Pole, cover plate assembly and battery monomer

Abstract

The utility model discloses a pole, a cover plate assembly and a battery monomer. Wherein the pole comprises a main body part and a connecting part; the connecting part is annular, and the main body part is axially arranged at one end of the connecting part, so that a material reducing space with an opening in the lower end is formed between the main body part and the connecting part; and a welding part thinner than the total thickness of the main body part is arranged at the upper end of the material reducing space. The cover plate assembly comprises the pole, and the battery monomer comprises the cover plate assembly. The battery pole has the beneficial effects that the material reduction space is formed by enclosing the main body part and the connecting part, so that the weight of the pole can be effectively reduced, and the energy density of the battery can be effectively improved while the manufacturing cost is saved. And the welding of the pole and the switching piece is facilitated by arranging the welding part with relatively thin thickness, so that the welding reliability is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage components, and in particular to a pole, a cover plate assembly and a battery cell. Background Art

[0002] Injection molded cover plates are widely used in the production of battery cells because of their simple process and large overcurrent. However, due to the relatively complex processing technology of the pole (friction welding / cold heading, CNC lathe, CNC milling, etc.), the manufacturing cost has increased significantly, which has directly led to an increase in the price of the cover plate assembly and battery cells, thus having a certain impact on the comprehensive popularization of the injection molded cover plate process. At the same time, since the traditional injection molded cover plate pole is an overall solid structure, it can withstand high current charging and discharging, but it is relatively wasteful for relatively small current charging and discharging, and it also increases the weight of the battery and reduces the energy density of the battery.

[0003] Therefore, there is an urgent need for a new type of pole structure and a cover plate assembly and a battery cell having the pole to reduce processing and manufacturing costs and improve the energy density of the battery. Utility Model Content

[0004] One of the objectives of the present application is to provide a pole that can solve at least one of the defects in the above-mentioned background technology.

[0005] Another object of the present application is to provide a cover plate assembly that can solve at least one of the defects in the above-mentioned background technology.

[0006] Another object of the present application is to provide a battery cell that can solve at least one defect in the above-mentioned background technology.

[0007] In order to achieve at least one of the above-mentioned purposes, the technical solution adopted in the present application is: a pole, including a main body and a connecting part; the connecting part is annular, and the main body is arranged at one end of the connecting part, so that a material reduction space with an open lower end is formed between the main body and the connecting part; the upper end of the material reduction space is provided with a welding part whose thickness is thinner than the overall thickness of the main body.

[0008] Preferably, the welding portion is located in the middle of the upper end of the material reduction space, and the thickness of the welding portion is 0.2-0.5 mm.

[0009] Preferably, the upper end surface of the main body is provided with a downward avoiding groove, so that the main body forms the welding portion in a corresponding area of ​​the avoiding groove.

[0010] Preferably, the upper portion of the air avoidance groove is used for installing a dustproof sticker, and the dustproof sticker is used to seal the air avoidance groove after welding.

[0011] Preferably, the cross-sectional shape of the material reduction space is circular, and the other end of the connecting portion is provided with a radially extending portion outwardly.

[0012] Preferably, the pole is integrally stamped from an aluminum plate or a copper-aluminum composite plate, and the thickness of the plate is 1 to 3 mm.

[0013] A cover plate assembly comprises the above-mentioned pole, and also comprises an insulating member and a substrate; the insulating member is formed by integral injection molding so that the substrate and the pole are spaced and connected through the insulating member.

[0014] Preferably, a groove and a buckle that engage with each other are respectively provided on the outer side of the connecting portion of the pole and the inner side of the insulating member.

[0015] A battery cell comprises the above-mentioned cover plate assembly, and also comprises a shell and a battery cell assembly; the battery cell assembly is arranged in the shell, and an adapter is welded to the end of the battery cell assembly; the cover plate assembly is tightly connected to the open end of the shell so that the adapter corresponds to the welding area of ​​the cover plate assembly and is welded.

[0016] Preferably, an explosion-proof notch is provided at the bottom of the shell, and an elastic portion corresponding to the explosion-proof notch is provided on the adapter plate welded at the bottom end of the battery cell assembly.

[0017] Compared with the prior art, the beneficial effects of this application are:

[0018] By enclosing the main body and the connecting part to form a material reduction space, the weight of the pole can be effectively reduced, thereby saving manufacturing costs and effectively improving the energy density of the battery. In addition, by setting a thinner welding part, the welding of the pole and the adapter is facilitated to ensure the reliability of the welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of the battery cell in this application.

[0020] Figure 2 This is a schematic diagram of the disassembled state of a battery cell in this application.

[0021] Figure 3 This is a schematic diagram of the bottom structure of the inner shell in this application.

[0022] Figure 4 This is a schematic diagram of the structure of the first adapter in this application.

[0023] Figure 5 This is a schematic diagram of the structure of the second adapter in this application.

[0024] Figure 6It is a schematic diagram of the partial cross-sectional structure of the lower part of the battery cell in this application.

[0025] Figure 7 This is a schematic diagram of the exploded state of the cover assembly in this application.

[0026] Figure 8 It is a schematic diagram of the cross-sectional structure of the pole in this application.

[0027] Fig. 9 The structure of the insulating member in this application is shown in FIG. Figure 1 .

[0028] Fig.10 The structure of the insulating member in this application is shown in FIG. Figure 2 .

[0029] Fig.11 It is a schematic diagram of the cross-sectional structure of the substrate in this application.

[0030] Fig.12 It is a schematic diagram of the partial cross-sectional structure of the upper part of the battery cell in this application.

[0031] Fig.13 For this application Fig.12 A local enlarged schematic diagram of point A in the middle.

[0032] In the figure: battery cell 10, cover assembly 11, pole 111, material reduction space 1110, main body 1111, connecting part 1112, extension part 1113, avoidance groove 1114, installation groove 1115, limit groove 1116, card slot 1117, insulating member 113, covering cavity 1130, boss part 1131, support part 1132, rib plate 1136, cavity 1137, avoidance groove 1133, buckle 1134, positioning groove 1135, substrate 114, Positioning hole 1141, sealing groove 1142, injection hole 1143, dustproof sticker 115, aluminum nail 116, ball 117, shell 12, outer shell 121, edging 1211, inner shell 122, explosion-proof notch 1220, battery cell assembly 13, first adapter 14, first connecting column 141, first step portion 142, first heat dissipation hole 143, second adapter 15, second connecting column 151, second step portion 152, second heat dissipation hole 153, elastic portion 154. DETAILED DESCRIPTION

[0033] Below, the present application is further described in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] In the description of the present application, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present application.

[0035] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0036] The terms "including" and "having" and any variations thereof in the specification and claims of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0037] One aspect of the present application provides a battery cell 10, such as Figure 1 and Figure 2 As shown, one preferred embodiment includes a cover plate assembly 11, a shell 12, a battery cell assembly 13 and a transfer plate. One end of the shell 12 is opened so that a mounting cavity can be formed inside the shell 12. The battery cell assembly 13 can be installed in the mounting cavity of the shell 12, so that the battery cell assembly 13 is protected by the shell 12. The transfer plate can be welded and installed at the end of the battery cell assembly 13, so that the transfer plate can be installed in the mounting cavity of the shell 12 together with the battery cell assembly 13. The cover plate assembly 11 can be installed at the open end of the shell 12 and tightly connected, so that the mounting cavity of the shell 12 forms a sealing structure through the installation of the cover plate assembly 11, thereby ensuring that the electrolyte injected into the mounting cavity will not leak. And when the cover plate assembly 11 is installed, the cover plate assembly 11 can correspond to and contact the transfer plate at the end of the battery cell assembly 13, and then the cover plate assembly 11 can be welded with the transfer plate, so that the battery cell assembly 13 can be stably electrically connected to the cover plate assembly 11 through the transfer plate.

[0038] It should be known that the cover plate assembly 11 can be used as the positive electrode of the battery cell 10, or as the negative electrode of the battery cell 10; that is, the cover plate assembly 11 can be set at both ends of the battery cell 10 for electrical connection, or one end of the battery cell 10 is electrically connected by setting the cover plate assembly 11. The specific number and location of the cover plate assembly 11 can be selected according to the actual needs of those skilled in the art. Figure 1 and Figure 2 As shown, in one specific example, the number of the cover plate assembly 11 is one and it is installed at one end of the battery cell assembly 13. In order to facilitate the description of the subsequent content, the end of the battery cell assembly 13 where the cover plate assembly 11 is installed can be set as the upper end, and the corresponding other end is the lower end.

[0039] It is understandable that when designing the battery cell 10, in order to ensure the electrical connection of the electrode position is stable, both ends of the battery cell assembly 13 need to be stably connected to the cover assembly 11 and the housing 12 through the adapter. For easy understanding, the specific installation process of the battery cell 10 will be described in detail below.

[0040] Specifically, Figure 2 , Figure 6 and Fig.12 As shown, the adapter includes a first adapter 14 and a second adapter 15 respectively arranged at the upper and lower ends of the battery cell assembly 13. Before installing the battery cell assembly 13, the first adapter 14 and the second adapter 15 can be respectively welded to the two ends of the battery cell assembly 13, so that the first adapter 14 and the second adapter 15 are respectively electrically connected to the positive and negative electrodes of the battery cell assembly 13 in a stable manner. Then, the battery cell assembly 13 together with the welded first adapter 14 and the second adapter 15 are installed in the installation cavity of the shell 12, so that the second adapter 15 is against the bottom of the installation cavity of the shell 12, and then the bottom of the shell 12 is welded to the second adapter 15 on the outside of the shell 12 by laser penetration welding, so that the second adapter 15 is electrically connected to the shell 12 in a stable manner. Next, the cover plate assembly 11 can be installed on the upper end of the battery cell assembly 13 along the opening of the shell 12 and contact the first adapter 14, and then the opening of the shell 12 is welded to the cover plate assembly 11 by laser welding to ensure that the cover plate assembly 11 is stably and tightly connected to the shell 12. Finally, the first adapter 14 is welded to the conductive part of the cover plate assembly 11 by laser penetration welding to ensure that the conductive part of the cover plate assembly 11 is stably and electrically connected to the first adapter 14.

[0041] It should be known that the specific method of laser penetration welding is a well-known technology for those skilled in the art, so it will not be elaborated in detail here. At the same time, the cross-sectional shape of the battery cell 10 can be circular, that is, the battery cell 10 is cylindrical; the cross-sectional shape of the battery cell 10 can also be rectangular or elliptical, etc., which can be designed according to the actual needs of those skilled in the art. Generally speaking, when a plurality of battery cells 10 are arranged for use, the cylindrical battery cells 10 can leave gaps between each other to facilitate heat dissipation. At the same time, the production process of the cylindrical battery cells 10 is relatively mature, so in this embodiment, the battery cell 10 is preferably cylindrical. The corresponding first adapter 14 and the second adapter 15 are also circular structures.

[0042] Specifically, Figure 4 and Fig.12 As shown, the diameter of the first adapter 14 is smaller than the diameter of the battery cell assembly 13, so that the first adapter 14 can maintain a gap with the inner wall of the shell 12 when it is installed and connected to the upper end surface of the battery cell assembly 13. The side of the first adapter 14 is provided with at least one raised first step portion 142 along the circumferential direction, and the first step portion 142 is formed by a stamping process. When installing the first adapter 14, the first adapter 14 can be welded to the conductive portion of the cover assembly 11 through the middle. When the cover assembly 11 is installed, the protruding direction of the first step portion 142 is away from the battery cell assembly 13, so that the first adapter 14 can contact the upper end surface of the battery cell assembly 13 through the remaining area to achieve electrical connection, and at the same time, the first step portion 142 and the upper end surface of the battery cell assembly 13 can form a gap for heat dissipation.

[0043] It is understandable that the number of first step portions 142 can be one or more. For one first step portion 142, in order to ensure that the force on the first adapter plate 14 is stable, the first step portion 142 is arranged in a ring shape on the side of the first adapter plate 14, and the first step portion 142 is spaced from the welding area in the middle of the first adapter plate 14 to ensure that the first adapter plate 14 has enough area to contact the battery cell assembly 13. For multiple first step portions 142, in order to ensure that the force on the first adapter plate 14 is stable, the multiple first step portions 142 need to be arranged at equal intervals along the circumferential direction of the first adapter plate 14; for ease of understanding, a specific example is as follows: Figure 4 As shown, three first step portions 142 are provided on the first adapter plate 14, and the extension length of each first step portion 142 in the circumferential direction is 0.1 to 0.2 times the circumference of the first adapter plate 14. This can ensure that the first step portion 142 can form a gap with good heat dissipation, while ensuring that the first adapter plate 14 and the upper end surface of the battery cell assembly 13 have sufficient contact area.

[0044] In this embodiment, in order to further improve the heat dissipation of the battery cell assembly 13, as shown in FIG. Figure 4 As shown, the first adapter plate 14 is evenly distributed with first heat dissipation holes 143 in the non-welding area. Specifically, the first step portion 142 and the contact area between the first adapter plate 14 and the battery cell assembly 13 are both provided with first heat dissipation holes 143.

[0045] In this embodiment, Figure 5 and Figure 6 As shown, the side of the second adapter 15 is provided with at least one raised second step portion 152 along the circumferential direction, and the middle of the second adapter 15 is provided with a second connecting column 151. When installing the second adapter 15, the second step portion 152 and the second connecting column 151 are both raised in the direction away from the lower end surface of the battery cell assembly 13, and the second adapter 15 is welded to the lower end surface of the battery cell assembly 13 by removing the remaining area of ​​the second step portion 152 and the second connecting column 151. When installing the battery cell assembly 13, the second adapter 15 is abutted against the bottom end of the installation cavity of the shell 12 through the second step portion 152 and the second connecting column 151, and then the second adapter 15 is welded to the bottom of the shell 12 through the second connecting column 151. The structure of the second step portion 152 is basically the same as that of the first step portion 142, so it will not be elaborated here in detail. For details, please refer to the relevant content of the first step portion 142 mentioned above. The second adapter plate 15 is provided with a second heat dissipation hole 153 . The second heat dissipation hole 153 is located in a non-raised area of ​​the adapter plate 15 to dissipate heat at a position in contact with the battery cell assembly 13 .

[0046] In this embodiment, Figure 3 As shown, the bottom of the housing 12 is provided with an explosion-proof notch 1220. When thermal runaway occurs during the use of the battery cell 10, the explosion-proof notch 1220 can rupture, thereby dissipating the heat inside the battery cell 10 to avoid the battery cell 10 catching fire and causing major safety accidents such as fire.

[0047] It should be known that the required explosion-proof notch 1220 is formed by making grooves inward on the outer side of the lower end of the shell 12; that is, the thickness of the bottom of the shell 12 at the explosion-proof notch 1220 is thinner than that at other positions. Therefore, when thermal runaway occurs in the battery cell 10, the position of the explosion-proof notch 1220 is a weak area of ​​the shell 12 and will be the first to rupture to dissipate heat.

[0048] It can be understood that the explosion-proof notch 1220 can be a closed structure along the circumferential direction of the housing 12 or a non-closed structure. If the explosion-proof notch 1220 adopts a closed structure, when the explosion-proof notch 1220 breaks, a part of the structure at the bottom of the housing 12 within the explosion-proof notch 1220 will break off and fall. If the explosion-proof notch 1220 adopts a non-closed structure, when the explosion-proof notch 1220 breaks, it will warp towards the non-closed position, that is, the part of the structure at the bottom of the housing 12 within the explosion-proof notch 1220 remains connected to the whole. In order to avoid secondary damage to the battery cell 10 that may be caused by the falling of part of the structure of the housing 12 and to facilitate the recovery of the battery cell 10 after rupture, in this embodiment, the explosion-proof notch 1220 preferably adopts a non-closed structure.

[0049] It should also be known that there are various specific shapes of the non-closed structure explosion-proof notch 1220, such as arc-shaped and U-shaped, etc. As Figure 3 shown, since the housing 12 is cylindrical, in this embodiment, the explosion-proof notch 1220 preferably adopts an arc shape, and the explosion-proof notch 1220 is concentrically arranged with the housing 12.

[0050] In this embodiment, as Figure 5 and Figure 6 shown, an arched elastic part 154 is arranged on the second step part 152 of the second adapter piece 15. When the battery core assembly 13 is completely installed, the elastic part 154 corresponds to the inner area of the explosion-proof notch 1220 at the bottom of the housing 12, and the elastic part 154 is in an elastically compressed state. When the battery core assembly 13 has a thermal runaway, the elastic part 154 can, through its own elastic restoring force, break the bottom of the housing 12 along the position of the explosion-proof notch 1220 before the bottom of the housing 12 melts, so as to realize the breaking process of the explosion-proof notch 1220 in advance, thereby realizing the advance control of the thermal runaway of the battery core assembly 13 and further increasing the use safety of the battery cell 10.

[0051] It can be understood that when the battery core assembly 13 is working normally, the overall temperature of the battery core assembly 13 is within the set range. At this time, the structural strength of the area corresponding to the explosion-proof notch 1220 at the bottom of the housing 12 is sufficient, so that the elastic part 154 is in a stable elastically compressed state. When the battery core assembly 13 has a thermal runaway, as the temperature of the battery core assembly 13 rises, the bottom of the housing 12 is gradually heated through heat transfer. When the temperature at the bottom of the housing 12 rises to a certain extent, the structural strength of the position of the explosion-proof notch 1220 at the bottom of the housing 12 gradually decreases. Until the structural strength cannot meet the compression of the elastic part 154, the elastic part 154 will perform elastic reset, and then squeeze the bottom of the housing 12 along the explosion-proof notch 1220 through the reset elastic force, so that the inside of the housing 12 is communicated with the outside to realize the heat dissipation of the battery core assembly 13.

[0052] It should be known that there are many specific structures of the elastic part 154. The elastic part 154 may be formed by welding an arched metal sheet on the second step part 152. The elastic part 154 may also be formed by stamping the second step part 152 after cutting it. The specific structure can be selected according to the actual needs of those skilled in the art. The number of elastic parts 154 can be set to multiple, such as each second step part 152 is provided with an elastic part 154, and then the explosion-proof notch 1220 at the bottom of the housing 12 can have an elastic part 154 corresponding to it at any installation position.

[0053] In this embodiment, Figure 2 , Figure 3 and Fig.12 As shown, the shell 12 includes an outer shell 121 and an inner shell 122; the inner shell 122 is made of metal for the conduction of the battery cell assembly 13, and the outer shell 121 is made of insulating material for insulating and protecting the battery cell 10. The outer shell 121 is tubular and has edging 1211 at both ends; the inner shell 122 is embedded in the outer shell 121, and the upper end of the inner shell 122 is provided with an opening, and the explosion-proof notch 1220 is provided on the outer side of the lower end of the inner shell 122; the battery cell assembly 13 and the electrolyte are both contained in the inner cavity of the inner shell 122. When installing the cover assembly 11, the cover assembly 11 can be welded to the upper end of the inner shell 122 through the side, and after the welding is completed, the outer shell 121 can tightly cover the upper end surface side of the cover assembly 11 through the edging 1211 at the upper end to reduce oxidation at the welding position and improve the aesthetics. The outer shell 121 is connected to the outer side of the lower end of the inner shell 122 by wrapping the lower end of the edge 1211 .

[0054] Another aspect of the present application provides a cover plate assembly 11, which can be applied to the above-mentioned battery cell 10. Figure 7 and Fig.12 As shown, one of the preferred embodiments includes a pole 111, an insulating member 113 and a substrate 114. The insulating member 113 is integrally injection molded so that the substrate 114 and the pole 111 are spaced and connected through the insulating member 113. Specifically, the pole 111 and the substrate 114 can be assembled to the set position in the mold first, and then the insulating member 113 can be injection molded through processes such as mold closing and injection molding, so as to obtain a cover assembly 11 in which the pole 111 and the substrate 114 are connected together through the insulating member 113. When installing the cover assembly 11, the pole 111 can be welded to the first adapter 15, and the substrate 114 is used to be welded to the inner shell 122 and to be wrapped and connected to the outer shell 121. The insulating member 113 insulates and isolates the substrate 114 from the pole 111 to prevent the shell 12 from contacting the pole 111 as the conductive part to cause a short circuit of the battery cell assembly 13.

[0055] In this embodiment, the substrate 114 can be connected to the outer side of the insulating member 113 through the positioning structure, and the inner side of the insulating member 113 and the outer side of the pole 111 can be connected through the limiting structure. By setting the positioning structure and the limiting structure, the connection strength between the substrate 114 and the insulating member 113, and between the insulating member 113 and the pole 111 can be ensured.

[0056] In this embodiment, there are many specific structures of the limit structure that can achieve the above functions. For the sake of easy understanding, one of the structures will be described in detail below. Figure 8 , Fig. 9 , Fig.10 as well as Fig.12 As shown, the center of the insulating member 113 is provided with an axially penetrating covering cavity 1130, and the insulating member 113 can cover the outer side of the pole 111 through the covering cavity 1130. The limiting structure includes a slot 1117 and a buckle 1134; the slot 1117 and the buckle 1134 are respectively provided on the inner side of the covering cavity 1130 and the outer side of the pole 111; the buckle 1134 and the slot 1117 are mutually engaged in the radial direction of the battery cell 10, so that the pole 111 and the insulating member 113 are limitedly matched in the axial direction of the battery cell 10, thereby ensuring that the connection between the pole 111 and the insulating member 113 is stable when the cover plate assembly 11 is installed.

[0057] It should be known that there are two ways to set the slot 1117 and the buckle 1134; the first is that the slot 1117 is set on the inner wall of the covering cavity 1130, and the buckle 1134 is set on the outer side of the pole 111; the second is that the slot 1117 is set on the outer side of the pole 111, and the buckle 1134 is set on the inner wall of the covering cavity 1130. Both of these settings can meet the requirements of this application, and can be selected according to the actual needs of those skilled in the art; for ease of understanding, such as Figure 8 , Fig. 9 and Fig.12 As shown, in this embodiment, the second method is preferably used for setting the card slot 1117 and the buckle 1134, and the subsequent content will also be described in detail using the second method as an example.

[0058] Specifically, when designing the pole 111, a slot 1117 can be first set on the outside of the pole 111, and then when the insulating part 113 is molded, the outside of the pole 111 can be used as the side wall of the cavity for injection molding of the insulating part 113. Furthermore, when the insulating part 113 is injection molded, the insulating part 113 will form a conformal buckle 1134 at the position of the slot 1117 of the pole 111, thereby increasing the fixing strength of the pole 111 to ensure that the pole 111 remains stably connected in the axial direction of the battery cell 10.

[0059] It should be known that the injection molding process of the insulating member 113 is a common injection molding process, such as a nano injection molding process, etc. The specific process is a well-known technology for those skilled in the art, so it will not be elaborated in detail here.

[0060] In this embodiment, the cross-sectional profiles of the slot 1117 and the buckle 1134 are adapted; the cross-sectional profiles of the slot 1117 and the buckle 1134 can be in various shapes, such as arc shape and trapezoidal shape; for example Fig.13 As shown, in this embodiment, the cross-sectional profile of the buckle 1134 and the slot 1117 is preferably semicircular.

[0061] In this embodiment, the slot 1117 and the buckle 1134 can be arranged along a circle surrounding the pole 111 and the covering cavity 1130 respectively; the slot 1117 and the buckle 1134 can also be provided in plurality, and are arranged at equal intervals around the pole 111 and the covering cavity 1130 respectively. Both methods can meet the requirements of this application, such as Fig.13 As shown, in this embodiment, the slot 1117 and the buckle 1134 are preferably arranged around a circle.

[0062] In this embodiment, there are multiple specific structures of the positioning structure that can achieve the above functions. For the sake of easy understanding, one of the structures will be used for detailed description below. Fig. 9 , Fig.11 and Fig.12 As shown, the insulating member 113 includes a boss portion 1131 and a support portion 1132; the boss portion 1131 is arranged at the center of the support portion 1132, so that the covering cavity 1130 that passes through the boss portion 1131 and the support portion 1132 has sufficient height to cover and connect the pole 111. A positioning groove 1135 is arranged on the outer side of the boss portion 1131 near the bottom of the support portion 1132 along the circumference direction, and a positioning hole 1141 is arranged at the center of the substrate 114; the substrate 114 can be installed on the upper end surface of the support portion 1132 of the insulating member 113 and engage with the positioning groove 1135 through the positioning hole 1141 to form a positioning structure. Thereby, the connection between the substrate 114 and the insulating member 113 can be ensured to be stable, and then when the cover plate assembly 11 is installed, the substrate 114 is connected with the housing 12 through cooperation to form a stable and tight connection structure.

[0063] It should be known that when the insulating member 113 is formed, the substrate 114 can be positioned first so that the positioning hole 1141 at the center of the substrate 114 serves as a part of the cavity for forming the insulating member 113, and then after the insulating member 113 is formed by the injection molding process, the insulating member 113 can form a positioning groove 1135 corresponding to the positioning hole 1141 at the outer bottom of the boss portion 1131. The cross-sectional shapes of the support portion 1132, the boss portion 1131 and the substrate 114 are various, such as regular polygons and circles. Since the battery cell 10 is a cylindrical structure, in order to further reduce the weight of the insulating member 113 and the substrate 114 to improve the energy density of the battery cell 10, in this embodiment, the cross-sectional shapes of the support portion 1132, the boss portion 1131 and the substrate 114 of the insulating member 113 are preferably circular.

[0064] In this embodiment, in order to ensure the installation safety of the cover plate assembly 11, the support portion 1132 of the insulating member 113 needs to have sufficient thickness in the axial direction to ensure that there is sufficient spacing height between the substrate 114 and the first adapter plate 14. In order to reduce the weight of the insulating member 113 and improve the energy density of the battery cell 10, a cavity 1137 can be provided inside the support portion 1132, so that the weight can be effectively reduced while maintaining the support portion 1132 with sufficient thickness.

[0065] It should be known that the insulating member 113 is an injection molded member, and its structural strength is weaker than that of a metal member; especially in the case of rubber injection molding, the structural strength of the insulating member 113 is poor. The cavity 1137 provided in the support portion 1132 will further weaken the structural strength of the support portion 1132. Therefore, the cavity 1137 of the support portion 1132 needs to be structurally reinforced, so as to ensure that the support portion 1132 is light enough and light enough.

[0066] Specifically, Fig.10 As shown, the cavity 1137 has a downward opening, and the support portion 1132 is provided with a plurality of ribs 1136 along the circumferential direction, and the cavity 1137 can be divided into a plurality of spacing areas by the ribs 1136; the ribs 1136 can greatly increase the structural strength of the support portion 1132 in the axial direction, so as to ensure that when the cover plate assembly 11 is tightly installed through the substrate 114, the support portion 1132 has sufficient supporting strength to support the substrate 114.

[0067] In this embodiment, Figure 7 , Fig.11 and Fig.12As shown, a liquid injection hole 1143 is provided on one side of the substrate 114. After the cover assembly 11 is installed, electrolyte can be injected into the installation cavity of the housing 12 through the liquid injection hole 1143. After the electrolyte is injected, the liquid injection hole 1143 can be blocked by an aluminum nail 116 to prevent the battery cell 10 from leaking at the position of the liquid injection hole 1143 during use.

[0068] It should be known that, based on the diameter size of the aluminum nail 116, there are two ways to seal and cooperate with the aluminum nail 116 and the injection hole 1143. The first is that the diameter of the aluminum nail 116 corresponds to the diameter of the injection hole 1143, so that the aluminum nail 116 and the injection hole 1143 are interference fit. The second is that the diameter of the aluminum nail 116 is significantly larger than the diameter of the injection hole 1143, then a sealing groove 1142 with a size corresponding to the aluminum nail 116 can be set at the upper end of the injection hole 1143, that is, the sealing groove 1142 and the injection hole 1143 cooperate to form a stepped hole; then the aluminum nail 116 can seal the injection hole 1143 by interference fit with the sealing groove 1142. Both matching methods can meet the requirements of this application, but in order to further facilitate the installation of the aluminum nail 116, this embodiment preferably adopts the above-mentioned second method for the matching method of the aluminum nail 116 and the injection hole 1143.

[0069] In this embodiment, in order to further improve the blocking effect of the injection hole 1143; Figure 7 , Fig.11 and Fig.12 As shown, before the aluminum nail 116 seals the injection hole 1143, a ball 117 can be placed in the injection hole 1143 to mechanically seal the injection hole 1143, and then the aluminum nail 116 and the sealing groove 1142 are sealed. In order to further improve the sealing effect of the aluminum nail 116 on the injection hole 1143, the aluminum nail 116 can be welded, and the interference fit between the aluminum nail 116 and the sealing groove 1142 can be loose to a transition or clearance fit, and the aluminum nail 116 only needs to be kept to stably seal the injection hole 1143 after welding.

[0070] In this embodiment, Fig. 9 , Fig.10 and Fig.12 As shown, a shunting groove 1133 is provided on one side of the supporting portion 1132 of the insulating member 13. Therefore, when the insulating member 113 is injection molded, the molding position of the shunting groove 1133 can correspond to the injection hole 1143 on the substrate 114, thereby ensuring that when the electrolyte is subsequently injected, the electrolyte can flow into the interior of the housing 12 along the injection hole 1143 through the shunting groove 1133, so as to ensure that the electrolyte can be smoothly injected into the interior of the housing 12.

[0071] In this embodiment, Figure 8 and Fig.12 As shown, in order to ensure reliable positioning accuracy of the insulating part 113 during injection molding, a limiting groove 1116 can be provided along the circumferential direction on the side of the upper end surface of the pole 111. Therefore, when the mold for injection molding the insulating part 113 is closed, the mold can ensure the sealing of the cavity by fitting the limiting groove 1116, thereby improving the molding accuracy of the insulating part 113 and avoiding problems such as glue leakage.

[0072] Another aspect of the present application provides a pole 111, which can be applied to the above-mentioned cover plate assembly 11 to be used as a conductive part. Figure 7 , Figure 8 and Fig.12 As shown, one of the preferred embodiments includes a main body 1111 and a connecting portion 1112. The connecting portion 1112 is annular, and the main body 1111 is arranged at one end of the connecting portion 1112, so that a material-reducing space 1110 with an open lower end is formed between the main body 1111 and the connecting portion 1112; at the same time, a welding portion thinner than the overall thickness of the main body 1111 is arranged at the upper end of the material-reducing space 1110. When installing the cover plate assembly 11, the material-reducing space 1110 can be aligned with the first adapter plate 14 welded on the upper end surface of the battery cell assembly 13, and then after the cover plate assembly 11 is welded and installed with the shell 12, the welding portion can be welded to the first adapter plate 14 on the outside of the main body 1111 by laser welding, thereby ensuring the electrical connection between the first adapter plate 14 and the pole 111 is stable.

[0073] It should be known that the pole 111 is generally made of metal material with good conductivity; since traditional poles often adopt a columnar solid structure, this will result in a larger overall weight of the pole 111; generally speaking, the thickness of a solid traditional pole is 4 to 6 mm. When the overall mass of the battery cell 10 is constant, the greater the weight of the pole 111, the lower the energy density of the battery cell 10 needs to be. In this embodiment, by forming a material reduction space 1110 on the pole 111, the wall thickness of the pole 111 can be reduced to 1 to 3 mm, thereby effectively reducing the weight of the pole 111 to increase the energy density of the battery cell 10. The specific thickness of the pole 111 can be selected according to the specific usage scenario. For example, the appropriate thickness can be selected by calculating the current size of the battery cell 10 during charging and discharging.

[0074] At the same time, due to the solid structure of the traditional pole, the thickness is relatively thick, which makes it inconvenient to perform laser penetration welding to achieve welding with the first adapter plate 14. In this embodiment, a thinner welding portion can be set on the upper end surface of the material reduction space 1110, and the thickness of the welding portion is generally 0.2-0.5 mm; the welding portion is used to weld with the first adapter plate 14, so that the pole 111 and the first adapter plate 14 can be smoothly welded to ensure the electrical connection stability between the pole 111 and the first adapter plate 14.

[0075] Specifically, Figure 4 , Figure 8 and Fig.12 As shown, a first connecting column 141 protruding upward is provided in the middle of the first adapter plate 14, and the first connecting column 141 can be obtained by stamping and stretching. The first connecting column 141 can serve as a welding area between the first adapter plate 14 and the pole 111. Therefore, when installing the cover plate assembly 11, the material reduction space 1110 can play a guiding role to achieve alignment with the first connecting column 141, so that the upper end surface of the first connecting column 141 is in contact and aligned with the welding portion of the upper end surface of the material reduction space 1110. At this time, the welding portion can be stably welded to the upper end surface of the first connecting column 141 by laser penetration welding on the outside of the main body 1111 to ensure the electrical connection between the pole 111 and the battery cell assembly 13.

[0076] It should be known that in order to ensure the reliability of welding and reduce the probability of welding through, it is necessary to weld from thin to thick during laser penetration welding. Therefore, for the welding between the pole 111 and the first adapter plate 14, welding can be performed from the outside of the pole 111 along the thinner welding portion to the first connecting column 141.

[0077] It is understandable that the cross-sectional shape of the material-reducing space 1110 is various, such as circular and polygonal. Considering that the battery cell 10 adopts a cylindrical structure, by setting the cross-sectional shape of the material-reducing space 1110 to a circular shape under the same structural space, it can ensure that the material-reducing space 1110 has a maximum contact area while effectively reducing the weight of the pole 111; therefore, in this embodiment, the cross-sectional shape of the material-reducing space 1110 is preferably circular, that is, the connecting portion 1112 is in a circular ring shape.

[0078] In this embodiment, Figure 8 and Fig.12As shown, a radially extending extension portion 1113 is provided outwardly at the other end of the connecting portion 1112 away from the main body 1111. Therefore, when the cover plate assembly 11 is installed, the pole 111 can contact the upper end surface of the first adapter plate 14 through the lower end surface of the extension portion 1113, and then the contact area between the pole 111 and the first adapter plate 14 can be increased through the extension portion 1113 to improve the installation stability of the pole 111 and the entire cover plate assembly 11. At the same time, the connection stability between the insulating member 113 and the pole 111 during molding can be further improved by the provision of the extension portion 1113. It should be noted that the insulating member 113 and the connecting portion 1112 of the pole 111 are firmly matched and connected through a limiting structure, that is, the card groove 1117 is provided on the outside of the connecting portion 1112. When the insulating member 113 is injection molded, the limiting groove 1116 for sealing and positioning the cavity can be provided on the side of the upper end surface of the main body 1111.

[0079] In this embodiment, there are many specific ways to form the welding portion. For ease of understanding, two specific examples are used below for detailed description.

[0080] Example 1: Figure 8 and Fig.12 As shown, the upper end surface of the main body 1111 is provided with a downward avoidance groove 1114. The thickness of the corresponding position of the main body 1111 can be thinned by the provision of the avoidance groove 1114, and then a welding portion can be formed at the bottom of the main body 1111 at the avoidance groove 1114. Specifically, the thickness of the main body 1111 can be thinned from 1 to 3 mm to 0.2 to 0.5 mm by the avoidance groove 1114 to form the required welding portion. Therefore, when the cover plate assembly 11 is welded to the shell 12, laser penetration welding can be performed on the outside of the pole 111 in the avoidance groove 1114, so that the main body 1111 at the bottom of the avoidance groove 1114 is stably electrically connected to the first connecting column 141 of the first adapter plate 14.

[0081] Example 2: The main body 1111 may be a multi-layer structure, so that a through-hole avoidance groove 1114 may be provided on at least one outer layer, and then a welding portion is formed through at least one inner layer. In a specific example, the main body 1111 may be provided with two layers, the thickness of the outer layer is 0.8 to 2.5 mm, and the thickness of the inner layer is 0.2 to 0.5 mm. Then, a through-hole avoidance groove 1114 may be provided on the outer layer, so that the area of ​​the inner layer corresponding to the through-hole avoidance groove 1114 is used as a welding portion.

[0082] It should be known that both of the above methods can meet the requirements of this application, and can be selected according to actual needs. It should be noted that the cross-sectional shape of the welding part can be circular or polygonal; in order to adapt to the structure of the material reduction space 1110, the cross-sectional shape of the welding part in this embodiment can be preferably circular, and the corresponding cross-sectional shape of the first connecting column 141 is also circular. The cross-sectional diameter of the welding part is smaller than the cross-sectional diameter of the material reduction space 1110, so the welding part may not be concentric with the material reduction space 11110 when it is set. However, in order to ensure the stability of the welding between the welding part and the first connecting column 141, and the uniform overall force of the cover plate assembly 11, the setting of the welding part in this embodiment is preferably concentric with the material reduction space 1110, that is, the air avoidance groove 1114 is set in the middle of the main body 1111.

[0083] In this embodiment, after the pole 111 is welded to the first adapter plate 141 through the welding portion, if the air-avoiding groove 1114 is in an exposed state, foreign matter may fall into it and affect the use of the battery cell 10. To avoid this problem, Figure 7 and Fig.12 As shown, after the welding part is welded to the first adapter plate 14, a dustproof sticker 115 can be installed on the upper part of the air avoidance groove 1114 to seal the air avoidance groove 1114 after welding.

[0084] It is understandable that there are many specific installation methods for the dustproof sticker 115. For easy understanding, two specific examples will be used for detailed description below.

[0085] Installation method 1: The air avoidance groove 1114 is an axially equal-diameter groove, and the dustproof sticker 115 is columnar and has an interference fit or transition fit with the upper portion of the air avoidance groove 1114. The dustproof sticker 115 can also be bonded to the upper portion of the air avoidance groove 1114. Thus, the air avoidance groove 1114 can be sealed after the welding portion and the first adapter plate 14 are welded.

[0086] Installation method 2: Figure 8 and Fig.12 As shown, the outer end surface of the main body 1111 is provided with a mounting groove 1115 corresponding to the upper part of the air avoidance groove 1114, and the cross-sectional size of the mounting groove 1115 is larger than the diameter of the air avoidance groove 1114. After the welding part at the bottom of the air avoidance groove 1114 is welded to the first adapter plate 14, the dustproof sticker 115 can be installed in the mounting groove 1115 by interference fit or bonding to achieve sealing of the air avoidance groove 1114.

[0087] It should be known that both of the above two installation methods can meet the requirements of this application, and this embodiment preferably adopts the above example 2. In addition, the cross-sectional shape of the installation groove 1115 can be circular or polygonal, and can be selected according to actual needs. In this embodiment, the cross-sectional shape of the installation groove 1115 is preferably circular and is concentrically arranged with the air avoidance groove 1114, so the cross-sectional shape of the dustproof sticker 1115 is also circular accordingly.

[0088] In this embodiment, there are many specific ways to form the pole 111. It can be formed by welding a separate main body 1111, a connecting portion 1112, and an extension portion 1113, or it can be formed by integral stamping of a plate. Since the stamping process is a commonly used process in this field, the technology is mature and the cost is low, in this embodiment, the pole 111 is preferably formed by a stamping process. Specifically, when producing the pole 111, the plate can be first made into a coil, and then the coil is placed in the mold through a feeding system and formed in one go by stamping, without the need for additional machining, thereby effectively improving the production efficiency of the pole 111 and greatly reducing the production cost of the pole 111. The pole 111 obtained by integral stamping has a uniform wall thickness, and has stable conductivity and structural strength.

[0089] In this embodiment, the plate material used for the production of the pole 111 needs to have good electrical conductivity and welding stability. The plates commonly used as the pole 111 in this field include aluminum plates and copper-aluminum composite plates, etc.; so when the pole 111 is produced, it can be obtained by integrally stamping the aluminum plate or the copper-aluminum composite plate, and the thickness of the plate is generally 1 to 3 mm. The specific thickness of the plate material can be selected according to the specific use scenario of the pole 111. For example, the appropriate thickness can be selected by calculating the current size of the battery cell 10 during charging and discharging. Then, the appropriate punch tonnage is matched according to the selected plate thickness to avoid waste caused by excessive tonnage and poor product forming due to too small tonnage.

[0090] It should be known that when the pole 111 is used as the positive electrode of the battery cell 10, the plate material of the pole 111 is an aluminum plate material; when the pole 111 is used as the negative electrode of the battery cell 10, the plate material of the pole 111 is a copper-aluminum composite plate material. The specific type of plate material can be determined according to the actual use scenario of the pole 111.

[0091] It is understood that when the pole 111 is used as a positive electrode, the pole 111 can adopt the above-mentioned example 1 to obtain a welding portion by setting the air-avoiding groove 1114. When the pole 111 is used as a negative electrode, the pole 111 can adopt the above-mentioned example 2 to obtain a welding portion by setting the air-avoiding groove 1114.

[0092] The above describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited by the above embodiments, and the above embodiments and the specification only describe the principles of the present application. The present application may have various changes and improvements without departing from the spirit and scope of the present application, and these changes and improvements fall within the scope of the present application for which protection is sought. The scope of protection claimed by the present application is defined by the attached claims and their equivalents.

Claims

1. A pole, characterized in that: It comprises a main body and a connecting part; the connecting part is annular, and the main body is arranged at one end of the connecting part, so that a material reduction space with an open lower end is formed between the main body and the connecting part; a welding part with a thickness thinner than the overall thickness of the main body is arranged at the upper end of the material reduction space.

2. The pole according to claim 1, characterized in that The welding part is located in the middle of the upper end of the material reduction space, and the thickness of the welding part is 0.2-0.5 mm.

3. The pole according to claim 1, characterized in that: The upper end surface of the main body is provided with a downward avoiding groove, so that the main body forms the welding part at the bottom of the avoiding groove.

4. The pole according to claim 3, characterized in that: The upper part of the air avoidance groove is used for installing a dustproof sticker, and the dustproof sticker is used for sealing the air avoidance groove after welding.

5. The pole according to claim 1, characterized in that: The cross-sectional shape of the material reduction space is circular, and the other end of the connecting portion is provided with a radially extending portion outwardly.

6. The pole according to any one of claims 1 to 5, characterized in that: The pole is formed by integrally stamping an aluminum plate or a copper-aluminum composite plate, and the thickness of the plate is 1 to 3 mm.

7. A cover plate assembly, characterized in that: The pole comprises the pole according to any one of claims 1 to 6, and further comprises an insulating member and a substrate; the insulating member is integrally injection molded so that the substrate and the pole are spaced and connected via the insulating member.

8. The cover plate assembly according to claim 7, characterized in that: The outer side of the connecting portion of the pole and the inner side of the insulating member are respectively provided with a clamping groove and a clamping buckle which are engaged with each other.

9. A battery cell, characterized in that: It includes the cover plate assembly as described in claim 7 or 8, and also includes a shell and a battery cell assembly; the battery cell assembly is arranged in the shell, and a transition piece is welded to the end of the battery cell assembly; the cover plate assembly is tightly connected to the open end of the shell so that the transition piece corresponds to the welding part of the cover plate assembly and is welded.

10. The battery cell according to claim 9, characterized in that: The bottom of the shell is provided with an explosion-proof notch, and the adapter welded at the bottom end of the battery core assembly is provided with an elastic part corresponding to the explosion-proof notch.

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