Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, a first electrode terminal, an electrode assembly and a first current collecting member. The shell has an end wall and a side wall connected with each other. The first electrode terminal is arranged on the end wall. The electrode assembly comprises a main body part and a first tab. The first current collecting member comprises a terminal current collecting part and a tab current collecting part connected with each other, and the first tab comprises a first connecting part located on the side of the tab current collecting part away from the main body part in a second direction, which is welded with the tab current collecting part and forms a first welding mark part. Wherein, a plurality of convex parts are formed on the side of the first connecting part away from the tab current collecting part, and the convex parts protrude from the first welding mark part in the direction of the main body part pointing to the side wall; and the first welding mark part is located between two adjacent convex parts in the arrangement direction of the plurality of convex parts. The technical scheme provided by the application can effectively improve the reliability of the battery device.

Description

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] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In the development of battery technology, how to improve the reliability of battery devices is a technical problem that urgently needs to be solved. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device. The technical solution provided by this application can effectively improve the reliability of the battery device.

[0005] This application is achieved through the following technical solution:

[0006] In a first aspect, some embodiments of this application provide a battery cell, which includes a casing, a first electrode terminal, an electrode assembly, and a first current collector. The casing has an end wall and a side wall connected to each other. The thickness direction of the end wall is parallel to a first direction, and the thickness direction of the side wall is parallel to a second direction. The first direction is perpendicular to the second direction. The first electrode terminal is disposed on the end wall. The electrode assembly is disposed within the casing and includes a main body and a first tab. The first tab is connected to the end of the main body near the side wall in the second direction. The first current collector is disposed within the casing and includes a terminal current collector and a tab current collector connected to each other. At least a portion of the terminal current collector is located between the main body and the end wall and connected to the first electrode terminal. The tab current collector extends from the terminal current collector to the space between the main body and the side wall. The first tab includes a first connecting portion located on the side of the tab current collector opposite to the main body in the second direction. The first connecting portion is welded to the tab current collector to form a first solder mark. Among them, the first connecting part has multiple protrusions on the side away from the electrode tab current collector. Along the direction of the main body part pointing towards the side wall, the protrusions protrude from the first solder mark part; along the arrangement direction of the multiple protrusions, the first solder mark part is located between two adjacent protrusions.

[0007] In the battery cell provided above, the first electrode terminal is disposed on the end wall, and the first tab is disposed on the end of the main body facing the side wall. That is, the first electrode terminal and the first tab are disposed on opposite sides, which can reduce the space occupied by their stacking due to their being disposed on the same side, so that the battery cell has a higher volumetric energy density. In this design, the first connecting portion has multiple protrusions on the side opposite to the tab current collector. These protrusions extend beyond the first solder mark, which is located between two protrusions. When the battery cell is subjected to external force causing the electrode assembly to shake inside the casing, the protrusions will abut against the sidewall before the first solder mark, thus providing support. This helps to prevent the first solder mark or welding slag from piercing the insulation structure between the electrode assembly and the casing and colliding with the sidewall, reducing the risk of internal short circuits in the battery cell and improving the reliability of the battery cell, thereby improving the reliability of the battery device. On the other hand, compared to designs where the first connecting portion does not have protrusions, the abutment between the protrusions and the sidewall reduces the deformation of the first current collector towards the sidewall and slows down the deformation angle of the first current collector. This reduces the risk of cracking at the bending points between the tab current collector and the terminal current collector, and / or at the connection points between them, improving the fatigue life of the first current collector and enhancing the reliability of the battery cell, which in turn improves the reliability of the battery device.

[0008] According to some embodiments of this application, the first electrode tab includes a plurality of stacked first electrode tab sheets. The number of first electrode tab sheets is greater than or equal to 30 layers and less than or equal to 150 layers; and / or the thickness of the first electrode tab sheets is greater than or equal to 0.003 mm and less than or equal to 0.02 mm.

[0009] In the above scheme, by limiting the number of first tabs to greater than or equal to 30 layers, when the first tabs are welded to the first current collector to form the first solder mark, multiple first tabs will bulge under force to effectively form a protrusion protruding from the first solder mark, thereby effectively reducing the risk of the first solder mark piercing the insulation structure and overlapping the shell and the first current collector fatigue cracking. By limiting the number of first tabs to less than or equal to 150 layers, the risk of the battery cell volume energy density decreasing due to excessive thickness of the first tabs can be avoided to a certain extent.

[0010] By limiting the thickness of the first tab to be greater than or equal to 0.003 mm, when the first tab is welded to the first current collector to form the first solder mark, multiple first tabs can be forced to bulge, effectively forming a protrusion protruding from the first solder mark. By limiting the thickness of the first tab to be less than or equal to 0.02 mm, the risk of a decrease in the volumetric energy density of the battery cell due to excessive thickness of the first tab can be avoided to a certain extent.

[0011] According to some embodiments of this application, the area through which the first electrode tab is passed by the first solder mark forms a solder mark area, the surface area of ​​the first electrode tab on one side in its thickness direction is S1, and the total area of ​​the solder mark area is S2, satisfying 0.075%≤S2 / S1≤5%.

[0012] In the above scheme, by limiting the ratio of the total area of ​​the solder area to the surface area of ​​the first tab to greater than or equal to 0.075%, a higher connection quality between the first tab and the first current collector can be achieved, which is beneficial to improving the current carrying capacity. By limiting the ratio of the total area of ​​the solder area to the surface area of ​​the first tab to less than or equal to 5%, sufficient space can be provided on the first connection part to form a protrusion, thereby effectively reducing the risk of the solder area piercing the insulation structure and causing a short circuit inside the battery cell.

[0013] According to some embodiments of this application, the first solder mark is strip-shaped and extends along a third direction. The first direction, the second direction, and the third direction are perpendicular to each other, and the protrusions are located on both sides of the first solder mark along the first direction.

[0014] Compared to the scheme where the first solder mark extends along the first direction, in the above scheme, the solder mark is strip-shaped and extends along the third direction. This facilitates the multi-layer tabs on both sides of the first solder mark along the first direction to bulge due to welding stress, forming protrusions. When the electrode assembly shakes, the protrusions abut against the sidewalls, reducing the deformation of the tab current collector relative to the terminal current collector, and mitigating the deformation angle between the tab current collector and the terminal current collector. This reduces the risk of cracking at the bending points of the tab current collector and the terminal current collector, improves the fatigue life of the first current collector component, and enhances the reliability of the battery cell, thereby improving the reliability of the battery device.

[0015] According to some embodiments of this application, there are multiple first solder pads, and the multiple first solder pads are arranged at intervals along a first direction.

[0016] In the above solution, by setting multiple first solder marks and arranging them at intervals along a first direction, it can improve the connection quality and current carrying capacity between the first electrode tab and the first current collector. On the other hand, it can form multiple protrusions at intervals along the first direction on the side of the first connection portion facing the sidewall. When the electrode assembly shakes, the protrusions abut against the sidewall, reducing the deformation degree of the electrode tab current collector relative to the terminal current collector, and slowing down the deformation angle between the electrode tab current collector and the terminal current collector. This reduces the risk of cracking at the bending part of the electrode tab current collector and the terminal current collector, improves the fatigue life of the first current collector, and improves the reliability of the battery cell, thereby improving the reliability of the battery device.

[0017] According to some embodiments of this application, along the first direction, the spacing between two adjacent first solder pads is greater than or equal to 1 mm and less than or equal to 10 mm.

[0018] In the above scheme, along the first direction, the protrusion is located between two adjacent first solder marks. By setting the distance between the two first solder marks to be greater than or equal to 1 mm, there is a suitable space between the two first solder marks to form the protrusion. By setting the distance between the first solder marks to be less than or equal to 10 mm, the problem of insufficient number and welding area of ​​first solder marks on the first connection part and the current collector part of the electrode tab can be reduced due to the excessive distance between the first solder marks. This ensures the electrical connection stability between the first electrode tab and the first current collector to a certain extent, so that the battery cell has high reliability.

[0019] According to some embodiments of this application, along the arrangement direction of the plurality of protrusions, the size of the protrusions is greater than or equal to 1 mm and less than or equal to 10 mm.

[0020] In the above scheme, along the arrangement direction of the multiple protrusions, the solder mark is located between two adjacent protrusions. The dimension of the protrusion along its arrangement direction can be its width. By limiting the width of the protrusion to greater than or equal to 1 mm, it can effectively abut against the sidewall, thereby providing a protective barrier for the first solder mark located between the two protrusions. This reduces the risk of the solder mark piercing the insulation structure and overlapping with the shell, and effectively reduces the deformation degree of the tab current collector relative to the terminal current collector, mitigating the deformation angle between the tab current collector and the terminal current collector. By limiting the width of the protrusion to less than or equal to 10 mm, the risk of the solder mark arrangement being affected by the excessive size of the protrusion can be avoided to a certain extent. This ensures that there is sufficient welding area between the first tab and the first current collector, guaranteeing the electrical connection stability between the first tab and the first current collector to a certain extent, thus giving the battery cell high reliability.

[0021] According to some embodiments of this application, the terminal current collector is welded to the tab current collector to form a second solder mark.

[0022] In the above scheme, the first current collector is a split structure. After the terminal current collector and the tab current collector are respectively connected to the first electrode terminal and the first tab, a second solder joint is formed between the terminal current collector and the tab current collector and they are connected to each other by welding. This makes the assembly of the battery cell easier and improves the manufacturing efficiency of the battery cell. At the same time, by providing a protrusion on the side of the first connection portion facing the sidewall, the protrusion can abut against the sidewall when the electrode assembly shakes, reducing the deformation of the tab current collector relative to the terminal current collector and mitigating the deformation angle between the tab current collector and the terminal current collector. This reduces the risk of cracking at the bending parts of the tab current collector and the terminal current collector and in the heat-affected zone caused by welding, resulting in high structural reliability of the battery cell and improving the reliability of the battery device.

[0023] According to some embodiments of this application, the first current collector is partially bent such that at least a portion of the terminal current collector is located between the main body and the end wall, and the tab current collector extends from the terminal current collector to between the main body and the side wall; the second solder mark is located near the portion where the first current collector is partially bent.

[0024] In the above solution, the part where the first current collector is partially bent is the stress concentration point of the first current collector, which is prone to fatigue cracking due to the shaking of the electrode assembly. By setting the second solder part close to the part where the first current collector is partially bent, the second solder part and the stress concentration point of the first current collector are concentrated. In the embodiment where a protrusion is provided on the first connection part to reduce the deformation angle of the first current collector, the problem of fatigue cracking of the first current collector due to the shaking of the electrode assembly and the cracking of the connection between the tab current collector and the terminal current collector can be further improved, so that the battery cell has higher reliability, and thus the battery device has higher reliability.

[0025] According to some embodiments of this application, the terminal current collector and the tab current collector are stacked, one end of the second solder mark protrudes from the side of the terminal current collector away from the tab current collector, and the other end of the second solder mark protrudes from the side of the tab current collector away from the terminal current collector.

[0026] In the above scheme, the terminal current collector and the tab current collector are connected to each other by a through-welding process. The two ends of the second solder mark protrude from the side of the terminal current collector away from the tab current collector and the side of the tab current collector away from the terminal current collector, respectively. This results in high welding quality between the terminal current collector and the tab current collector, which is beneficial to improving the structural strength and current carrying capacity of the first current collector component. This enables the first current collector component to effectively resist the impact caused by the shaking of the electrode assembly, thereby making the battery cell more reliable and thus the battery device more reliable.

[0027] According to some embodiments of this application, the terminal current collector includes a first portion and a second portion, which are arranged along the end wall in the direction pointing towards the main body, and the first portion protrudes from the second portion in the direction pointing towards the side wall from the main body. A tab current collector is stacked on the second portion, and a second solder mark is located between the first portion and the tab current collector.

[0028] In the above scheme, the terminal current collector and the tab current collector are connected to each other by a lap welding process. The tab current collector is lapped on the second part of the terminal current collector. By welding the first part and the tab current collector, the second solder mark is located between the first part and the tab current collector, which can reduce the welding difficulty of the terminal current collector and the tab current collector and help improve the manufacturing efficiency of the battery cell.

[0029] According to some embodiments of this application, the group margin of a single battery cell along the second direction is greater than or equal to 92% and less than or equal to 98%.

[0030] In the above scheme, by setting the group margin of the battery cell along the second direction to greater than or equal to 92%, the internal space of the casing is effectively utilized, resulting in a high volumetric energy density for the battery cell. By setting the group margin of the battery cell along the second direction to less than or equal to 98%, the risk of excessive internal pressure affecting the reliability of the battery cell can be avoided to a certain extent after a certain number of charge-discharge cycles. In some embodiments that limit the group margin of the battery cell along the second direction, by forming a protrusion on one side of the first electrode tab along the second direction, the risk of electrode assembly shaking along the second direction, causing the first solder joint to pierce the insulation structure and overlap with the casing, resulting in an internal short circuit in the battery cell, can be effectively reduced, as can the risk of fatigue cracking of the first current collector due to excessive deformation can also be reduced.

[0031] According to some embodiments of this application, the housing includes an adjacent first wall and a second wall, which are integrally formed. The inner surfaces of the first wall and the second wall are connected by a first arc surface. The electrode assembly has an adjacent first surface and a second surface, with the first surface facing the first wall and the second surface facing the second wall. The first surface and the second surface are connected by a first transition surface. Along the direction from the outer surface of the first wall to the inner surface of the first wall, the distance from the first transition surface to the second wall gradually decreases.

[0032] In the above scheme, the first wall and the second wall are integrally formed, giving the outer shell high structural strength and effectively resisting impacts to the outside and inside of the battery cell, thus improving the reliability of the battery cell. Furthermore, connecting the first and second surfaces of the electrode assembly, corresponding to the first and second walls, via a first transition surface effectively avoids the first arc surface formed by the integral forming of the first and second walls. This reduces the risk of interference between the electrode assembly and the first arc surface, which could lead to structural damage to the electrode assembly, thereby ensuring high reliability of the battery cell and consequently, high reliability of the battery device.

[0033] According to some embodiments of this application, the electrode assembly includes N electrode groups, which are arranged along the outer surface of the first wall pointing towards the inner surface of the first wall. Each electrode group includes a negative electrode and a positive electrode arranged along the thickness direction of the first wall. Along the direction from the outer surface of the first wall to the inner surface of the first wall, the distance from the electrode group to the second wall gradually decreases from the first electrode group to the Mth electrode group, so that the electrode assembly forms a first transition surface, where M < N.

[0034] In the above scheme, the electrode assembly includes N electrode groups arranged along the thickness direction of the first wall. Each electrode group includes a negative electrode and a positive electrode arranged along the thickness direction of the first wall. Along the direction from the outer surface of the first wall to the inner surface of the first wall, from the first electrode group to the Mth electrode group, the distance from the electrode group to the second wall is gradually reduced to form a first transition surface. This allows the electrode assembly to avoid the first arc surface, reducing the risk of structural damage to the electrode assembly, resulting in higher reliability for the battery cell and consequently, higher reliability for the battery device.

[0035] According to some embodiments of this application, the dimension of the first arc surface along the thickness direction of the first wall is R1, and the dimension of the first arc surface along the thickness direction of the second wall is R2. Along the thickness direction of the second wall, the first electrode group has a first end facing the second wall, the distance between the first end and the second surface along the thickness direction of the first wall is D1, and the distance between the first end and the second wall along the thickness direction of the second wall is D2, satisfying R1 < D1 < 3*R1, R2 < D2 < 3*R2.

[0036] In the above scheme, limiting the distance D1 from the first end of the first electrode group to the second surface to be greater than R1 allows the electrode assembly to effectively avoid the first arc surface, reducing the risk of interference between the electrode assembly and the first arc surface, which could damage the electrode assembly structure. Limiting the distance D1 from the first end of the first electrode group to the second surface to less than 3 times R1 reduces the risk of the electrode assembly volume decreasing due to the first transition surface, thus affecting the volumetric energy density of the battery cell. Similarly, limiting the distance D2 from the first end of the first electrode group to the second wall to be greater than R2 allows the electrode assembly to effectively avoid the first arc surface, reducing the risk of interference between the electrode assembly and the first arc surface, which could damage the electrode structure. Limiting the distance D2 from the first end of the first electrode group to the second wall to less than 3 times R2 reduces the risk of the electrode assembly volume decreasing due to the first transition surface, which could affect the volumetric energy density of the battery cell.

[0037] According to some embodiments of this application, the battery cell further includes a first insulating portion located between the first wall and the electrode assembly along the thickness direction of the first wall, and the thickness of the first insulating portion is H1. The dimension of the first arc surface along the thickness direction of the first wall is R1, satisfying 0 < H1 < R1.

[0038] In the above scheme, the battery cell also includes a first insulating portion, which is located between the first wall and the electrode assembly to insulate and isolate the first wall and the electrode assembly. By limiting the thickness H1 of the first insulating portion to be greater than 0, the first insulating portion can play an insulating and isolating role. By limiting the thickness H1 of the first insulating portion to be smaller than the dimension R1 of the first arc surface along the thickness direction of the first wall, the thickness H1 of the first insulating portion can be made as small as possible without the electrode assembly interfering with the first arc surface, thereby improving the volumetric energy density of the battery cell and, consequently, the volumetric energy density of the battery device.

[0039] According to some embodiments of this application, the battery cell further includes a second insulating portion located between the second wall and the electrode assembly along the thickness direction of the second wall, and the thickness of the second insulating portion is H2. The dimension of the first arc surface along the thickness direction of the second wall is R2, satisfying 0 < H1 < R2.

[0040] In the above scheme, the battery cell also includes a second insulating portion, which is located between the second wall and the electrode assembly to insulate and isolate the second wall and the electrode assembly. By limiting the thickness H2 of the second insulating portion to be greater than 0, the second insulating portion can play an insulating and isolating role. By limiting the thickness H2 of the second insulating portion to be smaller than the dimension R2 of the first arc surface along the thickness direction of the second wall, the thickness H2 of the second insulating portion can be made as small as possible without the electrode assembly interfering with the first arc surface, thereby improving the volumetric energy density of the battery cell and, consequently, the volumetric energy density of the battery device.

[0041] According to some embodiments of this application, the battery cell further includes a protective adhesive that covers the end of the electrode assembly corresponding to the location of the first transition surface.

[0042] In the above scheme, the battery cell also includes a protective adhesive, which covers the end face of the first transition surface corresponding to the electrode assembly. This adhesive can fix the burrs at the end of the electrode assembly, reduce the risk of short circuit inside the battery cell caused by the burrs overlapping with the outer shell, thereby making the battery cell highly reliable and thus making the battery device highly reliable.

[0043] Secondly, some embodiments of this application also provide a battery device, which includes the battery cell provided in the first aspect.

[0044] Thirdly, some embodiments of this application also provide an electrical device, which includes the battery cell provided in the first aspect and / or the battery device provided in the second aspect.

[0045] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0046] 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.

[0047] Figure 1 This is a schematic diagram of a vehicle in some embodiments of this application;

[0048] Figure 2 This is an exploded perspective view of the battery device in some embodiments of this application;

[0049] Figure 3 This is a perspective view of a single battery cell in some embodiments of this application;

[0050] Figure 4 This is an exploded perspective view of a battery cell in some embodiments of this application;

[0051] Figure 5 This is a top view of a battery cell in some embodiments of this application;

[0052] Figure 6 for Figure 5 A sectional view along the AA direction;

[0053] Figure 7 for Figure 6 Enlarged view of point B in the middle;

[0054] Figure 8 This is a perspective view of the electrode assembly, the first current collector, and the end wall in some embodiments of this application;

[0055] Figure 9 This is a schematic diagram of the structure of the electrode assembly and the first current collector in some embodiments of this application;

[0056] Figure 10 This is a schematic diagram of the first electrode and the first current collector in some embodiments of this application;

[0057] Figure 11 This is a schematic diagram of the terminal current collector, the electrode current collector, and the second solder mark in some embodiments of this application;

[0058] Figure 12 This is a schematic diagram of the terminal current collector, the electrode current collector, and the second solder mark in other embodiments of this application;

[0059] Figure 13 This is a partial schematic diagram of the internal structure of a battery cell in some embodiments of this application;

[0060] Figure 14 This is a schematic diagram of the first wall, the second wall, and the N electrode groups in some embodiments of this application;

[0061] Figure 15 This is a partial structural diagram of the first wall, the second wall, and the electrode assembly in some embodiments of this application.

[0062] Icons: 1000 - Vehicle; 100 - Battery Unit; 200 - Controller; 300 - Motor; 10 - Battery Cell; 30 - Housing; 31 - First Housing Body; 32 - Second Housing Body; 11 - Outer Shell; 110 - Cover; 111 - Housing; 112 - End Wall; 113 - Side Wall; 114 - First Wall; 115 - Second Wall; 116 - First Arc Surface; 12a - First Electrode Terminal; 12b - Second Electrode Terminal; 13 - Electrode Assembly; 130 - Main Body; 1300 - First Surface; 1301 - Second Surface; 1302 - First Transition Surface; 131 - First Tab; 1310 - First Tab Sheet ; 132-First connecting part; 1320-Protrusion; 1321-First solder mark part; 133-Electrode assembly; 1330-Negative electrode; 1331-Positive electrode; 1332-Separating membrane; 14a-First current collector; 140-Terminal current collector; 1400-First part; 1401-Second part; 1402-First segment; 1403-Second segment; 141-Taper current collector; 142-Second solder mark part; 14b-Second current collector; 15-First insulating part; 16-Second insulating part; 17-Protective adhesive; 18-Insulating film; 19-Insulating component; z-First direction; x-Second direction; y-Third direction. Detailed Implementation

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] In this application, "multiple" means two or more (including two).

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0076] 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.

[0077] 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.

[0078] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0079] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0080] 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.

[0081] 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.

[0082] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0083] In some implementations, the electrode assembly has a stacked structure.

[0084] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0085] 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.

[0086] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0087] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0088] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0089] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0090] 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.

[0091] In some implementations, a battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes.

[0092] The battery apparatus 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.

[0093] 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 together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0094] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0095] 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.

[0096] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. The energy storage device includes energy storage containers, energy storage cabinets, etc. In some embodiments, one or more energy storage devices may constitute at least part of an energy storage system.

[0101] 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, and discharge capacity. Furthermore, the reliability of the battery device must also be taken into account.

[0102] In related technologies, a battery cell includes a casing, electrode terminals, a current collector, and an electrode assembly. The casing includes a housing and a cover. The electrode terminals are disposed on the cover. The electrode assembly includes a main body and tabs. The tabs are disposed on opposite sides of the electrode terminals and extend from the main body, electrically connecting to the current collector. This allows the tabs to be electrically connected to the electrode terminals via the current collector to achieve the input or output of electrical energy. The current collector includes mutually bent terminal current collectors and tab current collectors. The terminal current collectors are connected to the electrode terminals, and the tab current collectors are connected to the tabs. However, when the battery cell is subjected to vibration, the electrode assembly inside the battery cell shakes and pulls on the first current collector, causing the first current collector to deform towards the sidewall. With increasing amplitude and frequency of shaking, the first current collector may experience fatigue cracking, or even breakage, affecting the reliability of the battery cell and consequently the reliability of the battery device.

[0103] In view of this, to improve the problem of battery cell vibration causing electrode assembly to shake and resulting in cracking or even breakage of the first current collector, some embodiments of this application provide a battery cell. The battery cell includes a casing, a first electrode terminal, an electrode assembly, and a first current collector. The casing has an end wall and a side wall connected to each other. The thickness direction of the end wall is parallel to a first direction, and the thickness direction of the side wall is parallel to a second direction. The first direction is perpendicular to the second direction. The first electrode terminal is disposed on the end wall. The electrode assembly is disposed within the casing and includes a main body and a first tab. The first tab is connected to the end of the main body near the side wall in the second direction. The first current collector is disposed within the casing and includes a terminal current collector and a tab current collector connected to each other. At least a portion of the terminal current collector is located between the main body and the end wall and connected to the first electrode terminal. The tab current collector extends from the terminal current collector to the space between the main body and the side wall. The first tab includes a first connecting portion located on the side of the tab current collector opposite to the main body in the second direction. The first connecting portion is welded to the tab current collector to form a first solder mark. The first connecting part has multiple protrusions on the side away from the electrode tab current collector. The protrusions protrude from the first solder mark part along the direction from the main body to the side wall. The first solder mark part is located between two adjacent protrusions along the arrangement direction of the multiple protrusions.

[0104] In the battery cell provided above, the first electrode terminal is disposed on the end wall, and the first tab is disposed on the end of the main body facing the side wall. That is, the first electrode terminal and the first tab are disposed on opposite sides, which can reduce the space occupied by their stacking when they are disposed on the same side, so that the battery cell has a higher volumetric energy density. The first tab is electrically connected to the first electrode terminal through a first current collector. The first current collector includes a terminal current collector and a tab current collector. The terminal current collector is connected to the first electrode terminal, and the tab current collector is located on the side of the first connection portion of the first tab away from the side wall and is welded to the first connection portion to form a first solder mark portion.

[0105] In this design, the first connecting portion has multiple protrusions on the side opposite to the current collector of the electrode tab. These protrusions extend beyond the first solder mark, which is located between two protrusions. When the battery cell is subjected to external force causing the electrode assembly to shake inside the casing, the protrusions will abut against the sidewall before the solder mark, thus providing support. This helps to prevent the first solder mark or welding slag from piercing the insulation structure between the electrode assembly and the casing and colliding with the sidewall, reducing the risk of internal short circuits in the battery cell and improving the reliability of the battery cell, thereby improving the reliability of the battery device. On the other hand, compared to designs where the first connecting portion does not have protrusions, the abutment between the protrusions and the sidewall reduces the deformation of the first current collector towards the sidewall and slows down the deformation angle of the first current collector, thereby reducing the risk of cracking of the first current collector, improving the fatigue life of the first current collector, and thus improving the reliability of the battery cell and the battery device.

[0106] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.

[0107] The technical solutions described in the embodiments of this application are applicable to battery devices, energy storage devices using battery devices, and electrical devices using battery devices.

[0108] Energy storage devices may include energy storage containers, energy storage cabinets, etc. For example, an energy storage cabinet may include a cabinet and one or more battery cells and / or battery devices mounted on the cabinet.

[0109] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be new energy vehicles, including pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The electrical devices in the embodiments of this application include, but are not limited to, those mentioned above.

[0110] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0111] Figure 1 This is a schematic diagram of vehicle 1000 in some embodiments of this application.

[0112] The electrical device is a vehicle 1000. Inside the vehicle 1000, a controller 200, a motor 300, and a battery device 100 can be installed. The controller 200 controls the battery device 100 to supply power to the motor 300. For example, the battery device 100 can be installed 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 operating power source for the vehicle 1000's electrical system, such as meeting the power requirements for starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000 but also as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power to the vehicle 1000.

[0113] Please refer to Figure 2 , Figure 2 This is an exploded perspective view of the battery device 100 in some embodiments of this application. The battery device 100 includes a housing 30 and battery cells 10, the battery cells 10 being housed within the housing 30.

[0114] The housing 30 provides assembly space for the battery cell 10, and can adopt various structures. In some embodiments, the housing 30 may include a first housing body 31 and a second housing body 32, which overlap each other, and together define an assembly space for accommodating the battery cell 10. The second housing body 32 may be a hollow structure open at one end, and the first housing body 31 may be a plate-like structure, with the first housing body 31 covering the open side of the second housing body 32 so that the first housing body 31 and the second housing body 32 together define the assembly space; alternatively, the first housing body 31 and the second housing body 32 may both be hollow structures open on one side, with the open side of the first housing body 31 covering the open side of the second housing body 32.

[0115] Of course, the box 30 formed by the first box body 31 and the second box body 32 can be of various shapes, such as cylinder, cuboid or cube.

[0116] In the battery device 100, there can be one or more battery cells 10 disposed within the housing 30. When there are multiple battery cells 10 disposed within the housing 30, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 10 are connected in both series and parallel configurations. Multiple battery cells 10 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 10 is housed within the housing 30. Alternatively, the battery device 100 can also consist of multiple battery cells 10 first connected in series, in parallel, or in a mixed configuration to form battery modules, and then multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 30.

[0117] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple battery cells 10 to achieve electrical connection between the multiple battery cells 10.

[0118] For example, the housing 30 is provided with a plurality of battery cell assemblies, each battery cell assembly including a plurality of battery cells 10 stacked on top of each other, and the plurality of battery cells 10 are connected in series with each other through a busbar. In some embodiments, the plurality of battery cell assemblies can be connected in series with each other through a busbar.

[0119] Each battery cell 10 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 10 can be in the form of a cuboid, cylinder, prism, or other shapes.

[0120] This application provides a battery cell 10; please refer to [link / reference]. Figures 3-9 , Figure 3 This is a perspective view of the battery cell 10 in some embodiments of this application. Figure 4 This is an exploded perspective view of the battery cell 10 in some embodiments of this application. Figure 5 This is a top view of a battery cell 10 in some embodiments of this application. Figure 6 for Figure 5 Sectional view in the middle AA direction. Figure 7 for Figure 6 Enlarged view at point B in the middle. Figure 8 This is a perspective view of the electrode assembly 13, the first current collector 14a, and the end wall 112 in some embodiments of this application. Figure 9 This is a schematic diagram of the structure of the electrode assembly 13 and the first current collector 14a in some embodiments of this application.

[0121] The battery cell includes a casing 11, a first electrode terminal 12a, an electrode assembly 13, and a first current collector 14a. The casing 11 has an end wall 112 and a side wall 113 connected to each other. The thickness direction of the end wall 112 is parallel to a first direction z, and the thickness direction of the side wall 113 is parallel to a second direction x. The first direction z is perpendicular to the second direction x. The first electrode terminal 12a is disposed on the end wall 112. The electrode assembly 13 is disposed inside the casing 11. The electrode assembly 13 includes a main body 130 and a first tab 131. The first tab 131 is connected to the end of the main body 130 near the side wall 113 in the second direction x. A first current collector 14a is disposed within the housing 11. The first current collector 14a includes a terminal current collector 140 and a tab current collector 141 connected to each other. At least a portion of the terminal current collector 140 is located between the main body 130 and the end wall 112 and is connected to the first electrode terminal 12a. The tab current collector 141 extends from the terminal current collector 140 to the area between the main body 130 and the side wall 113. The first tab 131 includes a first connecting portion 132 located on the side of the tab current collector 141 opposite to the main body 130 in the second direction x. The first connecting portion 132 is welded to the tab current collector 141 to form a first solder mark 1321. A plurality of protrusions 1320 are formed on the side of the first connecting portion 132 opposite to the tab current collector 141, protruding from the first solder mark 1321 along the direction from the main body 130 to the side wall 113. Along the arrangement direction of the plurality of protrusions 1320, the first solder mark 1321 is located between two adjacent protrusions 1320.

[0122] The battery cell 10 can be in the form of a cuboid, cylinder, prism, or other shapes, and correspondingly, the outer casing 11 can be in the form of a cuboid, cylinder, prism, pouch, or other shapes. In some embodiments of this application, the battery cell 10 is a cuboid and the outer casing 11 is a cuboid as an example.

[0123] The battery cell 10 includes a housing 11, which is a component for housing the electrode assembly 13. The housing 11 can also be used to house an electrolyte, such as an electrolyte solution. Please see below. Figure 4 In some embodiments, the housing 11 includes a housing 111 and a cover 110. The housing 111 has an interior cavity for accommodating the electrode assembly 13. The housing 111 has an opening communicating with the cavity. The cover 110 closes to the opening of the housing 111 to form a closed space for accommodating the electrode assembly 13 and the electrolyte. Optionally, there are two covers 110. The housing 111 has two openings opposite to each other, and the covers 110 are respectively connected to the housing 111 and respectively close the two openings.

[0124] In some embodiments, the housing 11 can be a sealed structure or a non-sealed structure. As an example, when the housing 11 is a sealed structure, it can protect the electrode assembly 13 and prevent, to some extent, electrolyte leakage. When the housing 11 is a non-sealed structure, it can still protect the electrode assembly 13, and a sealing bag may be included between the housing 11 and the electrode assembly 13. The sealing bag is used to encapsulate the electrode assembly 13 and the electrolyte, etc. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0125] In some embodiments, the housing 111 may be made of metal or a combination of metal and non-metal. For example, the housing 111 may be made of metal, such as copper, iron, aluminum, steel, stainless steel or aluminum alloy.

[0126] In some embodiments, the cover 110 may be made of metal or a combination of metal and non-metal. For example, the cover 110 may be made of metal, such as copper, iron, aluminum, steel, or aluminum alloy. In other embodiments, the cover 110 may be made of non-metallic materials, such as plastic or ceramic.

[0127] In some embodiments, the cover 110 may be made of the same material as the housing 111, and the two are connected to each other.

[0128] In some embodiments of this application, the outer casing 11 has an end wall 112 and a side wall 113 connected to each other. Optionally, the end wall 112 can be a cover 110, or the end wall 112 can be a wall portion of the casing 111 opposite to the cover 110. The side wall 113 can be a wall portion. Some embodiments of this application are illustrated by taking the end wall 112 as the cover 110 and the side wall 113 as a wall portion of the casing 111 adjacent to the cover 110 as an example.

[0129] A first electrode terminal 12a is provided on the end wall 112. The first electrode terminal 12a can be insulatedly disposed on the end wall 112, for example, the first electrode terminal 12a is disposed on the end wall 112 by means of plastic.

[0130] Optionally, the material of the first electrode terminal 12a can be metal or composite metal, such as copper, iron, aluminum, steel or aluminum alloy, or copper-aluminum composite metal, copper-steel composite metal, etc.

[0131] In some embodiments, the first electrode terminal 12a may be riveted to the end wall 112. In other embodiments, the first electrode terminal 12a may be fixed to the end wall 112 by a welding ring.

[0132] The first electrode terminal 12a is used to electrically connect with the first tab 131 of the electrode assembly 13 to realize the input and output of electrical energy.

[0133] Optionally, the battery cell 10 also includes a second electrode terminal 12b, which can be disposed on the end wall 112 for electrical connection with the second tab of the electrode assembly 13 to realize the input and output of electrical energy.

[0134] The electrode assembly 13 is disposed within the housing 11, and the electrode assembly 13 can be a wound structure or a stacked structure. Some embodiments of this application are illustrated using the first electrode assembly 13 as a stacked structure as an example.

[0135] The electrode assembly 13 includes a main body 130 and a first tab 131. The first main body 130 includes a positive electrode 1331, a negative electrode 1330, and a separator 1332 stacked together. The separator 1332 is disposed between the positive electrode 1331 and the negative electrode 1330, and the positive electrode 1331 and the negative electrode 1330 have opposite polarities. The first tab 131 is connected to either the positive electrode 1331 or the negative electrode 1330. For example, the first tab 131 is connected to the positive electrode 1331. The first tab 131 is used to electrically connect to the first electrode terminal 12a.

[0136] Optionally, the electrode assembly 13 further includes a second tab, which is connected to the other of the positive electrode 1331 or the negative electrode 1330 for electrically connecting the second electrode terminal 12b.

[0137] In some embodiments, the first electrode tab 131 includes a plurality of first electrode tab pieces 1310 stacked together, and the first electrode tab pieces 1310 are connected to electrodes of corresponding polarities.

[0138] The phrase “the first electrode 131 is connected to the end of the main body 130 near the side wall 113 in the second direction x” can be understood as the first electrode 131 being led out from one side of the main body 130 along the second direction x, and the first electrode 131 being located between the side wall 113 and the main body 130.

[0139] Please see Figure 4 The first electrode terminal 12a is located on one side of the main body 130 along the first direction z, and the first electrode tab 131 is located on one side of the main body 130 along the second direction x. The first electrode terminal 12a and the first electrode tab 131 are arranged on opposite sides and are electrically connected through the first current collector 14a.

[0140] The first current collector 14a is a structural component that electrically connects the first tab 131 and the first electrode terminal 12a. The material of the first current collector 14a includes, but is not limited to, copper, iron, aluminum, steel, stainless steel, or aluminum alloy. In some embodiments, the surface of the first current collector 14a may be provided with a metal plating layer, such as a nickel plating layer.

[0141] In some embodiments, the first current collector 14a includes a terminal current collector 140 and a tab current collector 141. The terminal current collector 140 is connected to the first electrode terminal 12a, and all or part of the terminal current collector 140 may be located between the main body 130 and the end wall 112. The tab current collector 141 is located between the side wall 113 and the main body 130, and the tab current collector 141 is electrically connected to the first tab 131. Referring to 7, the first current collector 14a is generally L-shaped, with a portion located between the main body 130 and the end wall 112 to connect to the first electrode terminal 12a, and another portion located between the main body 130 and the side wall 113 to connect to the first tab 131.

[0142] Optionally, the first current collector 14a is an integrally formed structure. Optionally, the first current collector 14a is a split structure, for example, the terminal current collector 140 and the tab current collector 141 are connected to each other, and the connection relationship between the terminal current collector 140 and the tab current collector 141 is diverse, including but not limited to welding, bonding, snap-fitting and other methods.

[0143] The first tab 131 may include a root and a first connecting portion 132. The first connecting portion 132 is connected to the main body 130 through the root. The first connecting portion 132 is bent at the root to be folded over the side of the tab current collector 141 away from the main body 130, so that the tab current collector 141 is located between the first connecting portion 132 and the main body 130.

[0144] Please see Figure 7 and Figure 9 The first connecting portion 132 is welded to the tab current collector portion 141 to form a first solder mark portion 1321. Optionally, the first connecting portion 132 and the tab current collector portion 141 can be welded together by laser welding, ultrasonic welding, or other methods to form the first solder mark portion 1321. The first solder mark portion 1321 is the part formed by welding and melting the first connecting portion 132 and the tab current collector portion 141 together.

[0145] In some embodiments, the shape of the first solder mark 1321 may be dot-shaped, ring-shaped, strip-shaped, or other shapes.

[0146] Optionally, the first solder mark 1321 can be strip-shaped, and the extension direction of the first solder mark 1321 can be parallel to the first direction z, or the extension direction of the first solder mark 1321 can be parallel to the third direction y, with the first direction z, the second direction x, and the third direction y being perpendicular to each other.

[0147] Optionally, there can be multiple first solder marks 1321, which can be arranged along a first direction z or along a third direction y. For example, the first solder marks 1321 are strip-shaped and extend along a third direction y, and multiple first solder marks 1321 are arranged at intervals along the first direction z.

[0148] For example, after the first tab 131 is smoothed once, the first current collector 14a is placed on the first tab 131. The first tab 131 undergoes a second smoothing. After the second smoothing, the first tab 131 is placed on the side of the adapter plate away from the main body 130. The total thickness of the first tab 131 is H1, the thickness of the first current collector 14a is H2, and the effective penetration depth of the first tab 131 weld is H3, where 1 / 4 ≤ H3 / H2 ≤ 3 / 4.

[0149] The protrusion 1320 is formed on the side of the first connecting portion 132 away from the electrode current collector portion 141, and is closer to the sidewall 113 than the first solder mark portion 1321. "The first solder mark portion 1321 is located between two adjacent protrusions 1320 along the arrangement direction of the plurality of protrusions 1320" can be understood as the first solder mark portion 1321 being located between two protrusions 1320, so that along the direction from the main body portion 130 to the sidewall 113, the two protrusions 1320 protect the first solder mark portion 1321 between them, so that the protrusion 1320 abuts against the sidewall 113 before the first solder mark portion 1321 and the burrs or slag generated by welding.

[0150] The protrusion 1320 can be a structural component disposed on the surface of the first electrode tab 131, or it can be a structure of the first electrode tab 131 itself.

[0151] For example, the protrusion 1320 is the structure of the first tab 131 itself. During the welding process between the first connecting portion 132 and the tab current collector 141, in the area corresponding to the first solder mark 1321, multiple first tab pieces 1310 are tightly closed to connect with the tab current collector 141. On both sides of the area corresponding to the first solder mark 1321, multiple tab pieces are relatively loose to form the protrusion 1320. When there is a first solder mark 1321 between the first connecting portion 132 and the tab current collector 141, the first connecting portion 132 forms protrusions 1320 on both sides of the first solder mark 1321. When the number of first solder marks 1321 is n, the number of protrusions 1320 is at least n+1.

[0152] by Figure 9For example, the first solder mark 1321 is strip-shaped and extends along the third direction y. Multiple first solder marks 1321 are arranged at intervals along the first direction z. The first connecting part 132 is formed with multiple protrusions 1320 arranged at intervals along the first direction z. There is a first solder mark 1321 between two adjacent protrusions 1320.

[0153] In the battery cell 10 provided above, the first electrode terminal 12a is disposed on the end wall 112, and the first tab 131 is disposed on the end of the main body 130 facing the side wall 113. That is, the first electrode terminal 12a and the first tab 131 are disposed on opposite sides, which can reduce the space occupied by their stacking due to their being disposed on the same side, so that the battery cell 10 has a higher volumetric energy density. The first tab 131 is electrically connected to the first electrode terminal 12a through a first current collector 14a. The first current collector 14a includes a terminal current collector 140 and a tab current collector 141. The terminal current collector 140 is connected to the first electrode terminal 12a, and the tab current collector 141 is located on the side of the first connecting portion 132 of the first tab 131 away from the side wall 113 and is welded to the first connecting portion 132 to form a first solder mark 1321.

[0154] The first connecting portion 132 has multiple protrusions on the side opposite to the tab current collector 141. These protrusions extend beyond the first solder mark 1321, which is located between two protrusions 1320. When the battery cell 10 is subjected to external force causing the electrode assembly 13 to shake inside the housing 11, the protrusions will abut against the side wall 113 before the first solder mark 1321, thus providing support. This helps to prevent the first solder mark 1321 or welding slag from piercing the insulation structure between the electrode assembly 13 and the housing 11 and colliding with the side wall 113, reducing the risk of internal short circuits in the battery cell 10. 10 has high reliability, which in turn makes the battery device 100 have high reliability. On the other hand, compared with the solution where the first connecting part 132 does not have a protrusion 1320, the abutment of the protrusion 1320 against the side wall 113 can reduce the degree of deformation of the first current collector 14a and slow down the deformation angle of the first current collector 14a. This reduces the risk of cracking at the bending part between the tab current collector 141 and the terminal current collector 140 and / or at the connection between the two, improves the fatigue life of the first current collector 14a, and is conducive to improving the reliability of the battery cell 10, which in turn is conducive to improving the reliability of the battery device 100.

[0155] According to some embodiments of this application, please refer to Figure 10 , Figure 10 This is a schematic diagram of the first tab 131 and the first current collector 14a in some embodiments of this application.

[0156] The first tab 131 includes a plurality of stacked first tab pieces 1310. The number of first tab pieces 1310 is greater than or equal to 30 layers and less than or equal to 150 layers; and / or the thickness of the first tab pieces 1310 is greater than or equal to 0.003 mm and less than or equal to 0.02 mm.

[0157] In some embodiments, the first tab 131 includes a plurality of first tab pieces 1310 stacked together. The first tab pieces 1310 are connected to the tab pieces of the corresponding polarity. The first tab pieces 1310 are bent on the side of the tab current collector 141 away from the main body 130 and form a first connecting portion 132. The first connecting portion 132 is welded to the tab current collector 141.

[0158] The number of first pole tabs 1310 can be 30, 40, 50...140, 150 or any value between two adjacent values.

[0159] Optionally, the first tab 131 can be unfolded, and the multiple first tab pieces 1310 can be separated and counted to obtain the number of first tab pieces 1310 in the first tab 131.

[0160] The thickness of the first electrode lug 1310 can be 0.003mm, 0.004mm, 0.005mm...0.018mm, 0.019mm, 0.02mm or any value between two adjacent values.

[0161] Optionally, the first tab 131 can be unfolded, and the multiple first tab pieces 1310 can be separated. The thickness of one of the first tab pieces 1310 can be measured individually, or the thickness of multiple first tab pieces 1310 can be measured and the average value can be taken to obtain the thickness of the first tab piece 1310.

[0162] In the above scheme, by limiting the number of first tabs 1310 to greater than or equal to 30 layers, when the first tab 131 is welded to the first current collector 14a to form the first solder mark 1321, the multiple first tabs 1310 are forced to bulge to effectively form protrusions 1320 protruding from the first solder mark 1321. This effectively reduces the risk of the first solder mark 1321 piercing the insulation structure and overlapping the outer shell 11 and the first current collector 14a due to fatigue cracking. By limiting the number of first tabs 1310 to less than or equal to 150 layers, the risk of a decrease in the volumetric energy density of the battery cell 10 due to excessive thickness of the first tab 131 can be avoided to a certain extent.

[0163] By limiting the thickness of the first tab 1310 to be greater than or equal to 0.003 mm, when the first tab 131 is welded to the first current collector 14a to form the first solder mark 1321, the multiple first tabs 1310 are forced to bulge, effectively forming protrusions 1320 protruding from the first solder mark 1321. By limiting the thickness of the first tab 1310 to be less than or equal to 0.02 mm, the risk of a decrease in the volumetric energy density of the battery cell 10 due to excessive thickness of the first tab 131 can be avoided to a certain extent.

[0164] According to some embodiments of this application, the area through which the first electrode tab 1310 is penetrated by the first solder mark 1321 forms a solder mark area, the surface area of ​​the first electrode tab 1310 on one side in its thickness direction is S1, and the total area of ​​the solder mark area is S2, satisfying 0.075% ≤ S2 / S1 ≤ 5%.

[0165] The solder area is the region on the first tab 1310 corresponding to the first solder part 1321. The total area of ​​the solder area can be the sum of the areas of all the regions on the first tab 1310 corresponding to the first solder parts 1321.

[0166] In some embodiments, the ratio S2 / S1 of the total area of ​​the solder area S2 and the surface area of ​​the first electrode tab 1310 on one side in the thickness direction can be 0.075%, 0.085%, 0.095%...4.995%, 5% or any value between two adjacent values.

[0167] Optionally, when calculating S2 / S1, the first tab 131 can be unfolded to separate the multiple first tab pieces 1310 individually. First, the surface area of ​​the first tab piece 1310 along its thickness direction is measured to obtain S1, and then the area of ​​the region on the first tab piece 1310 that is traversed by the first solder mark 1321 is measured to obtain S2.

[0168] Optionally, when calculating S2 / S1, the electrode assembly 13 can be unfolded to obtain the first electrode plate and the first electrode tab 1310 protruding from the outer edge of the first electrode tab 131. The surface area of ​​the first electrode tab 1310 along its thickness direction is measured to obtain S1, and the area of ​​the region on the first electrode tab 1310 through which the first solder mark 1321 passes is measured to obtain S2.

[0169] In the above scheme, by limiting the ratio of the total area of ​​the solder area to the surface area of ​​the first tab 1310 to greater than or equal to 0.075%, a higher connection quality can be achieved between the first tab 131 and the first current collector 14a, which is beneficial to improving the current carrying capacity. By limiting the ratio of the total area of ​​the solder area to the surface area of ​​the first tab 1310 to less than or equal to 5%, sufficient space can be provided on the first tab 131 to form a protrusion 1320 to abut against the sidewall 113. This reduces the degree of deformation of the tab current collector 141 relative to the terminal current collector 140, slows down the deformation angle between the tab current collector 141 and the terminal current collector 140, thereby reducing the risk of cracking at the bending part of the tab current collector 141 and the terminal current collector 140, improving the fatigue life of the first current collector 14a, which is beneficial to improving the reliability of the battery cell 10, and thus to improving the reliability of the battery device 100.

[0170] According to some embodiments of this application, please refer to Figure 9 The first solder mark 1321 is strip-shaped and extends along the third direction y. The first direction z, the second direction x and the third direction y are perpendicular to each other. The protrusion 1320 is located on both sides of the first solder mark 1321 along the first direction z.

[0171] In some embodiments of this application, the first solder mark 1321 is strip-shaped and extends along a third direction y. Optionally, the first solder mark 1321 is rectangular in shape, with its length direction along a third direction y.

[0172] For example, the first connecting portion 132 and the tab current collector portion 141 are welded along a third direction y in a straight line trajectory to form a first solder mark portion 1321. Along the first direction z, a plurality of first tab pieces 1310 corresponding to both sides of the first solder mark portion 1321 are raised toward the side away from the tab current collector portion 141, and the gap between the first tab pieces 1310 is larger than the gap between the first tab pieces 1310 corresponding to the area where the first solder mark portion 1321 is located, so as to form protrusions 1320 on both sides of the first solder mark portion 1321 along the first direction z.

[0173] Compared to the scheme where the first solder mark 1321 extends along the first direction z, in the above scheme, the solder mark is strip-shaped and extends along the third direction y. This facilitates the multilayer tabs on both sides of the first solder mark 1321 along the first direction z to bulge due to welding stress to form protrusions 1320. When the electrode assembly 13 shakes, the protrusions 1320 abut against the sidewall 113, reducing the degree of deformation of the tab current collector 141 relative to the terminal current collector 140, and mitigating the deformation angle between the tab current collector 141 and the terminal current collector 140. This reduces the risk of cracking at the bending points of the tab current collector 141 and the terminal current collector 140, improves the fatigue life of the first current collector 14a, and is beneficial to improving the reliability of the battery cell 10, thereby improving the reliability of the battery device 100.

[0174] According to some embodiments of this application, please refer to Figure 9 The number of first solder marks 1321 is multiple, and the multiple first solder marks 1321 are arranged at intervals along the first direction z.

[0175] In some embodiments, a plurality of first solder marks 1321 are provided between the first connecting portion 132 and the tab current collector 141. The plurality of first solder marks 1321 are arranged along the first direction z. A plurality of protrusions 1320 are formed on the side of the first connecting portion 132 away from the main body portion 130. The plurality of protrusions 1320 are arranged along the first direction z. Each first solder mark 1321 is located between two adjacent protrusions 1320.

[0176] In the above solution, by setting multiple first solder marks 1321 and arranging them at intervals along the first direction z, on the one hand, the connection area between the first electrode tab 131 and the first current collector 14a is increased, which is beneficial to improving the connection quality and current carrying capacity between the first electrode tab 131 and the first current collector 14a; on the other hand, multiple protrusions 1320 arranged at intervals along the first direction z are formed on the side of the first connecting portion 132 facing the sidewall 113, thereby... When the electrode assembly 13 shakes, the abutment between the protrusion 1320 and the side wall 113 reduces the degree of deformation of the tab current collector 141 relative to the terminal current collector 140, and slows down the deformation angle between the tab current collector 141 and the terminal current collector 140. This reduces the risk of cracking at the bending part of the tab current collector 141 and the terminal current collector 140, improves the fatigue life of the first current collector 14a, and is beneficial to improving the reliability of the battery cell 10, thereby improving the reliability of the battery device 100.

[0177] According to some embodiments of this application, along the first direction z, the distance between two adjacent first solder pads 1321 is greater than or equal to 1 mm and less than or equal to 10 mm.

[0178] In some embodiments, a plurality of first solder marks 1321 are arranged at intervals along a first direction z, and the spacing W1 between two adjacent first solder marks 1321 is 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between two adjacent values.

[0179] Optionally, along the first direction z, the distance between two adjacent first solder marks 1321 can be obtained by laser ranging or direct measurement.

[0180] In the above scheme, along the first direction z, the protrusion 1320 is located between two adjacent first solder portions 1321. By setting the distance between the two first solder portions 1321 to be greater than or equal to 1 mm, there is a suitable space between the two first solder portions 1321 to form the protrusion 1320. By setting the distance between the first solder portions 1321 to be less than or equal to 10 mm, the problem of insufficient number and welding area of ​​first solder portions 1321 on the first connecting portion 132 and the tab current collector portion 141 due to excessive distance between the first solder portions 1321 can be reduced. This ensures the electrical connection stability between the first tab 131 and the first current collector 14a to a certain extent, so that the battery cell 10 has high reliability.

[0181] According to some embodiments of this application, along the arrangement direction of the plurality of protrusions 1320, the size of the protrusions 1320 is greater than or equal to 1 mm and less than or equal to 10 mm.

[0182] The dimension of the protrusion 1320 along its arrangement direction can be the width of the protrusion 1320.

[0183] In some embodiments, see Figure 9 Multiple protrusions 1320 are arranged along the first direction z. The size W2 of the protrusion 1320 along the first direction z can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between two adjacent values.

[0184] In other embodiments, a plurality of protrusions 1320 are arranged along a third direction y. The size W2 of the protrusion 1320 along the third direction y can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or any value between two adjacent values.

[0185] Alternatively, the width of the protrusion 1320 can be obtained by laser ranging or direct measurement.

[0186] In the above scheme, along the arrangement direction of the plurality of protrusions 1320, the solder mark is located between two adjacent protrusions 1320. The dimension of the protrusion 1320 along its arrangement direction can be its width. By limiting the width of the protrusion 1320 to greater than or equal to 1 mm, it can effectively abut against the side wall 113, thereby providing a void protection for the first solder mark 1321 located between the two protrusions 1320, reducing the risk of the first solder mark 1321 piercing the insulation structure and overlapping with the outer shell 11, and effectively reducing the degree of deformation of the tab current collector 141 relative to the terminal current collector 140, and slowing down the deformation angle between the tab current collector 141 and the terminal current collector 140. By limiting the width of the protrusion 1320 to less than or equal to 10 mm, the risk of affecting the arrangement of the soldering part due to the excessive size of the protrusion 1320 can be avoided to a certain extent. This ensures that there is sufficient welding area between the first tab 131 and the first current collector 14a, and to a certain extent, guarantees the electrical connection stability between the first tab 131 and the first current collector 14a, thus making the battery cell 10 have high reliability.

[0187] According to some embodiments of this application, please refer to Figure 9 The terminal current collector 140 is welded to the tab current collector 141 to form the second solder mark 142.

[0188] In some embodiments, the terminal current collector 140 and the tab current collector 141 are separate structures, which are welded together to form a second solder mark 142. The second solder mark 142 is the part formed by welding and melting the terminal current collector 140 and the tab current collector 141 together.

[0189] Optionally, the terminal current collector 140 and the tab current collector 141 are welded together by laser welding, ultrasonic welding or other methods.

[0190] Optionally, the shape of the second solder mark 142 can be varied, including but not limited to circular, annular, strip-shaped, triangular, or other shapes. For example, using... Figure 9 For example, the second solder mark 142 is strip-shaped and extends along the third direction y.

[0191] Optionally, the number of second solder marks 142 is not limited, and the number of second solder marks 142 can be one, two, three or more.

[0192] In the above scheme, the first current collector 14a is a split structure. After the terminal current collector 140 and the tab current collector 141 are connected to the first electrode terminal 12a and the first tab 131 respectively, a second solder mark 142 is formed between the terminal current collector 140 and the tab current collector 141 and they are connected to each other by welding. This makes the assembly of the battery cell 10 easier and helps to improve the manufacturing efficiency of the battery cell 10. Meanwhile, by providing a protrusion 1320 on the side of the first connection portion 132 facing the side wall 113, when the electrode assembly 13 shakes, the protrusion 1320 abuts against the side wall 113 to reduce the degree of deformation of the tab current collector 141 relative to the terminal current collector 140, and slow down the deformation angle between the tab current collector 141 and the terminal current collector 140. This reduces the risk of cracking at the bending parts of the tab current collector 141 and the terminal current collector 140, as well as the heat-affected zone caused by welding, resulting in high structural reliability of the battery cell 10 and improving the reliability of the battery device 100.

[0193] According to some embodiments of this application, the first current collector 14a is partially bent such that at least a portion of the terminal current collector 140 is located between the main body 130 and the end wall 112, and the tab current collector 141 extends from the terminal current collector 140 to between the main body 130 and the side wall 113. The second solder mark 142 is located near the portion of the first current collector 14a that is partially bent.

[0194] The first current collector 14a is partially bent such that at least a portion of the terminal current collector 140 is located between the main body 130 and the end wall 112, and at least a portion of the tab current collector 141 is located between the main body 130 and the side wall 113. For example, please refer to... Figure 11 The terminal current collector 140 includes a first segment 1402 and a second segment 1403. The first segment 1402 is located between the main body 130 and the end wall 112. The second segment 1403 is bent between the first segment 1402 and the main body 130 and the side wall 113. The second segment 1403 is welded to the tab current collector 141 to form a second solder mark 142. The second solder mark 142 is close to the bent portion between the first segment 1402 and the second segment 1403.

[0195] Optionally, the phrase "closer to the portion of the first current collector 14a that is partially bent" in the second solder mark 142 can be understood as the distance between the second solder mark 142 and the portion of the first current collector 14a that is partially bent being greater than or equal to 0 and less than or equal to 15 mm. Figure 11 For example, the distance L1 between the second solder mark 142 and the bent portion between the second segment 1403 and the first segment 1402 can be 0, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm...14mm, 15mm or any value between two adjacent values.

[0196] Optionally, when measuring the distance L1 between the second solder mark 142 and the bending portion between the second segment 1403 and the first segment 1402, the measurement is performed along the first direction z, starting from the edge of the second solder mark 142 closest to the end wall 112, and ending at the bending portion of the second segment 1403 (for example, if the first segment 1402 and the second segment 1403 are connected by a rounded corner, the measurement end point is the junction of the rounded corner and the second segment 1403). The measurement is performed using a measuring ruler or laser rangefinder.

[0197] In the above solution, the part where the first current collector 14a is partially bent is the stress concentration part of the first current collector 14a, which is prone to fatigue cracking due to the shaking of the electrode assembly 13. By setting the second solder part 142 close to the part where the first current collector 14a is partially bent, the second solder part 142 and the stress concentration part of the first current collector 14a are concentrated, and a protrusion 1320 is provided on the first connection part 132 to reduce the deformation angle of the first current collector 14a. In this embodiment, the problem of fatigue cracking of the first current collector 14a due to the shaking of the electrode assembly 13 and the cracking of the connection between the tab current collector 141 and the terminal current collector 140 can be further improved, so that the battery cell 10 has higher reliability, and thus the battery device 100 has higher reliability.

[0198] According to some embodiments of this application, please refer to Figure 11 , Figure 11 This is a schematic diagram of the terminal current collector 140, the tab current collector 141, and the second solder mark 142 in some embodiments of this application.

[0199] The terminal current collector 140 and the tab current collector 141 are stacked. One end of the second solder mark 142 protrudes from the side of the terminal current collector 140 away from the tab current collector 141, and the other end of the second solder mark 142 protrudes from the side of the tab current collector 141 away from the terminal current collector 140.

[0200] In some embodiments, the terminal current collector 140 and the tab current collector 141 are welded together using a through-welding process. The terminal current collector 140 includes a first segment 1402 and a second segment 1403. The first segment 1402 is located between the main body 130 and the end wall 112, and the second segment 1403 extends from the end of the first segment 1402 to the area between the main body 130 and the side wall 113. The tab current collector 141 is stacked on the side of the second segment 1403 facing away from the main body 130, and the tab current collector 141 is welded to the second segment 1403 to form a second solder mark 142. One end of the second solder mark 142 protrudes from the side of the tab current collector 141 facing away from the second segment 1403, and the other end protrudes from the side of the second segment 1403 facing away from the tab current collector 141.

[0201] Optionally, the electrode current collector 141 includes a fourth segment and a fifth segment. Along the direction from the main body 130 towards the sidewall 113, the fourth segment protrudes beyond the fifth segment. The fourth segment is stacked on top of the second segment 1403, and the fifth segment is welded to the first connecting portion 132. On the same projection plane perpendicular to the first direction z, the projection of the second segment 1403 at least partially overlaps with the projection of the fifth segment, and the projection of the fourth segment at least partially overlaps with the projection of the first connecting portion 132.

[0202] In the above scheme, the terminal current collector 140 and the tab current collector 141 are connected to each other by a through-welding process. The two ends of the second solder mark 142 protrude from the side of the terminal current collector 140 away from the tab current collector 141 and the side of the tab current collector 141 away from the terminal current collector 140, respectively. This results in high welding quality between the terminal current collector 140 and the tab current collector 141, which is beneficial to improving the structural strength and current carrying capacity of the first current collector 14a. This allows the first current collector 14a to effectively resist the impact caused by the shaking of the electrode assembly 13, thereby making the battery cell 10 have high reliability, and thus making the battery device 100 have high reliability.

[0203] According to other embodiments of this application, please refer to Figure 12 , Figure 12 This is a schematic diagram of a terminal current collector 140, a tab current collector 141, and a second solder joint 142 in other embodiments of this application. The terminal current collector 140 includes a first portion 1400 and a second portion 1401. The first portion 1400 and the second portion 1401 are arranged along the end wall 112 in the direction pointing towards the main body 130, and along the direction from the main body 130 towards the side wall 113, the first portion 1400 protrudes from the second portion 1401. The tab current collector 141 is stacked on the second portion 1401, and the second solder joint 142 is located between the first portion 1400 and the tab current collector 141.

[0204] In some embodiments, the terminal current collector 140 and the tab current collector 141 are welded together using a lap welding process. The terminal current collector 140 includes a first segment 1402 and a second segment 1403. The first segment 1402 is located between the main body 130 and the end wall 112, and the second segment 1403 extends from the end of the first segment 1402 to the area between the main body 130 and the side wall 113. The second segment 1403 includes a first portion 1400 and a second portion 1401 arranged along a first direction z. The second portion 1401 is further away from the end wall 112 than the first portion 1400. The first portion 1400 protrudes from the second portion 1401 in the direction from the main body 130 to the side wall 113. The tab current collector 141 is stacked on the side of the second portion 1401 facing away from the main body 130, and the end of the tab current collector 141 is welded to the first portion 1400 to form a second solder mark 142.

[0205] In the above scheme, the terminal current collector 140 and the tab current collector 141 are connected to each other by a lap welding process. The tab current collector 141 is lapped on the second part 1401 of the terminal current collector 140. By welding the first part 1400 and the tab current collector 141, the second solder mark is located between the first part 1400 and the tab current collector 141, which can reduce the welding difficulty of the terminal current collector 140 and the tab current collector 141 and improve the manufacturing efficiency of the battery cell 10.

[0206] According to some embodiments of this application, the group margin of the battery cell 10 along the second direction x is greater than or equal to 92% and less than or equal to 98%.

[0207] Group margin typically refers to the proportion of active material regions. In some embodiments, the group margin of the battery cell 10 along the second direction x is greater than or equal to 92% and less than or equal to 98%.

[0208] Optionally, the battery cell 10 can be disassembled, and the dimensions of the negative electrode 1330 along the second direction x and the dimensions of the inner cavity of the casing 11 along the second direction x can be directly measured. The two measurements are then divided to obtain the group margin of the battery cell 10 along the second direction x.

[0209] In the above scheme, by setting the group margin of the battery cell 10 along the second direction x to greater than or equal to 92%, the internal space of the casing 11 is effectively utilized, resulting in a high volumetric energy density for the battery cell 10. By setting the group margin of the battery cell 10 along the second direction x to less than or equal to 98%, the risk of excessive internal pressure affecting the reliability of the battery cell 10 can be avoided to a certain extent after a certain number of charge-discharge cycles. In some embodiments that limit the group margin of the battery cell 10 along the second direction x, by forming a protrusion 1320 on one side of the first tab 131 along the second direction x, the risk of the electrode assembly 13 shaking along the second direction x, causing the first solder joint 1321 to puncture the insulation structure and overlap with the casing 11, resulting in an internal short circuit in the battery cell 10, can be effectively reduced, as can the risk of the first current collector 14a fatigue cracking due to excessive deformation can also be reduced.

[0210] According to some embodiments of this application, please refer to Figure 13 , Figure 13This is a partial schematic diagram of the internal structure of the battery cell 10 in some embodiments of this application. The outer casing 11 includes an adjacent first wall 114 and a second wall 115, which are integrally formed. The inner surfaces of the first wall 114 and the second wall 115 are connected by a first arc surface 116. The electrode assembly 13 has an adjacent first surface 1300 and a second surface 1301. The first surface 1300 faces the first wall 114, and the second surface 1301 faces the second wall 115. The first surface 1300 and the second surface 1301 are connected by a first transition surface 1302. Along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114, the distance from the first transition surface 1302 to the second wall 115 gradually decreases.

[0211] In some embodiments, the housing 111 includes a bottom wall and a plurality of wall portions surrounding the bottom wall. The plurality of wall portions may include two large wall portions disposed opposite each other along the thickness direction of the housing 111, and two small wall portions disposed opposite each other along the length direction of the housing 111. The large wall portions and the small wall portions are connected along the circumference of the housing 111. In some embodiments, the first wall 114 may be a large wall portion and the second wall 115 may be a bottom wall portion; or, the first wall 114 may be a small wall portion and the second wall 115 may be a bottom wall portion; or the first wall 114 may be a large wall portion and the second wall 115 may be a small wall portion.

[0212] In some embodiments, the housing 11 may include a housing 111 and two covers 110. The housing 111 has two openings at each end, and the two covers 110 are respectively connected to the housing 111 and close the two openings. Along the circumference of the housing 111, the housing 111 includes a plurality of interconnected walls. In some embodiments, the first wall 114 and the second wall 115 may be two adjacent walls of the housing 111.

[0213] The first wall 114 and the second wall 115 are integrally formed structures, which can be understood as the first wall 114 and the second wall 115 being prepared by an integral forming process from a sheet material. For example, the first wall 114 and the second wall 115 are prepared by a stamping and / or stretching process from a sheet material.

[0214] The inner surface of the first wall 114 is the surface of the first wall 114 facing the electrode assembly 13, and the inner surface of the second wall 115 is the surface of the second wall 115 facing the electrode assembly 13. The inner surfaces of the first wall 114 and the second surface 1301 are connected by a first arc surface 116. Exemplarily, the first wall 114 and the second wall 115 are connected by a rounded corner, and the inner surface of the rounded corner is the first arc surface 116.

[0215] The first surface 1300 is the outer surface of the electrode assembly 13 facing the first wall 114, and the second surface 1301 is the outer surface of the electrode assembly 13 facing the second wall 115.

[0216] In some embodiments, the electrode assembly 13 includes a main body 130 and a tab. The main body 130 is the main part of the electrode assembly 13. The tab is connected to the main body 130 and electrically connected to the electrode terminal of the battery cell 10 or to the wall of the housing 11 to realize the input or output of electrical energy.

[0217] Optionally, the electrode assembly 13 has a stacked structure, with the main body 130 including a plurality of positive electrode sheets 1331, a plurality of separators 1332, or a plurality of negative electrode sheets 1330 stacked together. Optionally, the electrode assembly 13 has a wound structure, with the main body 130 including a plurality of positive electrode sheets 1331, a plurality of separators 1332, or a plurality of negative electrode sheets 1330 stacked together, and the positive electrode sheets 1331, separators 1332, and negative electrode sheets 1330 wound into a shape. The first surface 1300 and the second surface 1301 can be the outer surfaces of the main body 130.

[0218] The first surface 1300 and the second surface 1301 are connected by a first transition surface 1302. The distance from the first transition surface 1302 to the second wall 115 gradually decreases along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114. The first transition surface 1302 can be a straight surface or a curved surface.

[0219] Please see Figure 13 When the electrode assembly 13 shakes or is inserted into the housing, the first surface 1300 will contact the inner surface of the housing 111 before the first transition surface 1302, and the second surface 1301 will contact the inner surface of the housing 111 before the first transition surface 1302. This allows the portion of the electrode assembly 13 corresponding to the first arc surface 116 to avoid the first arc surface 116, thereby effectively reducing the risk of interference between the first arc surface 116 and the outer contour of the electrode assembly 13.

[0220] In the above scheme, the first wall 114 and the second wall 115 are integrally formed, which gives the outer shell 11 high structural strength and effectively resists the impacts on the outside and inside of the battery cell 10, thus improving the reliability of the battery cell 10. Furthermore, connecting the first surface 1300 and the second surface 1301 of the electrode assembly 13 corresponding to the first wall 114 and the second wall 115 via the first transition surface 1302 effectively avoids the first arc surface 116 formed by the integral forming of the first wall 114 and the second wall 115. This reduces the risk of interference between the electrode assembly 13 and the first arc surface 116, which could lead to structural damage to the electrode assembly 13. This results in higher reliability for the battery cell 10, and consequently, higher reliability for the battery device 100.

[0221] According to some embodiments of this application, please refer to Figure 14 , Figure 14 This is a schematic diagram of the first wall 114, the second wall 115, and the N electrode groups 133 in some embodiments of this application.

[0222] The electrode assembly 13 includes N electrode groups 133, which are arranged along the outer surface of the first wall 114 towards the inner surface of the first wall 114. Each electrode group 133 includes a negative electrode 1330 and a positive electrode 1331 arranged along the thickness direction of the first wall 114. Along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114, the distance from the electrode group 133 to the second wall 115 gradually decreases from the first electrode group 133 to the Mth electrode group 133, so that the electrode assembly 13 forms a first transition surface 1302, where M < N.

[0223] The electrode assembly 13 includes N electrode groups 133 arranged along the outer surface of the first wall 114 in the direction pointing towards the inner surface. Each electrode group 133 includes a negative electrode 1330 and a positive electrode 1331 arranged along the thickness direction of the first wall 114. A separator 1332 is disposed between adjacent negative electrode 1330 and positive electrode 1331.

[0224] Optionally, the outer periphery of the electrode assembly 13 is covered with an insulating film 18. The insulating film 18 can be attached to the outer surface of the electrode assembly 13 along the outer contour of the electrode assembly 13.

[0225] Optionally, to reduce the risk of lithium plating, in adjacent negative electrode 1330 and positive electrode 1331, the dimension of negative electrode 1330 along the thickness direction of the second wall 115 is larger than the dimension of positive electrode 1331 along the thickness direction of the second wall 115.

[0226] Please see Figure 13 The electrode group 133 closest to the first wall 114 is the first electrode group 133, and the electrode group 133 furthest from the first wall 114 is the Nth electrode group 133. Taking the electrode group 133 located between the first electrode group 133 and the Nth electrode group 133 as the Mth electrode group 133 as an example, along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114, the distance from the electrode group 133 to the second wall 115 gradually decreases from the first electrode group 133 to the Mth electrode group 133, so that the electrode assembly 13 forms the first transition surface 1302.

[0227] Optionally, the housing 11 includes two first walls 114 facing each other, each first wall 114 being connected to a second wall 115. In the first to the Mth electrode groups 133 of the electrode assembly 13, the distance between the electrode group 133 and the second wall 115 gradually decreases; in the Pth to the Nth electrode groups 133 of the electrode assembly 13, the distance between the electrode group 133 and the second wall 115 gradually decreases, where P is an integer greater than M. For example, taking N as 50, M as 10, and P as 40, the distance between the first to the 10th electrode groups 133 of the electrode assembly 13 and the second wall 115 gradually decreases; the distance between the 40th to the 50th electrode groups 133 of the electrode assembly 13 and the second wall 115 gradually decreases.

[0228] Please see Figure 13 The separator 1332 is bent along the direction of decreasing size of the electrode assembly 133, and the insulating film 18 is bent along the direction of decreasing size of the electrode assembly 133 so that the electrode assembly 13 forms a first transition surface 1302.

[0229] In the above scheme, the electrode assembly 13 includes N electrode groups 133 arranged along the thickness direction of the first wall 114. Each electrode group 133 includes a negative electrode 1330 and a positive electrode 1331 arranged along the thickness direction of the first wall 114. Along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114, from the first electrode group 133 to the Mth electrode group 133, the distance from the electrode group 133 to the second wall 115 is gradually reduced, so that the electrode assembly 13 forms a first transition surface 1302. This allows the electrode assembly 13 to avoid the first arc surface 116, reducing the risk of damage to the electrode structure, thus giving the battery cell 10 higher reliability, and consequently, the battery device 100 higher reliability.

[0230] Based on some embodiments of this application, please refer to... Figure 14 and Figure 15 , Figure 15 This is a partial structural diagram of the first wall 114, the second wall 115, and the electrode assembly 13 in some embodiments of this application.

[0231] The dimension of the first arc surface 116 along the thickness direction of the first wall 114 is R1, and the dimension of the first arc surface 116 along the thickness direction of the second wall 115 is R2. Along the thickness direction of the second wall 115, the first electrode group 133 has a first end facing the second wall 115. The distance between the first end and the second surface 1301 along the thickness direction of the first wall 114 is D1, and the distance between the first end and the second wall 115 along the thickness direction of the second wall 115 is D2, satisfying R1 < D1 < 3*R1, R2 < D2 < 3*R2.

[0232] The first electrode group 133 has a first end facing the second wall 115. The first end can be the end wall 112 that is furthest from the second wall 115 among the ends of the N electrode groups 133 facing the second wall 115.

[0233] Please see Figure 14 Along the thickness direction of the first wall 114, the dimension of the first arc surface 116 is R1. Please refer to [link / reference]. Figure 15 Along the thickness direction of the first wall 114, the distance from the first end to the second surface 1301 is D1, where R1 < D1 < 3 * R1. Optionally, R1 < D1 < 1.5 * R1, or R1 < D1 < 2 * R1, or the value of D1 can be any value greater than R1 and less than 3 times R1.

[0234] Please see Figure 14 Along the thickness direction of the second wall 115, the dimension of the first arc surface 116 is R2. Please refer to [link / reference]. Figure 15 Along the thickness direction of the second wall 115, the distance from the first end to the plane containing the inner surface of the second wall 115 is D2, where R2 < D2 < 3*R2. Optionally, R2 < D2 < 1.5*R22, or R2 < D2 < 2*R2, or the value of D2 can be any value greater than R2 and less than 3 times R2.

[0235] For example, the values ​​R1 and R2 can be obtained directly by cutting the outer shell 11. In order to reduce the impact of cutting on material deformation, a supporting material can be filled into the outer shell 11 or the outer shell 11 can be cut.

[0236] For example, the aforementioned values ​​D1 and D2 can be measured by measuring the size of the electrode assembly 13 using calipers. For instance, after removing the insulating film 18 wrapped around the electrode assembly 13 and removing the isolation film 1332 covering the surface of the electrode assembly 13 to expose the first tab group, the relevant values ​​D1 and D2 of the first end can be measured.

[0237] In the above scheme, limiting the distance D1 from the first end of the first electrode group 133 to the second surface 1301 to be greater than R1 allows the electrode assembly 13 to effectively avoid the first arc surface 116, reducing the risk of interference between the electrode assembly 13 and the first arc surface 116, which could lead to structural damage to the electrode assembly 13. Limiting the distance D1 from the first end of the first electrode group 133 to the second surface 1301 to less than 3 times R1 reduces the risk of the electrode assembly 13's volume decreasing due to the first transition surface 1302, thus affecting the volumetric energy density of the battery cell 10. Similarly, limiting the distance D2 from the first end of the first electrode group 133 to the second wall 115 to be greater than R2 allows the electrode assembly 13 to effectively avoid the first arc surface 116, reducing the risk of interference between the electrode assembly 13 and the first arc surface 116, which could lead to structural damage to the electrode. By limiting the distance D2 from the first end of the first electrode assembly 133 to the second wall 115 to less than 3 times R2, the risk of the volume of the electrode assembly 13 being reduced due to the setting of the first transition surface 1302, thus affecting the volumetric energy density of the battery cell 10, can be reduced.

[0238] According to some embodiments of this application, please refer to Figure 14 The battery cell 10 also includes a first insulating portion 15, which is located between the first wall 114 and the electrode assembly 13 along the thickness direction of the first wall 114. The thickness of the first insulating portion 15 is H1. The dimension of the first arc surface 116 along the thickness direction of the first wall 114 is R1, satisfying 0 < H1 < R1.

[0239] The first insulating portion 15 is made of an insulating material. Optionally, the battery cell 10 also includes an insulating film 18, which covers the outer periphery of the electrode assembly 13, and the first insulating portion 15 is a part of the insulating film 18. Along the thickness direction of the first wall 114, the first insulating portion 15 is located between the first wall 114 and the electrode assembly 13.

[0240] The thickness of the first insulating portion 15 can be understood as the dimension of the first insulating portion 15 along the thickness direction of the first wall 114. The thickness H1 of the first insulating portion 15 and the dimension R1 of the first arc surface 116 along the thickness direction of the first wall 114 satisfy 0 < H1 < R1. Optionally, 0 < H1 < 0.5 * R1, or the value of H1 can be any value greater than 0 and less than R1.

[0241] In the above scheme, the battery cell 10 also includes a first insulating portion 15, which is located between the first wall 114 and the electrode assembly 13 to insulate and isolate the first wall 114 and the electrode assembly 13. By limiting the thickness H1 of the first insulating portion 15 to be greater than 0, the first insulating portion 15 can play the role of insulation and isolation. By limiting the thickness H1 of the first insulating portion 15 to be smaller than the dimension R1 of the first arc surface 116 along the thickness direction of the first wall 114, the thickness H1 of the first insulating portion 15 can be made as small as possible without the electrode assembly 13 interfering with the first arc surface 116. This is beneficial to improving the volumetric energy density of the battery cell 10, and thus beneficial to improving the volumetric energy density of the battery device 100.

[0242] According to some embodiments of this application, the battery cell 10 further includes a second insulating portion 16, which is located between the second wall 115 and the electrode assembly 13 along the thickness direction of the second wall 115, and the thickness of the second insulating portion 16 is H2. The dimension of the first arc surface along the thickness direction of the second wall 115 is R2, satisfying 0 < H2 < R2.

[0243] The second insulating portion 16 is made of an insulating material. Optionally, the battery cell 10 also includes an insulating film 18, which covers the outer periphery of the electrode assembly 13, and the second insulating portion 16 is a part of the insulating film 18. Along the thickness direction of the second wall 115, the second insulating portion 16 is located between the second wall 115 and the electrode assembly 13.

[0244] The thickness of the second insulating portion 16 can be understood as the dimension of the second insulating portion 16 along the thickness direction of the second wall 115. The thickness H2 of the second insulating portion 16 and the dimension R2 of the first arc surface 116 along the thickness direction of the second wall 115 satisfy 0 < H2 < R2. Optionally, 0 < H2 < 0.5 * R2, or the value of H2 can be any value greater than 0 and less than R2.

[0245] In the above scheme, the battery cell 10 also includes a second insulating portion 16, which is located between the second wall 115 and the electrode assembly 13 to insulate and isolate the second wall 115 and the electrode assembly 13. By limiting the thickness H2 of the second insulating portion 16 to be greater than 0, the second insulating portion 16 can play the role of insulation and isolation. By limiting the thickness H2 of the second insulating portion 16 to be smaller than the dimension R2 of the first arc surface along the thickness direction of the second wall 115, the thickness H2 of the second insulating portion 16 can be made as small as possible without the electrode assembly 13 interfering with the first arc surface 116, thereby facilitating the improvement of the volumetric energy density of the battery cell 10, and further facilitating the improvement of the volumetric energy density of the battery device 100.

[0246] According to some embodiments of this application, please refer to Figure 13The battery cell 10 also includes a protective adhesive 17, which covers the end of the electrode assembly 133 corresponding to the location of the first transition surface 1302.

[0247] In some embodiments, the electrode assembly 13 can be formed with a first transition surface 1302 by cutting the ends of the electrode sheet.

[0248] In some embodiments, adhesive is applied to the cut portion at the tip of the electrode to form a protective adhesive 17.

[0249] In the above scheme, the battery cell 10 also includes a protective adhesive 17. The protective adhesive 17 covers the end face of the first transition surface 1302 corresponding to the electrode group 133, which can fix the end burrs of the electrode group and reduce the risk of short circuit inside the battery cell 10 caused by the burrs overlapping with the outer shell 11, thereby making the battery cell 10 highly reliable and thus making the battery device 100 highly reliable.

[0250] According to some embodiments of this application, some embodiments of this application also provide a battery device 100, which includes a battery cell 10 provided in the first aspect.

[0251] Among them, see Figure 2 As shown, the battery device 100 may also include a housing 30, in which the battery cells 10 are housed.

[0252] In some embodiments, the housing 30 may include a first housing body 31 and a second housing body 32, the first housing body 31 and the second housing body 32 covering each other, the first housing body 31 and the second housing body 32 together defining an assembly space for accommodating the battery cell 10.

[0253] Optionally, the second box body 32 can be a hollow structure with one end open, and the first box body 31 can be a plate-like structure. The first box body 31 covers the open side of the second box body 32 so that the first box body 31 and the second box body 32 together define the assembly space; the first box body 31 and the second box body 32 can also both be hollow structures with one side open, and the open side of the first box body 31 covers the open side of the second box body 32.

[0254] Of course, the box 30 formed by the first box body 31 and the second box body 32 can be of various shapes, such as a cylinder or a cuboid. For example, in... Figure 2 In the middle, box 30 has a rectangular structure.

[0255] Optionally, the battery cell 10 disposed within the housing 30 can be one or more. For example, in... Figure 2In the battery device 100, multiple battery cells 10 are arranged inside the housing 30. The multiple battery cells 10 can be connected in series, parallel, or in a mixed manner. A mixed connection means that the multiple battery cells 10 are connected in both series and parallel. The multiple battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of the multiple battery cells 10 is housed in the housing 30. Of course, the battery device 100 can also be formed by first connecting multiple battery cells 10 in series, parallel, or in a mixed manner to form a battery module, and then connecting multiple battery modules in series, parallel, or in a mixed manner to form a whole assembly, which is also housed in the housing 30.

[0256] The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component that connects multiple battery cells 10 to achieve electrical connection between the multiple battery cells 10.

[0257] It should be noted that in some embodiments, the battery device 100 may not have a housing 30. The battery device 100 includes multiple battery cells 10, and the battery device 100 composed of multiple battery cells 10 can be directly mounted onto the electrical device to provide power to the electrical device through the multiple battery cells 10. That is, the housing 30 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 30 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 30 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 30 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0258] Some embodiments of this application also provide an electrical device, which includes the battery cell 10 provided above and / or the battery device 100 provided above, wherein the battery cell 10 is used to provide electrical energy.

[0259] The electrical device can be any of the aforementioned applications of battery cell 10 and / or battery device 100. For example, the electrical device can be a vehicle 1000, which can be a range-extended vehicle, a pure electric vehicle, or a gasoline-powered vehicle. The electrical energy provided by the battery cell 10 can be used to meet the power needs of the vehicle 1000 during startup, navigation, and operation.

[0260] Some embodiments of this application provide a single battery cell 10; please refer to [link to relevant documentation]. Figures 3-15 .

[0261] The battery cell 10 includes a casing 11, a first electrode terminal 12a, a second electrode terminal 12b, an electrode assembly 13, and a first current collector 14a and a second current collector 14b. The casing 11 includes a cover 110 and a housing 111. The cover 110 is connected to the housing 111 and closes the opening of the housing 111. The cover 110 is an end wall 112. The housing 111 includes a bottom wall and side walls 113 connected around the bottom wall. The bottom wall and the end wall 112 are opposite to each other, and the side walls 113 are connected to the end wall 112. The following example illustrates the situation with the thickness direction of the end wall 112 as the first direction z, the thickness direction of the side wall 113 as the second direction x, and the first direction z, the second direction x, and the third direction y being perpendicular to each other.

[0262] The first electrode terminal 12a and the second electrode terminal 12b are disposed on the end wall 112, and the first electrode terminal 12a and the second electrode terminal 12b are arranged along a third direction y. A pressure relief mechanism is also provided on the end wall 112 for relieving pressure inside the battery cell 10. An electrolyte injection hole is also provided on the end wall 112 for injecting electrolyte into the casing 11. The electrolyte injection hole can be sealed with a sealing pin.

[0263] Optionally, in some embodiments, the outer periphery of the housing 111 is covered with an insulating element 19, which may be blue adhesive.

[0264] The electrode assembly 13 includes a main body 130, a first electrode tab 131, and a second electrode tab, which are respectively disposed on both sides of the main body 130 along the second direction x. The first electrode tab 131 can be one of a positive electrode tab and a negative electrode tab, and the second electrode tab can be the other of a positive electrode tab and a negative electrode tab.

[0265] The first electrode tab 131 is electrically connected to the first electrode terminal 12a via the first current collector 14a, and the second electrode tab is electrically connected to the second electrode terminal 12b via the second current collector 14b. Some embodiments of this application are illustrated by the first electrode tab 131, the first current collector 14a, and the first electrode terminal 12a.

[0266] The first current collector 14a includes a terminal current collector 140 and a tab current collector 141. The terminal current collector 140 and the tab current collector 141 are welded together to form a second solder mark 142. At least a portion of the terminal current collector 140 is located between the main body 130 and the end wall 112 and is electrically connected to the first electrode terminal 12a. The tab current collector 141 is located between the main body 130 and the side wall 113 and is electrically connected to the first tab 131.

[0267] The first tab 131 includes a plurality of stacked first tab pieces 1310. The plurality of first tab pieces 1310 extend from the end face of the main body 130 facing the side wall 113. Parts of the plurality of first tab pieces 1310 are folded over the side of the tab current collector 141 opposite to the main body 130 to form a first connecting portion 132. The first connecting portion 132 is welded to the tab current collector 141 to form a first solder mark 1321. The first solder mark 1321 is strip-shaped and extends along a third direction y. There are multiple first solder marks 1321, which are spaced apart along a first direction z. See also... Figure 7 During the formation of the first solder mark 1321, the density of the plurality of first electrode tabs 1310 in the first connecting portion 132 changes. The plurality of first electrode tabs 1310 are tightly fitted at the corresponding part of the first solder mark 1321, while the plurality of first electrode tabs 1310 are loosened at the two sides of the first solder mark 1321 along the first direction z to form a protrusion 1320. The protrusion 1320 protrudes from the first solder mark 1321 in the direction from the main body portion 130 to the side wall 113.

[0268] When the battery cell 10 is subjected to external force causing the electrode assembly 13 to shake inside the housing 11, the protrusion will abut against the side wall 113 before the first solder mark 1321, thus providing support. On the one hand, this avoids to some extent the risk of the insulation structure between the electrode assembly 13 and the housing 11 being damaged due to the first solder mark 1321 or welding slag abutting against the side wall 113, causing it to overlap with the side wall 113 and resulting in a short circuit inside the battery cell 10. This ensures that the battery cell 10 has high reliability, and consequently, the battery device 100 has high reliability. On the other hand, In contrast to the solution where the first connecting portion 132 does not have a protrusion 1320, the abutment between the protrusion 1320 and the side wall 113 can reduce the degree of deformation of the first current collector 14a toward the side wall 113 and slow down the deformation angle of the first current collector 14a. This reduces the risk of cracking at the bending portion and / or the connection portion between the tab current collector 141 and the terminal current collector 140, improves the fatigue life of the first current collector 14a, and is beneficial to improving the reliability of the battery cell 10, thereby improving the reliability of the battery device 100.

[0269] Please see Figure 13 The housing 111 includes an adjacent first wall 114 and a second wall 115, the second wall 115 being disposed opposite to the end wall 112, the first wall 114 being adjacent to the side wall 113, and the first wall 114 and the side wall 113 surrounding the second wall 115.

[0270] The first wall 114 and the second wall 115 are integrally formed structures, directly connected by rounded corners. The inner surfaces of the first wall 114 and the second wall 115 are connected by a first arc surface 116, and the outer surfaces of the first wall 114 and the second wall 115 are also transitioned by an arc surface. The main body 130 has an adjacent first surface 1300 and a second surface 1301. The first surface 1300 faces the first wall 114, and the second surface 1301 faces the second wall 115. The first surface 1300 and the second surface 1301 are connected by a first transition surface 1302. Along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114, the distance from the first transition surface 1302 to the second wall 115 gradually decreases.

[0271] Optionally, please see Figure 14 The electrode assembly 13 includes N electrode groups 133, which are arranged along the outer surface of the first wall 114 towards the inner surface of the first wall 114. Each electrode group 133 includes a negative electrode 1330 and a positive electrode 1331 arranged along the thickness direction of the first wall 114. Along the direction from the outer surface of the first wall 114 to the inner surface of the first wall 114, the distance from the electrode group 133 to the second wall 115 gradually decreases from the first electrode group 133 to the Mth electrode group 133, so that the electrode assembly 13 forms a first transition surface 1302, where M < N.

[0272] The dimensions of the first N electrode groups 133 closest to the first wall 114 of the electrode assembly 13 are adjusted so that the distance between the first N electrode groups 133 and the second wall 115 gradually decreases, so that the electrode assembly 13 forms a first transition surface 1302. This effectively avoids the first arc surface 116 formed by the integral molding of the first wall 114 and the second wall 115, thereby reducing the risk of interference between the electrode of the electrode assembly 13 and the first arc surface 116, which could lead to damage to the electrode structure. This results in higher reliability of the battery cell 10, and consequently, higher reliability of the battery device 100.

[0273] 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 battery cell, characterized by, include: The outer casing has an end wall and a side wall that are connected to each other. The thickness direction of the end wall is parallel to a first direction, and the thickness direction of the side wall is parallel to a second direction. The first direction is perpendicular to the second direction. The first electrode terminal is disposed on the end wall; An electrode assembly is disposed within the housing. The electrode assembly includes a main body and a first electrode tab, the first electrode tab being connected to one end of the main body near the sidewall in the second direction. A first current collector is disposed within the housing. The first current collector includes a terminal current collector and a tab current collector connected to each other. At least a portion of the terminal current collector is located between the main body and the end wall and is connected to the first electrode terminal. The tab current collector extends from the terminal current collector to the area between the main body and the side wall. The first tab includes a first connecting portion located in the second direction on the side of the tab current collector opposite to the main body. The first connecting portion is welded to the tab current collector to form a first solder mark. The first connecting portion has a plurality of protrusions on the side away from the tab current collector. Along the direction from the main body to the side wall, the protrusions protrude from the first solder mark portion. Along the arrangement direction of the plurality of protrusions, the first solder mark portion is located between two adjacent protrusions.

2. The battery cell according to claim 1, characterized in that, The first electrode tab includes a plurality of stacked first electrode tab pieces; The number of the first electrode tabs is greater than or equal to 30 layers and less than or equal to 150 layers; and / or The thickness of the first electrode tab is greater than or equal to 0.003 mm and less than or equal to 0.02 mm.

3. The battery cell according to claim 2, characterized in that, The area through which the first electrode tab is passed by the first solder mark forms a solder mark area. The surface area of ​​the first electrode tab on one side in its thickness direction is S1, and the total area of ​​the solder mark area is S2, satisfying 0.075% ≤ S2 / S1 ≤ 5%.

4. The battery cell according to claim 1, characterized in that, The first solder mark is strip-shaped and extends along a third direction. The first direction, the second direction, and the third direction are perpendicular to each other. The protrusion is located on both sides of the first solder mark along the first direction.

5. The battery cell according to claim 4, characterized in that, The number of the first solder marks is multiple, and the multiple first solder marks are arranged at intervals along the first direction.

6. The battery cell according to claim 5, characterized in that, Along the first direction, the distance between two adjacent first solder marks is greater than or equal to 1 mm and less than or equal to 10 mm.

7. The battery cell according to claim 1, characterized in that, Along the arrangement direction of the plurality of protrusions, the size of the protrusions is greater than or equal to 1 mm and less than or equal to 10 mm.

8. The battery cell according to claim 1, characterized in that, The terminal current collector is welded to the tab current collector to form a second solder mark.

9. The battery cell according to claim 8, characterized in that, The first current collector is partially bent such that at least a portion of the terminal current collector is located between the main body and the end wall, and the tab current collector extends from the terminal current collector to between the main body and the side wall; the second solder mark is located near the portion of the first current collector that is partially bent.

10. The battery cell according to claim 8, characterized in that, The terminal current collector and the tab current collector are stacked on top of each other. One end of the second solder mark protrudes from the side of the terminal current collector away from the tab current collector, and the other end of the second solder mark protrudes from the side of the tab current collector away from the terminal current collector.

11. The battery cell according to claim 8, characterized in that, The terminal current collector includes a first part and a second part, the first part and the second part are arranged along the end wall in the direction pointing to the main body, and along the main body in the direction pointing to the side wall, the first part protrudes from the second part; The electrode current collector is stacked on the second part, and the second solder mark is located between the first part and the electrode current collector.

12. The battery cell according to claim 1, characterized in that, The group margin of the battery cell along the second direction is greater than or equal to 92% and less than or equal to 98%.

13. The battery cell according to any one of claims 1-12, characterized in that, The outer shell includes an adjacent first wall and a second wall, the first wall and the second wall are integrally formed, and the inner surface of the first wall and the inner surface of the second wall are connected by a first arc surface. The electrode assembly has an adjacent first surface and a second surface. The first surface faces the first wall, and the second surface faces the second wall. The first surface and the second surface are connected by a first transition surface. Along the direction from the outer surface of the first wall to the inner surface of the first wall, the distance from the first transition surface to the second wall gradually decreases.

14. The battery cell according to claim 13, characterized in that, The electrode assembly includes N electrode groups, which are arranged along the outer surface of the first wall and pointing towards the inner surface of the first wall. Each electrode group includes a negative electrode and a positive electrode arranged along the thickness direction of the first wall. Along the direction from the outer surface of the first wall to the inner surface of the first wall, in the first to the Mth electrode groups, the distance from the electrode group to the second wall gradually decreases, so that the electrode assembly forms the first transition surface, M < N.

15. The battery cell according to claim 14, characterized in that, The dimension of the first arc surface along the thickness direction of the first wall is R1, and the dimension of the first arc surface along the thickness direction of the second wall is R2; Along the thickness direction of the second wall, the first electrode group has a first end facing the second wall, the distance between the first end and the second surface along the thickness direction of the first wall is D1, and the distance between the first end and the second wall along the thickness direction of the second wall is D2, satisfying R1<D1<3*R1, R2<D2<3*R2.

16. The battery cell according to claim 13, characterized in that, The battery cell further includes a first insulating portion, which is located between the first wall and the electrode assembly along the thickness direction of the first wall, and the thickness of the first insulating portion is H1; The dimension of the first arc surface along the thickness direction of the first wall is R1, which satisfies 0 < H1 < R1.

17. The battery cell according to claim 13, characterized in that, The battery cell further includes a second insulating portion, which is located between the second wall and the electrode assembly along the thickness direction of the second wall, and the thickness of the second insulating portion is H2; The dimension of the first arc surface along the thickness direction of the second wall is R2, which satisfies 0 < H1 < R2.

18. The battery cell according to claim 14, characterized in that, The battery cell also includes a protective adhesive, which covers the end of the electrode assembly corresponding to the location of the first transition surface.

19. A battery device characterized by comprising: Includes the battery cell as described in any one of claims 1-18.

20. An electrical device, comprising: Includes the battery cell according to any one of claims 1-18, and / or the battery device according to claim 19.

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