Battery cell cover plate assembly and battery cell

Abstract

The utility model provides a battery cell cover plate assembly and a battery cell, and relates to the technical field of battery cell parts, the battery cell cover plate comprises a first lower insulating part, a second lower insulating part and a cover plate body, the second lower insulating part is arranged on one side of the first lower insulating part in the thickness direction and is connected with the first lower insulating part, and the second lower insulating part is arranged on the other side of the first lower insulating part in the thickness direction. The first lower insulating part and the second lower insulating part are consistent with the extending direction of the cover plate body, the surface, far away from the second lower insulating part, of the first lower insulating part is attached to the cover plate body, and the surface, close to the second lower insulating part, of the first lower insulating part is used for being attached to a tab connecting piece; and one surface of the second lower insulator far away from the first lower insulator is contacted with the end surface of the pole core. On the premise of preventing contact short circuit, the limiting effect on the pole core is good due to the fact that the contact area between the second lower insulating part and the pole core in the extending direction is large.

Description

Technical Field

[0001] The utility model relates to the technical field of battery core components, and in particular to a battery core cover assembly and a battery core. Background Art

[0002] The cell cover is welded and sealed to the cell shell to protect the internal structure of the cell, such as the electrode core. The cell cover includes a cover body, a lower plastic, and positive and negative electrode tab connecting pieces. The lower plastic is located between the cover body and the positive and negative electrode tab connecting pieces. Because the electrode core is connected to the positive and negative electrode tab connecting pieces on the lower plastic through bent tabs, there is usually a gap between the electrode core and the lower plastic. As a result, when the cell vibrates, the electrode core moves relative to the lower plastic, causing the tabs to tear and be damaged. Therefore, the existing lower plastic not only needs to prevent the cover body from contacting the positive and negative electrode tab connecting pieces, and the cover body from contacting the electrode core, which may cause a short circuit, but also needs to limit the movement of the electrode core.

[0003] In order to limit the movement of the pole core, the existing lower plastic is usually provided with protrusions facing the pole core at both ends of its extension direction. When the pole core vibrates, the pole core contacts the protrusions to limit the movement of the pole core. Although the movement of the pole core can be limited to a certain extent, the force on the pole core is mainly concentrated at the two ends, and the force is uneven, which makes it very easy to be damaged. Utility Model Content

[0004] The utility model aims to solve the technical problem that the existing lower plastic cannot avoid stress concentration when the pole core vibrates under the premise of preventing contact short circuit.

[0005] On the one hand, the utility model provides a battery cell cover assembly, including a first lower insulating member, a second lower insulating member and a cover body, the second lower insulating member is arranged on one side of the thickness direction of the first lower insulating member and is connected to the first lower insulating member, the first lower insulating member and the second lower insulating member are both consistent with the extension direction of the cover body, the side of the first lower insulating member away from the second lower insulating member is fitted with the cover body, the side of the first lower insulating member close to the second lower insulating member is used to fit with the pole ear connecting piece, and the side of the second lower insulating member away from the first lower insulating member is used to contact the end face of the pole core.

[0006] Optionally, in a battery cell in which two of the pole cores are arranged in parallel, the pole ears of the two pole cores are bent to form a placement space therebetween, and the second lower insulating member is used to be placed in the placement space and is recessed in a direction away from the first lower insulating member to form a concave structure, the extension direction of the concave structure is consistent with the extension direction of the second lower insulating member, and the bottom wall of the concave structure is away from the first lower insulating member. The side of the end face of the pole core is used to contact the end face of the pole core.

[0007] Optionally, the two opposite side walls of the concave structure include a first bending wall and a second bending wall that are connected to each other and set at angles to each other, the first bending wall is connected to the bottom wall of the concave structure at one end away from the second bending wall, and the distance between the first bending walls of the two side walls gradually increases from the end close to the bottom wall toward the direction away from the bottom wall, and the second bending wall is used to fit with the connection area of ​​the tab and the tab connecting sheet.

[0008] Optionally, a plurality of reinforcing ribs are provided in the groove of the concave structure, and at least some of the reinforcing ribs are arranged crosswise.

[0009] Optionally, the first lower insulating member is provided with a first exhaust hole at a position corresponding to the explosion-proof valve of the battery cell, the bottom wall of the concave structure is provided with a second exhaust hole, and an exhaust channel is formed between the first lower insulating member and the second lower insulating member, and the exhaust channel is respectively connected to the first exhaust hole and the second exhaust hole.

[0010] Optionally, a size of the second exhaust hole at a position on the second lower insulating member opposite to the explosion-proof valve is larger than sizes of the remaining second exhaust holes.

[0011] Optionally, the first lower insulating member and the second lower insulating member are snap-connected;

[0012] And / or, both ends of the first lower insulating member along the extension direction thereof extend beyond the second lower insulating member, and a portion of the first lower insulating member extending beyond the second lower insulating member is provided with a limiting protrusion protruding toward one side of the second lower insulating member.

[0013] Optionally, the first lower insulating member is provided with a diverter at a position opposite to the liquid injection hole of the cover body, the diverter is provided with a flow channel connected to the liquid injection hole, and the circumferential side wall of the diverter is provided with a liquid outlet of the flow channel.

[0014] On the other hand, the utility model proposes a battery cell, comprising a pole core, a pole tab connecting piece and the above-mentioned battery cell cover assembly, wherein the pole tab connecting piece is located between the first lower insulating part and the second lower insulating part of the battery cell cover assembly, and is fitted with the first lower insulating part, and the pole tab of the pole core is fitted and connected with the pole tab connecting piece.

[0015] Optionally, it includes two pole cores arranged in parallel, and the battery core also includes a pole column, the pole tab connecting piece is U-shaped, and the pole tab connecting piece is composed of two parts on the opposite sides of the U-shape, which are respectively fitted and connected with the pole tabs of the two pole cores, and the pole column passes through the pole tab connecting piece, the first lower insulating member and the cover plate body in sequence.

[0016] The battery cover assembly and battery cell of the present invention have at least the following advantages over the prior art:

[0017] By dividing the lower plastic into a first lower insulating member and a second lower insulating member that are installed in cooperation with each other, the two sides of the first lower insulating member in the thickness direction are respectively fitted with the cover body and the tab connecting piece, and the tab connecting piece is connected to the tab of the pole core, so as to achieve insulation between the cover body and the tab connecting piece, and insulation between the cover body and the pole core; the second lower insulating member is located on the side of the first lower insulating member facing the pole core, or on the side of the tab connecting piece facing the pole core, and can fill the gap between the tab connecting piece and the pole core, and play a limiting role for the tab connecting piece and the pole core to prevent relative movement between the two; in addition, compared with the point contact limiting method of the protrusions provided at both ends of the lower plastic and the two ends of the end face of the pole core, since the second lower insulating member is an elongated structure consistent with the extension direction of the first lower insulating member, the contact area between the second lower insulating member and the end face of the pole core is larger, and can contact the middle part of the end face of the pole core. When the battery cell vibrates in the Z direction, the pole core is subjected to more uniform force, avoiding damage due to excessive local stress. Moreover, since the second lower insulating member and the first lower insulating member in this embodiment are two independent structures, during assembly, the tab connecting piece and the tab that are fitted together can be connected to the first lower insulating member, and then the second lower insulating member and the first lower insulating member can be assembled and connected, which can facilitate the assembly of the tab connecting piece and the tab. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a battery cell according to an embodiment of the present utility model;

[0019] Figure 2 This is a schematic structural diagram of a battery cell from another perspective of an embodiment of the utility model;

[0020] Figure 3 This is a schematic structural diagram of the first lower insulating member according to an embodiment of the present utility model;

[0021] Figure 4 This is a schematic structural diagram of the second lower insulating member according to an embodiment of the present utility model;

[0022] Figure 5 This is a structural schematic diagram of the second lower insulating member from another perspective of an embodiment of the utility model;

[0023] Figure 6 This is a structural diagram of a battery cover assembly according to an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the exploded structure of the battery cover assembly according to an embodiment of the present invention;

[0025] Figure 8This is a structural schematic diagram of the battery cover assembly from another perspective of an embodiment of the utility model;

[0026] Figure 9 for Figure 8 Middle AA section view.

[0027] Description of reference numerals:

[0028] 1. Cell cover assembly; 11. First lower insulating member; 111. First exhaust hole; 112. Limiting protrusion; 113. Diverter; 114. First limiting step; 12. Second lower insulating member; 121. Concave structure; 1211. First bending wall; 1212. Second bending wall; 122. Reinforcing rib; 123. Second exhaust hole; 124. Second limiting step; 13. Cover body; 131. Filling hole; 132. Mounting hole; 14. Upper insulating member; 2. Tab connecting piece; 3. Pole; 4. Sealing rubber ring; 5. Riveted block; 6. Explosion-proof valve; 61. Explosion-proof plate; 62. Explosion-proof valve protection plate; 100. Pole core; 101. End face; 200. Tab. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0030] In the description of this utility model, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "matched" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integral connection; they may refer to direct connection, indirect connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0031] In addition, it should be noted that in the description of the present invention, it should be noted that the terminology in each embodiment, such as "upper", "lower", "front", "back" and other words indicating direction, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the components and devices referred to must be operated in accordance with the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute a limitation on the present invention.

[0032] An XYZ coordinate system is established herein. It should also be noted that the aforementioned X-axis, Y-axis, and Z-axis are intended solely for the purpose of facilitating and simplifying the description of the present invention. They do not indicate or imply that the devices or components referred to must have specific orientations, be constructed, or operate in specific orientations. Therefore, they should not be construed as limitations on the present invention.

[0033] like Figure 1-Figure 7As shown, a battery cell cover assembly 1 of an embodiment of the utility model includes a first lower insulating member 11, a second lower insulating member 12 and a cover body 13. The second lower insulating member 12 is arranged on one side of the thickness direction of the first lower insulating member 11 and is connected to the first lower insulating member 11. The first lower insulating member 11 and the second lower insulating member 12 are both consistent with the extension direction of the cover body 13. The side of the first lower insulating member 11 away from the second lower insulating member 12 is fitted with the cover body 13, the side of the first lower insulating member 11 close to the second lower insulating member 12 is used to fit with the pole ear connecting piece 2, and the side of the second lower insulating member 12 away from the first lower insulating member 11 is used to contact the end face of the pole core 100.

[0034] Specifically, the first lower insulator 11 and the second lower insulator 12 are disposed on the side of the cover body 13 facing the electrode core 100, i.e., on the inner side of the cover body 13, to insulate the cover body 13 from the electrode core 100 and the tab 200 of the battery cell. Both the first lower insulator 11 and the second lower insulator 12 can be plastic. The cover body 13 can be a plain aluminum sheet.

[0035] The first lower insulating member 11, the second lower insulating member 12, and the cover plate body 13 can all be extended along the Y direction. The first lower insulating member 11 can be a thin plate-like structure. The thickness direction of the first lower insulating member 11 is the Z direction. The second lower insulating member 12 can be located on the negative side of the first lower insulating member 11 along the Z axis. The positive side of the first lower insulating member 11 along the Z axis can be crimped with the cover plate body 13. The tab connecting piece 2 is arranged between the first lower insulating member 11 and the second lower insulating member 12. The negative side of the first lower insulating member 11 along the Z axis is in contact with the tab connecting piece 2.

[0036] In this embodiment, the lower plastic is divided into a first lower insulating member 11 and a second lower insulating member 12 which are installed in cooperation with each other, and the two sides of the first lower insulating member 11 in the thickness direction are respectively fitted with the cover body 13 and the tab connecting piece 2, and the tab connecting piece 2 is connected to the tab 200 of the pole core 100, so as to achieve insulation between the cover body 13 and the tab connecting piece 2, and insulation between the cover body 13 and the pole core 100; the second lower insulating member 12 is located on the side of the first lower insulating member 11 facing the pole core 100, or on the side of the tab connecting piece 2 facing the pole core 100, and can fill the tab connecting piece 2 and the pole core 100. 00, serves as a limit for the tab connection piece 2 and the pole core 100, preventing relative movement between the two. In addition, compared to point contact between the protrusions provided at both ends of the lower plastic and the ends of the end face of the pole core 100, because the second lower insulating member 12 is an elongated structure extending in the same direction as the first lower insulating member 11, the second lower insulating member 12 has a larger contact area with the end face 101 of the pole core 100 and can contact the middle of the end face 101 of the pole core 100. When the battery cell vibrates in the Z direction, the pole core 100 is subjected to more uniform force, avoiding damage caused by excessive local stress. Furthermore, because the second lower insulating member 12 and the first lower insulating member 11 in this embodiment are two independent structures, during assembly, the tab connection piece 2 and the pole tab 200 can be connected to the first lower insulating member 11, and then the second lower insulating member 12 and the first lower insulating member 11 can be assembled and connected. This facilitates the assembly of the tab connection piece 2 and the pole tab 200.

[0037] like Figure 1-Figure 2 、 Figure 4-Figure 5 As shown, optionally, in a battery cell with two pole cores 100 arranged in parallel, the pole ears 200 of the two pole cores 100 are bent to form a placement space between the two, and the second lower insulating member 12 is used to be placed in the placement space and is recessed in a direction away from the first lower insulating member 11 to form a concave structure 121. The extension direction of the concave structure 121 is consistent with the extension direction of the second lower insulating member 12, and the bottom wall of the concave structure 121 is away from the first lower insulating member 11. The side is used to contact the end face of the pole core 100.

[0038] Specifically, the cell cover plate assembly 1 is generally used in a cell with bipolar cores arranged in parallel. A pole core 100 is provided on the side of the second lower insulating member 12 away from the first lower insulating member 11. The pole core 100 is a rectangular parallelepiped structure with a relatively small thickness, i.e., a relatively small size in the X direction. The two pole cores 100 are connected in parallel and arranged in parallel along the X direction. Two tabs 200 are connected to the end face 101 of the pole core 100 in the positive direction of the Z axis. The two tabs 200 are spaced apart along the Y direction, and are respectively a positive pole tab and a negative pole tab. Two tab connecting pieces 2 are spaced apart along the Y direction, and are respectively a positive pole tab connecting piece and a negative pole tab connecting piece. The two ends of the U-shaped positive pole tab connecting piece are respectively connected to the positive pole tabs of the two pole cores 100, and the two ends of the U-shaped negative pole tab connecting piece are respectively connected to the negative pole tabs of the two pole cores 100, thereby realizing the parallel connection of the two pole cores 100.

[0039] The pole tabs 200 of the two pole cores 100 are arranged relative to each other, and a placement space is formed between the pole tabs 200 of the two pole cores 100. The placement space provides an accommodation space for the second lower insulating member 12, which is beneficial to increasing the contact area between the second lower insulating member 12 and the end faces 101 of the two pole cores 100, and improving the limiting effect of the second lower insulating member 12 between the pole tab connecting sheet 2 and the pole core 100, so as to effectively limit the movement of the pole core 100 along the Z direction and avoid the pole tab 200 from being torn and broken.

[0040] The second lower insulating member 12 is placed in the placement space and contacts the end face 101 of the pole core 100. The end face 101 is a rectangular end face with its length direction in the Y direction. The second lower insulating member 12 extends along the Y direction. One end of the second lower insulating member 12 can be placed between the positive pole tabs of the two pole cores 100, and the other end can be placed between the negative pole tabs of the two pole cores 100, effectively ensuring the contact area. For example, the end parts of the two positive pole tabs can be bent toward each other to be inserted between the second lower insulating member 12 and the first lower insulating member 11, respectively, to achieve a fitting connection with the positive pole tab connecting piece between the second lower insulating member 12 and the first lower insulating member 11, and the end parts of the two negative pole tabs can also be bent toward each other to be inserted between the second lower insulating member 12 and the first lower insulating member 11, respectively, to achieve a fitting connection with the negative pole tab connecting piece between the second lower insulating member 12 and the first lower insulating member 11.

[0041] In this embodiment, the second lower insulating member 12 is recessed in a direction away from the first lower insulating member 11 , so that the bottom wall of the concave structure 121 can better contact the end face 101 of the pole core 100 , thereby limiting the pole core 100 .

[0042] In some other embodiments, the battery cell cover assembly 1 can also be used in a single-pole battery cell.

[0043] like Figure 5As shown, optionally, the two opposite side walls of the concave structure 121 (the side walls along the X direction) include a first bending wall 1211 and a second bending wall 1212 that are connected to each other and set at angles to each other, and the end of the first bending wall 1211 away from the second bending wall 1212 is connected to the bottom wall of the concave structure 121, and the distance between the first bending walls 1211 of the two side walls gradually increases from the end close to the bottom wall toward the direction away from the bottom wall, and the second bending wall 1212 is used to fit with the connection area of ​​the tab 200 and the tab connecting sheet 2.

[0044] Specifically, the tabs 200 of the two pole cores 100 are first bent away from each other and then toward each other to form a placement space. The bent tabs 200 are generally V-shaped with their openings facing the X-direction. The tabs 200 of the two pole cores 100 are symmetrically arranged to form a placement space similar to an inverted trapezoid. This provides a larger placement space and facilitates accommodating the second lower insulator 12.

[0045] The bottom wall of the concave structure 121 can be arranged along the XY plane, and the distance between the first bent walls 1211 of the two side walls gradually increases from the end closest to the bottom wall toward the direction away from the bottom wall. In other words, the first bent wall 1211 is arranged at an angle relative to the bottom wall, allowing the first bent wall 1211 to be smoothly inserted through the V-shaped opening of the tab 200, thereby preventing interference between the second lower insulator 12 and the tab 200. The end of the first bent wall 1211 away from the bottom wall is connected to the second bent wall 1212, and the other end of the second bent wall 1212 extends toward the outside of the concave structure 121. The second bent wall 1212 can be arranged relatively parallel to the cover body 13.

[0046] The bent pole tab 200 includes a first part and a second part which are connected in sequence and arranged at an angle. The first part is connected to the pole core 100, and the second part is parallel to the pole tab connecting piece 2 and welded and fixed. The second bending wall 1212 is located on the side of the second part away from the pole tab connecting piece 2. The size of the second bending wall 1212 in the XY plane can be larger than the size of the second part. The fine welding slag generated when the pole tab 200 is welded to the pole tab connecting piece 2 can be received by the second bending wall 1212 to avoid the risk of falling into the pole core 100 and causing a short circuit.

[0047] like Figure 4 As shown, optionally, a plurality of reinforcing ribs 122 are provided in the groove of the concave structure 121, and at least some of the reinforcing ribs 122 are cross-arranged.

[0048] Specifically, the multiple reinforcing ribs 122 intersect to form a grid pattern, giving the second lower insulating member 12 a relatively uniform overall structure and high strength. When the battery cell vibrates, the force applied to the pole core 100 is transmitted sequentially through the bottom wall of the concave structure 121 of the second lower insulating member 12 and the reinforcing ribs 122 to the first lower insulating member 11. This evenly distributes the force to the pole core 100, ensuring greater stability.

[0049] like Figure 3 As shown, optionally, the first lower insulating member 11 is provided with a first exhaust hole 111 at a position corresponding to the explosion-proof valve 6 of the battery cell, and the bottom wall of the concave structure 121 is provided with a second exhaust hole 123, and an exhaust channel is formed between the first lower insulating member 11 and the second lower insulating member 12, and the exhaust channel is respectively connected to the first exhaust hole 111 and the second exhaust hole 123.

[0050] Specifically, the first vent 111 is positioned corresponding to the explosion-proof valve 6 of the battery cell, typically in the middle of the first lower insulating member 11. In the event of thermal runaway, heat within the battery cell can be discharged more effectively and promptly through the first vent 111. Furthermore, the first vent 111 reduces the weight of the first lower insulating member 11, thereby reducing the weight of the battery cell cover assembly 1 and improving the mass energy density of the battery cell. The second lower insulating member 12 can be provided with multiple second vents 123 on the bottom wall of the concave structure 121 to improve exhaust efficiency.

[0051] In this embodiment, a first exhaust hole 111 is provided on the first lower insulating member 11, a second exhaust hole 123 is provided on the second lower insulating member 12, and an exhaust channel is formed between the first lower insulating member 11 and the second lower insulating member 12 after they are assembled. When the battery cell thermally runs away, the heat inside the battery cell can be discharged from the explosion-proof valve 6 through the second exhaust hole 123, the exhaust channel, and the first exhaust hole 111 in sequence, thereby preventing the battery cell from bursting.

[0052] It should be noted that the first lower insulating member 11 cannot achieve insulation between the cover body 13 and the pole core 100 at the first exhaust hole 111 or around the explosion-proof valve 6, but the second lower insulating member 12 can achieve insulation between the cover body 13 and the pole core 100.

[0053] like Figure 4 As shown, optionally, the size of the second exhaust hole 123 at a position on the second lower insulating member 12 opposite to the explosion-proof valve 6 is larger than the sizes of the other second exhaust holes 123 .

[0054] Specifically, the first exhaust hole 111 is relatively large in size, ensuring exhaust efficiency and preventing the cell cover assembly 1 from melting and adhering at high temperatures, thereby preventing the explosion-proof valve 6 from being blocked. At the same time, the weight reduction effect is more obvious.

[0055] The second vent hole 123 on the second lower insulator 12 corresponding to the explosion-proof valve 6 is larger than the remaining second vent holes 123 to ensure exhaust efficiency. For example, the second vent hole 123 on the second lower insulator 12 corresponding to the explosion-proof valve 6 can be an oblong through-hole, while the second vent holes 123 at the remaining locations can be circular through-holes.

[0056] like Figure 3 and Figure 9 As shown, optionally, the second lower insulating member 12 extends from both ends of the first lower insulating member 11 along its extension direction, and the portion of the first lower insulating member 11 extending from the second lower insulating member 12 is provided with a limiting protrusion 112 protruding toward one side of the pole core 100, and the limiting protrusion 112 is flush with the side of the second lower insulating member 12 away from the first lower insulating member 11.

[0057] Specifically, the extension length of the first lower insulating member 11 along the Y direction is greater than the extension length of the second lower insulating member 12 along the Y direction. The second lower insulating member 12 extends from both ends of the first lower insulating member 11 in the Y direction, and the extended portions are provided with limiting protrusions 112 protruding toward one side of the pole core 100. The limiting protrusions 112 at both ends can be used to contact the ends of the end surface 101 of the pole core 100 to achieve position limiting of the pole core 100 at both ends. The second lower insulating member 12 contacts the portion of the end surface 101 between its ends, that is, the middle portion of the end surface 101, to achieve position limiting of the middle portion of the pole core 100. This ensures that the overall position of the pole core 100 is uniform and the force is more stable.

[0058] Here, the protruding end surface of the limiting protrusion 112 can be made substantially flush with the side of the second lower insulating member 12 away from the first lower insulating member 11 , ensuring that the limiting protrusion 112 and the second lower insulating member 12 have consistent limiting capabilities at all locations of the pole core 100 .

[0059] like Figure 3 As shown, optionally, the first lower insulating member 11 is provided with a diverter 113 at a position corresponding to the liquid injection hole 131 of the cover body 13, and the diverter 113 is provided with a flow channel connected to the liquid injection hole 131, and the flow channel is provided with a liquid outlet on the circumferential side wall of the diverter 113.

[0060] Here, the diverter 113 can be integrally formed with the first lower insulating member 11. The diverter 113 can be a protrusion provided on the side of the first lower insulating member 11 facing the second lower insulating member 12, with a flow channel provided therein. The circumferential sidewall of the diverter 113 is provided with multiple liquid outlets. The end of the diverter 113 pointing to the second lower insulating member 12 is closed. After the electrolyte enters the liquid injection hole 131 and flows out from the liquid outlet through the flow channel, it will not directly flush the pole core 100 through the second exhaust hole 123 on the second lower insulating member 12, but will be more evenly distributed to various positions so that the pole core 100 can be more evenly and quickly infiltrated. The liquid injection hole 131 on the cover body 13 is welded with a sealing nail after the battery cell is exhausted to ensure the sealing effect inside the battery cell.

[0061] like Figure 3-Figure 4 As shown, optionally, the first lower insulating member 11 and the second lower insulating member 12 are snap-connected.

[0062] Specifically, the first lower insulating member 11 is respectively provided with a first limiting step 114 at both ends along its extension direction, and the first limiting step 114 is located between the two limiting protrusions 112. The second lower insulating member 12 is respectively provided with a second limiting step 124 at both ends along its extension direction, and the second limiting step 124 is installed in cooperation with the first limiting step 114, and the ends of the two second limiting steps 124 away from each other are respectively in contact with the corresponding limiting protrusions 112. Here, the first limiting step 114 is a two-level step. The cross-sectional dimension of the end where the two first limiting steps 114 face each other is smaller, and the cross-sectional dimension of the end where the two first limiting steps 114 depart from each other is larger. The second limiting step 124 is matched with the first limiting step 114 to realize the matching installation of the first lower insulating member 11 and the second lower insulating member 12. The first limiting step 114 and the second limiting step 124 are respectively provided with a card hole and a card buckle. When the first limiting step 114 is matched with the second limiting step 124, the card hole and the card buckle are plugged in to realize the assembly of the first lower insulating member 11 and the second lower insulating member 12.

[0063] The ends of the two second limiting steps 124 that are away from each other are in contact with the limiting protrusion 112 to limit the shaking of the second limiting steps 124, so that the assembly stability of the second lower insulating member 12 and the first lower insulating member 11 is improved.

[0064] In some other embodiments, buckles and holes may be provided on two opposite long sides of the first lower insulating member 11 and the second lower insulating member 12 to further improve the connection stability between the two.

[0065] like Figure 1 、 Figure 2 、 Figure 7 and Figure 9As shown, another embodiment of the present invention proposes a battery cell, including a pole core 100, a pole tab connecting piece 2 and the above-mentioned battery cell cover assembly 1, the pole tab connecting piece 2 is located between the first lower insulating piece 11 and the second lower insulating piece 12 of the battery cell cover assembly 1, and is fitted with the first lower insulating piece 11, and the pole tab 200 of the pole core 100 is fitted and connected with the pole tab connecting piece 2.

[0066] In this embodiment, the electrode core 100 is located within the housing and sealed by the cell cover assembly 1. The thickness direction of the first lower insulating member 11 is the Z-direction. The Z-direction side surfaces of the first lower insulating member 11 are respectively in contact with the cover body 13 and the tab connecting piece 2. The tab connecting piece 2 is connected to the tab 200 of the electrode core 100, thereby achieving insulation between the cover body 13 and the tab connecting piece 2, and between the cover body 13 and the electrode core 100. The end surfaces 101 of the two electrode cores 100 are respectively provided with a tab 200 at the ends facing away from each other, so that the tabs 200 of the two electrode cores 100 are as far apart as possible. This not only prevents interference between the tabs 200 of the two electrode cores 100 when assembled into the housing, but also provides sufficient X-direction space between the tabs 200 of the two electrode cores 100 for the placement of the second lower insulating member 12, thereby limiting the position of the electrode core 100 by the second lower insulating member 12.

[0067] like Figure 7-Figure 9 As shown, optionally, it includes two pole cores 100 arranged in parallel, and also includes a pole column 3, the pole tab connecting piece 2 is U-shaped, and the pole tab connecting piece 2 is composed of two parts of the sheet body on the opposite sides of the U-shape, which are respectively fitted and connected with the pole tabs 200 of the two pole cores 100, and the pole column 3 passes through the pole tab connecting piece 2, the first lower insulating member 11 and the cover plate body 13 in sequence.

[0068] Specifically, the cell cover assembly 1 may further include an upper insulating member 14, which is arranged on the side of the cover body 13 away from the pole core 100. The upper insulating member 14 may be a plastic member. The arrangement of the positive and negative poles of the cell is similar. For the convenience of description, only the installation of the positive pole of the cell is taken as an example. The pole column 3 is the positive pole column, the tab connector 2 is the positive tab connector, the sealing rubber ring 4 is the positive sealing rubber ring, the upper insulating member 14 is the positive upper insulating member, and the rivet block 5 is the positive rivet block. One end of the positive pole column is welded to the positive tab connector, and the other end passes through the positive sealing rubber ring, the first lower insulating member 11, the cover body 13, the positive upper insulating member, and is fixed through the positive rivet block. After that, the positive rivet block is welded to the positive pole column, thereby completing the installation of the positive pole of the cell.

[0069] The explosion-proof valve 6 also includes an explosion-proof valve protection plate 62. The cover body 13 is provided with a runway-shaped mounting hole 132. The explosion-proof plate 61 is welded into the mounting hole 132. The explosion-proof valve protection plate 62 covers the explosion-proof plate 61 and can be bonded and fixed to the cover body 13. The explosion-proof valve protection plate 62 is used to protect the explosion-proof plate 61. The explosion-proof plate 61 can be etched to form a thinned portion. When the battery cell thermally runs away, a large amount of high-temperature flammable gas is generated inside the battery cell, causing the internal pressure of the battery cell to increase. When the gas pressure exceeds the mechanical strength of the etched portion on the explosion-proof plate 61, the explosion-proof plate 61 tears along the etched portion, and the explosion-proof valve protection plate 62 opens along with the explosion-proof plate 61, quickly discharging the high-temperature flammable gas inside the battery cell and preventing the battery cell from exploding.

[0070] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A battery cover assembly, characterized in that: The invention comprises a first lower insulating member (11), a second lower insulating member (12) and a cover plate body (13); the second lower insulating member (12) is arranged on one side of the thickness direction of the first lower insulating member (11) and is connected to the first lower insulating member (11); the first lower insulating member (11) and the second lower insulating member (12) are both in the same extension direction as the cover plate body (13); a side of the first lower insulating member (11) away from the second lower insulating member (12) is in contact with the cover plate body (13); a side of the first lower insulating member (11) close to the second lower insulating member (12) is used to be in contact with the pole lug connecting piece (2); and a side of the second lower insulating member (12) away from the first lower insulating member (11) is used to be in contact with the end face (101) of the pole core (100).

2. The battery cover assembly according to claim 1, characterized in that: In an electric core in which two pole cores (100) are arranged in parallel, the pole ears (200) of the two pole cores (100) are bent to form a placement space between the two, the second lower insulating member (12) is used to be placed in the placement space, and is recessed in a direction away from the first lower insulating member (11) to form a concave structure (121), the extension direction of the concave structure (121) is consistent with the extension direction of the second lower insulating member (12), and the bottom wall of the concave structure (121) is away from the first lower insulating member (11) and is used to contact the end face (101) of the pole core (100).

3. The battery cover assembly according to claim 2, characterized in that: The two opposite side walls of the concave structure (121) each include a first bending wall (1211) and a second bending wall (1212) that are connected to each other and arranged at an angle to each other, the end of the first bending wall (1211) away from the second bending wall (1212) is connected to the bottom wall of the concave structure (121), and the distance between the first bending walls (1211) of the two side walls gradually increases from the end close to the bottom wall toward the direction away from the bottom wall, and the second bending wall (1212) is used to fit with the connection area of ​​the tab (200) and the tab connecting piece (2).

4. The battery cover assembly according to claim 2, characterized in that: A plurality of reinforcing ribs (122) are provided in the groove of the concave structure (121), and at least some of the reinforcing ribs (122) are arranged in a cross-like manner.

5. The battery cover assembly according to claim 2, characterized in that: The first lower insulating member (11) is provided with a first exhaust hole (111) at a position corresponding to the explosion-proof valve (6) of the battery cell, the bottom wall of the concave structure (121) is provided with a second exhaust hole (123), and an exhaust channel is formed between the first lower insulating member (11) and the second lower insulating member (12), and the exhaust channel is respectively communicated with the first exhaust hole (111) and the second exhaust hole (123).

6. The battery cover assembly according to claim 5, characterized in that: The size of the second exhaust hole (123) at a position on the second lower insulating member (12) opposite to the explosion-proof valve (6) is larger than the sizes of the other second exhaust holes (123).

7. The battery cover assembly according to claim 1, characterized in that: The first lower insulating member (11) and the second lower insulating member (12) are snap-connected; And / or, the first lower insulating member (11) extends out of the second lower insulating member (12) at both ends along its extension direction, and the portion of the first lower insulating member (11) extending out of the second lower insulating member (12) is provided with a limiting protrusion (112) protruding toward one side of the second lower insulating member (12).

8. The battery cover assembly according to claim 1, characterized in that: The first lower insulating member (11) is provided with a diverter member (113) at a position opposite to the liquid injection hole (131) of the cover plate body (13); the diverter member (113) is provided with a flow channel connected to the liquid injection hole (131); and a liquid outlet of the flow channel is provided on a circumferential side wall of the diverter member (113).

9. A battery cell, characterized in that: It comprises a pole core (100), a pole tab connecting piece (2) and a cell cover assembly (1) as described in any one of claims 1 to 8, wherein the pole tab connecting piece (2) is located between a first lower insulating piece (11) and a second lower insulating piece (12) of the cell cover assembly (1) and is fitted with the first lower insulating piece (11), and the pole tab (200) of the pole core (100) is fitted and connected with the pole tab connecting piece (2).

10. The battery cell according to claim 9, characterized in that: The invention comprises two pole cores (100) arranged in parallel, and also comprises a pole column (3); the pole tab connecting piece (2) is U-shaped; the pole tab connecting piece (2) forms two parts of the sheet body on opposite sides of the U-shape, which are respectively fitted and connected with the pole tabs (200) of the two pole cores (100); and the pole column (3) passes through the pole tab connecting piece (2), the first lower insulating member (11) and the cover plate body (13) in sequence.

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