top wall of the housing 100, and separates the connection piece 200 from the inner surface of the top wall of the housing 100.

[0061] In this embodiment, structurally, by providing the top insulating member 602 on the upper side of the connection piece 200, the connection piece 200 is separated from the inner surface of the top wall of the housing 100 and the sealing plate 400, avoiding the short - circuiting between the connection piece 200 and the inner surface of the top wall of the housing 100 and the sealing plate 400, which may cause the leakage of the housing 100, and improving the reliability of the battery cell.

[0062] In one embodiment, please refer to Figures 6 to 8 , a bottom insulating member 603 is provided on the lower side of the inner surface of the top wall of the housing 100. The bottom insulating member 603 is located between a pair of through - slots 102. The bottom insulating member 603 extends in the direction of the two through - slots 102 and separates the connection piece 200 from the inner surface of the top wall of the housing 100.

[0063] In this embodiment, the staff arranges the bottom insulating member 603 at the position between the two through - slots 102 on the inner surface of the top wall of the housing 100, separating the part of the inner surface of the top wall of the housing 100 between the two through - slots 102 from the end of the connection piece 200 extending towards the middle of the inner surface of the top wall of the housing 100, enabling the connection piece 200 to extend to the 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 the leakage of the housing 100. In addition, since the connection piece 200 has sufficient length, it also provides sufficient space for the connection between the connection piece 200 and the tab 301, reducing the situation that the poor contact between the tab 301 and the connection piece 200 affects the performance of the battery cell.

[0064] In one embodiment, please refer to Figures 6 to 8, an explosion-proof valve 104 is provided between a pair of through grooves 102 on the inner surface of the top wall of the housing 100.

[0065] In this embodiment, the explosion-proof valve 104 is used to release the internal pressure of the battery cell during thermal runaway of the battery cell, preventing the battery from exploding.

[0066] In some of the above embodiments, the lower insulating member 603 is disposed opposite to the explosion-proof valve 104, and a plurality of exhaust holes penetrating the lower insulating member 603 in the thickness direction are formed in the lower insulating member 603, so that when thermal runaway occurs inside the battery cell, gas can pass through the exhaust holes and pass through the ruptured explosion-proof valve 104.

[0067] 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.

[0068] 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. At the same time, the sealing plate 400 and the insulating pad 500 have reliable connection strength, greatly reducing the occurrence of electric leakage after the battery cells are assembled, improving the product reliability, and improving the production efficiency of the battery pack.

[0069] 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: include: A housing, a pair of poles being provided on the top wall, and a pair of through slots being provided on the top wall of the housing between the pair of poles; A pair of connecting pieces, arranged on the inner surface of the top wall of the shell, one end of each connecting piece extends to the lower side of the through slot and is arranged opposite to the through slot; A pole group is arranged in the shell, and one end of the pole group is provided with two sets of pole ears, and the two sets of pole ears are respectively arranged in one-to-one correspondence with a pair of through grooves, and the pole ears extend along the inner surface direction of the top wall of the shell and bend toward the corresponding connecting piece, and the bent portion of the pole ears abuts against the upper surface of the connecting piece; A pair of sealing plates, the peripheral side profiles of which are respectively adapted to the corresponding through slots and welded to the slot walls of the through slots, at least one coupling slot is provided on the lower side plate surface of the sealing plate, and the slot size of the coupling slot is smaller than the size of the slot bottom; A pair of insulating pads are arranged at the lower side of the corresponding sealing plate. The insulating pads are integrally arranged with the corresponding sealing plate through injection molding. The insulating pads are provided with a plurality of coupling parts integrally injection molded with the insulating pads, and the coupling parts are adapted to the coupling grooves.

2. The battery cell according to claim 1, characterized in that: The coupling groove is a truncated cone-shaped groove, and the groove diameter of the coupling groove is d, and satisfies 0.5mm≤d≤6mm.

3. The battery cell according to claim 2, characterized in that: The diameter of the groove bottom of the coupling groove is D, and satisfies D=d+3mm.

4. The battery cell according to claim 3, characterized in that: The distance between the upper plate surface of the sealing plate and the groove bottom of the combining groove is t, and 0.2mm≤t≤1.5mm.

5. The battery cell according to claim 4, characterized in that: The depth of the coupling groove is H, and 0.3 mm ≤ H ≤ 1.2 mm.

6. The battery cell according to claim 1, characterized in that: A connecting hole is provided on the top wall of the shell at a position corresponding to the pole, the pole passes through the connecting hole and is connected to the top wall of the shell, a sealing ring is provided on the inner side of the connecting hole, the sealing ring is arranged around the pole and separates the pole from the inner surface of the top wall of the shell.

7. The battery cell according to claim 6, characterized in that: An upper insulating member is provided on the lower side of the shell top wall. The upper insulating member is arranged parallel to the shell top wall and extends in the direction of the through slot and separates the connecting piece from the inner surface of the shell top wall.

8. The battery cell according to claim 7, characterized in that: A lower insulating member is provided on the lower side of the top wall of the shell, and the lower insulating member is located between the pair of through slots. The lower insulating member extends toward the two through slots and separates the connecting piece from the inner surface of the top wall of the shell.

9. The battery cell according to claim 8, characterized in that: An explosion-proof valve is provided on the top wall of the shell body between a pair of through grooves.

10. A battery pack, characterized in that: include: A plurality of battery cells according to any one of claims 1 to 9.

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