Battery cell, battery device, and electric device

Abstract

Provided are a battery cell (100), a battery device (1100), and an electric device. The battery cell (100) comprises a casing (20) and electrode assemblies (10), wherein the casing (20) is provided with electrode lead-out portions (2011); the electrode assemblies (10) are at least partially arranged in the casing (20), each electrode assembly (10) comprises a first electrode sheet (1), the first electrode sheet (1) comprises conductive members (11), a current collector (12), and an active material layer (13), the current collector (12) is made of a metal material, and the conductive members (11) are electrically connected to the electrode lead-out portions (2011); the current collector (12) comprises a main body portion (121), the main body portion (121) comprises a first metal portion (1211) and a second metal portion (1212) arranged in a first direction and connected to each other, and the first direction is perpendicular to the thickness direction of the current collector; the first metal portion (1211) is at least partially covered with the active material layer (13), and the second metal portion (1212) is not covered with the active material layer (13); the conductive members (11) are electrically connected to the second metal portion (1212).

Description

Battery cells, battery packs and electrical devices Technical Field

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

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] To address the issue of slow battery charging, increasingly higher demands are being placed on the charging speed of individual battery cells, meaning that the charging and discharging currents of individual battery cells are becoming larger. When a large current passes through the tabs of the battery cell's electrodes, the temperature at the tabs can easily rise, even exceeding the design temperature of the tabs, thus limiting the overcurrent capacity of the tabs and affecting the fast-charging performance of the battery cell. Therefore, improving the fast-charging performance of individual battery cells is an important research direction in the field of battery technology.

[0004] The above statements are for the purpose of providing background information in relation to this application only and do not necessarily constitute prior art.

[0005] Application content

[0006] The purpose of this application is to provide a battery cell, a battery device, and an electrical device that can improve the fast charging performance of the battery cell.

[0007] The technical solution adopted in the embodiments of this application is:

[0008] In a first aspect, a battery cell is provided, comprising a casing and an electrode assembly. The casing has an electrode lead-out portion. At least a portion of the electrode assembly is disposed within the casing. The electrode assembly includes a first electrode plate, which includes a conductive member, a current collector, and an active material layer. The current collector is made of a metallic material. The conductive member is electrically connected to the electrode lead-out portion. The current collector includes a main body portion, which includes a first metal portion and a second metal portion arranged and connected along a first direction perpendicular to the thickness direction of the current collector. At least a portion of the first metal portion is covered with an active material layer, while the second metal portion is not covered with an active material layer. The conductive member is electrically connected to the second metal portion.

[0009] By adopting the technical solution of this embodiment, current can flow into or out of the first electrode through the electrode lead-out portion, thereby realizing the charging and discharging of the battery cell; and the conductive component is electrically connected to the second metal part of the main body of the current collector, that is, the conductive component is directly electrically connected to the main body of the current collector, and the current can flow directly from the second metal part of the main body to the conductive component, which reduces the overcurrent pressure at the tab of the first electrode, improves the overcurrent capacity of the first electrode, reduces the risk of overheating when the tab of the first electrode passes through a large current, and improves the fast charging capability of the battery cell.

[0010] In some embodiments, along the second direction, the size of the first metal portion is L1 and the size of the second metal portion is L2, wherein 0.8≤L2 / L1≤1, and wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0011] By adopting the technical solution of this embodiment, the design of 0.8≤L2 / L1≤1 makes the size of the first metal part and the size of the second metal part equal or not much different along the second direction, which is beneficial to increase the connection area between the second metal part and the conductive component, thereby improving the overcurrent capacity of the first electrode and improving the fast charging performance of the battery cell.

[0012] In some embodiments, L2 / L1 = 1.

[0013] By adopting the technical solution of this embodiment, the size of the first metal part and the size of the second metal part are equal along the second direction, so that the main body is of equal length, which is more conducive to increasing the connection area between the second metal part and the conductive component, thereby improving the overcurrent capacity of the first electrode and improving the fast charging performance of the battery cell.

[0014] In some embodiments, the conductive member includes a first connection portion and at least one second connection portion connected to each other, the second connection portion being electrically connected to an electrode lead-out portion, the first connection portion being soldered to a current collector to form a first solder mark, the first solder mark including a first solder mark portion, and the first connection portion being soldered to the surface of a second metal portion to form a first solder mark portion.

[0015] By adopting the technical solution of this embodiment, the first connecting part of the conductive component is welded to the second metal part, and the electrical connection between the conductive component and the second metal part is simple and convenient to process and manufacture.

[0016] [Correction 30.04.2025 according to Rule 91] In some embodiments, along the second direction, the length of the first solder mark is L3 and the size of the second metal part is L2, wherein 0.8≤L3 / L2≤1, and wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0017] By adopting the technical solution of this embodiment, along the second direction, the size L3 of the first solder mark is equal to or not much different from the size L2 of the second metal part, the welding area of ​​the second metal part and the first connection part is large, the current carrying capacity of the first electrode is good, and the fast charging performance of the battery cell is good.

[0018] [According to Rule 91 Correction 30.04.2025] In some embodiments, L3 / L2 = 1.

[0019] By adopting the technical solution of this embodiment, along the second direction, the size L3 of the first solder mark is equal to the size L2 of the second metal part, which can effectively increase the connection area between the second metal part and the first connecting part, thereby improving the overcurrent capacity of the first electrode and improving the fast charging performance of the battery cell.

[0020] In some embodiments, the size of the first solder mark is W1 along the first direction, wherein 1mm≤W1≤4mm, and optionally, 2mm≤W1≤3mm.

[0021] By adopting the technical solution of this embodiment, the first connecting part and the second metal part have a large welding area. On the one hand, this allows for a stable welding of the first connecting part and the second metal part together. On the other hand, the large welding area between the first connecting part and the second metal part improves the current carrying capacity of the first electrode and the fast charging capability of the battery cell. Furthermore, it reduces the space occupied by the first solder joint and the second metal part, reduces the risk of interference between the first electrode and the casing (e.g., end caps), and improves the energy density of the battery cell. Therefore, it can balance the energy density and fast charging performance of the battery cell.

[0022] In some embodiments, there are multiple second connecting portions, which are spaced apart along a second direction and electrically connected to the electrode leads, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0023] By adopting the technical solution of this embodiment, the first metal part can be divided into multiple regions along the second direction according to multiple second connecting parts, and each region can correspond to one second connecting part. Electrons in each region can be transmitted to the electrode lead-out part through the corresponding second connecting part, so that the electrons of the first metal part are transmitted in regions, and the electron transmission path in each region to the corresponding second connecting part is short, which is beneficial to reduce the transmission distance of electrons, reduce the overall resistance of the first electrode, and improve the fast charging performance and reliability of the battery cell.

[0024] In some embodiments, the current collector further includes at least one protrusion, and a second metal portion is connected between the first metal portion and the protrusion; along a second direction, the size of the protrusion is smaller than the size of the second metal portion, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0025] [Correction based on Rule 91, 19.09.2025] By adopting the technical solution of this embodiment, the design of the protrusion can remove part of the current collector material, which is beneficial to reduce the space occupied by the first electrode, reduce the risk of interference between the first electrode and the casing (e.g., end cap, etc.), and improve the energy density of the battery cell.

[0026] In some embodiments, the first solder mark includes a second solder mark portion, the first connection portion includes a first connection sub-part and at least one second connection sub-part, the second connection sub-part is connected between the first connection sub-part and the second connection portion; the first connection sub-part is soldered to the second metal portion to form the first solder mark portion, and the second connection sub-part is soldered to the protrusion to form the second solder mark portion.

[0027] By adopting the technical solution of this embodiment, the protrusion and the second metal part are simultaneously welded to the first connecting part, which helps to increase the welding area of ​​the conductive component and the current collector, improves the current carrying capacity of the first electrode, and improves the fast charging performance of the battery cell.

[0028] In some embodiments, along a second direction, the second solder mark extends from one side of the second connector to the other side of the second connector.

[0029] By adopting the technical solution of this embodiment, along the second direction, the second solder mark extends from one side of the second connector to the other side of the second connector, which can increase the welding area of ​​the second connector and the protrusion, improve the current carrying capacity of the protrusion and the second connector, improve the fast charging capability of the battery cell, and also help improve the welding reliability of the conductive component and the current collector.

[0030] In some embodiments, the first solder mark and the second solder mark are directly connected.

[0031] By adopting the technical solution of this embodiment, the first solder mark and the second solder mark form a whole first solder mark, which is convenient for processing and manufacturing and helps to reduce the manufacturing cost of the first electrode sheet.

[0032] In some embodiments, there are multiple protrusions, multiple second connecting portions, and multiple second connecting sub-parts; along a second direction, multiple protrusions are spaced apart, multiple second connecting sub-parts are spaced apart, and multiple second connecting portions are spaced apart; each second connecting sub-part is connected to each other in a one-to-one correspondence; the first connecting sub-parts are continuously arranged along the second direction, multiple second connecting sub-parts are connected to the first connecting sub-parts, each second connecting sub-part is welded to each protrusion in a one-to-one correspondence, and multiple second connecting portions are electrically connected to the electrode leads.

[0033] By adopting the technical solution of this embodiment, the first connecting sub-parts are continuously arranged along the second direction, and multiple second connecting sub-parts can be connected into a whole. The first connecting sub-parts can provide good support for the second connecting sub-parts, which can reduce the risk between the second connecting sub-parts and the electrode plates of the inserted electrode assembly when the second connecting sub-parts are bent, reduce the short circuit risk of the battery cell, and help improve the reliability of the battery cell. In addition, the first connecting sub-parts are large in size along the second direction, which helps to increase the welding area between the first connecting sub-parts and the second metal part, which helps to improve the current carrying capacity of the first electrode plate, and improve the fast charging performance and reliability of the battery cell.

[0034] In some embodiments, along the first direction, at least a portion of the second connector is located on the side of the protrusion facing away from the active material layer.

[0035] By adopting the technical solution of this embodiment, at least part of the second connection portion is located on the side of the protrusion facing away from the active material layer along the first direction, which is equivalent to reducing the size of the protrusion in the first direction, reducing space occupation, reducing the risk of interference between the first electrode and the casing (e.g., end cap, etc.), and improving the energy density of the battery cell.

[0036] In some embodiments, along the direction from the first metal portion to the second metal portion, the side of the second connecting portion away from the active material layer does not protrude from the side of the current collector away from the active material layer.

[0037] By adopting the technical solution of this embodiment, the second connecting part and the protrusion are stacked, and the second connecting part and the protrusion can be connected to the electrode lead at the same time, which is beneficial to improving the connection reliability between the first electrode and the electrode lead and the overcurrent capacity between the first electrode and the electrode lead, and is beneficial to improving the fast charging performance of the battery cell.

[0038] In some embodiments, the size of the first solder mark along the first direction is W2, wherein 2mm≤W2≤6mm, and optionally, 3mm≤W2≤5mm.

[0039] By adopting the technical solution of this embodiment, the conductive component and the current collector have a large welding area. On the one hand, this allows for stable welding of the conductive component and the current collector together; on the other hand, it provides a large welding area between the conductive component and the current collector, improving the current-carrying capacity of the first electrode and the fast-charging capability of the battery cell. Furthermore, it reduces the space occupied by the first solder joint and the current collector, reduces the risk of interference between the first electrode and the casing (e.g., end caps), and improves the energy density of the battery cell. Therefore, it can balance the energy density and fast-charging performance of the battery cell.

[0040] In some embodiments, the first solder mark and the active material layer are spaced apart along the first direction.

[0041] By adopting the technical solution of this embodiment, when the conductive component and the current collector are welded, the active material layer will not be welded, reducing welding defects such as incomplete welding, which is conducive to improving welding quality, improving the connection reliability and overcurrent capacity between the conductive component and the current collector, and improving the reliability and fast charging capability of the battery cell.

[0042] In some embodiments, the first connecting portion is spaced apart from the active material layer along the first direction.

[0043] By adopting the technical solution of this embodiment, the first connecting part does not come into contact with the active material layer, which can reduce the mutual influence between the two and improve the reliability of the battery cell.

[0044] In some embodiments, the distance between the first connecting portion and the active material layer is W3, wherein 0.3mm≤W3≤5mm, and optionally, 0.5mm≤W3≤2.8mm.

[0045] By adopting the technical solution of this embodiment, a certain gap is formed between the first connecting part and the active material layer, reducing their mutual influence and improving the reliability of the battery cell. The closer distance between the first connecting part and the active material layer results in a compact first electrode structure, which helps to reduce space waste and improve the energy density of the battery cell. Furthermore, with a fixed current collector dimension along the first direction, a smaller distance between the first connecting part and the active material layer allows the current collector to have more space to cover the active material layer, which helps to improve the capacity and energy density of the battery cell. Therefore, both the energy density and reliability of the battery cell can be considered.

[0046] In some embodiments, the first electrode includes a first insulating member, at least a portion of which is located between the first connection portion and the active material layer.

[0047] By adopting the technical solution of this embodiment, the first insulating member can cover the portion of the second metal part located between the first connecting portion and the active material layer. The first insulating member can provide support for this portion, thereby reducing the risk of cracking in this portion. In addition, the first insulating member covering the portion of the second metal part located between the first connecting portion and the active material layer can also achieve insulation of this portion, reduce the short circuit risk of the battery cell, and improve the reliability of the battery cell.

[0048] In some embodiments, the electrode assembly further includes a second electrode with a polarity opposite to that of the first electrode. The second electrode includes a main functional portion and an electrode tab arranged along a first direction. The end of the main functional portion near the second metal portion has a first end face, and the electrode tab extends outward from the first end face. Along the thickness direction of the current collector, the projection of the first end face is located within the projection of the first insulating member.

[0049] By adopting the technical solution of this embodiment, the first end face is disposed opposite to the first insulating member, and the first insulating member can block burrs at the first end face, reduce the short circuit risk of the battery cell, and improve the reliability of the battery cell.

[0050] In some embodiments, the first electrode includes a second insulating element that covers at least a portion of the first solder mark.

[0051] By adopting the technical solution of this embodiment, the second insulating component covers the first solder mark, which can block burrs, metal debris and other components on the first solder mark, reduce the short circuit risk of the battery cell and help improve the reliability of the battery cell.

[0052] In some embodiments, the first electrode includes a first insulating member, at least a portion of which is located between the first connection portion and the active material layer; along a first direction, one side of the second insulating member covers the first solder mark, and the other side of the second insulating member covers at least a portion of the area of ​​the portion of the first insulating member located between the first connection portion and the active material layer.

[0053] By adopting the technical solution of this embodiment, the first insulating component and the second insulating component can achieve double-layer insulation, reduce the short-circuit risk of battery cells, and improve the reliability of battery cells.

[0054] In some embodiments, along a first direction, one side of the second insulating member covers the first solder mark, and the other side of the second insulating member is covered by an active material layer.

[0055] By adopting the technical solution of this embodiment, the second insulating member extends from the first solder mark to the active material layer. The second insulating member has a wide coverage area and good insulation effect, which is beneficial to improving the reliability of the battery cell. The second insulating member can cover the end of the active material layer near the second metal part, which can block burrs on the active material layer near the second metal part, reduce the short circuit risk of the battery cell, and improve the reliability of the battery cell.

[0056] In some embodiments, along the first direction, the size of the portion of the second insulating member covering the active material layer is W4, wherein 0.2mm≤W4≤1mm, and optionally, 0.3mm≤W4≤0.8mm.

[0057] By adopting the technical solution of this embodiment, the second insulating member can cover a portion of the active material layer. The second insulating member can insulate the portion of the second metal part located between the conductive member and the active material layer, which is beneficial to improving the insulation effect of the first electrode and improving the reliability of the battery cell. In addition, it also reduces the space occupied by the second insulating member and improves the energy density of the battery cell. Therefore, the reliability and energy density of the battery cell can be balanced.

[0058] In some embodiments, the electrode assembly further includes a second electrode with a polarity opposite to that of the first electrode. The second electrode includes a main functional portion and an electrode tab arranged along a first direction. The end of the main functional portion near the second metal portion has a first end face, and the electrode tab extends outward from the first end face. Along the thickness direction of the current collector, the projection of the first end face is located within the projection of the second insulating member.

[0059] By adopting the technical solution of this embodiment, the first end face and the second insulating member are disposed opposite to each other. The second insulating member can block the burrs at the first end face, reduce the short circuit risk of the battery cell, and improve the reliability of the battery cell.

[0060] In some embodiments, the number of conductive components is n1, the thickness of the first connection portion is T1, the number of second insulating components is n2, the thickness of the second insulating component is T2, the thickness of the second metal portion is T3, the maximum total thickness of the first electrode at the active material layer is T4, and n1*T1+n2*T2+T3≤T4; n1 and n2 are positive integers.

[0061] By adopting the technical solution of this embodiment, the thickness of the edge of the first electrode is less than or equal to the maximum total thickness of the first electrode in the active material layer, so that the problem of bulging edges of the electrode assembly can be reduced during the winding process of the electrode assembly.

[0062] In some embodiments, the size of the second insulating member along the first direction is W5, wherein 3mm≤W5≤9mm, and optionally, 4.5mm≤W5≤6.5mm.

[0063] By adopting the technical solution of this embodiment, the second insulating component can better cover the first solder mark, blocking burrs, metal debris, etc. on the first solder mark, reducing the short circuit risk of the battery cell and improving the reliability of the battery cell; in addition, it can also reduce the space occupied by the second insulating component and increase the energy density of the battery cell; therefore, it can balance the reliability and energy density of the battery cell.

[0064] In some embodiments, there are two conductive components, and the first connecting portions of the two conductive components are respectively welded to the two opposite surfaces of the current collector along the thickness direction to form two first solder marks; there are two active material layers, and the two active material layers respectively cover the two opposite surfaces of the first metal part along the thickness direction of the current collector.

[0065] By adopting the technical solution of this embodiment, both opposite sides of the current collector are covered with an active material layer, which can increase the capacity of the active material on the first electrode, which is beneficial to improving the capacity and energy density of the battery cell; two conductive components are welded to the opposite sides of the second metal part, so that electrons can flow to the electrode lead-out part through the two conductive components, which can realize parallel current splitting, reduce the flow resistance of electrons, and reduce the heat generation at the electrode tab of the first electrode.

[0066] In some embodiments, the first electrode includes two second insulating members, which respectively cover two first solder marks. In the direction from the first metal portion to the second metal portion, the portion of the second insulating member protruding from the first connection portion forms a blocking portion. In a second direction, the blocking portion is located on one side of the second connection portion, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0067] By adopting the technical solution of this embodiment, the blocking part can block burrs, metal debris and other components on the edge of the first connecting part away from the active material layer, thereby reducing the short circuit risk of the battery cell and improving the reliability of the battery cell.

[0068] In some embodiments, along a first direction, the blocking portions of the two second insulating members are abutted together.

[0069] By adopting the technical solution of this embodiment, after the blocking parts of the two second insulating parts are attached, the burrs, metal debris and other components on the edge of the first connecting part can be wrapped, reducing the risk of metal debris falling off, reducing the short circuit risk of the battery cell, and improving the reliability of the battery cell.

[0070] In some embodiments, the second connection portions of the two conductive components are welded together to form a second solder mark.

[0071] By adopting the technical solution of this embodiment, the second connecting parts of the two conductive components are welded together to form a whole, which can be easily connected to the electrode lead-out part.

[0072] In some embodiments, the first solder mark and the second solder mark are directly connected.

[0073] By adopting the technical solution of this embodiment, the first and second solder marks can be obtained by welding in one step, which can save the manufacturing process of the first electrode, improve the production efficiency of the first electrode, and reduce the manufacturing cost of the first electrode. The close distance between the first and second solder marks can reduce space waste, reduce the risk of interference between conductive components and the casing (e.g., end cap), and improve the reliability and energy density of the battery cell.

[0074] In some embodiments, the first electrode includes a second insulating element that covers at least a portion of the second solder mark.

[0075] By adopting the technical solution of this embodiment, the second insulating component can cover the second solder mark, which can block the sharp protrusions, metal debris and other components on the second solder mark, reduce the short circuit risk of the battery cell and improve the reliability of the battery cell.

[0076] In some embodiments, the current collector is an aluminum current collector.

[0077] By adopting the technical solution of this embodiment, the aluminum current collector has poor conductivity, and the second metal part of the first electrode is welded to the conductive component, thereby effectively improving the overcurrent capacity at the tab of the first electrode, and thus effectively improving the fast charging performance of the battery cell.

[0078] In some embodiments, the aluminum content of the aluminum current collector ranges from 99.00% to 99.7%.

[0079] By adopting the technical solution of this embodiment, the aluminum content of the aluminum current collector is set to be in the range of 99.00% to 99.7%, which makes the current collector of the first electrode have good conductivity and the first electrode have good overcurrent capacity, which is beneficial to improving the fast charging performance of the battery cell.

[0080] In some embodiments, the current collector is a copper current collector.

[0081] By adopting the technical solution of this embodiment, the first electrode is a negative electrode, the copper current collector has good conductivity, and the second metal part of the first electrode is welded to the conductive component, thereby effectively improving the overcurrent capacity at the tab of the first electrode, and thus effectively improving the fast charging performance of the battery cell.

[0082] In some embodiments, the active material layer includes a first active material portion and a second active material portion arranged along the first direction, the first active material portion being connected to the end of the second active material portion near the second metal portion, and the thickness of the first active material portion being less than the thickness of the second active material portion.

[0083] By adopting the technical solution of this embodiment, the active material layer can be rolled during the forming process of the first electrode to compress the active material layer; and the setting of the first active material part can reduce the rolling pressure on the edge of the active material layer and reduce the risk of edge cracking of the active material layer.

[0084] In some embodiments, at least a portion of the thickness of the first metal portion is less than the thickness of the second metal portion.

[0085] By adopting the technical solution of this embodiment, at least a portion of the thickness of the first metal part is smaller than the thickness of the second metal part, the second metal part has a larger thickness, and the second metal part has a better current carrying capacity, which is beneficial to improving the current carrying capacity of the first electrode and improving the fast charging performance of the battery cell.

[0086] Secondly, a battery device is provided, comprising a plurality of the aforementioned battery cells.

[0087] The battery device in this application embodiment uses the aforementioned battery cell. The battery cell has good fast charging performance, which helps to reduce the charging waiting time of the battery device, facilitates the use of the battery device, and also helps to improve the applicability of the battery device.

[0088] Thirdly, an electrical device is provided, including the aforementioned battery cell or battery device, wherein the battery cell or battery device is used to store or provide electrical energy.

[0089] The power device in this application embodiment uses the above-mentioned battery cell or battery device. The battery cell and battery device have good fast charging performance, which helps to reduce the charging waiting time of the power device, reduce the range anxiety of the power device, and make the power device more convenient and faster to use.

[0090] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0091] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0092] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0093] Figure 2 is a schematic diagram of the structure of a battery device provided in some embodiments of this application.

[0094] Figure 3 is a schematic diagram of the structure of a battery provided in some embodiments of this application.

[0095] Figure 4 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application.

[0096] Figure 5 is a cross-sectional view along line AA in Figure 4.

[0097] Figure 6 is a schematic diagram of the structure of the first electrode sheet in the unfolded state according to some embodiments of this application.

[0098] Figure 7 is a schematic diagram of the structure after the first electrode shown in Figure 6 has its conductive components hidden.

[0099] Figure 8 is a magnified view of part D in Figure 7.

[0100] Figure 9 is a cross-sectional view along line BB in Figure 6.

[0101] Figure 10 is a cross-sectional view along line CC in Figure 6.

[0102] Figure 11 is a cross-sectional view along line BB in Figure 6 of the first electrode sheet in an unfolded state according to some other embodiments of this application.

[0103] Figure 12 is a cross-sectional view of the first electrode shown in Figure 11 along line CC in Figure 6.

[0104] Figure 13 is a cross-sectional view along line BB in Figure 6 of the first electrode sheet in an unfolded state according to some other embodiments of this application.

[0105] Figure 14 is a cross-sectional view of the first electrode shown in Figure 13 along line CC in Figure 6.

[0106] Figure 15 is a cross-sectional view along line BB in Figure 6 of the first electrode sheet in an unfolded state according to some embodiments of this application.

[0107] Figure 16 is a schematic diagram of the structure of the first electrode sheet in the unfolded state according to some embodiments of this application.

[0108] Figure 17 is a cross-sectional view along line EE in Figure 16.

[0109] Figure 18 is a cross-sectional view along line FF in Figure 16.

[0110] Figure 19 is a cross-sectional view along line EE in Figure 16 of the first electrode in an unfolded state according to some embodiments of this application.

[0111] Figure 20 is a cross-sectional view along line BB in Figure 6 of the first electrode sheet in an unfolded state according to some embodiments of this application.

[0112] The following are the labeling elements in the figure:

[0113] 1000, Vehicle; 1100, Battery assembly; 1200, Controller; 1300, Motor; 100, Battery cell; 10, Electrode assembly; 1, First electrode; 11, Conductive component; 111, First connecting part; 1111, First connecting sub-part; 1112, Second connecting sub-part; 112, Second connecting part; 12, Current collector; 121, Main body; 1211, First metal part; 1212, Second metal part; 12121, First section; 12122, Second section; 12123, Third section; 122, Protrusion; 1 3. Active material layer; 131. First active material section; 132. Second active material section; 2. Second electrode plate; 21. Main functional section; 211. First end face; 22. Electrode tab; 3. Isolator; 41. First solder mark; 411. First solder mark section; 412. Second solder mark section; 42. Second solder mark; 51. First insulating component; 52. Second insulating component; 521. Blocking part; 20. Outer shell; 201. End cap; 2011. Electrode lead-out part; 202. Housing; 300. Box body; 301. First box body section; 302. Second box body section. Detailed Implementation

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] In this application, "multiple" means two or more (including two).

[0121] A single battery cell can be a rechargeable battery, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0122] A battery device can refer to a single physical module that includes one or more battery cells to provide higher voltage and capacity.

[0123] A single battery cell typically includes an electrode assembly and a housing for containing the electrode assembly. The electrode assembly typically includes a positive electrode, a negative electrode, and a separator that separates the positive and negative electrodes.

[0124] The electrode assembly's electrode (e.g., positive or negative electrode) includes a current collector, an active material layer, and a conductive member. The current collector is a pure metal current collector, which includes a main body and a protrusion extending outward from the edge of the main body. The active material layer covers the surface of the main body, and the conductive member is welded only to the protrusion to form a solder mark. The conductive member is electrically connected to the electrode leads on the casing. The portions of the conductive member and the current collector not covered by the active material layer form the tabs of the electrode. During the charging and discharging process of the battery cell, current can flow from the main body through the protrusion to the conductive member and finally out from the electrode leads, or the current flowing in from the electrode leads can flow from the conductive member through the protrusion to the main body.

[0125] According to Joule's law: Q = I 2 Rt; Q is the heat generated by the current flowing through the conductor (in joules, J). I is the current flowing through the conductor (in amperes, A). R is the resistance of the conductor (in ohms, Ω). t is the time it takes for the current to flow through the conductor (in seconds, s).

[0126] This law states that the amount of charge passing through a conductor (i.e., current multiplied by time) is directly proportional to the conductor's resistance, and the heat generated is directly proportional to the square of the current and the duration of the current flow.

[0127] According to the law of resistance: R = ρL / S; R: resistance of the conductor (unit: ohm, Ω); ρ: resistivity of the material (unit: ohm-meter, Ω·m); L: length of the conductor (unit: meter, m); S: cross-sectional area of ​​the conductor (unit: square meter, m²). 2 ).

[0128] This law states that resistance is directly proportional to resistivity, directly proportional to the length of the conductor, and inversely proportional to the cross-sectional area.

[0129] Therefore, under the condition of constant heat generation, the larger the cross-sectional area S of the tab, the better the current carrying capacity of the tab. The cross-sectional area S of the tab = W * D, where W is the width of the tab and D is the thickness of the tab. Since the width of the main body is greater than the width of the protrusion, the main body has good current carrying capacity, and the conductive component has good conductivity. The current carrying capacity at the connection between the protrusion and the conductive component is also good. Therefore, the current carrying capacity of the portion of the protrusion located between the solder mark and the main body is poor.

[0130] Based on the aforementioned principles, the current-carrying capacity of the tabs can be improved by increasing the width or number of protrusions, thereby enhancing the fast-charging capability of individual battery cells. However, within the limited space of the casing, increasing the width or number of protrusions is finite, limiting the improvement in the current-carrying capacity of the tabs and hindering the increase in the capacity of individual battery cells. Therefore, in practical design processes, how to design the tab structure is a crucial issue for improving the fast-charging capability of individual battery cells.

[0131] In view of this, the present application provides a technical solution that improves the current-carrying capacity at the electrode tab by rationally designing the electrical connection position between the conductive component and the current collector, thereby improving the fast-charging performance of the battery cell and taking into account the capacity of the battery cell to a certain extent.

[0132] The battery cells described in this application are applicable to battery devices and electrical devices that use battery devices. Electrical devices can be equipment that uses battery devices as a power source or various energy storage systems that use battery devices as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0133] The battery cells described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0134] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0135] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device.

[0136] As shown in Figure 1, a battery device 1100 is installed inside the vehicle 1000. The battery device 1100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 1100 can be used to power the vehicle 1000; for example, the battery device 1100 can serve as the operating power source for the vehicle 1000.

[0137] The vehicle 1000 may also include a controller 1200 and a motor 1300. The controller 1200 is used to control the battery device 1100 to supply power to the motor 1300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0138] In some embodiments of this application, the battery device 1100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0139] As shown in Figure 2, the battery device 1100 includes a housing 300 and a battery cell 100, with the battery cell 100 housed within the housing 300.

[0140] The housing 300 is used to accommodate the battery cell 100, and the housing 300 can have various structures. In some embodiments, the housing 300 may include a first housing portion 301 and a second housing portion 302, which overlap each other, and together define a receiving space for accommodating the battery cell 100. The second housing portion 302 may be a hollow structure with one end open, and the first housing portion 301 may be a plate-like structure, with the first housing portion 301 covering the open side of the second housing portion 302 to form a housing 300 with a receiving space; alternatively, both the first housing portion 301 and the second housing portion 302 may be hollow structures with one side open, with the open side of the first housing portion 301 covering the open side of the second housing portion 302 to form a housing 300 with a receiving space. Of course, the first housing portion 301 and the second housing portion 302 can have various shapes, such as cylinders, cuboids, etc.

[0141] To improve the sealing performance after the first housing part 301 and the second housing part 302 are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 301 and the second housing part 302.

[0142] Assuming that the first box part 301 covers the top of the second box part 302, the first box part 301 can also be called the upper box cover, and the second box part 302 can also be called the lower box 300.

[0143] In the battery device 1100, there can be one or more battery cells 100. If there are multiple battery cells 100, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 100 are connected in both series and parallel.

[0144] Multiple battery cells 100 can be directly connected in series, parallel, or in a mixed manner, and then the whole composed of multiple battery cells 100 can be housed in the housing 300; of course, multiple battery cells 100 can also be connected in series, parallel, or in a mixed manner to form a battery module, and multiple battery modules can then be connected in series, parallel, or in a mixed manner to form a whole, and housed in the housing 300.

[0145] For example, the battery cell 100 may be the smallest unit that makes up the battery device 1100.

[0146] As shown in Figures 3 and 4, in some embodiments, the battery cell 100 includes a housing 20 and an electrode assembly 10, at least a portion of which is housed within the housing 20.

[0147] The outer shell 20 may be a hollow structure, with an internal space for accommodating the electrode assembly 10 and the electrolyte.

[0148] In some embodiments, the housing 20 includes a housing 202 and an end cap 201, the housing 202 having an opening and the end cap 201 for closing the opening.

[0149] The housing 202 is a component used to cooperate with the end cap 201 to form an internal cavity of the battery cell 100. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0150] The housing 202 and the end cap 201 can be separate components. For example, an opening can be provided on the housing 202, and the end cap 201 can be used to close the opening to form an internal cavity of the battery cell 100.

[0151] The housing 202 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 202 can be determined according to the specific shape and size of the electrode assembly 10. The housing 202 can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, aluminum-plastic film, steel-plastic film, etc.

[0152] The shape of the end cap 201 can be adapted to the shape of the housing 202 to fit the housing 202. The material of the end cap 201 can be the same as or different from the material of the housing 202. Optionally, the end cap 201 can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 201 is not easily deformed when subjected to compression and impact, so that the battery cell 100 can have higher structural strength and improve reliability.

[0153] The end cap 201 is connected to the housing 202 by welding, bonding, snap-fitting or other means.

[0154] The housing 202 may be open at one end or open at both ends. In some examples, the housing 202 may be a structure with an opening on one side, with one end cap 201 covering the housing 202. In other examples, the housing 202 may be a structure with openings on both sides, with two end caps 201 covering the two openings of the housing 202 respectively.

[0155] In some embodiments, the battery cell 100 further includes an electrolyte contained within the housing 20. The electrolyte acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid.

[0156] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0157] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0158] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0159] The solvent may also be an ether solvent. Ether solvents may include one or more of the following: ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0160] In some embodiments, the gel electrolyte comprises a polymer-based backbone network coupled with an ionic liquid-lithium salt.

[0161] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0162] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0163] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0164] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0165] In some embodiments, the electrode assembly 10 is a component in the battery cell 100 where an electrochemical reaction occurs. The electrode assembly 10 may be entirely housed within the housing 20 or partially housed within the housing 20. For example, a portion of the tab of the electrode assembly 10 may extend outside the housing 20. Optionally, the electrode assembly 10 may be entirely housed within the housing 20.

[0166] Referring to Figures 4 and 5, in some embodiments, the electrode assembly 10 includes a first electrode 1 and a second electrode 2 with opposite polarities.

[0167] For example, one of the first electrode 1 and the second electrode 2 is a positive electrode and the other is a negative electrode.

[0168] In some embodiments, the positive electrode sheet may include a positive current collector and a layer of positive active material disposed on at least one surface of the positive current collector.

[0169] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0170] As an example, the positive current collector can be made of metal foil, conductive polymer material, or carbon material. For example, as a metal foil, it can be made of pure metal, alloy, or surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium, or silver.

[0171] As an example, the positive electrode active material layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. Other conventional materials that can be used as the positive electrode active material layer of the battery cell 100 may also be used as the positive electrode active material layer. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphates include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM211), LiNi 0.6 Co 0.2 Mn 0.2O2 (also known as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi) 0.80 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0172] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0173] As an example, the negative electrode current collector can be made of metal foil, conductive polymer material, or carbon material. For example, as a metal foil, it can be made of pure metal, alloy, or surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium, or silver.

[0174] As an example, the negative electrode active material layer includes a negative electrode active material. The negative electrode active material may be a negative electrode active material known in the art for use in a battery cell 100. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may include at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may include at least one of elemental tin, tin oxide compounds, and tin alloys. The negative electrode active material of this application may also use other conventional materials that can be used as negative electrode active materials for battery cells 100. These negative electrode active materials may be used alone or in combination of two or more.

[0175] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0176] In some embodiments, the electrode assembly 10 further includes a separator 3 for separating the first electrode 1 and the second electrode 2. The separator 3 can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0177] In some embodiments, the separator 3 includes a separator membrane. The separator membrane in this application can be any known porous structure separator membrane with good chemical and mechanical stability.

[0178] As an example, the main material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator 3 may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0179] In some embodiments, the separator 3 is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, serving both to transport ions and to isolate the positive and negative electrodes.

[0180] In some embodiments, the electrode assembly 10 is a wound structure. Exemplarily, the first electrode 1 and the second electrode 2 are both strip structures, and the first electrode 1, the spacer 3, and the second electrode 2 are wound into a wound structure.

[0181] In some embodiments, the electrode assembly 10 has a stacked structure.

[0182] As an example, multiple first electrode 1 and multiple second electrode 2 can be set, and multiple first electrode 1 and multiple second electrode 2 can be stacked alternately.

[0183] As an example, multiple first electrode plates 1 can be provided, and second electrode plates 2 can be folded to form multiple stacked folded segments, with a first electrode plate 1 sandwiched between adjacent folded segments.

[0184] As an example, both the first electrode 1 and the second electrode 2 are folded to form multiple stacked folded segments.

[0185] As an example, multiple separators 3 can be provided, each disposed between any adjacent first electrode 1 or second electrode 2.

[0186] As an example, the separator 3 can be continuously arranged between any adjacent first electrode 1 or second electrode 2 by folding or rolling.

[0187] In some embodiments, the electrode assembly 10 may be cylindrical, flat, or polygonal, etc.

[0188] In some embodiments, the battery cell 100 includes two electrode leads 2011. The two electrode leads 2011 are insulated from each other and are electrically connected to a positive electrode and a negative electrode, respectively, for outputting or inputting electrical energy into the battery cell 100.

[0189] The electrode lead-out portion 2011 is used to connect to an external circuit to enable charging or discharging of the battery cell 100. For example, when multiple battery cells 100 are assembled into a group, the electrode lead-out portion 2011 is used to connect to a busbar component.

[0190] In some examples, the electrode lead-out portion 2011 can be an electrode terminal disposed on the housing 20. The electrode terminal is formed independently of the housing 20 and assembled together during the production process of the battery cell 100. As an example, the electrode terminal is insulatedly disposed on the end cap 201 or the housing 202.

[0191] In some examples, the electrode lead-out portion 2011 may also be part of the housing 20. For example, the electrode lead-out portion 2011 may be the end cap 201 of the housing 20, or the electrode lead-out portion 2011 may be the end wall of the housing 202 opposite to the end cap 201.

[0192] Please refer to Figures 6-10. In some embodiments of this application, a battery cell 100 is provided. The battery cell 100 includes a housing 20 and an electrode assembly 10. The housing 20 is provided with an electrode lead-out portion 2011. At least a portion of the electrode assembly 10 is disposed within the housing 20. The electrode assembly 10 includes a first electrode plate 1, which includes a conductive member 11, a current collector 12, and an active material layer 13. The current collector 12 is made of a metal material. The conductive member 11 is electrically connected to the electrode lead-out portion 2011. The current collector 12 includes a main body portion 121, which includes a first metal portion 1211 and a second metal portion 1212 arranged and connected along a first direction, which is perpendicular to the thickness direction of the current collector 12. At least a portion of the first metal portion 1211 is covered with the active material layer 13, while the second metal portion 1212 is not covered with the active material layer 13. The conductive member 11 is electrically connected to the second metal portion 1212.

[0193] The first electrode 1 can be either the positive electrode or the negative electrode as described above. The first electrode 1 includes a conductive member 11, a current collector 12, and an active material layer 13. When the first electrode 1 is a positive electrode, the active material layer 13 is a positive active material layer, and the current collector 12 can be a positive current collector. When the first electrode 1 is a negative electrode, the active material layer 13 is a negative active material layer, and the current collector 12 is a negative current collector.

[0194] It should be noted that in the first electrode 1, the current collector 12 is made of metallic material. It is understood that the material of the current collector 12 includes only metallic materials and does not include non-metallic materials. For example, the current collector 12 is made of the aforementioned metal foil; the current collector 12 is not a composite current collector.

[0195] The conductive component 11 can refer to a component used to electrically connect the electrode lead-out portion 2011 and the current collector 12. The conductive component 11 can be made of copper foil or aluminum foil to facilitate connection with the electrode lead-out portion 2011.

[0196] In some examples, the electrode lead 2011 can be directly connected to the conductive member 11; for example, the electrode lead 2011 is directly soldered to the conductive member 11.

[0197] In some examples, the electrode lead-out portion 2011 can be connected to the conductive member 11 via a conductive element (e.g., an adapter plate, a current collector, etc.), for example, one side of the conductive element is welded to the conductive member 11, and the other side of the conductive element is welded to the electrode lead-out portion 2011.

[0198] The first direction can refer to the direction perpendicular to the thickness direction of the current collector 12; the second direction can refer to the direction perpendicular to both the thickness direction of the current collector 12 and the first direction.

[0199] In some examples, the electrode assembly 10 is a wound structure. When the first electrode 1 is in the unfolded state, the first direction can be referred to as the width direction of the first electrode 1 (refer to the Z direction in Figure 6), and the thickness direction of the current collector 12 can be referred to as the thickness direction of the first electrode 1 (refer to the Y direction in Figure 9); the second direction can be referred to as the length direction of the first electrode 1 (refer to the X direction in Figure 6). When the first electrode 1 is in the wound state, the second direction can also be referred to as the winding direction of the first electrode 1 (refer to the direction indicated by arrow V in Figure 4).

[0200] In some examples, the electrode assembly 10 is a stacked structure, the first direction can be the width direction of the first electrode 1 (see the Z direction in Figure 6), and the second direction can be the length direction of the first electrode 1 (see the X direction in Figure 6).

[0201] The current collector 12 includes a main body 121, which can refer to the main part of the current collector 12. The main body 121 includes a first metal part 1211 and a second metal part 1212. The main body 121 is divided into two parts along a first direction, one part being the first metal part 1211 and the other part being the second metal part 1212. A portion of the first metal part 1211 is covered with an active material layer 13, or the entire first metal part 1211 is covered with an active material layer 13, while the second metal part 1212 is not covered with an active material layer 13. The first metal part 1211 and the second metal part 1212 can be divided by the end face of the active material layer 13 toward the second metal part 1212 (refer to the straight line M in Figure 9).

[0202] As an example, the length of the first metal part 1211 is equal to or nearly equal to the length of the second metal part 1212, that is, the main body part 121 is similar to an equal-length structure or a near-equal-length structure.

[0203] By adopting the technical solution of this embodiment, current can flow into or out of the first electrode 1 through the electrode lead-out portion 2011, thereby realizing the charging and discharging of the battery cell 100; and the conductive member 11 is electrically connected to the second metal portion 1212 of the main body portion 121 of the current collector 12, that is, the conductive member 11 is directly electrically connected to the main body portion 121 of the current collector 12, and the current can flow directly from the second metal portion 1212 of the main body portion 121 to the conductive member 11, which reduces the current restriction of the current collector 12, reduces the overcurrent pressure at the tab of the first electrode 1, improves the overcurrent capacity of the first electrode 1, reduces the risk of overheating when the tab of the first electrode 1 passes through a large current, and improves the fast charging capability of the battery cell 100.

[0204] Compared to the related art where the conductive member 11 is only electrically connected to the protrusion 122, the battery cell 100 of this application embodiment allows current to flow directly into the electrode lead-out portion 2011 through the main body portion 121. This reduces the current restriction imposed by the root of the protrusion 122 near the main body portion 121, reduces the overcurrent pressure at the tab of the first electrode 1, improves the overcurrent capacity of the first electrode 1, reduces the risk of overheating at the tab of the first electrode 1 when a large current passes through it, and improves the fast-charging capability of the battery cell 100. Furthermore, in some embodiments, the current collector 12 can eliminate the protrusion 122, and there is no need to increase the width of the protrusion 122, thereby better balancing the capacity and energy density of the battery cell 100.

[0205] In some embodiments, the active material layer 13 includes a first active material portion 131 and a second active material portion 132 arranged along a first direction. The first active material portion 131 is connected to the end of the second active material portion 132 near the second metal portion 1212. The thickness of the first active material portion 131 is less than the thickness t1 of the second active material portion 132.

[0206] As an example, the active material layer 13 is divided into two parts along the first direction, wherein the part closer to the second metal part 1212 is the first active material part 131, and the part farther away from the second metal part 1212 is the second active material part 132.

[0207] In some examples, the first active material portion 131 and the second active material portion 132 both cover the first metal portion 1211. The first active material portion 131 and the second active material layer 13 can have a generally equal thickness structure. The thickness of the first active material portion 131 is less than the thickness t1 of the second active material portion 132, so that the first active material portion 131 and the second active material portion 132 form a stepped structure.

[0208] In some examples, the second active material layer 13 may have a generally uniform thickness structure. Along the direction from the first metal portion 1211 to the second metal portion 1212, the thickness of the first active material portion 131 decreases starting from the second active material portion 132, such that the thickness of the first active material portion 131 is less than the thickness t1 of the second active material portion 132. The direction from the first metal portion 1211 to the second metal portion 1212 can be referred to as the positive direction of the Z-axis in Figure 9.

[0209] For example, along the direction from the first metal portion 1211 to the second metal portion 1212, the thickness of the first active material portion 131 decreases in a stepped manner, making the first active material portion 131 a stepped structure; or, along the direction from the first metal portion 1211 to the second metal portion 1212, the thickness of the first active material portion 131 decreases slowly, and the shape of the first active material portion 131 is more rounded or smooth, which helps to reduce stress concentration and improve the structural strength of the first electrode 1.

[0210] During the forming process of the first electrode 1, the active material layer 13 can be rolled to compress the active material layer 13; and the provision of the first active material part 131 can reduce the rolling pressure on the edge of the active material layer 13 and reduce the risk of edge cracking of the active material layer 13.

[0211] In some embodiments, along the second direction, the size of the first metal portion 1211 is L1, and the size of the second metal portion 1212 is L2, wherein 0.8≤L2 / L1≤1, and wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 12.

[0212] Along the second direction, the dimension L1 of the first metal part 1211 may refer to the length of the first metal part 1211.

[0213] Along the second direction, the dimension L2 of the second metal part 1212 can refer to the length of the second metal part 1212.

[0214] As an example, the value of L2 / L1 can be 0.8, 1, or any value between 0.8 and 1. For example, the value of L2 / L1 can be, but is not limited to, 0.8, 0.9, or 1.

[0215] 0.8≤L2 / L1≤1, along the second direction, the size L1 of the first metal part 1211 is equal to or not much different from the size L2 of the second metal part 1212, which is beneficial to increase the connection area between the second metal part 1212 and the conductive member 11, thereby improving the overcurrent capacity of the first electrode 1 and improving the fast charging performance of the battery cell 100.

[0216] In some embodiments, L2 / L1 = 1, and along the second direction, the size L1 of the first metal part 1211 is equal to the size L2 of the second metal part 1212, so that the main body 121 has an equal length structure, which is more conducive to increasing the connection area between the second metal part 1212 and the conductive member 11, thereby improving the overcurrent capacity of the first electrode 1 and improving the fast charging performance of the battery cell 100.

[0217] In some embodiments, 0.8 ≤ L2 / L1 < 1, along the second direction, the size L1 of the first metal part 1211 is greater than the size L2 of the second metal part 1212, along the second direction, the second metal part 1212 may be centrally disposed relative to the first metal part 1211, and the main body part 121 forms a notch structure at the opposite ends of the second metal part 1212, or, along the second direction, the second metal part 1212 may be disposed biased toward one end of the first metal part 1211. For example, one end of the second metal part 1212 is flush with one end of the first metal part 1211, and the main body part 121 forms a notch structure at the other end of the second metal part 1212.

[0218] In some embodiments, the conductive member 11 includes a first connecting portion 111 and at least one second connecting portion 112 connected to each other. The second connecting portion 112 is electrically connected to the electrode lead-out portion 2011. The first connecting portion 111 is soldered to the current collector 12 to form a first solder mark 41. The first solder mark 41 includes a first solder mark portion 411. The first connecting portion 111 is soldered to the surface of the second metal portion 1212 to form the first solder mark portion 411.

[0219] The conductive component 11 includes a first connecting portion 111 and a second connecting portion 112. The first connecting portion 111 may refer to the part welded to the current collector 12, and the trace left by the welding of the first connecting portion 111 to the current collector 12 is called the first solder mark 41. The second connecting portion 112 may refer to the part electrically connected to the conductive component 11. The number of second connecting portions 112 may be one or more. Multiple second connecting portions 112 are arranged at intervals along the length direction of the first electrode 1.

[0220] As an example, when the first electrode 1 is in the unfolded state, the first connecting portion 111 extends outward from the edge facing away from the active material layer 13 to form a protruding structure, and the entire protruding structure forms the second connecting portion 112. Alternatively, the entire protruding structure is divided into two parts along the first direction, wherein the part closer to the active material layer 13 belongs to the first connecting portion 111, and the part farther away from the active material layer 13 is the second connecting portion 112. The first connecting portion 111 is stacked on the surface of the second metal portion 1212 and welded to the surface of the second metal portion 1212. The trace left by the welding of the first connecting portion 111 and the second metal portion 1212 is the first solder mark 411. The first solder mark 411 belongs to a part of the first solder mark 41. A part of the first connecting portion 111 is welded to the second metal portion 1212. The part of the first connecting portion 111 belonging to the protruding structure is also welded to other parts of the current collector 12 (e.g., protruding portion 122, etc.). Alternatively, the first solder mark 411 is the first solder mark 41, and the entire protruding structure is not welded to the second metal portion 1212. The first connecting portion 111 and the second connecting portion 112 are separated by the edge of the first solder mark 41 facing away from the active material layer 13 (see straight line Q in Figure 6).

[0221] The first connecting part 111 and the second metal part 1212 can be welded by methods such as roll welding, laser welding, and ultrasonic welding.

[0222] In some examples, referring to Figure 6, during the fabrication of the first electrode 1, a conductive member 11 of equal width is welded to the edge of the current collector 12 to form an equal-width solder mark. Then, die-cutting is performed at the edge of the current collector 12 to obtain the first connection portion 111 and the second connection portion 112. If the horizontal die-cutting position of the current collector 12 is located on the side of the equal-width solder mark facing away from the active material layer 13, then the entire protruding structure of the conductive member 11 forms the second connection portion 112, and the equal-width solder mark is the first solder mark 41, which is also the first solder mark portion 411. If the horizontal die-cutting position of the current collector 12 passes through the equal-width solder mark, and the equal-width solder mark is die-cut away to obtain the first solder mark 41, a portion of the protruding structure of the conductive member 11 belongs to the first connection portion 111, the solder mark on the protruding structure of the conductive member 11 belongs to the first solder mark 41, and the portion of the first solder mark 41 located on the second metal portion 1212 is the first solder mark portion 411.

[0223] By adopting the technical solution of this embodiment, the first connecting part 111 of the conductive member 11 is welded to the second metal part 1212, and the electrical connection between the conductive member 11 and the second metal part 1212 is simple and convenient to process and manufacture.

[0224] [Correction 30.04.2025 according to Rule 91] In some embodiments, along the second direction, the length of the first solder mark 411 is L3 and the size of the second metal part 1212 is L2, wherein 0.8≤L3 / L2≤1, and wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 12.

[0225] Along the second direction, the dimension L3 of the first solder mark 411 can refer to the length of the first solder mark 411.

[0226] As an example, the value of L3 / L2 can be 0.8, 1, or any value between 0.8 and 1. For example, the value of L3 / L2 can be, but is not limited to, 0.8, 0.9, or 1.

[0227] 0.8≤L3 / L2≤1, along the second direction, the size L3 of the first solder part 411 is equal to or not much different from the size L2 of the second metal part 1212, the welding area of ​​the second metal part 1212 and the first connecting part 111 is large, the current carrying capacity of the first electrode 1 is good, and the fast charging performance of the battery cell 100 is good.

[0228] In some embodiments, L3 / L2 = 1, and along the second direction, the size L3 of the first solder portion 411 is equal to the size L2 of the second metal portion 1212, which can effectively increase the connection area between the second metal portion 1212 and the first connecting portion 111, thereby improving the overcurrent capacity of the first electrode 1 and improving the fast charging performance of the battery cell 100.

[0229] In some embodiments, the size of the first solder mark 411 along the first direction is W1, wherein 1mm≤W1≤4mm.

[0230] Along the first direction, the dimension W1 of the first solder mark 411 may refer to the width of the first solder mark 411.

[0231] As an example, the value of W1 can be 1mm, 4mm, or any value between 1mm and 4mm. For example, the value of W1 can be, but is not limited to, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, or 4mm.

[0232] The design with W1 ≥ 1mm provides a larger welding area between the first connecting portion 111 and the second metal portion 1212. This ensures stable welding of the first connecting portion 111 and the second metal portion 1212, and also provides a larger welding area between them, improving the current carrying capacity of the first electrode 1 and the fast charging capability of the battery cell 100. The design with W1 ≤ 4mm reduces the space occupied by the first solder mark portion 411 and the second metal portion 1212, reduces the risk of interference between the first electrode 1 and the casing 20 (e.g., end cap 201), and improves the energy density of the battery cell 100. Therefore, it can balance the energy density and fast charging performance of the battery cell 100.

[0233] In some embodiments, 2mm≤W1≤3mm can better balance the energy density and fast charging performance of a single battery cell 100.

[0234] In some embodiments, there are multiple second connection portions 112, which are spaced apart along a second direction and electrically connected to the electrode lead-out portion 2011, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 12.

[0235] It is understood that the edge of the first connecting portion 111 extends outward with multiple protruding structures, and the multiple protruding structures are spaced apart along the second direction, thereby forming multiple second connecting portions 112 arranged at intervals along the second direction.

[0236] Multiple second connection portions 112 are electrically connected to the electrode lead-out portion 2011. It is understood that the number of second connection portions 112 electrically connected to the electrode lead-out portion 2011 can be multiple. For example, all the second connection portions 112 are electrically connected to the electrode lead-out portion 2011. For example, after the first electrode 1 is wound, all the second connection portions 112 are gathered together in one place, thereby facilitating electrical connection to the electrode lead-out portion 2011.

[0237] By adopting the technical solution of this embodiment, the first metal part 1211 can be divided into multiple regions along the second direction according to multiple second connection parts 112, and each region can correspond to one second connection part 112. Electrons in each region can be transferred to the electrode lead-out part 2011 through the corresponding second connection part 112, so that the electrons of the first metal part 1211 are transferred in regions, and the electron transmission path in each region to the corresponding second connection part 112 is short, which is beneficial to reduce the electron transmission distance, reduce the overall resistance of the first electrode 1, and improve the fast charging performance and reliability of the battery cell 100.

[0238] In some embodiments, the current collector 12 further includes at least one protrusion 122, and a second metal portion 1212 is connected between the first metal portion 1211 and the protrusion 122; along a second direction, the size L4 of the protrusion 122 is smaller than the size L2 of the second metal portion 1212, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 12.

[0239] When the first electrode 1 is in the unfolded state, the second metal part 1212 extends outward from the side facing away from the first metal part 1211 to form a protrusion, which is the protrusion 122. Along the second direction, the size L4 of the protrusion 122 is smaller than the size L2 of the second metal part 1212. The protrusion 122 and the second metal part 1212 form a stepped structure. The plane on which the side of the second metal part 1212 facing away from the active material layer 13 is located is the interface between the protrusion 122 and the second metal part 1212 (see the straight line N in Figures 8 and 9).

[0240] During the fabrication of the first electrode 1, the horizontal die-cutting position passes through the edge of the current collector 12, thereby removing part of the material of the current collector 12, thus obtaining the protrusion 122. The protrusion 122 is provided corresponding to the protrusion structure of the conductive member 11, and the protrusion structure of the conductive member 11 covers the protrusion 122.

[0241] By adopting the technical solution of this embodiment, the design of the protrusion 122 can remove part of the material of the current collector 12, which is beneficial to reduce the space occupied by the first electrode 1 and also reduces the risk of interference between the first electrode 1 and the outer casing 20 (e.g., end cap 201, etc.), thereby improving the energy density of the battery cell 100.

[0242] In some embodiments, the first solder mark 41 includes a second solder mark portion 412, and the first connecting portion 111 includes a first connecting sub-portion 1111 and at least one second connecting sub-portion 1112, wherein the second connecting sub-portion 1112 is connected between the first connecting sub-portion 1111 and the second connecting portion 112; the first connecting sub-portion 1111 is soldered to the surface of the second metal portion 1212 to form the first solder mark portion 411, and the second connecting sub-portion 1112 is soldered to the surface of the protrusion 122 to form the second solder mark portion 412.

[0243] The first connecting part 1111 can refer to the portion where the first connecting part 111 is welded to the surface of the second metal part 1212, and the second connecting part 1112 can refer to the portion where the first connecting part 111 is welded to the surface of the protrusion 122. The trace left by welding the first connecting part 1111 to the surface of the second metal part 1212 is called the first solder mark 411, and the trace left by welding one second connecting part 1112 to the surface of the corresponding protrusion 122 is called the second solder mark 412. The number of second connecting parts 1112 can be one or more.

[0244] In some examples, when the first electrode 1 is in the unfolded state, the second connecting part 1112 may refer to the protrusion formed on the side of the first connecting part 1111 facing away from the edge of the active material layer 13. This protrusion is provided in a one-to-one correspondence with the protrusion 122. Along the thickness direction of the current collector 12, the portion of the conductive member 11 located within the projection range of the second metal part 1212 forms the first connecting part 111, and the portion of the conductive member 11 located within the projection range of the second solder part 412 forms the second connecting part 1112.

[0245] In some examples, along the direction from the first metal portion 1211 to the second metal portion 1212, the side of the first connecting sub-portion 1111 facing away from the active material layer 13 is flush with the side of the second metal portion 1212 facing away from the active material layer 13. The first connecting sub-portion 1111 and the second connecting sub-portion 1112 are separated by the plane containing the side of the second metal portion 1212 facing away from the active material layer 13 (see line N in Figures 8 and 9); the second connecting portion 112 and the second connecting sub-portion 1112 are separated by the edge of the second solder mark portion 412 facing away from the active material layer 13 (see line Q in Figure 9).

[0246] In some examples, during the fabrication of the first electrode 1, the horizontal die-cutting position passes through the equal-width solder mark, thereby removing part of the equal-width solder mark area to obtain the first solder mark 41. The first solder mark 41 can be divided into a first solder mark portion 411 and a second solder mark portion 412. The first solder mark portion 411 has an elongated structure and extends from one end of the first connecting part 1111 to the other end along the second direction. The second solder mark portion 412 can be equivalent to the protrusion of the edge of the first solder mark portion 411. The equal-width solder mark is located on the opposite sides of the second solder mark portion 412.

[0247] By adopting the technical solution of this embodiment, the protrusion 122 and the second metal part 1212 are simultaneously welded to the first connecting part 111, which helps to increase the welding area of ​​the conductive member 11 and the current collector 12, improves the current carrying capacity of the first electrode 1, and improves the fast charging performance of the battery cell 100.

[0248] In some embodiments, along a second direction, the second solder mark 412 extends from one side of the second connector 1112 to the other side of the second connector 1112.

[0249] Along the second direction, the size of the second solder mark 412 is equal to the size of the second connecting part 1112, that is, the length of the second solder mark 412 is equal to the length of the second connecting part 1112.

[0250] By adopting the technical solution of this embodiment, along the second direction, the second solder mark 412 extends from one side of the second connector 1112 to the other side of the second connector 1112, which can increase the welding area of ​​the second connector 1112 and the protrusion 122, improve the current carrying capacity of the protrusion 122 and the second connector 1112, improve the fast charging capability of the battery cell 100, and also help improve the welding reliability of the conductive component 11 and the current collector 12.

[0251] In some embodiments, the first solder mark 411 and the second solder mark 412 are directly connected.

[0252] In some examples, the first solder mark 411 and the second solder mark 412 form a single first solder mark 41 without a clear dividing line between them; the single first solder mark 41 may cover the dividing line between the protrusion 122 and the second metal part 1212; in the actual manufacturing process, the first solder mark 411 and the second solder mark 412 are formed by die-cutting the equal-width solder mark as described above.

[0253] In some examples, the first solder mark 411 and the second solder mark 412 adopt the structure of solder joints, and the spacing between solder joints in the first solder mark 411 is the same as the spacing between solder joints in the second solder mark 412; for example, the solder joints in the first solder mark 411 and the second solder mark 412 are not welded to the boundary line between the protrusion 122 and the second metal part 1212, and the distance between two adjacent solder joints in the first solder mark 411 and the second solder mark 412 is equal to the spacing between solder joints in the first solder mark 411; for example, the solder joints are welded to the boundary line between the protrusion 122 and the second metal part 1212, thereby connecting the first solder mark 411 and the second solder mark 412 into a single solder mark.

[0254] By adopting the technical solution of this embodiment, the first solder mark 411 and the second solder mark 412 form a whole first solder mark 41, which is convenient for processing and manufacturing and helps to reduce the manufacturing cost of the first electrode 1.

[0255] In some embodiments, there are multiple protrusions 122, multiple second connecting portions 112, and multiple second connecting sub-portions 1112. Along the second direction, the multiple protrusions 122 are spaced apart, the multiple second connecting portions 112 are spaced apart, and the multiple second connecting portions 112 are spaced apart. Each second connecting sub-portion 1112 is connected to each other in a one-to-one correspondence. The first connecting sub-portion 1111 is continuously arranged along the second direction. The multiple second connecting sub-portions 1112 are connected to the first connecting sub-portion 1111. The first connecting sub-portion 1111 is welded to the second metal portion 1212. Each second connecting sub-portion 1112 is welded to each protrusion 122 in a one-to-one correspondence. The multiple second connecting portions 112 are electrically connected to the electrode lead-out portion 2011.

[0256] In some examples, there are multiple second connecting portions 112 and multiple second connecting sub-portions 1112. Multiple second connecting sub-portions 1112 are spaced apart along the second direction and connected to the edge of the first connecting sub-portion 1111 facing away from the active material layer 13. Multiple second connecting portions 112 are respectively connected to the edge of the multiple second connecting sub-portions 1112 facing away from the active material layer 13.

[0257] For example, the first connecting sub-part 1111 extends outward from the edge of the active material layer 13 with a plurality of protruding structures, and the plurality of protruding structures are spaced apart along the second direction, thereby forming a plurality of second connecting parts 112 and a plurality of second connecting sub-parts 1112 arranged spaced apart along the second direction.

[0258] For example, there are two second connecting portions 112 and two second connecting sub-portions 1112. The two second connecting sub-portions 1112 are spaced apart along the second direction and connected to the edge of the first connecting sub-portion 1111 facing away from the active material layer 13. The two second connecting portions 112 are respectively connected to the edges of the two second connecting sub-portions 1112 facing away from the active material layer 13.

[0259] By adopting the technical solution of this embodiment, the first connecting sub-part 1111 is continuously arranged along the second direction, and multiple second connecting sub-parts 1112 can be connected into a whole. The first connecting sub-part 1111 can provide good support for the second connecting sub-parts 1112, which can reduce the risk between the second connecting sub-parts 112 and the electrode plates of the inserted electrode assembly 10 when the second connecting sub-parts 1112 are bent, reduce the short circuit risk of the battery cell 100, and help improve the reliability of the battery cell 100. In addition, the first connecting sub-part 1111 is large in size along the second direction, which helps to increase the welding area between the first connecting sub-part 1111 and the second metal part 1212, which helps to improve the current carrying capacity of the first electrode plate 1, and improve the fast charging performance and reliability of the battery cell 100.

[0260] In some embodiments, along a first direction, at least a portion of the second connection portion 112 is located on the side of the protrusion 122 facing away from the active material layer 13.

[0261] In some examples, when the first electrode 1 is in the unfolded state, the second connecting portion 112 is completely located on the side of the protrusion 122 facing away from the active material layer 13, and the projection of the second connecting portion 112 does not coincide with the projection of the protrusion 122 along the thickness direction of the current collector 12.

[0262] In some examples, when the first electrode 1 is in the unfolded state, along the direction from the first metal portion 1211 to the second metal portion 1212, a portion of the second connecting portion 112 covers the protrusion 122, and another portion is located on the side of the protrusion 122 away from the active material layer 13.

[0263] By adopting the technical solution of this embodiment, at least a portion of the second connecting portion 112 is located on the side of the protrusion 122 facing away from the active material layer 13 along the first direction, which is equivalent to reducing the size of the protrusion 122 in the first direction, reducing space occupation, reducing the risk of interference between the first electrode 1 and the outer casing 20 (e.g., end cap 201, etc.), and improving the energy density of the battery cell 100.

[0264] In some embodiments, as shown in Figures 11-14, along the direction from the first metal portion 1211 to the second metal portion 1212, the side of the second connecting portion 112 away from the active material layer 13 does not protrude from the side of the protrusion 122 away from the active material layer 13.

[0265] It is understood that the second connecting portion 112 covers the surface of the protrusion 122. In the direction from the first metal portion 1211 to the second metal portion 1212, the side of the second connecting portion 112 away from the active material layer 13 is flush with the side of the current collector 12 away from the active material layer 13. Alternatively, in the direction from the first metal portion 1211 to the second metal portion 1212, the side of the protrusion 122 away from the active material layer 13 protrudes from the side of the second connecting portion 112 away from the active material layer 13.

[0266] In some examples, along the thickness direction of the current collector 12, the projection of the second connecting portion 112 lies within the projection of the protrusion 122. For example, the first connecting sub-portion 1111 covers the second metal portion 1212, and both the second connecting sub-portion 1112 and the second connecting portion 112 cover the protrusion 122. Along the thickness direction of the current collector 12, the projections of the second connecting sub-portion 1112 and the second connecting portion 112 lie within the projection of the protrusion 122.

[0267] By adopting the technical solution of this embodiment, the second connecting part 112 and the protrusion 122 are stacked, and the second connecting part 112 and the protrusion 122 can be connected to the electrode lead 2011 at the same time. This is beneficial to improving the connection reliability between the first electrode 1 and the electrode lead 2011 and the overcurrent capacity between the first electrode 1 and the electrode lead 2011, and is beneficial to improving the fast charging performance of the battery cell 100.

[0268] In some embodiments, the size of the first solder mark 41 along the first direction is W2, wherein 2mm≤W2≤6mm.

[0269] Along the first direction, the dimension W2 of the first solder mark 41 can refer to the width of the first solder mark 41.

[0270] As an example, the value of W2 can be 2mm, 6mm, or any value between 2mm and 6mm. For example, the value of W2 can be, but is not limited to, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, and 6mm.

[0271] The design with W2 ≥ 2mm provides a larger welding area between the conductive component 11 and the current collector 12. On the one hand, this ensures stable welding of the conductive component 11 and the current collector 12 together. On the other hand, it provides a larger welding area between the conductive component 11 and the current collector 12, improving the current carrying capacity of the first electrode 1 and the fast charging capability of the battery cell 100. The design with W2 ≤ 6mm reduces the space occupied by the first solder mark 411 and the current collector 12, reduces the risk of interference between the first electrode 1 and the casing 20 (e.g., end cap 201), and improves the energy density of the battery cell 100. Therefore, it can balance the energy density and fast charging performance of the battery cell 100.

[0272] In some embodiments, 3mm≤W2≤5mm can better balance the energy density and fast charging performance of a single battery cell.

[0273] In some embodiments, the first solder mark 41 is spaced apart from the active material layer 13 along the first direction.

[0274] It is understandable that the first solder mark 41 is not in direct contact with the active material layer 13, and there is a gap between the first solder mark 41 and the active material layer 13.

[0275] By adopting the technical solution of this embodiment, when the conductive component 11 and the current collector 12 are welded, they will not be welded to the active material layer 13, reducing welding defects such as incomplete welding, which is conducive to improving welding quality, improving the connection reliability and overcurrent capacity between the conductive component 11 and the current collector 12, and improving the reliability of the battery cell 100 and its fast charging capability.

[0276] In some embodiments, referring to FIG9, the first connecting portion 111 is spaced apart from the active material layer 13 along the first direction.

[0277] It is understandable that the first connecting part 111 and the active material layer 13 are not in direct contact and there is a certain gap between them.

[0278] In some examples, the first electrode 1 is a positive electrode, and the first connection portion 111 does not contact the active material layer 13, which can reduce the risk of lithium plating and improve the reliability of the battery cell 100. In other examples, the first electrode 1 is a negative electrode, and the first connection portion 111 may or may not contact the active material layer 13.

[0279] By adopting the technical solution of this embodiment, the first connecting part 111 does not contact the active material layer 13, which can reduce the mutual influence between the two and improve the reliability of the battery cell 100.

[0280] In some embodiments, the distance between the first connecting portion 111 and the active material layer 13 is W3, wherein 0.3mm≤W3≤5mm.

[0281] As an example, the value of W3 can be 0.3mm, 5mm, or any value between 0.3mm and 5mm. For example, the value of W3 can be, but is not limited to, 0.3mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 2.8mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm.

[0282] The design with W3 ≥ 0.3mm allows for a certain gap between the first connecting part 111 and the active material layer 13, reducing their mutual influence and improving the reliability of the battery cell 100. The design with W3 ≤ 5mm results in a closer distance between the first connecting part 111 and the active material layer 13, leading to a compact structure of the first electrode 1, which helps reduce space waste and improves the energy density of the battery cell 100. Furthermore, with a fixed dimension of the current collector 12 along the first direction, a smaller distance between the first connecting part 111 and the active material layer 13 allows the current collector 12 to have more space to cover the active material layer 13, which is beneficial for improving the capacity and energy density of the battery cell 100. Therefore, both the energy density and reliability of the battery cell 100 can be considered.

[0283] In some embodiments, 0.5mm≤W3≤2.8mm can better balance the energy density and reliability of the battery cell 100.

[0284] In some embodiments, as shown in FIG15, the first electrode 1 includes a first insulating member 51, at least a portion of which is located between the first connecting portion 111 and the active material layer 13.

[0285] The first insulating element 51 can refer to an insulating component. The first insulating element 51 covers the surface of the second metal part 1212, and the first insulating element 51 and the active material layer 13 are distributed along a first direction. The first insulating element 51 can be, but is not limited to, an insulating coating, an insulating adhesive (e.g., hot melt adhesive), or an insulating tape. The material of the first insulating element 51 can be PP (Polypropylene), PET (Polyethylene Terephthalate), PI (Polyimide), etc.

[0286] A portion of the first insulating member 51 is located between the first connecting portion 111 and the active material layer 13, and another portion of the first insulating member 51 may extend between the first connecting portion 111 and the current collector 12; or, the entire first insulating member 51 is located between the first connecting portion 111 and the active material layer 13.

[0287] In some battery cells 100, the second connecting portion 112 is bent before being connected to the electrode lead-out portion 2011. During the bending of the second connecting portion 112, the second metal portion 1212 is also bent, which may cause cracks or other problems in the part of the second metal portion 1212 located between the first connecting portion 111 and the active material layer 13. The first insulating member 51 can cover the part of the second metal portion 1212 located between the first connecting portion 111 and the active material layer 13, and the first insulating member 51 can provide support for this part, thereby reducing the risk of cracks in this part. In addition, the first insulating member 51 covering the part of the second metal portion 1212 located between the first connecting portion 111 and the active material layer 13 can also achieve insulation of this part, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0288] In some embodiments, as shown in Figures 5 and 15, the electrode assembly 10 further includes a second electrode 2 with a polarity opposite to that of the first electrode 1. The second electrode 2 includes a main functional portion 21 and an electrode tab 22 arranged along a first direction. The end of the main functional portion 21 near the second metal portion 1212 has a first end face 211, and the electrode tab 22 extends outward from the first end face 211. Along the thickness direction of the current collector 12, the projection of the first end face 211 is located within the projection of the first insulating member 51.

[0289] The main functional part 21 may refer to the main structure of the second electrode 2, and the tab 22 may refer to the protruding structure extending from the end of the main functional part 21 near the second metal part 1212. The tab 22 is used to electrically connect with the electrode lead 2011. The conductive member 11 and the tab 22 are electrically connected to the electrode lead 2011 with different polarities to realize the charging and discharging of the battery cell 100.

[0290] In some examples, the main functional part 21 may refer to the part of the second electrode 2 covered with active material, and the tab part 22 may refer to the part of the second electrode 2 not covered with active material.

[0291] Of the two end faces of the main functional part 21 that are distributed opposite each other along the first direction, the end face closer to the second metal part 1212 forms the first end face 211.

[0292] By adopting the technical solution of this embodiment, the first end face 211 and the first insulating member 51 are disposed opposite to each other. The first insulating member 51 can block the burrs at the first end face 211, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0293] Please refer to Figures 16-19. In some embodiments, the first electrode 1 includes a second insulating element 52 that covers at least a portion of the first solder mark 41.

[0294] The second insulating element 52 can refer to an insulating component. The second insulating element 52 covers the surface of the conductive member 11 facing away from the current collector 12 and covers the first solder mark 41. The second insulating element 52 can cover the entire first solder mark 41 or a part of the first solder mark 41. The second insulating element 52 can be, but is not limited to, an insulating coating, insulating adhesive (e.g., hot melt adhesive), or insulating tape. The material of the second insulating element 52 can be PP (Polypropylene), PET (Polyethylene Terephthalate), PI (Polyimide), etc.

[0295] By adopting the technical solution of this embodiment, the second insulating component 52 covers the first solder mark 41, which can block burrs, metal debris and other components on the first solder mark 41, reduce the short circuit risk of the battery cell 100, and help improve the reliability of the battery cell 100.

[0296] In some embodiments, the first electrode 1 includes a first insulating member 51, at least a portion of which is located between the first connection portion 111 and the active material layer 13; along a first direction, one side of the second insulating member 52 covers the first solder mark 41, and the other side of the second insulating member 52 covers at least a portion of the area of ​​the portion of the first insulating member 51 located between the first connection portion 111 and the active material layer 13.

[0297] Along the thickness direction of the current collector 12, the projection of the first insulating member 51 coincides with the projection of the second insulating member 52.

[0298] The second insulating element 52 may cover a portion of the first insulating element 51 or the entire first insulating element 51.

[0299] In some examples, the second insulating member 52 can be fixed to the first insulating member 51 by adhesive or static adsorption. Of course, in other examples, the second insulating member 52 can also be fixed to the first insulating member 51 by other means.

[0300] By adopting the technical solution of this embodiment, the first insulating member 51 and the second insulating member 52 can achieve double-layer insulation, reduce the short-circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0301] In some embodiments, along a first direction, one side of the second insulating member 52 covers the first solder mark 41, and the other side of the second insulating member 52 covers the active material layer 13.

[0302] It is understood that, of the two sides of the second insulating member 52 that are distributed opposite each other along the first direction, one side covers the first solder mark 41 and the other side covers at least a portion of the active material layer 13. The second insulating member 52 may cover the end of the active material layer 13 facing the first connection portion 111 or it may cover the entire active material layer 13.

[0303] Along the first direction, the second insulating member 52 extends from the first solder mark 41 to the active material layer 13, such that the portions of the second metal portion 1212 and the first connecting portion 111 located between the first solder mark 41 and the active material layer 13 are covered by the second insulating member 52. The portion of the current collector 12 located between the first solder mark 41 and the active material layer 13 may or may not be covered by the first insulating member 51.

[0304] When the current collector 12 is not covered by the first insulating member 51, the active material layer 13 can occupy the position of the first insulating member 51, thereby increasing the coverage area of ​​the active material layer 13 of the first electrode 1, increasing the capacity of the active material of the first electrode 1, and increasing the capacity and energy density of the battery cell 100.

[0305] In some examples, the portion of the second metal portion 1212 located between the first solder mark 41 and the active material layer 13 may be covered by the first insulating member 51, and the second insulating member 52 may completely cover the first insulating member 51.

[0306] In some examples, the portion of the second metal part 1212 located between the first solder mark 41 and the active material layer 13 may not cover the first insulating member 51. The second insulating member 52 extends from the first solder mark 41 to the active material layer 13, thus covering the portion of the second metal part 1212 located between the first connecting portion 111 and the active material layer 13, achieving insulation in this portion. This is beneficial to improving the reliability of the battery cell 100. In addition, the first insulating member 51 can be omitted, saving costs. At the same time, the active material layer 13 can be used to cover the original position of the first insulating member 51, thus increasing the coverage area of ​​the active material layer 13 on the second metal part 1212, which is beneficial to improving the energy density of the battery cell 100.

[0307] By adopting the technical solution of this embodiment, the second insulating member 52 extends from the first solder mark 41 to the active material layer 13. The second insulating member 52 has a wide coverage area and good insulation effect, which is beneficial to improving the reliability of the battery cell 100. The second insulating member 52 can cover the end of the active material layer 13 near the second metal part 1212, which can block burrs on the active material layer 13 near the second metal part 1212, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0308] In some embodiments, along the first direction, the size of the portion of the second insulating member 52 covering the active material layer 13 is W4, wherein 0.2mm≤W4≤1mm, and optionally, 0.3mm≤W4≤0.8mm.

[0309] As an example, the value of W4 can be 0.2mm, 1mm, or any value between 0.2mm and 1mm. For example, the value of W4 can be, but is not limited to, 0.2mm, 0.25mm, 0.3mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm.

[0310] With a W4 ≥ 0.2 mm design, the second insulating member 52 can cover a portion of the active material layer 13. The second insulating member 52 can insulate the portion of the second metal part 1212 located between the conductive member 11 and the active material layer 13, which is beneficial to improving the insulation effect of the first electrode 1 and improving the reliability of the battery cell 100. With a W4 ≤ 1 mm design, the space occupied by the second insulating member 52 is reduced, and the energy density of the battery cell 100 is increased. Therefore, the reliability and energy density of the battery cell 100 can be balanced.

[0311] In some embodiments, 0.3mm≤W4≤0.8mm can better balance the reliability and energy density of the battery cell 100.

[0312] In some embodiments, referring to FIG5, the electrode assembly 10 further includes a second electrode 2 with a polarity opposite to that of the first electrode 1. The second electrode 2 includes a main functional portion 21 and an electrode tab 22 arranged along a first direction. The end of the main functional portion 21 near the second metal portion 1212 has a first end face 211, and the electrode tab 22 extends outward from the first end face 211. Along the thickness direction of the current collector 12, the projection of the first end face 211 is located within the projection of the second insulating member 52.

[0313] By adopting the technical solution of this embodiment, the first end face 211 and the second insulating member 52 are disposed opposite to each other. The second insulating member 52 can block the burrs at the first end face 211, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0314] In some embodiments, referring to FIG17, the number of conductive members 11 is n1, the thickness of the first connecting portion 111 is T1, the number of second insulating members 52 is n2, the thickness of the second insulating member 52 is T2; the thickness of the second metal portion 1212 is T3, the maximum total thickness of the first electrode 1 at the active material layer 13 is T4, n1*T1+n2*T2+T3≤T4; n1 and n2 are positive integers.

[0315] The number of conductive components 11 can be one or two, that is, n1 can be 1 or 2, and of course the number of conductive components 11 can also be greater than 2.

[0316] The number of the second insulating element 52 is one or two, that is, n2 can be 1 or 2, and of course the number of the second insulating element 52 can also be greater than 2.

[0317] When n1 = 1, a conductive member 11 is welded to one side of the second metal part 1212, and a conductive member 11 is not welded to the other side of the second metal part 1212. At this time, n2 = 1, and the second insulating member 52 covers the first solder mark 41 located on one side of the second metal part 1212.

[0318] When n1 = 2, conductive members 11 are welded to both opposite sides of the second metal part 1212. At this time, n2 = 2, and two second insulating members 52 cover the first solder marks 41 located on both sides of the second metal part 1212.

[0319] The maximum total thickness T4 of the first electrode 1 at the active material layer 13 can refer to the thickness of the first electrode 1 at the second active material portion 132. There can be one active material layer 13 covering one side of the first metal portion 1211. In this case, the maximum total thickness T4 of the first electrode 1 at the active material layer 13 is equal to the thickness of the first metal portion 1211 plus the thickness t1 of the second active material portion 132. Alternatively, there can be two active material layers 13 covering opposite sides of the first metal portion 1211. In this case, the maximum total thickness T4 of the first electrode 1 at the active material layer 13 is equal to the thickness of the first metal portion 1211 plus the thickness t1 of both second active material portions 132. If other conductive structures are provided between the active material layer 13 and the current collector 12, for example, the conductive structure is made of a mixture of a conductive agent and an adhesive. The adhesive bonds the active material layer 13 to the current collector 12, while the conductive agent is responsible for conducting electrons. The conductive agent can be carbon black, graphite, etc., and the binder can be polyvinylidene fluoride, etc. The maximum total thickness T4 of the first electrode 1 at the active material layer 13 also needs to include the thickness of these conductive structures.

[0320] n1*T1+n2*T2+T3 can represent the thickness of the first electrode 1 where the current collector 12 does not cover the active material layer 13, that is, the edge thickness of the first electrode 1. Since n1*T1+n2*T2+T3≤T4, the edge thickness of the first electrode 1 is less than or equal to the maximum total thickness T4 of the first electrode 1 at the active material layer 13. This reduces the problem of bulging edges on the electrode assembly 10 during the winding process of the electrode assembly 10.

[0321] In some embodiments, the second insulating member 52 has a dimension of W5 along the first direction, wherein 3mm≤W5≤9mm, and optionally 4.5mm≤W5≤6.5mm.

[0322] Along the first direction, the dimension W5 of the second insulating member 52 can refer to the dimension of the second insulating member 52 along the first direction when it is attached to the first solder mark 41, or it can refer to the width of the second insulating member 52 in the unfolded state.

[0323] As an example, the value of W5 can be 3mm, 9mm, or any value between 3mm and 9mm. For example, the value of W5 can be, but is not limited to, 3mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, and 9mm.

[0324] With a W5 ≥ 3mm design, the second insulating component 52 can better cover the first solder mark 41, blocking burrs, metal debris, etc. on the first solder mark 41, reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100. With a W5 ≤ 9mm design, the space occupied by the second insulating component 52 is reduced, and the energy density of the battery cell 100 is increased. Therefore, the reliability and energy density of the battery cell 100 can be balanced.

[0325] In some embodiments, 4.5mm≤W5≤6.5mm can better balance the reliability and energy density of the battery cell 100.

[0326] In some embodiments, there are two conductive members 11, and the first connecting portions 111 of the two conductive members 11 are respectively welded to the two opposite surfaces of the current collector 12 along the thickness direction to form two first solder marks 41; there are two active material layers 13, and the two active material layers 13 respectively cover the two opposite surfaces of the first metal portion 1211 along the thickness direction of the current collector 12.

[0327] By adopting the technical solution of this embodiment, the active material layer 13 is covered on both opposite sides of the current collector 12, which can increase the capacity of the active material on the first electrode 1, and is beneficial to improving the capacity and energy density of the battery cell 100; two conductive members 11 are welded on both opposite sides of the second metal part 1212, so that electrons can flow to the electrode lead-out part 2011 through the two conductive members 11, which can realize parallel current splitting, reduce the flow resistance of electrons, and reduce the heat generation at the electrode tab of the first electrode 1.

[0328] Referring to Figures 16-18, in some embodiments, the first electrode 1 includes two second insulating members 52, which respectively cover two first solder marks 41. In the direction from the first metal portion 1211 to the second metal portion 1212, the portion of the second insulating member 52 protruding from the first connecting portion 111 forms a blocking portion 521. In the second direction, the blocking portion 521 is located on one side of the second connecting portion 112, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 12.

[0329] The blocking portion 521 may refer to the portion of the second insulating member 52 that protrudes from the first connecting portion 111 on the side away from the active material layer 13, and the blocking portion 521 is located on the side of the second connecting portion 112 along the second direction. In some examples, the portion of the second insulating member 52 that protrudes from the edge of the first connecting portion 1111 away from the active material layer 13 and is located on the side of the second connecting portion 112 forms the blocking portion 521.

[0330] In some examples, the projection of the blocking portion 521 does not coincide with the projection of the conductive member 11 along the thickness direction of the current collector 12.

[0331] During the manufacturing process of the first electrode 1, the edge of the first connecting portion 111 away from the active material layer 13 of the conductive component 11 is die-cut. The edge of the first connecting portion 111 away from the active material layer 13 may generate burrs, metal debris, and other components. In the use of the first electrode 1, the edge of the first connecting portion 111 away from the active material layer 13 is also prone to generating metal debris when subjected to external forces, which increases the short circuit risk of the battery cell 100. The blocking portion 521 can block the burrs, metal debris, and other components of the edge of the first connecting portion 111 away from the active material layer 13, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0332] In some embodiments, the blocking portions 521 of the two second insulating members 52 are attached to each other.

[0333] Along the thickness direction of the current collector 12, two second insulating members 52 are located on opposite sides of the first electrode 1. Along the second direction, the blocking portions 521 of the two second insulating members 52 are offset from the second connecting portion 112, so that the blocking portions 521 of the two second insulating members 52 can be directly attached. The blocking portions 521 of the two second insulating members 52 can be attached by means of, but not limited to, bonding or static adsorption.

[0334] By adopting the technical solution of this embodiment, after the blocking portions 521 of the two second insulating members 52 are attached, the burrs, metal debris and other components on the edge of the first connecting portion 111 can be wrapped, reducing the risk of metal debris falling off, reducing the short circuit risk of the battery cell 100, and improving the reliability of the battery cell 100.

[0335] In some embodiments, the second connection portions 112 of the two conductive members 11 are welded together to form a second solder mark 42.

[0336] In some examples, along the direction from the first metal portion 1211 to the second metal portion 1212, the second connecting portion 112 has a portion protruding from the side of the protrusion 122 away from the active material layer 13, so that the second connecting portions 112 of the two conductive members 11 can be directly brought close to each other and welded together, and the weld mark left is the second solder mark 42. The second connecting portions 112 of the two conductive members 11 can be welded by ultrasonic welding, laser welding, or other methods.

[0337] By adopting the technical solution of this embodiment, the second connecting portions 112 of the two conductive components 11 are welded together to form a whole, which can be easily connected to the electrode lead-out portion 2011.

[0338] In some embodiments, the first solder mark 41 and the second solder mark 42 are directly connected.

[0339] The first solder mark 41 and the second solder mark 42 form a single solder mark. For example, the edges of the two conductive members 11 and the current collector 12 are obtained by a single roll welding to obtain the first solder mark 41 and the second solder mark 42.

[0340] By adopting the technical solution of this embodiment, the first solder mark 41 and the second solder mark 42 can be obtained by welding in one step, which can save the manufacturing process of the first electrode 1, improve the production efficiency of the first electrode 1, and reduce the manufacturing cost of the first electrode 1. The first solder mark 41 and the second solder mark 42 are close to each other, which can reduce space waste, reduce the risk of interference between the conductive component 11 and the outer casing 20 (e.g., end cap 201), and improve the reliability and energy density of the battery cell 100.

[0341] In some embodiments, the first electrode 1 includes a second insulating member 52 that covers at least a portion of the second solder mark 42.

[0342] The second insulating element 52 may cover a portion of the second solder mark 42, or the second insulating element 52 may cover the entire second solder mark 42.

[0343] By adopting the technical solution of this embodiment, the second insulating member 52 can cover the second solder mark 42, which can block the sharp protrusions, metal debris and other components on the second solder mark 42, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0344] In some embodiments, the current collector 12 is an aluminum current collector.

[0345] It is understandable that the first electrode 1 is a positive electrode, and the current collector 12 of the first electrode 1 is made of aluminum foil. The conductivity of aluminum foil is lower than that of copper foil (i.e., the negative current collector of the negative electrode). The current carrying capacity of aluminum foil is lower than that of copper foil. Therefore, the current carrying capacity at the tab of the first electrode 1 is an important factor limiting the improvement of the fast charging performance of the battery cell 100. In this application, the second metal part 1212 of the first electrode 1 is welded to the conductive member 11, which can effectively improve the current carrying capacity at the tab of the first electrode 1, thereby effectively improving the fast charging performance of the battery cell 100.

[0346] In some embodiments, the aluminum content of the aluminum current collector ranges from 99.00% to 99.7%.

[0347] The higher the aluminum content in the aluminum current collector, the higher the conductivity of the aluminum current collector, and the better the current carrying capacity of the first electrode 1.

[0348] As an example, the aluminum content of the aluminum current collector can be 99.00%, 99.7%, or any value between 99.00% and 99.7%; for example, the aluminum content of the aluminum current collector can be, but is not limited to, 99.00%, 99.05%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, or 99.7%.

[0349] By adopting the technical solution of this embodiment, the aluminum content of the aluminum current collector is set to be in the range of 99.00% to 99.7%, which makes the current collector 12 of the first electrode 1 have good conductivity and the first electrode 1 have good overcurrent capacity, which is beneficial to improving the fast charging performance of the battery cell 100.

[0350] In some embodiments, the current collector 12 is a copper current collector.

[0351] The first electrode 1 is a negative electrode. The current collector 12 of the first electrode 1 is made of copper foil. Copper foil has good conductivity. The second metal part 1212 of the first electrode 1 is welded to the conductive component 11, which can effectively improve the overcurrent capacity at the tab of the first electrode 1, thereby effectively improving the fast charging performance of the battery cell 100.

[0352] Referring to Figure 20, in some embodiments, at least a portion of the thickness t2 of the first metal portion 1211 is less than the thickness T3 of the second metal portion 1212.

[0353] For example, the first metal part 1211 and the second metal part 1212 are of equal thickness, the thickness of the first metal part 1211 is less than the thickness T3 of the second metal part 1212, and the first metal part 1211 and the second metal part 1212 form a stepped structure.

[0354] For example, the first metal part 1211 has a non-uniform thickness structure, and the second metal part 1212 has a uniform thickness structure. The first metal part 1211 is divided into a first part 12121 and a second part 12122. The first part 12121 is connected between the second part 12122 and the second metal part 1212. The thickness of the first part 12121 is greater than the thickness of the second part 12122. The thickness T3 of the second metal part 1212 is greater than the thickness of the second part 12122. The thickness T3 of the second metal part 1212 is greater than or equal to the thickness of the first part 12121. In the process, the first part 12121 and the second part 12122 can be directly connected, and the first part 12121 and the second part 12122 can also be connected through the third part 12123. Along the direction from the first metal part 1211 to the second metal part 1212, the thickness of the third part 12123 increases from the thickness of the second part 12122 to the thickness of the first part 12121. The third part 12123 can smoothly transition between the second part 12122 and the third part 12123, reducing stress concentration in the current collector 12 and improving the structural strength of the current collector 12.

[0355] By adopting the technical solution of this embodiment, the thickness t2 of at least a portion of the first metal part 1211 is less than the thickness T3 of the second metal part 1212. The thickness T3 of the second metal part 1212 is large, and the current carrying capacity of the second metal part 1212 is good, which is beneficial to improving the current carrying capacity of the first electrode 1 and improving the fast charging performance of the battery cell 100.

[0356] The following description is based on some specific embodiments.

[0357] Example 1

[0358] In this embodiment, referring to Figures 3-5, the battery cell 100 includes a housing 20 and an electrode assembly 10. The housing 20 includes an end cap 201 and a shell 202. The electrode assembly 10 is located inside the shell 202. The end cap 201 covers the opening of the shell 202 and has two electrode terminals. The electrode assembly 10 includes a first electrode 1, a second electrode 2, and a separator 3. The separator 3 is disposed between the first electrode 1 and the second electrode 2.

[0359] In this embodiment, referring to Figures 6-14, the first electrode 1 includes a conductive member 11, a current collector 12, and an active material layer 13. The current collector 12 is a pure metal current collector, which includes a main body 121 and a protrusion 122. The main body 121 includes a first metal part 1211 and a second metal part 1212 arranged and connected along a first direction, which is perpendicular to the thickness direction of the current collector 12. The active material layer 13 covers the opposite sides of the first metal part 1211, while the second metal part 1212 is not covered by the active material layer 13. The second metal part 1212 is connected between the protrusion 122 and the first metal part 1211.

[0360] In this embodiment, the conductive member 11 includes a first connecting portion 111 and a second connecting portion 112 connected to each other. The first connecting portion 111 includes a first connecting sub-portion 1111 and a second connecting sub-portion 1112. The second connecting sub-portion 1112 is connected between the first connecting sub-portion 1111 and the second connecting portion 112. The first connecting sub-portion 1111 is welded to the second metal portion 1212 to form a first solder mark 411. The second connecting sub-portion 1112 is welded to the protrusion 122 to form a second solder mark 412. The first solder mark 411 and the second solder mark 412 together form the first solder mark 41.

[0361] In this embodiment, the active material layer 13 includes a first active material portion 131 and a second active material portion 132 arranged and connected along a first direction. The first active material portion 131 is closer to the second metal portion 1212 than the second active material portion 132, and the thickness of the first active material portion 131 is less than the thickness t1 of the second active material portion 132.

[0362] Example 2

[0363] The difference between this embodiment and Embodiment 1 is that, as shown in FIG15, a first insulating member 51 is provided between the first connecting sub-part 1111 and the active material layer 13.

[0364] Example 3

[0365] The difference between this embodiment and Embodiment 1 is that, as shown in Figures 16-18, the first electrode 1 includes a second insulating member 52, one side of the second insulating member 52 covers the first solder mark 41, the other side of the second insulating member 52 covers the active material layer 13, and no first insulating member 51 is provided between the first connecting part 1111 and the active material layer 13.

[0366] Example 4

[0367] The difference between this embodiment and embodiment three is that, as shown in FIG19, a first insulating member 51 is provided between the first connecting sub-part 1111 and the active material layer 13, and a second insulating member 52 covers the first insulating member 51.

[0368] Example 5

[0369] The difference between this embodiment and Embodiment 1 is that, as shown in FIG20, the thickness t2 of at least a portion of the first metal part 1211 is less than the thickness T3 of the second metal part 1212.

[0370] In some embodiments, referring to FIG2, a battery device 1100 is provided, including a plurality of the above-described battery cells 100.

[0371] The battery device 1100 of this application embodiment adopts the above-mentioned battery cell 100. The battery cell 100 has good fast charging performance, which helps to reduce the charging waiting time of the battery device 1100, facilitates the use of the battery device 1100, and also helps to improve the applicability of the battery device 1100.

[0372] In some embodiments, referring to FIG1, an electrical device is provided, including the battery cell 100 or the battery device 1100 described above, wherein the battery cell 100 or the battery device 1100 is used to store or provide electrical energy.

[0373] The power device in this application embodiment uses the aforementioned battery cell 100 or battery device 1100. The battery cell 100 and battery device 1100 have good fast charging performance, which helps to reduce the charging waiting time of the power device, reduce the range anxiety of the power device, and make the power device more convenient and faster to use.

[0374] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0375] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, wherein, include: The outer casing is equipped with electrode leads; An electrode assembly, at least partially disposed within the housing, includes a first electrode plate, which includes a conductive member, a current collector, and an active material layer. The current collector is made of a metallic material, and the conductive member is electrically connected to the electrode lead-out portion. The current collector includes a main body, which includes a first metal part and a second metal part arranged and connected along a first direction, the first direction being perpendicular to the thickness direction of the current collector; at least a portion of the first metal part is covered with an active material layer, and the second metal part is not covered with the active material layer; The conductive component is electrically connected to the second metal part.

2. The battery cell according to claim 1, wherein: Along the second direction, the size of the first metal part is L1, and the size of the second metal part is L2, wherein 0.8≤L2 / L1≤1, and the second direction is perpendicular to the first direction and the thickness direction of the current collector.

3. The battery cell according to claim 2, wherein: L2 / L1 = 1.

4. The battery cell according to any one of claims 1 to 3, wherein: The conductive component includes a first connecting portion and at least one second connecting portion. The second connecting portion is electrically connected to the electrode lead-out portion. The first connecting portion is welded to the current collector to form a first solder mark. The first solder mark includes a first solder mark portion. The first connecting portion is welded to the surface of the second metal portion to form a first solder mark portion.

5. [Correction 30.04.2025 according to Rule 91] The battery cell according to claim 4, wherein: Along the second direction, the length of the first solder mark is L3, and the size of the second metal part is L2, wherein 0.8≤L3 / L2≤1, and the second direction is perpendicular to the first direction and the thickness direction of the current collector.

6. [Correction 30.04.2025 according to Rule 91] The battery cell according to claim 5, wherein: L3 / L2 = 1.

7. The battery cell according to any one of claims 4 to 6, wherein: Along the first direction, the size of the first solder mark is W1, wherein 1mm≤W1≤4mm, and optionally, 2mm≤W1≤3mm.

8. The battery cell according to any one of claims 4 to 7, wherein: The number of second connecting parts is multiple, and the multiple second connecting parts are spaced apart along a second direction. The multiple second connecting parts are electrically connected to the electrode lead-out part, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

9. The battery cell according to any one of claims 4 to 8, wherein: The current collector further includes at least one protrusion, and the second metal part is connected between the first metal part and the protrusion; along a second direction, the size of the protrusion is smaller than the size of the second metal part, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

10. The battery cell according to claim 9, wherein: The first solder mark includes a second solder mark portion, and the first connecting portion includes a first connecting sub-part and at least one second connecting sub-part, wherein the second connecting sub-part is connected between the first connecting sub-part and the second connecting portion; The first connecting part is welded to the second metal part to form the first solder mark, and the second connecting part is welded to the protrusion to form the second solder mark.

11. The battery cell according to claim 10, wherein: Along the second direction, the second solder mark extends from one side of the second connector to the other side of the second connector.

12. The battery cell according to claim 10 or 11, wherein: The first solder mark and the second solder mark are directly connected.

13. The battery cell according to any one of claims 10 to 12, wherein: The number of protrusions is multiple, the number of second connecting parts is multiple, and the number of second connecting subparts is multiple; Along the second direction, a plurality of protrusions are spaced apart, a plurality of second connecting sub-parts are spaced apart, and a plurality of second connecting parts are spaced apart; each second connecting sub-part is connected to each second connecting part in a one-to-one correspondence. The first connecting sub-parts are continuously arranged along the second direction, and a plurality of second connecting sub-parts are connected to the first connecting sub-parts. Each second connecting sub-part is welded to each of the protrusions in a one-to-one correspondence, and the plurality of second connecting sub-parts are electrically connected to the electrode lead-out portion.

14. The battery cell according to any one of claims 9 to 13, wherein: Along the first direction, at least a portion of the second connecting portion is located on the side of the protrusion away from the active material layer; or, along the direction from the first metal portion to the second metal portion, the side of the second connecting portion away from the active material layer does not protrude from the side of the current collector away from the active material layer.

15. The battery cell according to any one of claims 4 to 14, wherein: Along the first direction, the size of the first solder mark is W2. Wherein, 2mm≤W2≤6mm, and optionally, 3mm≤W2≤5mm.

16. The battery cell according to any one of claims 4 to 15, wherein: Along the first direction, the first solder mark is spaced apart from the active material layer.

17. The battery cell according to any one of claims 4 to 16, wherein: Along the first direction, the first connecting portion is spaced apart from the active material layer.

18. The battery cell according to claim 17, wherein: The distance between the first connecting part and the active material layer is W3, wherein 0.3mm≤W3≤5mm, and optionally 0.5mm≤W3≤2.8mm.

19. The battery cell according to claim 17 or 18, wherein: The first electrode includes a first insulating element, at least a portion of which is located between the first connection portion and the active material layer.

20. The battery cell according to claim 19, wherein: The electrode assembly further includes a second electrode with a polarity opposite to that of the first electrode. The second electrode includes a main functional part and an electrode tab arranged along the first direction. The end of the main functional part near the second metal part has a first end face, and the electrode tab extends outward from the first end face. Along the thickness direction of the current collector, the projection of the first end face lies within the projection of the first insulating element.

21. The battery cell according to any one of claims 4 to 20, wherein: The first electrode includes a second insulating element that covers at least a portion of the first solder mark.

22. The battery cell according to claim 21, wherein: The first electrode includes a first insulating member, at least a portion of which is located between the first connecting portion and the active material layer; Along the first direction, one side of the second insulating member covers the first solder mark, and the other side of the second insulating member covers at least a portion of the area of ​​the first insulating member located between the first connection portion and the active material layer.

23. The battery cell according to claim 21 or 22, wherein: Along the first direction, one side of the second insulating member covers the first solder mark, and the other side of the second insulating member covers the active material layer.

24. The battery cell according to claim 23, wherein: Along the first direction, the size of the portion of the second insulating member covering the active material layer is W4, wherein 0.2mm≤W4≤1mm, and optionally, 0.3mm≤W4≤0.8mm.

25. The battery cell according to any one of claims 21 to 24, wherein: The electrode assembly further includes a second electrode with a polarity opposite to that of the first electrode. The second electrode includes a main functional part and an electrode tab arranged along the first direction. The end of the main functional part near the second metal part has a first end face, and the electrode tab extends outward from the first end face. Along the thickness direction of the current collector, the projection of the first end face lies within the projection of the second insulating element.

26. The battery cell according to any one of claims 21 to 25, wherein: The number of conductive components is n1, the thickness of the first connecting part is T1, the number of second insulating components is n2, the thickness of the second insulating component is T2; the thickness of the second metal part is T3, the maximum total thickness of the first electrode at the active material layer is T4, n1*T1+n2*T2+T3≤T4; n1 and n2 are positive integers.

27. The battery cell according to any one of claims 21 to 26, wherein: Along the first direction, the size of the second insulating member is W5, wherein 3mm≤W5≤9mm, and optionally, 4.5mm≤W5≤6.5mm.

28. The battery cell according to any one of claims 4 to 27, wherein: The number of conductive components is two, and the first connecting portions of the two conductive components are respectively welded to the two opposite surfaces of the current collector along the thickness direction to form two first solder marks; the number of active material layers is two, and the two active material layers respectively cover the two opposite surfaces of the first metal part along the thickness direction of the current collector.

29. The battery cell according to claim 28, wherein: The first electrode includes two second insulating members, which respectively cover the two first solder marks. In the direction from the first metal portion to the second metal portion, the portion of the second insulating member protruding from the first connecting portion forms a blocking portion. In a second direction, the blocking portion is located on one side of the second connecting portion, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

30. The battery cell according to claim 29, wherein: Along the first direction, the blocking portions of the two second insulating members are attached to each other.

31. The battery cell according to any one of claims 28 to 30, wherein: The second connection portions of the two conductive components are welded together to form a second solder mark.

32. The battery cell according to claim 31, wherein: The first solder mark and the second solder mark are directly connected.

33. The battery cell according to claim 32, wherein: The first electrode includes a second insulating element that covers at least a portion of the second solder mark.

34. The battery cell according to any one of claims 1 to 33, wherein: The current collector is an aluminum current collector.

35. The battery cell according to claim 34, wherein: The aluminum content of the aluminum current collector ranges from 99.00% to 99.7%.

36. The battery cell according to any one of claims 1 to 35, wherein: The current collector is a copper current collector.

37. The battery cell according to any one of claims 1 to 36, wherein: The active material layer includes a first active material portion and a second active material portion arranged along the first direction. The first active material portion is connected to the end of the second active material portion near the second metal portion, and the thickness of the first active material portion is less than the thickness of the second active material portion.

38. The battery cell according to any one of claims 1 to 37, wherein: At least a portion of the thickness of the first metal portion is less than the thickness of the second metal portion.

39. A battery device, wherein: It includes multiple battery cells according to any one of claims 1 to 38.

40. An electrical device, wherein: Includes a battery cell according to any one of claims 1 to 38 or a battery device according to claim 39, wherein the battery cell or the battery device is used to store or provide electrical energy.

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