Battery cell, battery device and electric device

Abstract

The present application belongs to the technical field of batteries. Provided are a battery cell, a battery device and an electric device. The battery cell comprises a casing, an electrode assembly, a first electrode terminal, a first insulating member, and a protective layer. The electrode assembly is accommodated within the casing and is electrically connected to the first electrode terminal. The first electrode terminal comprises a lead-out member, which is configured to be welded to a busbar component and has a first connecting portion formed thereon. The first insulating member is disposed between the lead-out member and a wall portion in the thickness direction of the wall portion; in the projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the first insulating member at least partially overlaps the orthographic projection of the first connecting portion. The protective layer is disposed between the lead-out member and the first insulating member, the melting point of the protective layer being higher than that of the lead-out member; in the projection plane perpendicular to the thickness direction of the wall portion, at least part of the orthographic projection of the first connecting portion is located within the orthographic projection of the protective layer, thereby reducing the risk of the first insulating member being melted due to burn-through of the lead-out member during welding.

Description

Battery cells, battery packs and electrical devices Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, power batteries, as the power source, play an irreplaceable and crucial role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing. Battery devices, as core components of new energy vehicles, have high requirements in terms of performance.

[0003] In battery technology, a battery cell typically includes a casing and an electrode assembly housed within the casing. The casing has electrode terminals, which are electrically connected to the electrode assembly to enable the input or output of electrical energy into the battery cell. However, the electrode terminals of existing battery cells are highly susceptible to short circuits with the casing, which is detrimental to improving the reliability of the battery cell. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a casing, an electrode assembly, a first electrode terminal, a first insulating member, and a protective layer; the casing has a wall portion; the electrode assembly is housed within the casing; the first electrode terminal is electrically connected to the electrode assembly, the first electrode terminal includes a lead-out located on the side of the wall portion away from the electrode assembly, and the lead-out is used for welding to a busbar component and forming a first connection portion on the lead-out; at least a portion of the first insulating member is disposed between the lead-out and the wall portion in the thickness direction of the wall portion, and in a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the first insulating member overlaps with the orthographic projection of the first connection portion; at least a portion of the protective layer is disposed between the lead-out and the first insulating member, the melting point of the protective layer is greater than the melting point of the lead-out, and in a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the first connection portion is located within the orthographic projection of the protective layer.

[0006] In the above technical solution, the first electrode terminal is electrically connected to the electrode assembly, and the lead-out portion of the first electrode terminal located on the side of the wall away from the electrode assembly is used for welding connection with the busbar component, so as to realize the input or output of electrical energy of the battery cell through the first electrode terminal. A first insulating member is provided between the lead-out portion and the wall, so that the first insulating member can insulate and isolate the lead-out portion and the wall. However, since the projection of the first insulating member in the thickness direction of the wall overlaps at least partially with the projection of the first connecting portion in the thickness direction of the wall, a protective layer is provided between the lead-out portion and the wall. The melting point of the protective layer is greater than the melting point of the lead-out portion, and the lead-out portion is welded to the busbar component and connected to the lead-out portion. At least a portion of the projection of the first connecting portion formed on the lead-out component in the thickness direction of the wall portion is located within the protective layer. This allows the protective layer to provide a certain degree of protection and separation for the first insulating component when the lead-out component is welded to the busbar component. This reduces the phenomenon of the first insulating component being burned or melted after the lead-out component is welded through, thus eliminating the need to increase the thickness of the lead-out component to reduce the risk of it being welded through. This optimizes the thickness of the lead-out component while effectively reducing the risk of insulation failure between the lead-out component and the wall portion after the first insulating component is damaged. Consequently, it reduces the risk of short circuit between the first electrode terminal and the casing during use, thereby improving the reliability of the battery cell.

[0007] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the first connection portion is entirely located within the orthographic projection of the protective layer.

[0008] In the above technical solution, by welding the lead-out component to the busbar component and forming the first connection portion on the lead-out component, the projection of the first connection portion in the thickness direction of the wall portion is set to be entirely located within the protective layer. This allows the protective layer to effectively separate the first connection wall and the first insulating component in the thickness direction of the wall portion, thereby further reducing the phenomenon of burning or melting the first insulating component after the lead-out component is welded through. This further reduces the risk of insulation failure between the lead-out component and the wall portion after the first insulating component is damaged, thereby further reducing the risk of short circuit between the first electrode terminal and the casing during use, which is beneficial to further improve the reliability of the battery cell.

[0009] In some embodiments, the melting point of the protective layer is T1, and the melting point of the lead-out element is T2, satisfying that T1-T2≥200℃.

[0010] In the above technical solution, by setting the melting point of the protective layer to be 200 degrees Celsius or more higher than that of the lead-out component, the phenomenon of the protective layer being melted when the lead-out component and the busbar component are welded together can be further alleviated. This can further improve the separation and barrier effect of the protective layer, and help to further improve the protection effect of the protective layer on the first insulating component when the lead-out component and the busbar component are welded together.

[0011] In some embodiments, the melting point of the protective layer is T1, satisfying 1000℃≤T1≤3000℃.

[0012] In the above technical solution, on the one hand, the melting point of the protective layer is set to be greater than or equal to 1000 degrees Celsius so that the protective layer has a better high temperature resistance effect. This allows the protective layer to play a better role in separating and protecting the first insulating component when the lead-out component is welded to the busbar component, thereby reducing the risk of the lead-out component being burned or melted after being welded through. On the other hand, the melting point of the protective layer is set to be less than or equal to 3000 degrees Celsius to alleviate the phenomenon of excessive high temperature resistance of the protective layer. This reduces the difficulty of material selection and manufacturing of the protective layer, thereby reducing the manufacturing cost of the protective layer.

[0013] In some embodiments, the lead-out member and the protective layer are stacked along the thickness direction of the wall portion; wherein, in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the lead-out member is located within the orthographic projection of the protective layer.

[0014] In the above technical solution, by setting the lead-out component and the protective layer to be stacked along the thickness direction of the wall, and the projection of the lead-out component in the thickness direction of the wall is located within the protective layer, the protective layer can effectively separate the lead-out component and the first insulating component in the thickness direction of the wall, thereby further improving the protective effect of the protective layer on the first insulating component when the lead-out component is welded to the busbar component, and further reducing the risk of the lead-out component being burned or melted after being welded through.

[0015] In some embodiments, the maximum dimension of the protective layer and the lead-out member in the thickness direction of the wall portion is D1, which satisfies that D1 < 3 mm.

[0016] In the above technical solution, since the separation effect of the protective layer can reduce the risk of the lead being soldered through without increasing the thickness of the lead, the thickness dimension of the lead in the thickness direction of the wall can be optimized, so that the thickness dimension of the lead in the thickness direction of the wall can be reduced. In this way, the maximum dimension of the protective layer and the lead as a whole in the thickness direction of the wall can be set to less than 3mm, which can save the space occupied by the first electrode terminal and the protective layer in the thickness direction of the wall, thereby optimizing the overall size of the battery cell and improving the energy density of the battery cell.

[0017] In some embodiments, 1.8mm ≤ D1 ≤ 2.8mm.

[0018] In the above technical solution, on the one hand, setting the maximum dimension of the protective layer and lead-out component as a whole in the thickness direction of the wall to be greater than or equal to 1.8mm facilitates the setting of a thicker protective layer and lead-out component, which is beneficial to improving the separation and protection effect of the protective layer on the first insulating component when the lead-out component is welded to the busbar component, and also helps to improve the structural strength of the lead-out component, so as to reduce the risk of breakage or deformation of the lead-out component during use. On the other hand, setting the maximum dimension of the protective layer and lead-out component as a whole in the thickness direction of the wall to be less than or equal to 2.8mm can further save the space occupied by the lead-out component and protective layer as a whole in the thickness direction of the wall, so as to further optimize the overall size of the battery cell and further improve the energy density of the battery cell.

[0019] In some embodiments, along the thickness direction of the wall portion, the thickness of the protective layer is D2 and the thickness of the lead-out member is D3, satisfying 0.1≤D2 / D3≤0.25.

[0020] In the above technical solution, on the one hand, the thickness of the protective layer is set to be greater than or equal to 0.1 times the thickness of the lead-out component, so that the protective layer has sufficient thickness to separate and block the lead-out component when it is welded to the busbar component, thereby alleviating the phenomenon of the protective layer being welded through. This is beneficial to improving the separation and protection effect of the protective layer on the first insulating component when the lead-out component is welded to the busbar component. On the other hand, the thickness of the protective layer is set to be less than or equal to 0.25 times the thickness of the lead-out component, so as to reduce the waste caused by the excessive thickness of the protective layer. This is beneficial to reducing the manufacturing cost of the battery cell and can save the space occupied by the protective layer in the thickness direction of the wall, which is beneficial to optimizing the overall size of the battery cell.

[0021] In some embodiments, 0.3mm ≤ D2 ≤ 1mm.

[0022] In the above technical solution, on the one hand, setting the thickness of the protective layer in the thickness direction of the wall to be greater than or equal to 0.3 mm is beneficial to improving the structural strength of the protective layer and ensuring that the protective layer has sufficient thickness to separate and block the lead-out component and the busbar component during welding, thereby alleviating the phenomenon of the protective layer being welded through. This is beneficial to improving the separation and protection effect of the protective layer on the first insulating component when the lead-out component and the busbar component are welded together. On the other hand, setting the thickness of the protective layer in the thickness direction of the wall to be less than or equal to 1 mm reduces the waste caused by excessive thickness of the protective layer, which is beneficial to reducing the manufacturing cost of the battery cell and saving the space occupied by the protective layer in the thickness direction of the wall, thus optimizing the overall size of the battery cell.

[0023] In some embodiments, 1mm ≤ D3 ≤ 2.5mm.

[0024] In the above technical solution, on the one hand, setting the thickness of the lead-out component in the thickness direction of the wall to be greater than or equal to 1 mm is beneficial to improving the structural strength of the lead-out component, thereby reducing the risk of deformation or breakage during use. It also enables the lead-out component to have sufficient penetration depth when welded to the busbar component, which is beneficial to improving the reliability and stability of the connection between the lead-out component and the busbar component. On the other hand, setting the thickness of the lead-out component in the thickness direction of the wall to be less than or equal to 2.5 mm saves the space occupied by the lead-out component in the thickness direction of the wall, thereby optimizing the overall size of the battery cell and improving the energy density of the battery cell.

[0025] In some embodiments, along the thickness direction of the wall portion, the lead-out member has a first surface facing the wall portion, the first surface being provided with a recess, and at least a portion of the protective layer is accommodated within the recess.

[0026] In the above technical solution, by providing a recess on the first surface of the lead-out member facing the wall, and at least a portion of the protective layer is accommodated in the recess along the thickness direction of the wall, the protective layer can not only separate the lead-out member and the first insulating member, but also allow the protective layer and the lead-out member to share a portion of the space in the thickness direction of the wall. This is beneficial for optimizing the space occupied by the protective layer and the lead-out member as a whole in the thickness direction of the wall, thereby optimizing the overall size of the battery cell and improving the energy density of the battery cell.

[0027] In some embodiments, along the thickness direction of the wall portion, the protective layer has a second surface facing the wall portion, the second surface and the first surface being coplanar.

[0028] In the above technical solution, by setting the second surface of the protective layer facing the wall and the first surface of the lead-out member facing the wall as a coplanar structure, the protective layer is accommodated as a whole in the recess of the lead-out member. On the one hand, it can further optimize the space occupied by the protective layer and the lead-out member as a whole in the thickness direction of the wall, so as to further optimize the overall size of the battery cell and improve the energy density of the battery cell. On the other hand, the recess can play a certain role in stabilizing and protecting the protective layer, which helps to reduce the wear of the protective layer during use.

[0029] In some embodiments, along the thickness direction of the wall portion, the protective layer has a third surface facing away from the wall portion; wherein, one of the surface of the lead-out member facing the wall portion and the third surface is provided with a first limiting protrusion, and the other is provided with a first limiting groove, and the first limiting protrusion and the first limiting groove are inserted into each other.

[0030] In the above technical solution, by providing a first limiting protrusion on one of the surface of the lead-out member facing the wall and a third surface of the protective layer away from the wall, and providing a first limiting groove on the other that cooperates with the first limiting protrusion, the limiting and positioning between the protective layer and the lead-out member can be realized, thereby improving the assembly accuracy between the protective layer and the lead-out member and improving the assembly stability between the protective layer and the lead-out member, so as to reduce the risk of the protective layer shaking or shifting during use.

[0031] In some embodiments, the surface of the lead-out member facing the wall is provided with the first limiting groove, and the third surface is provided with the first limiting protrusion.

[0032] In the above technical solution, by setting the first limiting groove on the lead-out member and setting the first limiting protrusion on the protective layer, the mutual limiting and positioning cooperation between the lead-out member and the protective layer can be achieved, while also reducing the need for grooving in the area of ​​the protective layer corresponding to the lead-out member. This reduces the impact of the first limiting groove on the structural strength of the protective layer or on the effect of the protective layer in separating the lead-out member.

[0033] In some embodiments, one of the surfaces of the lead-out member facing the wall and the third surface is provided with a plurality of first limiting protrusions, and the other is provided with a plurality of first limiting grooves, with each first limiting protrusion inserted into the first limiting groove.

[0034] In the above technical solution, by providing multiple first limiting protrusions on one of the surface of the lead-out member facing the wall and the third surface of the protective layer facing away from the wall, and correspondingly providing multiple first limiting grooves on the other, and each first limiting protrusion cooperating with a first limiting groove, the limiting effect between the protective layer and the lead-out member is further improved, thereby further improving the assembly stability between the protective layer and the lead-out member, and further reducing the risk of the protective layer shaking or shifting during use.

[0035] In some embodiments, the first insulating member includes an insulating body and a flanged portion; the insulating body is disposed between the protective layer and the wall portion along the thickness direction of the wall portion; the flanged portion surrounds the outside of the lead-out member, and the end of the flanged portion near the electrode assembly in the thickness direction of the wall portion is connected to the insulating body.

[0036] In the above technical solution, the first insulating member is provided with an insulating body located between the protective layer and the wall portion and a flange portion surrounding the lead-out member. One end of the flange portion in the thickness direction of the wall portion is connected to the insulating body, so that the insulating body and the flange portion together form a groove structure for accommodating the lead-out member and the protective layer. On the one hand, it can further improve the insulation isolation effect of the first insulating member between the lead-out member and the wall portion, so as to further reduce the risk of short circuit between the lead-out member and the wall portion. On the other hand, it can improve the assembly stability between the first insulating member and the lead-out member, and improve the assembly reliability of the protective layer between the lead-out member and the first insulating member.

[0037] In some embodiments, along the thickness direction of the wall portion, the insulating body has a fourth surface facing away from the wall portion, and the flange portion protrudes from the fourth surface; wherein, the fourth surface is provided with a receiving groove, and at least a portion of the protective layer is received within the receiving groove.

[0038] In the above technical solution, by providing a receiving groove on the fourth surface of the insulating body facing the lead-out member, and at least part of the protective layer is accommodated in the receiving groove, the protective layer and the insulating body of the first insulating member can share a portion of the space in the thickness direction of the wall. This is beneficial to optimize the space occupied by the protective layer and the insulating body as a whole in the thickness direction of the wall, thereby optimizing the overall size of the battery cell and improving the energy density of the battery cell.

[0039] In some embodiments, a second limiting protrusion is provided on the outer peripheral surface of the protective layer, and a second limiting groove is provided on the side of the receiving groove, with the second limiting protrusion inserted into the second limiting groove.

[0040] In the above technical solution, by providing a second limiting protrusion on the outer peripheral surface of the protective layer and providing a second limiting groove on the side of the receiving groove that cooperates with the second limiting protrusion, the limiting and positioning between the protective layer and the insulating body of the first insulating component can be achieved. On the one hand, this can improve the assembly accuracy of the protective layer in the receiving groove, thereby improving the assembly quality of the protective layer between the lead-out component and the first insulating component. On the other hand, it can achieve circumferential locking between the protective layer and the insulating body, thereby reducing the phenomenon of circumferential rotation of the protective layer relative to the insulating body of the first insulating component.

[0041] In some embodiments, a plurality of second limiting protrusions are provided on the outer peripheral surface of the protective layer, the plurality of second limiting protrusions are arranged at intervals along the circumference of the protective layer, and a plurality of second limiting grooves are provided on the side of the receiving groove, each second limiting protrusion being inserted into a second limiting groove.

[0042] In the above technical solution, by providing multiple second limiting protrusions arranged at intervals on the outer peripheral surface of the protective layer, and by providing multiple second limiting grooves corresponding one-to-one with the second limiting protrusions on the side of the receiving groove, the limiting and positioning effects between the protective layer and the insulating body of the first insulating component are further improved. On the one hand, the assembly accuracy of the protective layer in the receiving groove can be further improved, thereby further improving the assembly quality of the protective layer between the lead-out component and the first insulating component. On the other hand, the phenomenon of circumferential rotation of the protective layer relative to the insulating body of the first insulating component can be further reduced.

[0043] In some embodiments, the second limiting groove extends through the fourth surface along the thickness direction of the wall portion.

[0044] In the above technical solution, by setting the second limiting groove to penetrate the fourth surface, the second limiting groove is a structure that simultaneously penetrates the fourth surface and the side of the receiving groove, thereby reducing the difficulty of setting the second limiting groove on the side of the receiving groove, and thus reducing the manufacturing difficulty of the first insulating component.

[0045] In some embodiments, along the thickness direction of the wall portion, a mounting groove is provided on the surface of the wall portion opposite to the electrode assembly, and at least a portion of the first insulating member is accommodated in the mounting groove.

[0046] In the above technical solution, by setting an assembly groove on the surface of the wall away from the electrode assembly, and at least part of the first insulating member is accommodated in the assembly groove, the battery cell with this structure can, on the one hand, limit and position the first insulating member through the assembly groove, which helps to reduce the difficulty of assembling the first insulating member between the wall and the lead-out member, and can reduce the phenomenon of shaking or displacement of the first insulating member during use, which helps to improve the assembly stability of the first insulating member. On the other hand, it can realize that the first insulating member and the wall share part of the space in the thickness direction of the wall, which helps to optimize the overall size of the battery cell.

[0047] In some embodiments, the wall portion is provided with an electrode lead-out hole, which penetrates the wall portion along its thickness direction; wherein, the first electrode terminal further includes a connector connected to the lead-out member, the connector passing through the electrode lead-out hole and being electrically connected to the electrode assembly.

[0048] In the above technical solution, the wall is provided with an electrode lead-out hole that penetrates the wall along the thickness direction of the wall, and the first electrode terminal is also provided with a connector that is connected to the lead-out member. After the connector is inserted into the electrode lead-out hole, it can be electrically connected to the electrode assembly located in the outer shell, so as to realize the input or output of the electrical energy of the battery cell through the first electrode terminal. The structure is simple and easy to assemble.

[0049] In some embodiments, the connector includes a body portion and a limiting portion; the body portion passes through the electrode lead-out hole along the thickness direction of the wall portion, and the body portion is connected to the lead-out member; the limiting portion protrudes from the outer peripheral surface of the body portion; wherein, along the thickness direction of the wall portion, the limiting portion is located on the side of the wall portion facing the electrode assembly, and at least a portion of the wall portion is located between the limiting portion and the lead-out member.

[0050] In the above technical solution, the connector of the first electrode terminal is provided with a body part and a limiting part protruding on the outer peripheral surface of the body part. The body part is connected to the lead-out part, and the limiting part is located on the side of the wall part away from the lead-out part, so that at least part of the wall part is located between the limiting part and the lead-out part, so that the limiting part and the lead-out part can cooperate to clamp the wall part, thereby realizing the assembly of the first electrode terminal onto the wall part. The structure is simple, easy to assemble, and can improve the structural stability of the first electrode terminal assembled onto the wall part.

[0051] In some embodiments, the battery cell further includes a second insulating member, at least a portion of which is disposed between the limiting portion and the wall portion along the thickness direction of the wall portion to insulate and isolate the limiting portion and the wall portion.

[0052] In the above technical solution, a second insulating component is provided between the limiting part and the wall part, so that the second insulating component can play a certain role in insulating and isolating the limiting part and the wall part, thereby reducing the risk of short circuit between the limiting part and the wall part, and reducing the phenomenon of short circuit in the battery cell during use.

[0053] In some embodiments, the body portion and the lead-out member are riveted together.

[0054] In the above technical solution, by setting the body of the connector and the lead-out part to be riveted to each other, it is beneficial to improve the connection stability between the connector and the lead-out part, thereby reducing the risk of connection failure of the first electrode terminal during use, and also to reduce the connection difficulty between the connector and the lead-out part, thereby improving the assembly efficiency of the battery cell.

[0055] In some embodiments, the battery cell further includes a seal; the seal is disposed between the connector and the wall portion, and the seal is configured to seal the gap between the connector and the wall surface of the electrode lead-out hole.

[0056] In the above technical solution, the battery cell is also provided with a sealing element. By placing the sealing element between the wall and the connector of the first electrode terminal, the sealing element can seal the gap between the connector and the hole wall of the electrode lead-out hole, thereby reducing the risk of leakage of the battery cell at the electrode lead-out hole and improving the stability and reliability of the battery cell.

[0057] In some embodiments, the material of the lead-out element includes aluminum, and the material of the protective layer includes steel, copper, ceramic, or mica.

[0058] In the above technical solution, the lead-out component is made of aluminum to give it good electrical conductivity. Furthermore, aluminum's low melting point facilitates welding the lead-out component to the busbar, reducing assembly difficulty. The protective layer is made of steel, copper, ceramic, or mica. These materials give the protective layer a high melting point, making it less prone to weld-through or melt-through during welding of the lead-out component to the busbar, thus improving its isolation and protection of the wall or other components.

[0059] In some embodiments, the first electrode terminal is the positive electrode of the battery cell.

[0060] In the above technical solution, by setting the first electrode terminal as the positive terminal of the battery cell, the first electrode terminal can be used as the positive output terminal of the battery cell to input or output the electrical energy of the battery cell.

[0061] In some embodiments, the housing includes a shell and an end cap; the interior of the shell has an opening in a receiving cavity in which the electrode assembly is received; the end cap closes the opening; wherein the end cap is the wall portion.

[0062] In the above technical solution, by setting the wall of the outer shell as an end cap for sealing the opening of the shell, the battery cell with this structure is easy to assemble the first electrode terminal on the end cap and easy to assemble and connect the first electrode terminal with the electrode assembly, and it is also easy to set a protective layer between the lead and the first insulating part, thereby reducing the assembly difficulty of the battery cell and improving the production efficiency of the battery cell.

[0063] In some embodiments, the housing includes a shell and an end cap; the shell includes an integrally formed sidewall and a bottom wall, the sidewall surrounding the bottom wall, one end of the sidewall being connected to the bottom wall along the thickness direction of the wall portion, and the other end forming an opening, the sidewall and the bottom wall together defining a receiving cavity, the electrode assembly being received within the receiving cavity; the end cap closes the opening; wherein, the bottom wall is the wall portion.

[0064] In the above technical solution, by setting the wall of the outer casing as a wall that is opposite to the end cover in the thickness direction of the wall, the battery cell with this structure can make the area where the first electrode terminal is installed on the outer casing far away from the end cover, and make the wall and the end cover not directly connected. This can alleviate the phenomenon that the force generated when the first electrode terminal and other components pull or twist the wall acts on the end cover, thereby reducing the risk of connection failure between the end cover and the casing, and thus helping to reduce the risk of leakage of the battery cell during use.

[0065] Secondly, embodiments of this application also provide a battery device, including a busbar component and the aforementioned battery cell; the busbar component is disposed on the side of the lead-out member away from the protective layer in the thickness direction of the wall portion, the busbar component is welded to the lead-out member to form a connection portion, the connection portion includes a first connection portion and a second connection portion that are interconnected, the first connection portion is embedded in the lead-out member, and the second connection portion is embedded in the busbar component.

[0066] In the above technical solution, the busbar component is welded to the lead-out part of the first electrode terminal, and a first connection part is formed on the lead-out part and a second connection part is formed on the busbar component. The first connection part and the second connection part are connected to each other to realize the assembly connection between the first electrode terminal and the busbar component. The battery device with this structure can improve the connection stability and reliability between the first electrode terminal and the busbar component, and is also conducive to improving the overcurrent effect between the first electrode terminal and the busbar component.

[0067] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall portion, the minimum distance between the outer edges of the orthographic projection of the first connection portion and the orthographic projection of the protective layer is L1, satisfying that 1mm≤L1≤2.5mm.

[0068] In the above technical solution, on the one hand, the minimum distance between the orthographic projection of the first connecting part along the thickness direction of the wall in the protective layer and the outer edge of the protective layer is set to be greater than or equal to 1mm, so as to improve the effect of the protective layer in separating the area where the lead-out forms a solder mark, thereby further improving the protective effect of the protective layer on the first insulating component, and further reducing the risk of the lead-out being soldered through and affecting the first insulating component. On the other hand, the minimum distance between the orthographic projection of the first connecting part along the thickness direction of the wall in the protective layer and the outer edge of the protective layer is set to be less than or equal to 2.5mm, so as to alleviate the phenomenon that the area where the lead-out is used for welding with the busbar is restricted due to excessive distance, thereby increasing the size of the connection formed by welding the lead-out and the busbar, and further improving the connection stability and current carrying effect between the lead-out and the busbar.

[0069] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall portion, the minimum distance between the outer edges of the orthographic projection of the first connecting portion and the orthographic projection of the lead-out member is L2, satisfying 1mm≤L2≤2.5mm.

[0070] In the above technical solution, on the one hand, the minimum distance between the outer edge of the orthographic projection of the first connecting part in the projection plane perpendicular to the thickness direction of the wall and the outer edge of the orthographic projection of the lead-out part in the projection plane perpendicular to the thickness direction of the wall is set to be greater than or equal to 1 mm. This increases the distance between the area where the solder mark is formed on the lead-out part and the outer edge of the lead-out part, which helps to reduce the phenomenon of melting at the outer edge of the lead-out part, thereby improving the welding quality between the lead-out part and the busbar component. On the other hand, the minimum distance between the outer edge of the orthographic projection of the first connecting part in the projection plane perpendicular to the thickness direction of the wall and the outer edge of the orthographic projection of the lead-out part in the projection plane perpendicular to the thickness direction of the wall is set to be less than or equal to 2.5 mm. This alleviates the phenomenon that the area where the lead-out part is used for welding with the busbar component is restricted due to excessive distance. This increases the size of the connection part formed by welding the lead-out part and the busbar component, thereby further improving the connection stability and current flow effect between the lead-out part and the busbar component.

[0071] In some embodiments, along the thickness direction of the wall portion, the thickness of the area where the busbar component is welded to the lead-out component is D4, satisfying 1.2mm≤D4≤3mm.

[0072] In the above technical solution, by setting the thickness of the area where the busbar is welded to the lead-out component to be between 1.2mm and 3mm, on the one hand, setting the thickness of the area where the busbar is welded to the lead-out component to be greater than or equal to 1.2mm can improve the current-carrying performance of the busbar, thereby improving the conductivity of the busbar. While improving the current-carrying performance of the busbar, it will also increase the welding power and the weld pool between the busbar and the lead-out component. Thus, by setting a protective layer on the side of the lead-out component facing the wall, the area where the lead-out component is welded through can be effectively separated, thereby reducing the risk of the lead-out component affecting other components after being welded through. On the other hand, setting the thickness of the area where the busbar is welded to the lead-out component to be less than or equal to 3mm can reduce the phenomenon of excessive waste of the busbar component or excessive welding power required, thereby reducing the welding difficulty between the busbar component and the lead-out component and reducing the manufacturing cost of the busbar component.

[0073] In some embodiments, along the thickness direction of the wall portion, the surface of the lead-out member facing the wall portion is provided with a first limiting groove, the protective layer has a third surface facing away from the wall portion, the third surface is provided with a first limiting protrusion, the first limiting protrusion is inserted into the first limiting groove; wherein, the first limiting groove forms a slot on the surface of the lead-out member facing the wall portion, and in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the first connecting portion is located outside the orthographic projection of the slot.

[0074] In the above technical solution, by providing a first limiting groove on the surface of the lead-out member facing the wall, and providing a first limiting protrusion on the third surface of the protective layer away from the wall to engage with the first limiting groove, the limiting and positioning between the protective layer and the lead-out member can be achieved, thereby improving the assembly accuracy and stability between the protective layer and the lead-out member. In particular, by setting the projection of the first connecting part of the connecting part in the thickness direction of the wall to be located outside the opening of the first limiting groove, the projections of the first connecting part and the groove wall surface of the first limiting groove in the thickness direction of the wall do not overlap, thereby reducing the impact of the first limiting groove on the welding connection between the lead-out member and the busbar component, which is beneficial to improving the welding quality between the lead-out member and the busbar component.

[0075] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery cell or the aforementioned battery device. Attached Figure Description

[0076] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0077] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0078] Figure 2 is an exploded view of the structure of a battery device provided in some embodiments of this application;

[0079] Figure 3 is an assembly diagram of a battery cell and a busbar component provided in some embodiments of this application;

[0080] Figure 4 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0081] Figure 5 is an exploded view of the structure of a battery cell provided in some embodiments of this application;

[0082] Figure 6 is a partial cross-sectional view of a battery cell provided in some embodiments of this application;

[0083] Figure 7 is a partial enlarged view of point A of the battery cell shown in Figure 6;

[0084] Figure 8 is a partial cross-sectional view of the interconnected battery cell and busbar component provided in some embodiments of this application;

[0085] Figure 9 is a partial cross-sectional view of a battery cell provided in some embodiments of this application;

[0086] Figure 10 is a partial cross-sectional view of the interconnected battery cell and busbar component provided in some embodiments of this application;

[0087] Figure 11 is a schematic diagram of the structure of the lead-out member of the first electrode terminal provided in some embodiments of this application;

[0088] Figure 12 is a schematic diagram of the structure of the protective layer provided in some embodiments of this application;

[0089] Figure 13 is a schematic diagram of the structure of the first insulating element provided in some embodiments of this application;

[0090] Figure 14 is a schematic diagram of the structure of the protective layer provided in some embodiments of this application.

[0091] Icons: 1000 - Vehicle; 100 - Battery assembly; 10 - Housing; 11 - First housing body; 12 - Second housing body; 20 - Battery cell; 21 - Housing; 211 - Wall; 2111 - Electrode lead-out hole; 2112 - Assembly slot; 212 - Housing; 2121 - Opening; 213 - End cap; 22 - Electrode assembly; 221 - Main body; 222 - Tab; 23 - Electrode terminal; 23a - First electrode terminal; 23b - Second electrode terminal; 231 - Lead-out piece; 2311 - Riveting hole; 2312 - First surface; 2313 - Recess; 2314 - First limiting groove; 2314a - Groove; 232 - Connector; 232 1-Main body; 2322-Limiting part; 24-First insulating member; 241-Insulating body; 2411-Fourth surface; 2412-Receiving groove; 2413-Second limiting groove; 2414-Second through hole; 242-Flanged part; 25-Protective layer; 251-Second surface; 252-Third surface; 253-First limiting protrusion; 254-Second limiting protrusion; 255-First through hole; 26-Current collector; 27-Pressure relief component; 28-Second insulating member; 29-Sealing member; 30-Current collector; 40-Connecting part; 41-First connecting part; 42-Second connecting part; 200-Controller; 300-Motor; X-Thickness direction of the wall part. Detailed Implementation

[0092] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0093] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0094] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0095] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0096] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0097] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0098] In this application, "multiple" means two or more (including two).

[0099] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0100] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0101] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, helps prevent short circuits to some extent while allowing active ions to pass through.

[0102] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0103] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0104] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0105] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 )), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0106] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0107] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0108] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0109] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0110] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0111] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0112] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0113] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0114] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0115] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0116] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0117] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0118] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0119] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0120] Among them, gel electrolytes include a polymer-based electrolyte backbone network combined with an ionic liquid-lithium salt.

[0121] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0122] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0123] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0124] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0125] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0126] In some implementations, the electrode assembly has a stacked structure.

[0127] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0128] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0129] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0130] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0131] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0132] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0133] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0134] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0135] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include, but are not limited to, square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0136] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0137] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0138] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0139] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0140] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0141] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0142] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0143] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0144] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0145] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, discharge capacity, and charge / discharge rate. Furthermore, the reliability of the battery device must also be taken into account.

[0146] For a typical battery cell, it includes a casing and an electrode assembly housed within the casing. The casing has an end cap with electrode terminals, each including a connector and a lead-out. The connector is inside the end cap, while the lead-out is located outside. Connecting the connector of the electrode terminal to the tabs of the electrode assembly allows for the input or output of electrical energy from the battery cell. An insulating component is provided between the end cap and the lead-out of the electrode terminal to reduce the risk of short circuits between the lead-out and the end cap. In related technologies, when multiple battery cells are assembled to form a battery device, a busbar is typically included within the battery device to connect multiple battery cells. The electrode terminals of individual battery cells are welded together to achieve series or parallel connection between multiple battery cells in a battery device. However, in order to meet the weld penetration requirements of the electrode terminal leads and the busbar components, the electrode terminals of the battery cells in related technologies are prone to weld breakdown when welded to the busbar components. This can easily cause the insulating components between the leads and the end cap to melt or be damaged, resulting in the risk of insulation failure between the leads and the end cap. This makes it easy for the electrode terminals of the battery cells to short-circuit with the casing during use, which is detrimental to improving the reliability of the battery cells.

[0147] Based on the above considerations, in order to solve the problem of low reliability of battery cells, this application provides a battery cell including a casing, an electrode assembly, a first electrode terminal, a first insulating member, and a protective layer. The casing has a wall portion. The electrode assembly is housed within the casing. The first electrode terminal is electrically connected to the electrode assembly and includes a lead-out located on the side of the wall portion away from the electrode assembly. The lead-out is used for welding to a busbar component and forms a first connection portion on the lead-out. At least a portion of the first insulating member is disposed between the lead-out and the wall portion in the thickness direction of the wall portion, and in a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the first insulating member overlaps with the orthographic projection of the first connection portion. At least a portion of the protective layer is disposed between the lead-out and the first insulating member. The melting point of the protective layer is greater than the melting point of the lead-out, and in a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the first connection portion is located within the orthographic projection of the protective layer.

[0148] In this type of battery cell, the first electrode terminal is electrically connected to the electrode assembly, and the lead-out portion located on the side of the wall away from the electrode assembly is used for welding connection to the busbar component, so as to realize the input or output of electrical energy of the battery cell through the first electrode terminal. A first insulating member is provided between the lead-out portion and the wall, so that the first insulating member can insulate and isolate the lead-out portion and the wall. However, since the projection of the first insulating member in the thickness direction of the wall overlaps at least partially with the projection of the first connecting portion in the thickness direction of the wall, a protective layer is provided between the lead-out portion and the wall. The melting point of the protective layer is greater than the melting point of the lead-out portion, and the lead-out portion is welded to the busbar component. At least a portion of the projection of the first connection portion formed on the lead-out member in the thickness direction of the wall portion is located within the protective layer. This allows the protective layer to provide a certain degree of protection and separation for the first insulating component when the lead-out member is welded to the busbar component, thereby reducing the phenomenon of burning or melting the first insulating component after the lead-out member is welded through. This eliminates the need to reduce the risk of the lead-out member being welded through by increasing its thickness. This optimizes the thickness of the lead-out member while effectively reducing the risk of insulation failure between the lead-out member and the wall portion after the first insulating component is damaged. Consequently, it reduces the risk of short circuit between the first electrode terminal and the casing during use, thereby improving the reliability of the battery cell.

[0149] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using battery cells and battery devices disclosed in this application. This helps to mitigate the problem of short circuits that easily occur in battery cells during use, thereby improving the reliability of the battery cells.

[0150] This application provides an electrical device that uses a single battery cell or battery assembly as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0151] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0152] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000. The battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, it can serve as the vehicle's operating power source or general power source. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 controls the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0153] In some embodiments of this application, the battery device 100 can not only serve as the operating power or power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0154] Please refer to Figures 2 and 3. Figure 2 is an exploded view of the battery device 100 provided in some embodiments of this application. Figure 3 is an assembly diagram of the battery cell 20 and the busbar component 30 provided in some embodiments of this application. Figure 4 is a structural diagram of the battery cell 20 provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, which are housed within the housing 10.

[0155] The housing 10 provides assembly space for the battery cell 20, and can adopt various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which overlap each other, and together define an assembly space for accommodating the battery cell 20. The second housing body 12 may be a hollow structure open at one end, and the first housing body 11 may be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12 so that the first housing body 11 and the second housing body 12 together define the assembly space; alternatively, the first housing body 11 and the second housing body 12 may both be hollow structures open on one side, with the open side of the first housing body 11 covering the open side of the second housing body 12.

[0156] Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder, a cuboid, or a cube. For example, in Figure 2, the shape of the box 10 is a cuboid.

[0157] In the battery device 100, there can be one or more battery cells 20 disposed within the housing 10. When there are multiple battery cells 20 disposed within the housing 10, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, in parallel, or in a mixed configuration to form battery modules, and then multiple battery modules connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10.

[0158] In some embodiments, as shown in FIG3, the battery device 100 may further include a busbar 30 for connecting a plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20.

[0159] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be in the form of a cuboid, cylinder, prism, or other shapes. For example, in Figure 4, the battery cell 20 has a cuboid structure.

[0160] According to some embodiments of this application, referring to Figures 3 and 4, and further referring to Figures 5, 6, 7, and 8, Figure 5 is an exploded view of the structure of a battery cell 20 provided in some embodiments of this application, Figure 6 is a partial cross-sectional view of a battery cell 20 provided in some embodiments of this application, Figure 7 is a partial enlarged view of point A of the battery cell 20 shown in Figure 6, and Figure 8 is a partial cross-sectional view of the battery cell 20 and the busbar component 30 provided in some embodiments of this application after being interconnected. This application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, a first electrode terminal 23a, a first insulating member 24, and a protective layer 25. The housing 21 has a wall portion 211. The electrode assembly 22 is housed within the housing 21. The first electrode terminal 23a is electrically connected to the electrode assembly 22, and the first electrode terminal 23a includes a lead-out 231 located on the side of the wall portion 211 opposite to the electrode assembly 22. The lead-out 231 is used for welding to the busbar component 30, and a first connection portion 41 is formed on the lead-out 231. At least a portion of the first insulating member 24 is disposed between the lead-out member 231 and the wall portion 211 in the thickness direction X of the wall portion, and in a projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the first insulating member 24 overlaps with the orthographic projection of the first connecting portion 41. At least a portion of the protective layer 25 is disposed between the lead-out member 231 and the first insulating member 24, the melting point of the protective layer 25 is greater than the melting point of the lead-out member 231, and in a projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the first connecting portion 41 is located within the orthographic projection of the protective layer 25.

[0161] The outer shell 21 can also be used to contain electrolytes, such as electrolyte solution. The outer shell 21 can have various structural forms, such as a cylinder or a cuboid. Similarly, the outer shell 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0162] In some embodiments, the housing 21 can be a sealed structure or a non-sealed structure. As an example, when the housing 21 is a sealed structure, it can protect the electrode assembly 22 and prevent, to some extent, electrolyte leakage. When the housing 21 is a non-sealed structure, it can still protect the electrode assembly 22, and a sealing bag may be included between the housing 21 and the electrode assembly 22. The sealing bag is used to encapsulate the electrode assembly 22 and the electrolyte, etc. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0163] Optionally, the housing 21 may include a housing 212 and an end cap 213. The housing 212 has an internal cavity for accommodating the electrode assembly 22 and has an opening 2121. That is, the housing 212 is a hollow structure with an opening 2121 at one end. The end cap 213 covers the opening 2121 of the housing 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0164] The housing 212 includes a bottom wall and a side wall. The bottom wall is disposed opposite to the end cap 213. The side wall surrounds the bottom wall, and one end of the side wall is connected to the bottom wall, while the other end forms an opening 2121.

[0165] It should be noted that the wall portion 211 can be the end cap 213 of the outer casing 21, or it can be a wall of the housing 212 of the outer casing 21. For example, in Figures 4 and 5, the wall portion 211 is the end cap 213. Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the wall portion 211 can also be the bottom wall of the housing 212 and the end cap 213 disposed opposite to each other, or the wall portion 211 can also be a side wall of the housing 212 and the end cap 213 that are adjacent to and connected to each other.

[0166] When assembling the battery cell 20, the electrode assembly 22 can be placed into the housing 212 first, and the electrolyte can be filled into the housing 212. Then, the end cap 213 can be closed onto the opening 2121 of the housing 212 to complete the assembly of the battery cell 20.

[0167] The housing 212 can have various shapes, such as a cylinder, cuboid, or prism. The shape of the housing 212 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a cylindrical housing 212 can be selected; if the electrode assembly 22 is a cuboid structure, a cuboid housing 212 can be selected. Of course, the end cap 213 can also have various structures, such as a plate-like structure or a hollow structure with one end open. For example, in Figures 4 and 5, the housing 212 is a cuboid structure.

[0168] Of course, it is understandable that the outer casing 21 is not limited to the structure described above. The outer casing 21 can also be other structures. For example, the outer casing 21 can include a housing 212 and two end caps 213. The housing 212 is a hollow structure with openings 2121 formed on both opposite sides. One end cap 213 is fitted onto one opening 2121 of the housing 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte. That is, the housing 212 has openings 2121 formed on both opposite sides, and the two end caps 213 are fitted onto both sides of the housing 212 to close the corresponding openings 2121.

[0169] Optionally, the structure of the electrode assembly 22 can be various. For example, the electrode assembly 22 can be a wound structure formed by winding a positive electrode, an insulating element and a negative electrode, or a stacked structure formed by arranging a positive electrode, an insulating element and a negative electrode in layers.

[0170] For example, the separator is a separator membrane, and the main material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0171] The electrode assembly 22 includes a main body 221 and a tab 222. The main body 221 is the main component of the electrode assembly 22 for electrochemical reactions to occur in the battery cell 20. For example, in FIG5, the tab 222 is connected to one end of the main body 221 facing the wall 211 in the thickness direction X of the wall. That is, in the thickness direction X of the wall, the tab 222 is located between the main body 221 and the wall 211 so that the tab 222 can be connected to the first electrode terminal 23a.

[0172] It should be noted that the tabs 222 of the electrode assembly 22 are either formed by stacking and connecting regions of the positive electrode sheet that are not coated with a positive active material layer, or by stacking and connecting regions of the negative electrode sheet that are not coated with a negative active material layer. If the tab 222 is the positive tab of the electrode assembly 22, then the tab 222 is formed by stacking and connecting regions of the positive electrode sheet that are not coated with a positive active material layer; if the tab 222 is the negative tab of the electrode assembly 22, then the tab 222 is formed by stacking and connecting regions of the negative electrode sheet that are not coated with a negative active material layer.

[0173] Optionally, the electrode assembly 22 housed within the housing 21 can be one or more. For example, in FIG5, the housing 21 of the battery cell 20 is provided with two electrode assemblies 22, which are stacked along the thickness direction of the battery cell 20. Of course, in other embodiments, the number of electrode assemblies 22 housed within the housing 21 of the battery cell 20 can also be three, four, five, or six, etc.

[0174] In this embodiment of the application, the battery cell 20 includes two electrode terminals 23, both of which serve to electrically connect to the electrode assembly 22, acting as the positive and negative electrodes of the battery cell 20, thereby enabling the input or output of electrical energy from the battery cell 20.

[0175] The two electrode terminals 23 include a first electrode terminal 23a and a second electrode terminal 23b with opposite polarities. For example, in this embodiment, the first electrode terminal 23a is the positive electrode of the battery cell 20, and the corresponding second electrode terminal 23b is the negative electrode of the battery cell 20. Of course, in other embodiments, the first electrode terminal 23a can also be the negative electrode of the battery cell 20, and the corresponding second electrode terminal 23b can be the positive electrode of the battery cell 20.

[0176] In Figures 4 and 5, the first electrode terminal 23a and the second electrode terminal 23b are spaced apart on the wall portion 211. Correspondingly, each electrode assembly 22 has two tabs 222. Both tabs 222 are connected to the end of the main body portion 221 facing the wall portion 211 in the thickness direction X of the wall portion. The two tabs 222 have opposite polarities and are spaced apart, that is, the two tabs 222 are the positive tab and the negative tab of the electrode assembly 22, respectively. The first electrode terminal 23a and the second electrode terminal 23b are electrically connected to the two tabs 222 of the electrode assembly 22, respectively, to realize the input or output of electrical energy of the battery cell 20.

[0177] In Figure 6, the electrode terminal 23 includes a lead-out member 231 and a connector 232. The lead-out member 231 is located on the side of the wall portion 211 away from the electrode assembly 22 in the thickness direction X of the wall portion. The lead-out member 231 is used for welding connection with the busbar component 30. The connector 232 is connected to the lead-out member 231 and is electrically connected to the tab 222 of the electrode assembly 22.

[0178] The connector 232 and the electrode tab 222 of the electrode assembly 22 can be directly connected, such as by welding or abutting, or they can be indirectly connected, such as by the electrode tab 222 of the electrode assembly 22 being connected to the connector 232 through other components.

[0179] In this embodiment, the busbar component 30 is disposed on the side of the lead-out member 231 facing away from the electrode assembly 22 in the thickness direction X of the wall portion, and the busbar component 30 is welded to the lead-out member 231. The lead-out member 231 is used to weld to the busbar component 30 and form a first connecting portion 41 on the lead-out member 231. That is, the first connecting portion 41 is a solder mark formed on the lead-out member 231 after the lead-out member 231 and the busbar component 30 are welded together. In other words, the lead-out member 231 is welded to the busbar component 30 to form a connecting portion 40. The connecting portion 40 includes a first connecting portion 41 and a second connecting portion 42 that are connected to each other. The first connecting portion 41 is embedded in the lead-out member 231, and the second connecting portion 42 is embedded in the busbar component 30. Correspondingly, the connecting portion 40 is the area where the lead-out member 231 and the busbar component 30 are welded together to form a fused area or a solder mark area. The first connecting part 41 is the part of the connecting part 40 embedded in the lead-out member 231, and the second connecting part 42 is the part of the connecting part 40 embedded in the busbar member 30, and the second connecting part 42 and the first connecting part 41 are connected to each other.

[0180] It should be noted that the busbar component 30 is connected to the electrode terminals 23 of multiple battery cells 20. The busbar component 30 can be used to achieve parallel connection between multiple battery cells 20, or it can be used to achieve series connection between multiple battery cells 20. For example, in Figure 3, each busbar component 30 connects to the electrode terminals 23 of different polarities in two adjacent battery cells 20. That is, each busbar component 30 connects the first electrode terminal 23a of one battery cell 20 and the second electrode terminal 23b of the other battery cell 20 to achieve series connection between multiple battery cells 20.

[0181] Optionally, the connection structure between the lead-out member 231 and the connector 232 can be various, such as welding or riveting. For example, as shown in Figure 6, the connector 232 and the lead-out member 231 are riveted to each other. The lead-out member 231 is provided with a riveting hole 2311, which penetrates the lead-out member 231 along the thickness direction X of the wall. The connector 232 is inserted into the riveting hole 2311 along the thickness direction X of the wall and is riveted to the lead-out member 231.

[0182] Referring to Figure 6, an electrode lead-out hole 2111 is provided on the wall portion 211. The electrode lead-out hole 2111 penetrates the wall portion 211 along the thickness direction X. The connector 232 is inserted into the electrode lead-out hole 2111 so that the connector 232 can be connected to the tab 222 of the electrode assembly 22.

[0183] The connector 232 includes a body portion 2321 and a limiting portion 2322 that are connected to each other. The body portion 2321 passes through the electrode lead-out hole 2111 and the riveting hole 2311 along the thickness direction X of the wall portion, and the body portion 2321 is riveted to the lead-out member 231. The limiting portion 2322 protrudes from the outer peripheral surface of the body portion 2321 and is located on the side of the wall portion 211 facing the electrode assembly 22, so that the limiting portion 2322 and the lead-out member 231 can cooperate to clamp the wall portion 211 to assemble the electrode terminal 23 onto the wall portion 211.

[0184] It should be noted that in the embodiments of this application, the second electrode terminal 23b is the negative electrode of the battery cell 20. Correspondingly, the lead-out part 231 of the second electrode terminal 23b is usually a composite structure, that is, the lead-out part 231 of the second electrode terminal 23b is a double-layer structure made of two metal materials, such as hot rolling or cold rolling. Correspondingly, the material of one layer of the lead-out part 231 of the second electrode terminal 23b is the same as the material of the busbar component 30, and the material of the other layer is the same as the material of the negative electrode tab of the electrode assembly 22.

[0185] In some embodiments, as shown in FIG5, the battery cell 20 may further include two current collectors 26. The two current collectors 26 are both disposed inside the housing 21 and are spaced apart. Each current collector 26 is used to connect a connector 232 of an electrode terminal 23 and a tab 222 of the same polarity in a plurality of electrode assemblies 22, so as to realize the electrical connection between the two electrode terminals 23 and the electrode assembly 22, which helps to reduce the assembly difficulty between the tab 222 and the electrode terminal 23.

[0186] For example, the current collector 26 is welded to the tab 222. Of course, in other embodiments, the current collector 26 and the tab 222 may also be connected by mutual contact or snap-fit.

[0187] For example, the material of the current collector 26 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0188] In this embodiment, the first insulating member 24 serves to insulate and isolate the lead-out member 231 and the wall portion 211, so that the lead-out member 231 is an insulated structure installed on the wall portion 211, and no electrical connection is formed between the lead-out member 231 and the wall portion 211.

[0189] Optionally, the first insulating element 24 can be made of various materials, such as rubber, plastic or silicone.

[0190] Wherein, at least a portion of the first insulating member 24 is disposed between the lead-out member 231 and the wall portion 211 in the thickness direction X of the wall portion. That is, the first insulating member 24 may be a structure in which the entire structure is located between the lead-out member 231 and the wall portion 211 in the thickness direction X of the wall portion, or it may be a structure in which the structure is only partially located between the lead-out member 231 and the wall portion 211 in the thickness direction X of the wall portion.

[0191] For example, in Figures 6 and 7, the first insulating member 24 is a structure that is only partially located between the lead-out member 231 and the wall portion 211 in the thickness direction X of the wall portion.

[0192] In the projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the first insulating member 24 overlaps with the orthographic projection of the first connecting portion 41. That is, the solder joint formed on the lead-out member 231 and the busbar member 30 is welded together, and at least a portion of the projection of the lead-out member 231 in the thickness direction X of the wall portion falls into the first insulating member 24.

[0193] In this embodiment, at least a portion of the protective layer 25 is disposed between the lead-out member 231 and the first insulating member 24 to separate the lead-out member 231 and the first insulating member 24 in the thickness direction X of the wall portion, thereby mitigating the damage to the first insulating member 24 when the lead-out member 231 is welded to the busbar 30.

[0194] The melting point of the protective layer 25 is greater than that of the lead-out member 231. That is, the protective layer 25 is more resistant to high temperature than the lead-out member 231. The temperature required for the protective layer 25 to be damaged, decomposed, softened or melted is higher than the temperature required for the lead-out member 231 to be melted.

[0195] For example, the lead-out element 231 is made of aluminum, and correspondingly, the protective layer 25 can be made of a metal, such as copper, iron, or steel. Of course, the protective layer 25 can also be made of a non-metallic material, such as ceramic or mica. It should be noted that in embodiments where the protective layer 25 is made of a non-metallic material, if the protective layer 25 does not have a fixed melting point, that is, the melting point of the protective layer 25 is a range value, then in this embodiment, the lowest melting point of the protective layer 25 made of this material is a structure with a melting point greater than that of the lead-out element 231.

[0196] In the projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the first connecting portion 41 is located within the orthographic projection of the protective layer 25. That is, the solder mark formed on the leading portion 231 by welding the lead-out member 231 and the bus member 30 together is such that at least a portion of the projection of the lead-out member 231 in the thickness direction X of the wall portion falls into the protective layer 25, so that the protective layer 25 can separate the first insulating member 24 and the first connecting portion 41 from each other in the thickness direction X of the wall portion.

[0197] In some embodiments, the protective layer 25 and the first electrode terminal 23a are separately disposed, that is, the protective layer 25 and the first electrode terminal 23a are two independent components. Along the thickness direction X of the wall portion, at least a portion of the protective layer 25 is disposed between the wall portion 211 and the lead-out member 231. In other words, the protective layer 25 is disposed on the side of the lead-out member 231 facing the wall portion 211 in the thickness direction X of the wall portion, so that the protective layer 25 and the lead-out member 231 are stacked in the thickness direction X of the wall portion.

[0198] Optionally, the protective layer 25 and the lead-out member 231 can be interconnected or unconnected. For example, in this embodiment, the protective layer 25 and the lead-out member 231 abut against each other along the first direction. Of course, in other embodiments, the protective layer 25 and the lead-out member 231 can also be bonded or welded together.

[0199] In some embodiments, as shown in Figures 4 and 5, the battery cell 20 may further include a pressure relief component 27, which is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0200] For example, the pressure relief component 27 is disposed on the end cap 213 of the housing 21. Of course, in other embodiments, the pressure relief component 27 may also be disposed on the housing 212 of the housing 21. Similarly, the pressure relief component 27 and the housing 21 may be integrally formed or separately disposed. If the pressure relief component 27 and the housing 21 are separately disposed, the pressure relief component 27 may be connected to the housing 21 by welding or other means. Correspondingly, the pressure relief component 27 may be a component such as an explosion-proof valve, explosion-proof disc, gas valve, pressure relief valve or safety valve. If the pressure relief component 27 and the housing 21 are integrally formed, the pressure relief component 27 is a region on the housing 21 with a weak structure, such as a region on the housing 21 with a groove.

[0201] In this embodiment, the first electrode terminal 23a is electrically connected to the electrode assembly 22, and the lead-out member 231 of the first electrode terminal 23a located on the side of the wall portion 211 away from the electrode assembly 22 is used for welding connection with the busbar component 30, so that the input or output of electrical energy of the battery cell 20 can be realized through the first electrode terminal 23a. A first insulating member 24 is provided between the lead-out member 231 and the wall portion 211, so that the first insulating member 24 can insulate and isolate the lead-out member 231 and the wall portion 211. However, since the projection of the first insulating member 24 in the thickness direction X of the wall portion at least partially overlaps with the projection of the first connecting portion 41 in the thickness direction X of the wall portion, a protective layer 25 is provided between the lead-out member 231 and the wall portion 211. The melting point of the protective layer 25 is greater than the melting point of the lead-out member 231, and the lead-out member 231 and the busbar component 30 are connected. At least a portion of the projection of the first connection portion 41 formed on the lead-out member 231 by welding is located within the protective layer 25 in the thickness direction X of the wall portion. This allows the protective layer 25 to provide a certain degree of protection and separation for the first insulating member 24 when the lead-out member 231 is welded to the busbar 30, thereby reducing the phenomenon of burning or melting of the first insulating member 24 after the lead-out member 231 is welded through. This eliminates the need to increase the thickness of the lead-out member 231 to reduce the risk of the lead-out member 231 being welded through. This optimizes the thickness of the lead-out member 231 while effectively reducing the risk of insulation failure between the lead-out member 231 and the wall portion 211 after the first insulating member 24 is damaged. This further reduces the risk of short circuit between the first electrode terminal 23a and the outer casing 21 during use, thereby improving the reliability of the battery cell 20.

[0202] In some embodiments, referring to FIG8, in a projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first connecting portion 41 is entirely within the orthographic projection of the protective layer 25. That is, the solder joint formed on the leading portion 231 by welding the lead-out member 231 and the bus member 30 together results in a structure where the projection of the lead-out member 231 in the thickness direction X of the wall portion falls entirely within the protective layer 25, so that the protective layer 25 can completely separate the first insulating member 24 and the first connecting portion 41 in the thickness direction X of the wall portion.

[0203] In this embodiment, by welding the lead-out member 231 to the busbar 30 and projecting the first connecting portion 41 formed on the lead-out member 231 in the thickness direction X of the wall portion into a structure in which the entire portion is located within the protective layer 25, the protective layer 25 can effectively separate the first connecting wall and the first insulating member 24 in the thickness direction X of the wall portion. This further reduces the phenomenon of burning or melting the first insulating member 24 after the lead-out member 231 is welded through, thereby further reducing the risk of insulation failure between the lead-out member 231 and the wall portion 211 after the first insulating member 24 is damaged. This further reduces the risk of short circuit between the first electrode terminal 23a and the outer casing 21 during use, which is beneficial to further improve the reliability of the battery cell 20.

[0204] According to some embodiments of this application, as shown in Figures 6 and 7, the melting point of the protective layer 25 is T1, and the melting point of the lead-out member 231 is T2, satisfying that T1-T2≥200℃.

[0205] For example, the melting point T1 of the protective layer 25 may be 200°C, 205°C, 210°C, 220°C, 230°C, 240°C, 250°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 900°C, 1000°C, 1100°C, or 1200°C higher than the melting point T2 of the lead-in 231.

[0206] In this embodiment, by setting the melting point of the protective layer 25 to be 200 degrees Celsius or more higher than that of the lead-out member 231, the phenomenon of the protective layer 25 being melted when the lead-out member 231 is welded to the busbar component 30 is further alleviated. This can further improve the separation and barrier effect of the protective layer 25, which is beneficial to further improve the protection effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 is welded to the busbar component 30.

[0207] In some embodiments, the melting point of the protective layer 25 is T1, satisfying 1000℃≤T1≤3000℃.

[0208] For example, the melting point T1 of the protective layer 25 can be 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, 1800℃, 1900℃, 2000℃, 2100℃, 2200℃, 2300℃, 2400℃, 2500℃, 2600℃, 2700℃, 2800℃, 2900℃, or 3000℃, etc.

[0209] In this embodiment, on the one hand, the melting point of the protective layer 25 is set to be greater than or equal to 1000 degrees Celsius so that the protective layer 25 has a better high-temperature resistance effect. This allows the protective layer 25 to play a better role in separating and protecting the first insulating component 24 when the lead-out component 231 is welded to the busbar component 30, thereby reducing the risk of the lead-out component 231 being burned or melted after being welded through. On the other hand, the melting point of the protective layer 25 is set to be less than or equal to 3000 degrees Celsius to alleviate the phenomenon of excessive high-temperature resistance of the protective layer 25. This reduces the difficulty of material selection and manufacturing of the protective layer 25, thereby reducing the manufacturing cost of the protective layer 25.

[0210] According to some embodiments of this application, as shown in Figures 6, 7 and 8, the lead-out member 231 and the protective layer 25 are stacked along the thickness direction X of the wall portion. In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the lead-out member 231 is located within the orthographic projection of the protective layer 25.

[0211] In the projection plane perpendicular to the thickness direction X of the wall, the orthographic projection of the lead-out member 231 is located within the orthographic projection of the protective layer 25. That is, the projection of the lead-out member 231 in the thickness direction X of the wall is located within the protective layer 25, so that the protective layer 25 is a structure that covers the lead-out member 231 in the thickness direction X of the wall.

[0212] In this embodiment, by setting the lead-out member 231 and the protective layer 25 to be stacked along the thickness direction X of the wall, and the projection of the lead-out member 231 in the thickness direction X of the wall is located within the protective layer 25, the protective layer 25 can effectively separate the lead-out member 231 and the first insulating member 24 in the thickness direction X of the wall, thereby further improving the protective effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 is welded to the busbar 30, and further reducing the risk of the lead-out member 231 being burned or the first insulating member 24 being melted after being welded through.

[0213] According to some embodiments of this application, as shown in Figures 6 and 7, the maximum dimension of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall is D1, which satisfies that D1 < 3 mm.

[0214] The maximum dimension of the protective layer 25 and the lead-out member 231 along the thickness direction X of the wall is D1, where D1 < 3mm. This means the maximum thickness of the protective layer 25 and the lead-out member 231 along the thickness direction X of the wall is less than 3mm, i.e., the space occupied by the protective layer 25 and the lead-out member 231 along the thickness direction X of the wall is less than 3mm. For example, referring to Figures 6 and 7, if the protective layer 25 and the lead-out member 231 are stacked along the thickness direction X of the wall, then the sum of the thickness of the protective layer 25 and the thickness of the lead-out member 231 along the thickness direction X of the wall is less than 3mm. Similarly, referring to Figures 9 and 10, Figure 9 is a partial cross-sectional view of the battery cell 20 provided in some embodiments of this application, and Figure 10 is a partial cross-sectional view of the battery cell 20 and the busbar component 30 after interconnection in some embodiments of this application. If the lead-out member 231 is stacked along the thickness direction X of the wall... In an embodiment where a recess 2313 is provided on the first surface 2312 facing the wall portion 211 in the X direction, and a portion of the protective layer 25 is accommodated in the recess 2313, the sum of the thickness of the lead-out member 231 in the thickness direction X of the wall portion and the size of the protective layer 25 protruding from the first surface 2312 is less than 3 mm. If the entire protective layer 25 is accommodated in the recess 2313 in the thickness direction X of the wall portion, that is, the protective layer 25 does not protrude from the first surface 2312 in the thickness direction X of the wall portion, then the thickness of the lead-out member 231 in the thickness direction X of the wall portion is less than 3 mm.

[0215] In this embodiment, since the separation effect of the protective layer 25 can reduce the risk of the lead 231 being soldered through without increasing the thickness of the lead 231, the thickness dimension of the lead 231 in the thickness direction X of the wall can be optimized. This allows the thickness dimension of the lead 231 in the thickness direction X of the wall to be reduced, and the maximum dimension of the protective layer 25 and the lead 231 as a whole in the thickness direction X of the wall to be less than 3mm. This saves the space occupied by the first electrode terminal 23a and the protective layer 25 in the thickness direction X of the wall, thereby optimizing the overall size of the battery cell 20 and improving the energy density of the battery cell 20.

[0216] According to some embodiments of this application, referring to Figures 6, 7 and 9, the maximum dimension of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall is D1, which satisfies 1.8mm≤D1≤2.8mm.

[0217] For example, the maximum dimension D1 of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall portion can be 1.8mm, 1.85mm, 1.9mm, 1.95mm, 2mm, 2.05mm, 2.1mm, 2.15mm, 2.2mm, 2.25mm, 2.3mm, 2.35mm, 2.4mm, 2.45mm, 2.5mm, 2.55mm, 2.6mm, 2.65mm, 2.7mm, 2.75mm or 2.8mm, etc.

[0218] In this embodiment, on the one hand, setting the maximum dimension of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall to be greater than or equal to 1.8 mm facilitates the setting of a thicker protective layer 25 and lead-out member 231, which is beneficial to improving the separation and protection effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 is welded to the busbar 30, and also helps to improve the structural strength of the lead-out member 231, so as to reduce the risk of breakage or deformation of the lead-out member 231 during use. On the other hand, setting the maximum dimension of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall to be less than or equal to 2.8 mm can further save the space occupied by the lead-out member 231 and the protective layer 25 in the thickness direction X of the wall, so as to further optimize the overall size of the battery cell 20 and further improve the energy density of the battery cell 20.

[0219] According to some embodiments of this application, referring to Figures 6 and 7, along the thickness direction X of the wall portion, the thickness of the protective layer 25 is D2, and the thickness of the lead-out member 231 is D3, satisfying that 0.1≤D2 / D3≤0.25.

[0220] Wherein, D2 is the maximum dimension of the protective layer 25 in the thickness direction X of the wall, and D3 is the maximum dimension of the lead-out member 231 in the thickness direction X of the wall.

[0221] It should be noted that, referring to Figure 9, in an embodiment where a recess 2313 is provided on the first surface 2312 of the lead-out member 231 facing the wall portion 211 in the thickness direction X of the wall portion, and a portion of the protective layer 25 is accommodated in the recess 2313, then D3 is the maximum distance between the surface of the lead-out member 231 on the side facing away from the wall portion 211 in the thickness direction X of the wall portion and the first surface 2312.

[0222] For example, the thickness D2 of the protective layer 25 can be 0.1 times, 0.11 times, 0.12 times, 0.13 times, 0.14 times, 0.15 times, 0.16 times, 0.17 times, 0.18 times, 0.19 times, 0.2 times, 0.21 times, 0.22 times, 0.23 times, 0.24 times, or 0.25 times the thickness D3 of the lead-out member 231.

[0223] In this embodiment, on the one hand, the thickness of the protective layer 25 is set to be greater than or equal to 0.1 times the thickness of the lead-out member 231, so that the protective layer 25 has sufficient thickness to separate and block when the lead-out member 231 is welded to the busbar component 30, thereby alleviating the phenomenon of the protective layer 25 being welded through. This is beneficial to improving the separation and protection effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 is welded to the busbar component 30. On the other hand, the thickness of the protective layer 25 is set to be less than or equal to 0.25 times the thickness of the lead-out member 231, so as to reduce the phenomenon of waste caused by excessive thickness of the protective layer 25. This is beneficial to reduce the manufacturing cost of the battery cell 20 and can save the space occupied by the protective layer 25 in the thickness direction X of the wall, which is beneficial to optimize the overall size of the battery cell 20.

[0224] According to some embodiments of this application, referring to FIG7, the thickness of the protective layer 25 along the thickness direction X of the wall is D2, which satisfies 0.3mm≤D2≤1mm, and further, 0.5mm≤D2≤0.8mm.

[0225] For example, the thickness D2 of the protective layer 25 in the thickness direction X of the wall portion can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm or 1mm, etc.

[0226] In this embodiment, on the one hand, the thickness of the protective layer 25 in the thickness direction X of the wall is set to be greater than or equal to 0.3 mm, which is beneficial to improve the structural strength of the protective layer 25 and ensures that the protective layer 25 has sufficient thickness to separate and block the lead-out member 231 and the busbar component 30 during welding connection, thereby alleviating the phenomenon of the protective layer 25 being welded through. This is beneficial to improve the separation and protection effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 and the busbar component 30 are welded together. On the other hand, the thickness of the protective layer 25 in the thickness direction X of the wall is set to be less than or equal to 1 mm, so as to reduce the phenomenon of waste caused by excessive thickness of the protective layer 25, which is beneficial to reduce the manufacturing cost of the battery cell 20 and can save the space occupied by the protective layer 25 in the thickness direction X of the wall, which is beneficial to optimize the overall size of the battery cell 20.

[0227] According to some embodiments of this application, referring to FIG7, the thickness of the lead-out member 231 along the thickness direction X of the wall is D3, which satisfies 1mm≤D3≤2.5mm, and further, 1.5mm≤D3≤2mm.

[0228] For example, the thickness D3 of the lead-out member 231 in the thickness direction X of the wall portion can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or 2.5 mm, etc.

[0229] In this embodiment, on the one hand, the thickness of the lead-out member 231 in the thickness direction X of the wall is set to be greater than or equal to 1 mm, which is beneficial to improve the structural strength of the lead-out member 231, thereby reducing the risk of deformation or breakage during use. It also allows the lead-out member 231 to have sufficient penetration depth when welded to the busbar component 30, which is beneficial to improve the reliability and stability of the connection between the lead-out member 231 and the busbar component 30. On the other hand, the thickness of the lead-out member 231 in the thickness direction X of the wall is set to be less than or equal to 2.5 mm, thereby saving the space occupied by the lead-out member 231 in the thickness direction X of the wall, thus optimizing the overall size of the battery cell 20 and improving the energy density of the battery cell 20.

[0230] According to some embodiments of this application, referring to Figures 9 and 10, along the thickness direction X of the wall portion, the lead-out member 231 has a first surface 2312 facing the wall portion 211, the first surface 2312 is provided with a recess 2313, and at least a portion of the protective layer 25 is accommodated in the recess 2313.

[0231] The recess 2313 is a groove structure provided on the surface of the lead-out member 231 facing the wall portion 211, and the recess 2313 penetrates the outer peripheral surface of the lead-out member 231.

[0232] At least a portion of the protective layer 25 is accommodated within the recess 2313, i.e., the protective layer 25 is a structure in which the protective layer 25 is inserted into the recess 2313 along the thickness direction X of the wall portion, such that the lead-out member 231 is a structure in which the portion projected in the thickness direction X of the wall portion is located within the protective layer 25.

[0233] In this embodiment, by providing a recess 2313 on the first surface 2312 of the lead-out member 231 facing the wall portion 211, and at least a portion of the protective layer 25 is accommodated in the recess 2313 along the thickness direction X of the wall portion, the protective layer 25 can not only act as a separator between the lead-out member 231 and the first insulating member 24, but also share a portion of the space in the thickness direction X of the wall portion. This is beneficial for optimizing the space occupied by the protective layer 25 and the lead-out member 231 as a whole in the thickness direction X of the wall portion, thereby optimizing the overall size of the battery cell 20 and improving the energy density of the battery cell 20.

[0234] In some embodiments, referring to FIG9, the protective layer 25 has a second surface 251 facing the wall portion 211 along the thickness direction X of the wall portion, and the second surface 251 and the first surface 2312 are coplanar.

[0235] Wherein, the second surface 251 and the first surface 2312 are coplanar, that is, the second surface 251 of the protective layer 25 facing the wall portion 211 and the first surface 2312 of the lead-out member 231 with the recess 2313 are flush with each other, so that the protective layer 25 is as a whole housed in the recess 2313.

[0236] Of course, in other embodiments, the protective layer 25 may also be a structure that protrudes from the first surface 2312, that is, the first surface 2312 is farther away from the wall 211 in the thickness direction X of the wall than the second surface 251, or the first surface 2312 is closer to the wall 211 in the thickness direction X of the wall than the second surface 251.

[0237] In this embodiment, by setting the second surface 251 of the protective layer 25 facing the wall portion 211 and the first surface 2312 of the lead-out member 231 facing the wall portion 211 as coplanar, the protective layer 25 is integrally housed within the recess 2313 of the lead-out member 231. On the one hand, this can further optimize the space occupied by the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall portion, thereby further optimizing the overall size of the battery cell 20 and improving the energy density of the battery cell 20. On the other hand, the recess 2313 can provide a certain degree of stability and protection for the protective layer 25, which helps to reduce wear and tear on the protective layer 25 during use.

[0238] According to some embodiments of this application, please refer to Figures 11 and 12. Figure 11 is a structural schematic diagram of the lead-out member 231 of the first electrode terminal 23a provided in some embodiments of this application, and Figure 12 is a structural schematic diagram of the protective layer 25 provided in some embodiments of this application. Along the thickness direction X of the wall portion, the protective layer 25 has a third surface 252 facing away from the wall portion 211. One of the surfaces of the lead-out member 231 facing the wall portion 211 and the third surface 252 is provided with a first limiting protrusion 253, and the other is provided with a first limiting groove 2314. The first limiting protrusion 253 and the first limiting groove 2314 are inserted into each other.

[0239] The first limiting protrusion 253 may protrude from the surface of the lead-out member 231 facing the wall portion 211. Correspondingly, the first limiting groove 2314 is disposed on the third surface 252 of the protective layer 25. Of course, the first limiting protrusion 253 may protrude from the third surface 252 of the protective layer 25. Correspondingly, the first limiting groove 2314 is disposed on the surface of the lead-out member 231 facing the wall portion 211.

[0240] It should be noted that, in conjunction with Figures 6, 11 and 12, if the lead-out member 231 and the protective layer 25 are stacked along the thickness direction X of the wall portion, that is, in the embodiment where the first surface 2312 of the lead-out member 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 facing away from the wall portion 211 are mutually facing each other, then one of the first surface 2312 of the lead-out member 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 facing away from the wall portion 211 is provided with a first limiting protrusion 253, and the other is provided with a first limiting groove 2314. Referring to Figure 9, in an embodiment where a recess 2313 is provided on the first surface 2312 of the lead-out member 231 facing the wall portion 211 in the thickness direction X of the wall portion, and a portion of the protective layer 25 is accommodated in the recess 2313, then one of the bottom surface of the recess 2313 facing the protective layer 25 in the thickness direction X of the wall portion and the third surface 252 of the protective layer 25 facing away from the wall portion 211 is provided with a first limiting protrusion 253, and the other is provided with a first limiting groove 2314.

[0241] In this embodiment, by providing a first limiting protrusion 253 on one of the surface of the lead-out member 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 away from the wall portion 211, and providing a first limiting groove 2314 that cooperates with the first limiting protrusion 253 on the other, the limiting and positioning between the protective layer 25 and the lead-out member 231 can be achieved. This can improve the assembly accuracy between the protective layer 25 and the lead-out member 231 and improve the assembly stability between the protective layer 25 and the lead-out member 231, thereby reducing the risk of the protective layer 25 shaking or shifting during use.

[0242] In some embodiments, as shown in Figures 11 and 12, the surface of the lead-out member 231 facing the wall portion 211 is provided with a first limiting groove 2314, and the third surface 252 is provided with a first limiting protrusion 253. That is, the first limiting groove 2314 is provided on the lead-out member 231, and correspondingly, the first limiting protrusion 253 is provided on the protective layer 25.

[0243] It should be noted that, referring to Figures 6, 11, and 12, if the lead-out member 231 and the protective layer 25 are stacked along the thickness direction X of the wall portion, that is, in an embodiment where the first surface 2312 of the lead-out member 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 facing away from the wall portion 211 are mutually facing each other, then the first limiting groove 2314 is provided on the first surface 2312 of the lead-out member 231 facing the wall portion 211. Referring to Figure 9, if a recess 2313 is provided on the first surface 2312 of the lead-out member 231 facing the wall portion 211 in the thickness direction X of the wall portion, and a portion of the protective layer 25 is accommodated in the recess 2313, then the first limiting groove 2314 is provided on the bottom surface of the recess 2313 facing the protective layer 25 in the thickness direction X of the wall portion.

[0244] In this embodiment, by setting the first limiting groove 2314 on the lead-out member 231 and correspondingly setting the first limiting protrusion 253 on the protective layer 25, the mutual limiting and positioning cooperation between the lead-out member 231 and the protective layer 25 can be achieved, while also reducing the need for slotting in the area of ​​the protective layer 25 corresponding to the lead-out member 231. This reduces the impact of the first limiting groove 2314 on the structural strength of the protective layer 25 or on the effect of the protective layer 25 in separating the lead-out member 231.

[0245] In some embodiments, please continue to refer to Figures 11 and 12, one of the surfaces of the lead-out member 231 facing the wall portion 211 and the third surface 252 is provided with a plurality of first limiting protrusions 253, and the other is provided with a plurality of first limiting grooves 2314, with each first limiting protrusion 253 inserted into the first limiting groove 2314.

[0246] For example, in Figure 11, the lead-out member 231 is provided with two first limiting grooves 2314, and in Figure 12, the protective layer 25 is provided with two corresponding first limiting protrusions 253, and the first limiting protrusions 253 and the first limiting grooves 2314 are in one-to-one correspondence.

[0247] In this embodiment, by providing a plurality of first limiting protrusions 253 on one of the surface of the lead-out member 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 facing away from the wall portion 211, and correspondingly providing a plurality of first limiting grooves 2314 on the other, and each first limiting protrusion 253 cooperating with a first limiting groove 2314, the limiting effect between the protective layer 25 and the lead-out member 231 is further improved, thereby further improving the assembly stability between the protective layer 25 and the lead-out member 231, and further reducing the risk of the protective layer 25 shaking or shifting during use.

[0248] According to some embodiments of this application, referring to Figures 6 and 7, and further referring to Figure 13, Figure 13 is a structural schematic diagram of the first insulating member 24 provided in some embodiments of this application. The first insulating member 24 may include an insulating body 241 and a flanged portion 242. The insulating body 241 is disposed between the protective layer 25 and the wall portion 211 along the thickness direction X of the wall portion, and the flanged portion 242 surrounds the outside of the lead-out member 231. The end of the flanged portion 242 near the electrode assembly 22 in the thickness direction X of the wall portion is connected to the insulating body 241.

[0249] The first insulating member 24 comprises two interconnected parts: an insulating body 241 and a flanged portion 242. The insulating body 241 is disposed between the protective layer 25 and the wall portion 211 along the thickness direction X of the wall portion. That is, the lead-out member 231, the protective layer 25, the insulating body 241, and the wall portion 211 are arranged in a structure that is stacked sequentially along the thickness direction X of the wall portion. For example, the insulating body 241 is a plate-like structure disposed between the protective layer 25 and the wall portion 211.

[0250] The flange 242 surrounds the outer side of the lead-out member 231. The end of the flange 242 near the electrode assembly 22 in the thickness direction X of the wall portion is connected to the insulating body 241. That is, the flange 242 is an annular structure surrounding the lead-out member 231 and the protective layer 25. The flange 242 is connected to the surface of the insulating body 241 on the side away from the wall portion 211, so that the insulating body 241 and the flange 242 together form a groove structure for accommodating the lead-out member 231 and the protective layer 25.

[0251] For example, the insulating body 241 and the flanged portion 242 are integrally formed, that is, the insulating body 241 and the flanged portion 242 of the first insulating member 24 are formed by an integral molding process, such as injection molding or extrusion molding. Of course, in other embodiments, the insulating body 241 and the flanged portion 242 can also be separate structures, and the flanged portion 242 can be connected to the insulating body 241 by means of adhesive or snap-fit ​​structures.

[0252] It should be noted that in some embodiments, the first insulating member 24 may not have a flange 242, that is, the first insulating member 24 may only include an insulating body 241, and the insulating body 241 is disposed between the protective layer 25 and the wall 211 in the thickness direction X of the wall.

[0253] In this embodiment, the first insulating member 24 is provided with an insulating body 241 located between the protective layer 25 and the wall portion 211 and a flange portion 242 surrounding the lead-out member 231. One end of the flange portion 242 in the thickness direction X of the wall portion is connected to the insulating body 241, so that the insulating body 241 and the flange portion 242 together form a groove structure for accommodating the lead-out member 231 and the protective layer 25. On the one hand, it can further improve the insulation isolation effect of the first insulating member 24 between the lead-out member 231 and the wall portion 211, so as to further reduce the risk of short circuit between the lead-out member 231 and the wall portion 211. On the other hand, it can improve the assembly stability between the first insulating member 24 and the lead-out member 231, and improve the assembly reliability of the protective layer 25 between the lead-out member 231 and the first insulating member 24.

[0254] According to some embodiments of this application, as shown in Figures 12 and 13, along the thickness direction X of the wall portion, the insulating body 241 has a fourth surface 2411 facing away from the wall portion 211, a flange portion 242 protruding from the fourth surface 2411, the fourth surface 2411 is provided with a receiving groove 2412, and at least a portion of the protective layer 25 is received in the receiving groove 2412.

[0255] The fourth surface 2411 is the surface of the insulating body 241 of the first insulating member 24 facing the lead-out member 231 in the thickness direction X of the wall portion, and is also the surface on which the insulating body 241 and the flange portion 242 are connected.

[0256] The fourth surface 2411 is provided with a receiving groove 2412, and at least a portion of the protective layer 25 is received within the receiving groove 2412. That is, the surface of the insulating body 241 facing the lead-out member 231 is provided with a receiving groove 2412 for receiving the protective layer 25. Optionally, the protective layer 25 may be a structure that is entirely received within the receiving groove 2412, or it may be a structure that is only partially received within the receiving groove 2412. Exemplarily, in this embodiment of the application, the surface of the protective layer 25 facing away from the wall portion 211 is closer to the wall portion 211 in the thickness direction X of the wall portion than the fourth surface 2411, so that the protective layer 25 has a structure in which the receiving groove 2412 does not extend out in the thickness direction X of the wall portion.

[0257] In this embodiment, by providing a receiving groove 2412 on the fourth surface 2411 of the insulating body 241 facing the lead-out member 231, and at least a portion of the protective layer 25 is accommodated in the receiving groove 2412, the protective layer 25 and the insulating body 241 of the first insulating member 24 can share a portion of the space in the thickness direction X of the wall. This is beneficial to optimizing the space occupied by the protective layer 25 and the insulating body 241 as a whole in the thickness direction X of the wall, thereby optimizing the overall size of the battery cell 20 and improving the energy density of the battery cell 20.

[0258] In some embodiments, referring to FIG13 and further referring to FIG14, FIG14 is a schematic diagram of the structure of the protective layer 25 provided in some embodiments of the present application. A second limiting protrusion 254 is provided on the outer peripheral surface of the protective layer 25, and a second limiting groove 2413 is provided on the side of the groove of the receiving groove 2412, and the second limiting protrusion 254 is inserted into the second limiting groove 2413.

[0259] The receiving groove 2412 may also be provided with a second limiting groove 2413 on its side wall, that is, the receiving groove 2412 is provided with a second limiting groove 2413, and the second limiting groove 2413 penetrates the side wall of the receiving groove 2412 so that the second limiting protrusion 254 protruding on the outer peripheral surface of the protective layer 25 can be inserted.

[0260] Optionally, there may be one or more second limiting protrusions 254 protruding from the outer peripheral surface of the protective layer 25. Correspondingly, the second limiting grooves 2413 provided on the side of the receiving groove 2412 correspond one-to-one with the second limiting protrusions 254.

[0261] It should be noted that in other embodiments, the second limiting protrusion 254 may also be protruding on the side of the receiving groove 2412, and correspondingly, the second limiting groove 2413 is disposed on the outer peripheral surface of the protective layer 25.

[0262] In this embodiment, by providing a second limiting protrusion 254 on the outer peripheral surface of the protective layer 25, and providing a second limiting groove 2413 on the side of the receiving groove 2412 that cooperates with the second limiting protrusion 254, the limiting and positioning between the protective layer 25 and the insulating body 241 of the first insulating member 24 can be achieved. On the one hand, the assembly accuracy of the protective layer 25 in the receiving groove 2412 can be improved, thereby improving the assembly quality of the protective layer 25 between the lead-out member 231 and the first insulating member 24. On the other hand, the circumferential locking between the protective layer 25 and the insulating body 241 can be achieved, thereby reducing the phenomenon of circumferential rotation of the protective layer 25 relative to the insulating body 241 of the first insulating member 24.

[0263] In some embodiments, please continue to refer to Figures 13 and 14. A plurality of second limiting protrusions 254 are provided on the outer peripheral surface of the protective layer 25. The plurality of second limiting protrusions 254 are arranged at intervals along the circumferential direction of the protective layer 25. A plurality of second limiting grooves 2413 are provided on the side of the receiving groove 2412. Each second limiting protrusion 254 is inserted into a second limiting groove 2413.

[0264] For example, in the projection plane perpendicular to the thickness direction X of the wall, the orthographic projection of the protective layer 25 and the orthographic projection of the receiving groove 2412 are both rectangular, and each side of the orthographic projection of the protective layer 25 is provided with a second limiting protrusion 254. Correspondingly, each of the four groove sides of the receiving groove 2412 is provided with a second limiting groove 2413, and each second limiting groove 2413 is inserted into and engaged with a first limiting protrusion 253. Of course, in other embodiments, the number of second limiting protrusions 254 protruding on the outer peripheral surface of the protective layer 25 and the number of second limiting grooves 2413 provided on the groove sides of the receiving groove 2412 can also be two, three, five, six or seven, etc.

[0265] In this embodiment, by providing a plurality of second limiting protrusions 254 spaced apart on the outer peripheral surface of the protective layer 25, and by providing a plurality of second limiting grooves 2413 corresponding one-to-one with the second limiting protrusions 254 on the groove side of the receiving groove 2412, the limiting and positioning effects between the protective layer 25 and the insulating body 241 of the first insulating member 24 are further improved. On the one hand, the assembly accuracy of the protective layer 25 in the receiving groove 2412 can be further improved, thereby further improving the assembly quality of the protective layer 25 between the lead-out member 231 and the first insulating member 24. On the other hand, the phenomenon of the protective layer 25 rotating circumferentially relative to the insulating body 241 of the first insulating member 24 can be further reduced.

[0266] In some embodiments, as shown in FIG13, the second limiting groove 2413 penetrates the fourth surface 2411 along the thickness direction X of the wall portion. That is, the second limiting groove 2413 extends to the fourth surface 2411 of the insulating body in the thickness direction X of the wall portion.

[0267] In this embodiment, by setting the second limiting groove 2413 to penetrate the fourth surface 2411, the second limiting groove 2413 is a structure that simultaneously penetrates the fourth surface 2411 and the side of the receiving groove 2412, thereby reducing the difficulty of setting the second limiting groove 2413 on the side of the receiving groove 2412, and thus reducing the manufacturing difficulty of the first insulating member 24.

[0268] According to some embodiments of this application, referring to Figures 6, 7 and 9, along the thickness direction X of the wall portion, the surface of the wall portion 211 facing away from the electrode assembly 22 is provided with an assembly groove 2112, and at least a portion of the first insulating member 24 is accommodated in the assembly groove 2112.

[0269] The assembly groove 2112 is disposed on the outer surface of the wall portion 211 away from the electrode assembly 22. At least a portion of the first insulating member 24 is accommodated within the assembly groove 2112. That is, the first insulating member 24 can be a structure that is entirely accommodated within the assembly groove 2112, or a structure that is only partially accommodated within the assembly groove 2112. For example, in Figures 6 and 9, the first insulating member 24 is only partially accommodated within the assembly groove 2112.

[0270] It should be noted that in the embodiment where the first insulating member 24 includes an insulating body 241 and a flange 242, at least a portion of the insulating body 241 is accommodated in the mounting groove 2112 along the thickness direction X of the wall.

[0271] In this embodiment, by providing an assembly groove 2112 on the surface of the wall portion 211 facing away from the electrode assembly 22, and at least a portion of the first insulating member 24 is accommodated in the assembly groove 2112, the battery cell 20 with this structure can, on the one hand, limit and position the first insulating member 24 through the assembly groove 2112, which helps to reduce the difficulty of assembling the first insulating member 24 between the wall portion 211 and the lead-out member 231, and can reduce the phenomenon of shaking or displacement of the first insulating member 24 during use, which helps to improve the assembly stability of the first insulating member 24. On the other hand, it can realize that the first insulating member 24 and the wall portion 211 share a part of the space in the thickness direction X of the wall portion, which helps to optimize the overall size of the battery cell 20.

[0272] According to some embodiments of this application, referring to Figures 6 and 9, the wall portion 211 is provided with an electrode lead-out hole 2111, which penetrates the wall portion 211 along the thickness direction X. The first electrode terminal 23a may further include a connector 232 connected to the lead-out member 231, the connector 232 passing through the electrode lead-out hole 2111 and electrically connected to the electrode assembly 22.

[0273] The lead-out member 231 and the connector 232 of the first electrode terminal 23a are interconnected. The lead-out member 231 is used to weld to the busbar component 30, and the connector 232 is electrically connected to the tab 222 of the electrode assembly 22, so as to realize the input or output of electrical energy of the battery cell 20 through the first electrode terminal 23a.

[0274] Optionally, the connection structure between the lead-out member 231 and the connector 232 can be various, such as welding or riveting.

[0275] The connector 232 passes through the electrode lead-out hole 2111 and is electrically connected to the electrode assembly 22. That is, the connector 232 is partially located in the electrode lead-out hole 2111 and part of the connector 232 is located inside the outer shell 21, so as to facilitate the assembly and connection of the connector 232 with the tab 222 of the electrode assembly 22.

[0276] In this embodiment, the wall portion 211 is provided with an electrode lead-out hole 2111 that penetrates the wall portion 211 along the thickness direction X, and the first electrode terminal 23a is also provided with a connector 232 that is connected to the lead-out member 231. After the connector 232 passes through the electrode lead-out hole 2111, it can be electrically connected to the electrode assembly 22 located in the outer casing 21, so as to realize the input or output of electrical energy of the battery cell 20 through the first electrode terminal 23a. The structure is simple and easy to assemble.

[0277] In some embodiments, referring to Figures 6 and 9, the connector 232 may include a body portion 2321 and a limiting portion 2322. The body portion 2321 passes through the electrode lead-out hole 2111 along the thickness direction X of the wall portion, and the body portion 2321 is connected to the lead-out member 231. The limiting portion 2322 protrudes from the outer peripheral surface of the body portion 2321. Along the thickness direction X of the wall portion, the limiting portion 2322 is located on the side of the wall portion 211 facing the electrode assembly 22, and at least a portion of the wall portion 211 is located between the limiting portion 2322 and the lead-out member 231.

[0278] In this embodiment, the body portion 2321 of the connector 232 is a structure that passes through the electrode lead-out hole 2111 of the wall portion 211 along the thickness direction X of the wall portion. The body portion 2321 is connected to the lead-out member 231 located on the side of the wall portion 211 opposite to the electrode assembly 22. It should be noted that in the embodiment where a protective layer 25 is provided between the lead-out member 231 and the first insulating member 24, as shown in FIG12, the protective layer 25 is also provided with a first through hole 255 through which the body portion 2321 passes, and the first through hole 255 penetrates the protective layer 25 along the thickness direction X of the wall portion. Similarly, the first insulating member 24 is also provided with a second through hole 2414 through which the body portion 2321 passes. In the embodiment where the first insulating member 24 includes an insulating body and a flange portion 242, the second through hole 2414 is provided on the insulating body and penetrates the insulating body along the thickness direction X of the wall portion. In the embodiment where a receiving groove 2412 is provided on the fourth surface 2411 of the insulating body, the second through hole 2414 penetrates the bottom surface of the receiving groove 2412 so that the second through hole 2414 and the receiving groove 2412 are interconnected.

[0279] Optionally, the connection structure between the body 2321 and the lead-out member 231 can be various, such as riveting, welding, or snap-fitting.

[0280] The limiting part 2322 protrudes from the outer peripheral surface of the body part 2321, meaning the limiting part 2322 is a structure connected to the outer peripheral surface of the body part 2321. Exemplarily, the limiting part 2322 and the body part 2321 are integrally formed, meaning the body part 2321 and the limiting part 2322 of the connector 232 are manufactured using an integral forming process, such as stamping or casting. Of course, in other embodiments, the limiting part 2322 and the body part 2321 can also be separate structures, with the limiting part 2322 connected to the body part 2321 via welding or other structures.

[0281] Along the thickness direction X of the wall portion, the limiting portion 2322 is located on the side of the wall portion 211 facing the electrode assembly 22, and at least a portion of the wall portion 211 is located between the limiting portion 2322 and the lead-out member 231. That is, the limiting portion 2322 and the lead-out member 231 are located on both sides of the wall portion 211 in the thickness direction X of the wall portion, and the limiting portion 2322 and the lead-out member 231 can cooperate to clamp at least a portion of the wall portion 211 to realize the assembly of the first electrode terminal 23a onto the wall portion 211.

[0282] In this embodiment, the connector 232 of the first electrode terminal 23a is provided with a body portion 2321 and a limiting portion 2322 protruding from the outer peripheral surface of the body portion 2321. The body portion 2321 is connected to the lead-out member 231, and the limiting portion 2322 is located on the side of the wall portion 211 away from the lead-out member 231, so that at least a portion of the wall portion 211 is located between the limiting portion 2322 and the lead-out member 231, so that the limiting portion 2322 and the lead-out member 231 can cooperate to clamp the wall portion 211, thereby realizing the assembly of the first electrode terminal 23a onto the wall portion 211. The structure is simple, easy to assemble, and can improve the structural stability of the first electrode terminal 23a assembled onto the wall portion 211.

[0283] According to some embodiments of this application, as shown in Figures 6 and 9, the battery cell 20 may further include a second insulating member 28. Along the thickness direction X of the wall portion, at least a portion of the second insulating member 28 is disposed between the limiting portion 2322 and the wall portion 211 to insulate and isolate the limiting portion 2322 and the wall portion 211.

[0284] The second insulating member 28 is disposed on the side of the wall portion 211 facing the electrode assembly 22. A portion of the second insulating member 28 is located between the limiting portion 2322 and the wall portion 211, so that the second insulating member 28 can insulate and isolate the limiting portion 2322 and the wall portion 211, so that the second insulating member 28 and the first insulating member 24 can cooperate to achieve the insulated installation of the first electrode terminal 23a on the wall portion 211. Furthermore, a portion of the second insulating member 28 is located between the wall portion 211 and the electrode assembly 22, so that the second insulating member 28 can also insulate and isolate the electrode assembly 22 and the wall portion 211.

[0285] For example, the material of the second insulating element 28 can be various, such as plastic, rubber or silicone.

[0286] In this embodiment, a second insulating member 28 is provided between the limiting part 2322 and the wall part 211, so that the second insulating member 28 can play a certain insulating isolation role between the limiting part 2322 and the wall part 211, thereby reducing the risk of short circuit between the limiting part 2322 and the wall part 211, and reducing the phenomenon of short circuit in the battery cell 20 during use.

[0287] According to some embodiments of this application, as shown in FIG6, the body portion 2321 and the lead-out member 231 are riveted together.

[0288] As shown in Figures 6 and 11, the lead-out member 231 is provided with a riveting hole 2311. The riveting hole 2311 penetrates the surfaces of both sides of the lead-out member 231 along the thickness direction X of the wall. Correspondingly, the body part 2321 of the connector 232 is inserted into the riveting hole 2311 and riveted to the lead-out member 231.

[0289] It should be noted that, in other embodiments, the main body 2321 of the lead-out member 231 and the connector 232 can also be connected to each other by welding or snap-fitting structures.

[0290] In this embodiment, by setting the body portion 2321 of the connector 232 and the lead-out member 231 to be riveted to each other, it is beneficial to improve the connection stability between the connector 232 and the lead-out member 231, thereby reducing the risk of connection failure of the first electrode terminal 23a during use, and also reducing the connection difficulty between the connector 232 and the lead-out member 231, thereby improving the assembly efficiency of the battery cell 20.

[0291] According to some embodiments of this application, referring to Figures 6 and 9, the battery cell 20 may further include a seal 29. The seal 29 is disposed between the connector 232 and the wall portion 211, and the seal 29 is configured to seal the gap between the connector 232 and the wall surface of the electrode lead-out hole 2111.

[0292] The sealing element 29 serves to seal the gap between the connecting element 232 and the hole wall of the electrode lead-out hole 2111. The sealing element 29 can be made of various materials, such as silicone, plastic or rubber.

[0293] Exemplarily, at least a portion of the seal 29 extends into the electrode lead-out hole 2111, such that at least a portion of the seal 29 is located between the connector 232 and the hole wall surface of the electrode lead-out hole 2111. It should be noted that in embodiments where the connector 232 includes a body portion 2321 and a limiting portion 2322, the seal 29 is a structure fitted onto the outside of the body portion 2321, such that at least a portion of the seal 29 is located between the outer peripheral surface of the body portion 2321 and the hole wall surface of the electrode lead-out hole 2111.

[0294] In this embodiment, the battery cell 20 is also provided with a sealing member 29. By placing the sealing member 29 between the wall portion 211 and the connector 232 of the first electrode terminal 23a, the sealing member 29 can seal the gap between the connector 232 and the hole wall of the electrode lead-out hole 2111, thereby reducing the risk of leakage of the battery cell 20 at the electrode lead-out hole 2111, which is beneficial to improving the stability and reliability of the battery cell 20.

[0295] According to some embodiments of this application, as shown in Figures 6 and 9, the material of the lead-out member 231 includes aluminum, and the material of the protective layer 25 includes steel, copper, ceramic, or mica.

[0296] In this embodiment, the lead-out member 231 is made of aluminum to give it good electrical conductivity. Furthermore, aluminum's low melting point facilitates welding the lead-out member 231 to the busbar component 30, reducing assembly difficulty. The protective layer 25 is made of steel, copper, ceramic, or mica. These materials give the protective layer 25 a high melting point, making it less prone to weld-through or melt-through during welding of the lead-out member 231 to the busbar component 30. This improves the protective layer 25's separation and protection of the wall portion 211 or other components.

[0297] According to some embodiments of this application, as shown in Figures 4, 5 and 6, the first electrode terminal 23a is the positive electrode of the battery cell 20, that is, the first electrode terminal 23a is electrically connected to the positive electrode of the electrode assembly 22.

[0298] In this embodiment, by setting the first electrode terminal 23a as the positive terminal of the battery cell 20, the first electrode terminal 23a can be used as the positive output terminal of the battery cell 20 to input or output the electrical energy of the battery cell 20.

[0299] According to some embodiments of this application, as shown in Figures 4 and 5, the housing 21 may include a housing 212 and an end cap 213. The housing 212 has an internal cavity with an opening 2121, in which the electrode assembly 22 is housed. The end cap 213 closes the opening 2121 and is a wall portion 211.

[0300] The end cap 213 is a wall portion 211, that is, the first electrode terminal 23a is installed on the end cap 213, and the lead-out part 231 of the first electrode terminal 23a is located on the side of the end cap 213 away from the electrode assembly 22. Correspondingly, the first insulating member 24 is disposed between the lead-out part 231 and the end cap 213.

[0301] In this embodiment, by setting the wall portion 211 of the outer casing 21 as an end cap 213 for closing the opening 2121 of the housing 212, the battery cell 20 with this structure is convenient to assemble the first electrode terminal 23a on the end cap 213 and to assemble and connect the first electrode terminal 23a with the electrode assembly 22. It is also convenient to set a protective layer 25 between the lead-out member 231 and the first insulating member 24, thereby reducing the assembly difficulty of the battery cell 20 and improving the production efficiency of the battery cell 20.

[0302] It should be noted that the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 can also have other structures. For example, the outer casing 21 can include a housing 212 and an end cap 213. The housing 212 includes an integrally formed side wall and a bottom wall. The side wall surrounds the bottom wall. Along the thickness direction X of the wall portion, one end of the side wall is connected to the bottom wall, and the other end forms an opening 2121. The side wall and the bottom wall together define a receiving cavity. The electrode assembly 22 is received in the receiving cavity. The end cap 213 closes the opening 2121. The bottom wall is the wall portion 211. That is, the wall portion 211 is the bottom wall of the housing 212 that is opposite to the end cap 213 in the thickness direction X of the wall portion. That is, the first electrode terminal 23a is disposed on the bottom wall of the housing 212, and the lead-out member 231 of the first electrode terminal 23a is located on the side of the bottom wall of the housing 212 away from the electrode assembly 22. Correspondingly, the first insulating member 24 is disposed between the lead-out member 231 and the bottom wall of the housing 212.

[0303] The shell 212 includes integrally formed side walls and bottom walls. In other words, the shell 212 is manufactured using an integral forming process, such as stamping, casting or extrusion molding. That is to say, the side walls and bottom walls of the shell 212 are an integral structure.

[0304] In this embodiment, by setting the wall portion 211 of the outer casing 21 as a wall of the casing 212 that is opposite to the end cap 213 in the thickness direction X of the wall portion, the battery cell 20 with this structure can make the area of ​​the outer casing 21 where the first electrode terminal 23a is installed far away from the end cap 213, and make it so that there is no direct connection between the wall portion 211 and the end cap 213. This can alleviate the phenomenon that the force generated when the first electrode terminal 23a and other components pull or twist the wall portion 211 acts on the end cap 213, thereby reducing the risk of connection failure between the end cap 213 and the casing 212, and thus helping to reduce the risk of leakage of the battery cell 20 during use.

[0305] According to some embodiments of this application, and in conjunction with Figures 2, 3, and 4, this application also provides a battery device 100, which includes a busbar component 30 and a battery cell 20 of any of the above embodiments. The busbar component 30 is disposed on the side of the lead-out member 231 facing away from the protective layer 25 in the thickness direction X of the wall portion. The busbar component 30 is welded to the lead-out member 231 to form a connection portion 40. The connection portion 40 includes a first connection portion 41 and a second connection portion 42 that are interconnected. The first connection portion 41 is embedded in the lead-out member 231, and the second connection portion 42 is embedded in the busbar component 30.

[0306] The current collector 30 serves to electrically connect the battery cell 20 within the battery device 100. For example, the current collector 30 can be made of various materials, such as copper, aluminum, or aluminum alloy.

[0307] The busbar component 30 is disposed on the side of the lead-out member 231 facing away from the protective layer 25 in the thickness direction X of the wall portion. That is, the busbar component 30 and the lead-out member 231 of the first electrode terminal 23a are stacked along the thickness direction X of the wall portion, and the lead-out member 231 is located between the busbar component 30 and the protective layer 25 in the thickness direction X of the wall portion, such that the busbar component 30 is located on the side of the lead-out member 231 facing away from the electrode assembly 22, while the protective layer 25 is located on the side of the lead-out member 231 facing the electrode assembly 22.

[0308] The busbar component 30 is welded to the lead-out component 231 to form a connecting portion 40. The connecting portion 40 is the area where the lead-out component 231 and the busbar component 30 are welded together to form a fused region or a weld mark. The first connecting portion 41 is the part of the connecting portion 40 embedded within the lead-out component 231, while the second connecting portion 42 is the part of the connecting portion 40 embedded within the busbar component 30. The second connecting portion 42 and the first connecting portion 41 are connected to each other. Correspondingly, the first connecting portion 41 is the weld mark formed on the lead-out component 231 by welding the lead-out component 231 and the busbar component 30, while the second connecting portion 42 is the weld mark formed on the busbar component 30 by welding the lead-out component 231 and the busbar component 30. Of course, in some embodiments, the connecting portion 40 may also include a third portion, which is the portion of the connecting portion 40 protruding from the surface of the busbar component 30 on the side opposite to the lead-out component 231. The second connecting portion 42 connects the first connecting portion 41 and the third portion.

[0309] Referring to Figure 2, the battery device 100 may also include a housing 10, in which the battery cells 20 are housed.

[0310] In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, the first housing body 11 and the second housing body 12 covering each other, the first housing body 11 and the second housing body 12 together defining an assembly space for accommodating the battery cell 20.

[0311] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12 so that the first box body 11 and the second box body 12 together define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0312] Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder or a cuboid. For example, in Figure 2, the box 10 is a cuboid structure.

[0313] Optionally, the battery cell 20 disposed within the housing 10 can be one or more. For example, in Figure 2, the housing 10 of the battery device 100 contains multiple battery cells 20. The multiple battery cells 20 are electrically connected via a busbar 30, and their structure can be series, parallel, or mixed. Mixed connection refers to a configuration where multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 can be directly connected in series, parallel, or mixed together, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or mixed to form a battery module, and then these battery modules are connected in series, parallel, or mixed to form a whole, which is then housed within the housing 10.

[0314] It should be noted that in some embodiments, the battery device 100 may not have a housing 10. The battery device 100 includes multiple battery cells 20, and the battery device 100 composed of multiple battery cells 20 can be directly mounted onto the electrical device to provide power to the electrical device through the multiple battery cells 20. That is, the housing 10 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 10 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 10 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0315] In this embodiment, the busbar component 30 is welded to the lead-out member 231 of the first electrode terminal 23a, and a first connection portion 41 is formed on the lead-out member 231 and a second connection portion 42 is formed on the busbar component 30. The first connection portion 41 and the second connection portion 42 are connected to each other to realize the assembly connection between the first electrode terminal 23a and the busbar component 30. The battery device 100 with this structure can improve the connection stability and reliability between the first electrode terminal 23a and the busbar component 30, and is also conducive to improving the overcurrent effect between the first electrode terminal 23a and the busbar component 30.

[0316] According to some embodiments of this application, as shown in Figures 8 and 10, in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the outer edge of the orthographic projection of the first connecting portion 41 and the orthographic projection of the protective layer 25 is L1, which satisfies 1mm≤L1≤2.5mm.

[0317] Referring to Figure 12, the protective layer 25 is provided with a first through hole 255 through which the connector 232 of the first electrode terminal 23a passes. Correspondingly, in the projection plane perpendicular to the thickness direction X of the wall, the minimum distance between the orthographic projection of the first connecting part 41 and the orthographic projection of the outer peripheral surface of the protective layer 25 is L1, and in the projection plane perpendicular to the thickness direction X of the wall, the minimum distance between the orthographic projection of the first connecting part 41 and the orthographic projection of the hole wall surface of the first through hole 255 is also L1.

[0318] For example, L1 can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm or 2.5mm.

[0319] In this embodiment, on the one hand, the minimum distance between the orthographic projection of the first connecting portion 41 along the thickness direction X of the wall portion within the protective layer 25 and the outer edge of the protective layer 25 is set to be greater than or equal to 1 mm, so as to improve the effect of the protective layer 25 in separating the area where the lead-out member 231 forms a solder mark, thereby further improving the protective effect of the protective layer 25 on the first insulating member 24, and further reducing the risk of the lead-out member 231 being soldered through and affecting the first insulating member 24. On the other hand, the minimum distance between the orthographic projection of the first connecting portion 41 along the thickness direction X of the wall portion within the protective layer 25 and the outer edge of the protective layer 25 is set to be less than or equal to 2.5 mm, so as to alleviate the phenomenon that the area where the lead-out member 231 is used for welding with the busbar component 30 is restricted due to excessive distance, thereby increasing the size of the connecting portion 40 formed by welding the lead-out member 231 and the busbar component 30, and further improving the connection stability and current flow effect between the lead-out member 231 and the busbar component 30.

[0320] According to some embodiments of this application, referring to Figures 8 and 10, in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the outer edges of the orthographic projection of the first connecting portion 41 and the orthographic projection of the lead-out member 231 is L2, which satisfies 1mm≤L2≤2.5mm.

[0321] In the projection plane perpendicular to the thickness direction X of the wall, the minimum distance between the outer edges of the orthographic projection of the first connecting part 41 and the orthographic projection of the lead-out member 231 is L2. That is, in the projection plane perpendicular to the thickness direction X of the wall, the minimum distance between the orthographic projection of the first connecting part 41 and the orthographic projection of the outer peripheral surface of the lead-out member 231 is L2. Of course, referring to Figure 11, in the embodiment where the lead-out member 231 is provided with a riveting hole 2311 that is riveted to the connecting part 232, the minimum distance between the orthographic projection of the first connecting part 41 and the orthographic projection of the hole wall surface of the riveting hole 2311 in the projection plane perpendicular to the thickness direction X of the wall is also L2.

[0322] For example, L2 can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm or 2.5mm.

[0323] In this embodiment, on the one hand, the minimum distance between the outer edges of the orthographic projection of the first connecting portion 41 in the projection plane perpendicular to the thickness direction X of the wall portion and the orthographic projection of the lead-out member 231 in the projection plane perpendicular to the thickness direction X of the wall portion is set to be greater than or equal to 1 mm. This increases the distance between the area where the solder mark is formed on the lead-out member 231 and the outer edge of the lead-out member 231, which helps to reduce the phenomenon of melting at the outer edge of the lead-out member 231, thereby improving the welding quality between the lead-out member 231 and the busbar component 30. On the other hand, the first connecting portion... The minimum distance between the outer edges of the orthographic projection of the lead-out member 231 in the projection plane perpendicular to the thickness direction X of the wall and the orthographic projection of the lead-out member 231 in the projection plane perpendicular to the thickness direction X of the wall is set to be less than or equal to 2.5 mm. This is to alleviate the phenomenon that the area of ​​the lead-out member 231 for welding with the busbar component 30 is limited due to excessive distance. This allows for an increase in the size of the connection portion 40 formed by welding the lead-out member 231 and the busbar component 30 together, thereby further improving the connection stability and current flow effect between the lead-out member 231 and the busbar component 30.

[0324] According to some embodiments of this application, as shown in Figures 8 and 10, the thickness of the area where the busbar 30 and the lead-out member 231 are welded together along the thickness direction X of the wall is D4, which satisfies 1.2mm≤D4≤3mm.

[0325] Wherein, along the thickness direction X of the wall, the thickness of the area where the busbar 30 and the lead-out member 231 are welded together is D4, and correspondingly, the maximum dimension of the second connecting part 42, in which the connecting part 40 is embedded in the busbar 30, is also D4 in the thickness direction X of the wall.

[0326] For example, D4 ​​can be 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, or 3mm, etc.

[0327] In this embodiment, by setting the thickness of the area where the busbar 30 is welded to the lead-out member 231 to be between 1.2 mm and 3 mm, on the one hand, setting the thickness of the area where the busbar 30 and the lead-out member 231 are welded to be greater than or equal to 1.2 mm can improve the current-carrying performance of the busbar 30, thereby improving the conductivity of the busbar 30. While improving the current-carrying performance of the busbar 30, it also increases the welding power and weld pool between the busbar 30 and the lead-out member 231. Thus, by providing a protective layer 25 on the side of the lead-out member 231 facing the wall portion 211, the area where the lead-out member 231 is welded through can be effectively separated, thereby reducing the risk of the lead-out member 231 affecting other components after being welded through. On the other hand, setting the thickness of the area where the busbar 30 and the lead-out member 231 are welded to be less than or equal to 3 mm can reduce the phenomenon of excessive waste of the busbar 30 or excessive welding power required, thereby reducing the welding difficulty between the busbar 30 and the lead-out member 231 and reducing the manufacturing cost of the busbar 30.

[0328] According to some embodiments of this application, and in conjunction with Figures 8, 10, 11, and 12, along the thickness direction X of the wall portion, the surface of the lead-out member 231 facing the wall portion 211 is provided with a first limiting groove 2314. The protective layer 25 has a third surface 252 facing away from the wall portion 211, and a first limiting protrusion 253 is protruding from the third surface 252. The first limiting protrusion 253 is inserted into the first limiting groove 2314. The first limiting groove 2314 forms a slot 2314a on the surface of the lead-out member 231 facing the wall portion 211. In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first connecting portion 41 is located outside the orthographic projection of the slot 2314a.

[0329] In the projection plane perpendicular to the thickness direction X of the wall, the orthographic projection of the first connecting part 41 is located outside the orthographic projection of the slot 2314a. That is, in the projection plane perpendicular to the thickness direction X of the wall, the orthographic projection of the first connecting part 41 and the orthographic projection of the slot wall of the first limiting slot 2314 do not overlap. In other words, the projection of the first connecting part 41 in the thickness direction X of the wall does not fall into the first limiting slot 2314.

[0330] In this embodiment, by providing a first limiting groove 2314 on the surface of the lead-out member 231 facing the wall portion 211, and correspondingly providing a first limiting protrusion 253 on the third surface 252 of the protective layer 25 away from the wall portion 211 to engage with the first limiting groove 2314, the limiting and positioning between the protective layer 25 and the lead-out member 231 can be achieved, thereby improving the assembly accuracy between the protective layer 25 and the lead-out member 231 and improving the assembly stability between the protective layer 25 and the lead-out member 231. In this embodiment, by setting the projection of the first connecting portion 41 of the connecting portion 40 in the thickness direction X of the wall portion to a structure located outside the groove opening 2314a of the first limiting groove 2314, the projections of the first connecting portion 41 and the groove wall surface of the first limiting groove 2314 in the thickness direction X of the wall portion do not overlap, thereby reducing the impact of the first limiting groove 2314 on the welding connection between the lead-out member 231 and the busbar component 30, which is beneficial to improving the welding quality between the lead-out member 231 and the busbar component 30.

[0331] According to some embodiments of this application, this application also provides an electrical device, which includes a battery cell 20 or a battery device 100 of any of the above schemes, and the battery cell 20 or the battery device 100 is used to provide electrical energy to the electrical device.

[0332] The electrical device can be any of the aforementioned devices or systems that use a single battery cell 20 or a battery device 100.

[0333] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0334] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A single battery cell, comprising: The outer shell has walls; Electrode assembly, housed within the housing; A first electrode terminal is electrically connected to the electrode assembly. The first electrode terminal includes a lead-out located on the side of the wall opposite to the electrode assembly, and the lead-out is used for welding to the busbar component and forming a first connection portion on the lead-out. A first insulating member is disposed at least partially between the lead-out member and the wall portion in the thickness direction of the wall portion, and in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the first insulating member overlaps at least partially with the orthographic projection of the first connecting portion. as well as A protective layer is at least partially disposed between the lead-out member and the first insulating member. The melting point of the protective layer is greater than that of the lead-out member, and at least a portion of the orthographic projection of the first connecting portion is located within the orthographic projection of the protective layer in a projection plane perpendicular to the thickness direction of the wall portion.

2. The battery cell according to claim 1, wherein, In the projection plane perpendicular to the thickness direction of the wall, the orthographic projection of the first connection portion is entirely located within the orthographic projection of the protective layer.

3. The battery cell of claim 1 or 2, wherein, The melting point of the protective layer is T1, and the melting point of the lead-out component is T2, satisfying that T1-T2≥200℃.

4. The battery cell of any one of claims 1-3, wherein, The melting point of the protective layer is T1, which satisfies the condition 1000℃≤T1≤3000℃.

5. The battery cell of any one of claims 1-4, wherein, The lead-out component and the protective layer are stacked along the thickness direction of the wall portion; Specifically, in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the lead-out member lies within the orthographic projection of the protective layer.

6. The battery cell of any one of claims 1-5, wherein, The maximum dimension of the protective layer and the lead-out member in the thickness direction of the wall is D1, which satisfies that D1 < 3mm.

7. The battery cell of claim 6, wherein, 1.8mm≤D1≤2.8mm.

8. The battery cell of any one of claims 1-7, wherein, Along the thickness direction of the wall portion, the thickness of the protective layer is D2, and the thickness of the lead-out member is D3, satisfying 0.1≤D2 / D3≤0.

25.

9. The battery cell of claim 8, wherein, 0.3mm≤D2≤1mm.

10. The battery cell of claim 9, wherein, 1mm≤D3≤2.5mm.

11. The battery cell of any one of claims 1-10, wherein, Along the thickness direction of the wall portion, the lead-out member has a first surface facing the wall portion, the first surface being provided with a recess, and at least a portion of the protective layer is accommodated within the recess.

12. The battery cell of claim 11, wherein, Along the thickness direction of the wall portion, the protective layer has a second surface facing the wall portion, the second surface and the first surface being coplanar.

13. The battery cell of any one of claims 1-12, wherein, Along the thickness direction of the wall portion, the protective layer has a third surface facing away from the wall portion; The lead-out member has a first limiting protrusion on one of the surfaces facing the wall and the third surface, and a first limiting groove on the other surface. The first limiting protrusion and the first limiting groove are inserted into each other.

14. The battery cell of claim 13, wherein, The lead-out member has a first limiting groove on the surface facing the wall, and the third surface has a first limiting protrusion.

15. The battery cell of claim 13 or 14, wherein, The lead-out member has a plurality of first limiting protrusions on one of the surfaces facing the wall and the third surface, and a plurality of first limiting grooves on the other surface, with each first limiting protrusion inserted into the first limiting groove.

16. The battery cell of any one of claims 1-15, wherein, The first insulating element includes: An insulating body is disposed between the protective layer and the wall portion along the thickness direction of the wall portion; A flanged portion surrounds the outside of the lead-out member, and the flanged portion is connected to the insulating body at one end of the wall portion near the electrode assembly in the thickness direction.

17. The battery cell of claim 16, wherein, Along the thickness direction of the wall portion, the insulating body has a fourth surface facing away from the wall portion, and the flange portion protrudes from the fourth surface; The fourth surface is provided with a receiving groove, and at least a portion of the protective layer is contained within the receiving groove.

18. The battery cell of claim 17, wherein, The outer peripheral surface of the protective layer is provided with a second limiting protrusion, and the side of the receiving groove is provided with a second limiting groove, and the second limiting protrusion is inserted into the second limiting groove.

19. The battery cell of claim 18, wherein, The outer peripheral surface of the protective layer is provided with a plurality of second limiting protrusions, which are arranged at intervals along the circumference of the protective layer. The side of the receiving groove is provided with a plurality of second limiting grooves, and each second limiting protrusion is inserted into a second limiting groove.

20. The battery cell according to claim 18 or 19, wherein, The second limiting groove penetrates the fourth surface along the thickness direction of the wall portion.

21. The battery cell of any one of claims 1-20, wherein, Along the thickness direction of the wall portion, a mounting groove is provided on the surface of the wall portion opposite to the electrode assembly, and at least a portion of the first insulating member is accommodated in the mounting groove.

22. The battery cell according to any one of claims 1-21, wherein, The wall portion is provided with an electrode lead-out hole, which penetrates the wall portion along the thickness direction; The first electrode terminal further includes a connector connected to the lead-out member, which passes through the electrode lead-out hole and is electrically connected to the electrode assembly.

23. The battery cell of claim 22, wherein, The connector includes: The main body is inserted into the electrode lead-out hole along the thickness direction of the wall portion, and the main body is connected to the lead-out member; A limiting part protrudes from the outer peripheral surface of the main body; Wherein, along the thickness direction of the wall portion, the limiting portion is located on the side of the wall portion facing the electrode assembly, and at least a portion of the wall portion is located between the limiting portion and the lead-out member.

24. The battery cell of claim 23, wherein, The battery cell further includes a second insulating member, at least a portion of which is disposed between the limiting portion and the wall portion along the thickness direction of the wall portion to insulate and isolate the limiting portion and the wall portion.

25. The battery cell of claim 23 or 24, wherein, The main body and the lead-out part are riveted together.

26. The battery cell of any one of claims 22-25, wherein, The battery cell also includes: A seal is disposed between the connector and the wall portion, the seal being configured to seal the gap between the connector and the wall surface of the electrode lead-out hole.

27. The battery cell according to any one of claims 1-26, wherein, The material of the lead-out element includes aluminum, and the material of the protective layer includes steel, copper, ceramic or mica.

28. The battery cell of any one of claims 1-27, wherein, The first electrode terminal is the positive electrode of the battery cell.

29. The battery cell of any one of claims 1-28, wherein, The outer casing includes: The housing has an internally formed receiving cavity with an opening, and the electrode assembly is received within the receiving cavity; End cap, to close the opening; The end cap is the wall portion.

30. The battery cell of any one of claims 1-28, wherein, The outer casing includes: The housing includes an integrally formed sidewall and a bottom wall. The sidewall surrounds the bottom wall. Along the thickness direction of the wall portion, one end of the sidewall is connected to the bottom wall, and the other end forms an opening. The sidewall and the bottom wall together define a receiving cavity, in which the electrode assembly is received. End cap, to close the opening; The bottom wall is the wall portion.

31. A battery device, comprising: The battery cell as described in any one of claims 1-30; as well as A busbar component is disposed on the side of the lead-out member away from the protective layer in the thickness direction of the wall portion. The busbar component is welded to the lead-out member to form a connection portion. The connection portion includes a first connection portion and a second connection portion that are connected to each other. The first connection portion is embedded in the lead-out member, and the second connection portion is embedded in the busbar component.

32. The battery device according to claim 31, wherein, In the projection plane perpendicular to the thickness direction of the wall, the minimum distance between the outer edges of the orthographic projection of the first connecting part and the orthographic projection of the protective layer is L1, which satisfies 1mm≤L1≤2.5mm.

33. The battery device of claim 31 or 32, wherein, In the projection plane perpendicular to the thickness direction of the wall portion, the minimum distance between the outer edges of the orthographic projection of the first connecting portion and the orthographic projection of the lead-out member is L2, which satisfies 1mm≤L2≤2.5mm.

34. The battery device of any one of claims 31-33, wherein, Along the thickness direction of the wall portion, the thickness of the area where the busbar component and the lead-out component are welded together is D4, which satisfies 1.2mm≤D4≤3mm.

35. The battery device according to any one of claims 31-34, wherein, Along the thickness direction of the wall portion, the surface of the lead-out member facing the wall portion is provided with a first limiting groove, and the protective layer has a third surface facing away from the wall portion. The third surface is provided with a first limiting protrusion, and the first limiting protrusion is inserted into the first limiting groove. The first limiting groove has a slot formed on the surface of the lead-out member facing the wall. In the projection plane perpendicular to the thickness direction of the wall, the orthographic projection of the first connecting part is located outside the orthographic projection of the slot.

36. An electrical device comprising a battery cell as described in any one of claims 1-30; or The battery device as described in any one of claims 31-35.

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