Battery cell and method for manufacturing the same, battery device, and electric device

Abstract

This disclosure relates to a battery cell and its manufacturing method, a battery device, and an electrical device. The battery cell includes an electrode assembly, which includes a main body and a tab extending from the main body along a first direction. The tab includes a convergence area and a bending area located on the side of the convergence area away from the main body. The bending area includes a bending portion, a connecting portion, and an overlapping portion. The free end of the bending area is folded towards the main body to form the bending portion. The connecting portion is located between the bending area and the convergence area. The overlapping portion is located on the side of the bending portion away from the connecting portion and is fixedly connected to the connecting portion. The connecting portion has a first solder group spaced apart from the edge of the tab in a second direction, intersecting the first direction. The overlapping portion has a second solder group spaced apart from the edge of the tab in the second direction. The battery cell of this disclosure can improve the reliability of the tab.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, and in particular to a battery cell and its manufacturing method, a battery device and an electrical device. Background Technology

[0002] The tabs are the core current collector components of a power battery, playing a crucial role in current flow control and current shunting. Typically, the multi-layer tabs of a power battery are first connected to the adapter plate using ultrasonic welding, and then the adapter plate is connected to the top cover using laser welding, thus achieving an effective connection between the tabs and the top cover.

[0003] To improve energy density, the foil thickness of power batteries is typically selected from 5 to 20 μm. However, due to the thinness of the foil, during the manufacturing process, the surface foil is often subjected to high-frequency friction from the welding head during ultrasonic welding of the tabs and adapters. This often causes cracking of single or multiple layers of foil, reducing the number of tab layers capable of carrying current. Consequently, the current carrying capacity of the power battery's tabs is weakened, ultimately affecting the reliability of the battery. Summary of the Invention

[0004] In a first aspect of this disclosure, a battery cell is provided, including an electrode assembly. The electrode assembly includes a main body and a tab extending from the main body along a first direction. The tab includes a convergence area and a bending area located on the side of the convergence area away from the main body. The bending area includes a bending portion, a connecting portion, and an overlapping portion. The free end of the bending area is folded toward the main body to form the bending portion. The connecting portion is located between the bending portion and the convergence area. The overlapping portion is located on the side of the bending portion away from the connecting portion and is fixedly connected to the connecting portion. The connecting portion has a first solder group, which is spaced apart from the edge of the tab in a second direction, and the second direction intersects the first direction. The overlapping portion has a second solder group, which is spaced apart from the edge of the tab in the second direction.

[0005] The battery cell of this disclosure, by folding the foil and providing a first solder group and a second solder group at the connecting portion and the overlapping portion respectively, can make the first solder group and the second solder group spaced apart along the length direction of the foil, reducing the space occupied by the tab in the first direction; the first solder group and the second solder group are spaced apart from the edge of the foil along the second direction, which can prevent the foil from cracking continuously along the second direction. Even if the foil at the edge of an individual solder is cracked, the foil nearby can still play an effective current-carrying role, which can improve the cracking compatibility of the foil, improve the reliability of the tab, and thus ensure the reliability of the battery cell.

[0006] In some embodiments, the first solder group and the second solder group are spaced apart along a first direction; and / or the first solder group and the second solder group are spaced apart along a second direction.

[0007] In this embodiment, by arranging two solder pads at intervals along a first direction and / or along a second direction, the solder pads can be staggered in space, avoiding all solder pad edges from overlapping in space. This improves the overcurrent reliability of the tab while reducing the thickness of the tab along a third direction and reducing the space occupied by the tab.

[0008] In some embodiments, the free end of the electrode tab is at a different distance from the first solder group to form a misalignment area, and the bent portion is located in the misalignment area.

[0009] In this embodiment, the multilayer foil is gathered on one side to form a misalignment area at the free end. The second solder group is located in the misalignment area at the end of the tab, which enables the reuse of redundant tabs that are misaligned in the thickness direction, thereby improving the utilization rate of the tabs. The overlapping part located in the misalignment area can also reduce the overall thickness of the bent tab, thereby improving the manufacturability of the power battery manufacturing process.

[0010] In some embodiments, when the free end of the electrode tab is in an unfolded state, the distance between the first solder group and the second solder group along the first direction is D1 = πT + A, where T is the thickness of the connecting part, and 1mm ≤ A ≤ 4mm.

[0011] In this embodiment, by making the interval distance D1 1 to 4 mm larger than the length of the semicircle arc, it is possible to better ensure that the second soldering group can be spatially staggered with the edge of the first soldering group when the foil is folded; at the same time, it can improve the utilization rate of the length and width of the electrode tab and reduce the production cost of the battery cell.

[0012] In some embodiments, the value of T ranges from 0.8 to 1.2 mm.

[0013] In this embodiment, by further limiting the range of the interval distance, it is possible to better ensure that the second soldering group can be spatially staggered with the edge of the first soldering group when the foil is folded.

[0014] In some embodiments, the first solder group includes a first solder segment, the second solder group includes a second solder segment, and both the first and second solder segments extend along a second direction.

[0015] The length of the first solder joint along the first direction is a first preset length W1, where W1 = B * T, 1 ≤ B ≤ 10, and T is the thickness of the connection. The length of the first solder joint along the second direction is a third preset length L1, where L1 = C * T, 1 ≤ C ≤ 20; and / or

[0016] The length of the second soldering segment along the first direction is the second preset length W2, where W2 = D * T, 1 ≤ D ≤ 10, and T is the thickness of the connection. The length of the second soldering segment along the second direction is the fourth preset length L2, where L2 = E * T, 1 ≤ E ≤ 20.

[0017] In this embodiment, each of the two solder stamp groups includes a solder stamp segment extending along the second direction, which can reduce the pre-soldering processing cost of the electrode tab. By setting the value range of the solder stamp segment along the first and second directions according to the cumulative thickness of the foil, the length and width of the solder stamp segment are appropriate. It is neither too long or too wide, which would affect the crack compatibility of the foil and increase the size of the electrode tab, nor too short or too narrow, which would affect the pre-soldering quality or cause excessive stress concentration at the edge of the solder stamp, thereby aggravating the cracking of the electrode tab.

[0018] In some embodiments, the value of T ranges from 0.8 to 1.2 mm.

[0019] In this embodiment, by setting the range of T, the range of the soldering segment along the first and second directions can be further limited, so that the length and width of the soldering segment are appropriate. It will not be too long or too wide, which will affect the cracking compatibility of the foil and increase the size of the tab. Nor will it be too short or too narrow, which will affect the pre-welding quality or cause the stress at the edge of the soldering to be too concentrated, thereby aggravating the cracking of the tab.

[0020] In some embodiments, the first solder group includes a first solder segment, the second solder group includes a second solder segment, both the first solder segment and the second solder segment extend along a second direction, the length of the first solder segment along the second direction is a third preset length L1, the length of the second solder segment along the second direction is a fourth preset length L2, and the fourth preset length L2 is greater than the third preset length L1.

[0021] In this embodiment, by setting the fourth preset length L2 to be greater than the third preset length L1, the length of the second soldering segment closer to the free side of the foil can be made longer, thereby avoiding loosening of the free side of the foil, optimizing the pre-soldering effect, and reducing the pre-soldering processing cost of the electrode tab.

[0022] In some embodiments, the distances between the second soldering segment and the two sides of the electrode tab along the second direction are a first preset distance D2 and a second preset distance D3, respectively, where the first preset distance D2 is equal to the second preset distance D3.

[0023] In this embodiment, by setting the first preset distance D2 on both sides of the second soldering segment along the second direction to be equal to the second preset distance D3, the second soldering segment is positioned in the center of the foil along the second direction, which can improve the reliability of the pre-soldering of the tab.

[0024] In some embodiments, D2 = D3 = F, and 1mm ≤ F ≤ 5mm.

[0025] In this embodiment, by setting the value range of the second soldering segment on both sides of the second direction, a sufficient safety distance can be reserved to improve the crack compatibility of the foil and improve the reliability of the electrode tab.

[0026] In some embodiments, the battery cell further includes:

[0027] A conductive protective component is welded to the electrode tab, and the conductive protective component and the electrode tab are welded to form a third solder group. The third solder group is located along the first direction on the side of the first solder group and the second solder group closer to the main body. The conductive protective component is configured to protect the end of the electrode tab away from the main body.

[0028] In this embodiment, the battery cell protects the end of the tab away from the main body by setting a conductive protective component, which can prevent the exposed foil from cracking at the solder edge, improve the reliability of the tab, and extend the service life of the tab.

[0029] In some embodiments, the conductive protective element is configured to cover the overlapping portion, the bend portion, and at least a portion of the connecting portion.

[0030] In this embodiment, by covering the overlapping portion, the bent portion, and at least part of the connecting portion with the conductive protective component, the bent portion, which is more prone to cracking, can be adequately protected, while preventing the foil from being exposed due to cracking at the solder edges of the overlapping portion and the connecting portion.

[0031] In some embodiments, the conductive protective element includes a first part, a second part, and a third part. The first part and the second part are disposed at a distance from each other along a second direction, and the third part is connected between the first part and the second part. The first part, the tab, and the second part are connected by a third solder group.

[0032] In this embodiment, by setting a U-shaped conductive protective component, the reliability of the protection of the electrode tab can be improved and the service life of the electrode tab can be extended.

[0033] In some embodiments, the first solder group includes a first solder segment extending along a second direction, the length of the first solder segment along the first direction is a first preset length W1, and the contact length between the conductive protective member and the electrode tab along the first direction is a fifth preset length W3, the fifth preset length W3 = G * W1, 2 ≤ G ≤ 5.

[0034] In this embodiment, by setting the contact length between the conductive protective component and the electrode tab along the first direction, the conductive protective component can fully cover the end of the electrode tab away from the main body, thereby improving the reliability of the welding between the conductive protective component and the foil.

[0035] In some embodiments, the first preset length W1 = H, where 4mm ≤ H ≤ 8mm.

[0036] In this embodiment, by setting the range of the first preset length W1 and further setting the range of the fifth preset length W3, the conductive protective component can fully cover the end of the electrode tab that is away from the main body, thereby improving the reliability of the welding between the conductive protective component and the foil.

[0037] In one aspect of this disclosure, a method for manufacturing a battery cell based on the aforementioned method is provided, comprising:

[0038] With the free end of the tab in an unfolded state, the connecting part is welded to form a first weld mark group on the connecting part, and the overlapping part is welded to form a second weld mark group on the overlapping part.

[0039] Fold the free end of the tab toward the main body to form a bent section;

[0040] This secures the overlapping and connecting parts together.

[0041] In the manufacturing method of this embodiment, by welding the first solder group and the second solder group to the connecting part and the overlapping part respectively, and then folding the tab, the first solder group and the second solder group can be spaced apart along the length direction of the foil, reducing the space occupied by the tab in the first direction; the first solder group and the second solder group are spaced apart from the edge of the foil along the second direction, which can prevent the foil from cracking continuously along the second direction. Even if the foil at the edge of an individual solder group cracks, the foil nearby can still play an effective current-carrying role, which can improve the cracking compatibility of the foil, improve the reliability of the tab, and thus improve the reliability of the battery cell.

[0042] In some embodiments, when the free end of the electrode tab is folded toward the main body to form a bent portion, the first solder group and the second solder group are spaced apart along a first direction; and / or

[0043] The first and second solder groups are spaced apart along the second direction.

[0044] In this embodiment, by arranging the two solder pads at intervals along the first direction and / or along the second direction, the solder pads can be staggered in space, avoiding all solder pad edges from overlapping in space. This improves the overcurrent reliability of the tab while reducing the thickness of the tab along the third direction and reducing the space occupied by the tab.

[0045] In some embodiments, the step of fixing the overlapping portion and the connecting portion together includes:

[0046] Welding is performed on the overlapping and connecting parts.

[0047] In this embodiment, by welding the overlapping part and the connecting part to achieve a fixed connection between the overlapping part and the connecting part, it is possible to prevent the overlapping part and the connecting part from separating and improve the reliability of the electrode lug.

[0048] In some embodiments, the free end of the electrode tab is at a different distance from the first solder group to form a misalignment area, and folding the free end of the electrode tab toward the direction closer to the main body to form a bent portion includes:

[0049] This ensures that the bent portion is located in the misalignment zone.

[0050] In this embodiment, by placing the bent portion in the misalignment area, the redundant tabs that are misaligned in the thickness direction can be reused, thereby improving the utilization rate of the tabs.

[0051] In some embodiments, the step of fixing the overlapping portion and the connecting portion together includes:

[0052] The overlapping portions, bends, and at least part of the connecting portions are covered by conductive protective components;

[0053] On the side of the first and second solder groups near the main body, the conductive protective component, the overlapping portion, and the connecting portion are welded to form a third solder group that fixes and connects the conductive protective component, the overlapping portion, and the connecting portion.

[0054] In this embodiment, by welding the conductive protective component to the tab to form a third solder group, the bending portion, which is more prone to cracking, can be adequately protected, while avoiding exposure of the foil due to cracking at the edges of the overlapping and connecting solder joints.

[0055] In one aspect of this disclosure, a battery device is provided, including the aforementioned battery cell.

[0056] The battery device using the battery cells described in the above embodiments has good reliability.

[0057] In one aspect of this disclosure, an electrical device is provided, including the aforementioned battery device.

[0058] The power supply device using the battery device described in the foregoing embodiments has good reliability. Attached Figure Description

[0059] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0060] Figure 1 This is a schematic diagram of the structure of some embodiments of the battery cell disclosed herein.

[0061] Figure 2 This is a schematic diagram of the electrode tabs in an unfolded state, representing some embodiments of the battery cell disclosed herein.

[0062] Figure 3 for Figure 2 A schematic diagram of the structure with the middle ear in a folded state.

[0063] Figure 4 This is a top view of some embodiments of the battery cell of this disclosure with the tabs in an extended state.

[0064] Figure 5 for Figure 4 A partial structural dimension diagram.

[0065] Figure 6 The following is a top view of some other embodiments of the battery cell of this disclosure with the tabs in an extended state.

[0066] Figure 7 This is a schematic diagram showing the tabs of a battery cell in some other embodiments of the present disclosure in an unfolded state.

[0067] Figure 8 for Figure 7 A schematic diagram of the structure with the middle ear in a folded state.

[0068] Figure 9 for Figure 3 A schematic diagram of the structure with added conductive protection components.

[0069] Figure 10 for Figure 8 A schematic diagram of the structure with added conductive protection components.

[0070] Figure 11 for Figure 9 A partial structural dimension diagram.

[0071] Figure 12 This is a flowchart of the method for manufacturing a single battery cell disclosed herein.

[0072] Figure 13 This is a schematic diagram of the structure of some embodiments of the battery device disclosed herein.

[0073] Figure 14 This is a schematic diagram of the structure of some embodiments of the electrical device disclosed herein.

[0074] The labels in each figure represent:

[0075] 1. Main body; 11. Converging area; 12. Bending area; 100. Individual battery cell;

[0076] 2. Electrode tab; 20. Foil sheet; 201. Bending part; 202. Connecting part; 203. Overlapping part; 21. First solder stamp group; 211. First solder stamp segment; 22. Second solder stamp group; 222. Second solder stamp segment; 223. Third solder stamp segment; 224. Fourth solder stamp segment; 200. Electrode assembly;

[0077] 3. Conductive protective components; 30. Third soldering group; 31. First part; 32. Second part; 33. Third part; 300. Battery assembly; 302. Housing; 303. Housing cover;

[0078] 400. Vehicle; 401. Controller; 402. Motor;

[0079] x, first direction; y, second direction; z, third direction. Detailed Implementation

[0080] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure, that is, this disclosure is not limited to the described embodiments.

[0081] In the description of this disclosure, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0082] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this disclosure. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0083] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0084] In this disclosure, "multiple" means two or more (including two).

[0085] In this embodiment of the disclosure, the battery cell 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment does not limit it.

[0086] Figure 1 This is a schematic diagram of the structure of some embodiments of the battery cell disclosed herein. Figure 2 This is a schematic diagram of the electrode tab in an unfolded state according to some embodiments of the battery cell 100 of this disclosure. Figure 3 for Figure 2 A schematic diagram of the structure with the middle ear in a folded state. Figure 4 This is a top view of some embodiments of the battery cell 100 of this disclosure with the foil in an unfolded state.

[0087] refer to Figures 1-4 This disclosure provides a battery cell 100, which includes an electrode assembly 200. The electrode assembly 200 includes a main body portion 1 and a tab portion 2 extending from the main body portion 1 along a first direction x. The tab portion 2 includes a convergence area 11 and a bending area 12 located on the side of the convergence area 11 away from the main body portion 1. The bending area 12 includes a bending portion 201, a connecting portion 202, and an overlapping portion 203. The free end of the bending area 12 is folded toward the main body portion 1 to form the bending portion 201. The connecting portion 202 is located between the bending portion 201 and the convergence area 11. The overlapping portion 203 is located on the side of the bending portion 201 away from the connecting portion 202. The overlapping portion 203 and the connecting portion 202 are stacked along the thickness direction, and the relative positions of the overlapping portion 203 and the connecting portion 202 are fixed.

[0088] The tab 2 can be composed of multiple layers of foil 20, with its free end folded toward the main body 1 to form a bent portion 201. The bent portion 201 divides the multiple layers of foil 20 into a connecting portion 202 and an overlapping portion 203. The connecting portion 202 and the overlapping portion 203 are fixedly connected. The connecting portion 202 is connected between the bent portion 201 and the main body 1, and the overlapping portion 203 is connected to the side of the bent portion 201 away from the connecting portion 202. A first solder group 21 is provided on the connecting portion 202. The first solder group 21 is spaced apart from the edge of the tab 2 (foil 20) in the second direction y, and the second direction y intersects with the first direction x. A second solder group 22 is provided on the overlapping portion 203. The second solder group 22 is spaced apart from the edge of the tab 2 (foil 20) in the second direction y.

[0089] In related technologies, only one pre-welding is provided for the electrode tab, and the welding covers the entire width direction (second direction y). In the event of a breakage, it is easy for single or multiple layers of foil to crack, reducing the number of foil layers that can pass through and decreasing the reliability of the electrode tab. This embodiment uses two welding stamps, a first welding stamp group 21 and a second welding stamp group 22, spaced apart, and a safe distance is provided between the first welding stamp group 21 and the second welding stamp group 22 and the edge of the foil 20 along the width direction (second direction y), which can prevent the foil from cracking completely.

[0090] In this embodiment, by folding the foil 20 and providing the first solder group 21 and the second solder group 22 at the connecting portion 202 and the overlapping portion 203 respectively, the first solder group 21 and the second solder group 22 can be spaced apart along the length direction of the foil 20, reducing the space occupied by the tab portion 2 in the first direction x; the first solder group 21 and the second solder group 22 are spaced apart from the edge of the foil 20 along the second direction y, which can prevent the foil 20 from cracking continuously along the second direction y. Even if the foil 20 at individual solder edges cracks, the foil 20 near it can still play an effective current-carrying role, which can improve the crack compatibility of the foil 20, improve the reliability of the tab portion 2, and thus ensure the reliability of the battery cell 100.

[0091] The free end of the tab 2 is in an unfolded state, i.e., the multilayer foil 20 is in an unfolded state; the free end of the tab 2 is in a folded state, i.e., the multilayer foil 20 is in a folded state. The multilayer foil 20 of the tab 2 is bent from the unfolded state and then folded. In the unfolded state, all multilayer foils 20 extend away from the main body 1; in the folded state, the foil 20 located at the overlapping portion 203 extends towards the main body 1. Regardless of whether the tab 2 is in the unfolded or folded state, the first solder group 21 and the second solder group 22 are spaced apart along the length of the foil 20.

[0092] As an example, in the folded state, both the foil 20 located at the connecting portion 202 and the foil 20 located at the overlapping portion 203 extend along the first direction x, such that the length of the tab 2 extends along the first direction x, and the width of the tab 2 extends along the second direction y, which is perpendicular to the first direction x.

[0093] As an example, the first solder group 21 is spaced apart from the edge of the foil 20 in the second direction y, that is, the first solder group 21 is spaced apart from the side of the foil 20 in the width direction at least partially along the second direction y. For example, the first solder group 21 is spaced apart from the side of the foil 20 on only one side along the second direction y, or the first solder group 21 is spaced apart from both sides of the foil 20 along both sides of the second direction y.

[0094] As an example, the second solder group 22 is spaced apart from the edge of the foil 20 in the second direction y, that is, the second solder group 22 is spaced apart from the side of the foil 20 in the width direction at least partially along the second direction y. For example, the second solder group 22 is spaced apart from the side of the foil 20 on only one side along the second direction y, or the second solder group 22 is spaced apart from both sides of the foil 20 along both sides of the second direction y.

[0095] As an example, the welding method for the first solder group 21 and / or the second solder group 22 of the tab 2 can be ultrasonic welding, laser welding, resistance welding, arc welding or pressure welding, etc.

[0096] In some embodiments, the first solder group 21 may include one or more solder groups, and the second solder group 22 may also include one or more solder groups.

[0097] In some embodiments, in the unfolded state, one or more other solder pads may also be provided on the foil 20 at intervals along the first direction x.

[0098] As an example, the first solder group 21 can extend along the second direction y, can be set at an angle to the second direction y, and can also be bent; the second solder group 22 can extend along the second direction y, can be set at an angle to the second direction y, and can also be bent.

[0099] In some embodiments, the electrode assembly 200 may include a first electrode and a second electrode with opposite polarities, and a separator disposed between the first electrode and the second electrode. In some embodiments, the first electrode is a positive electrode and the second electrode is a negative electrode. In other embodiments, the first electrode is a negative electrode and the second electrode is a positive electrode. During the charging and discharging process of the battery cell 100, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode. The separator, disposed between the positive and negative electrode, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0100] In some embodiments, the positive electrode may include a positive current collector substrate and a positive active material layer disposed on at least one surface of the positive current collector substrate.

[0101] As an example, the positive electrode current collector substrate has two surfaces opposite each other in its own thickness direction, and the positive electrode active material layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector substrate.

[0102] As an example, the positive electrode current collector substrate can be a metal foil or a composite current collector. For example, as a metal foil, silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc., can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by applying a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) onto a polymer material base material (such as a polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc. base material).

[0103] In some embodiments, the negative electrode sheet may include a negative current collector substrate.

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

[0105] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector substrate.

[0106] As an example, the negative electrode current collector substrate has two surfaces opposite each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector substrate.

[0107] As an example, the negative electrode active material layer may employ a negative electrode active material layer known in the art for use in battery cell 100. As an example, the negative electrode active material layer may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this disclosure is not limited to these materials, and other conventional materials that can be used as battery negative electrode active material layers may also be used. These negative electrode active material layers may be used alone or in combination of two or more.

[0108] In some embodiments, the positive electrode current collector substrate can be made of aluminum, and the negative electrode current collector substrate can be made of copper.

[0109] In some embodiments, the separator is a separator membrane. This disclosure does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0110] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrode plates, or it can be located between the positive and negative electrode plates while being attached to the surface of the positive electrode plate and / or the surface of the negative electrode plate.

[0111] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0112] Figure 5 for Figure 4 A partial structural dimension diagram.

[0113] refer to Figure 5 In some embodiments, the sum of the thicknesses of the multilayer foils 20 is a cumulative thickness T, or in other words, the thickness of the connecting portion 202 is T. The first solder group 21 includes a first solder segment 211, and the second solder group 22 includes a second solder segment 222. Both the first solder segment 211 and the second solder segment 222 extend along the second direction y.

[0114] The length of the first solder joint 211 along the first direction x is a first preset length W1, where W1 = B*T, 1 ≤ B ≤ 10; the length of the first solder joint 211 along the second direction y is a third preset length L1, where L1 = C*T, 1 ≤ C ≤ 20; and / or

[0115] The length of the second soldering segment 222 along the first direction x is the second preset length W2, where W2 = D * T, 1 ≤ D ≤ 10. The length of the second soldering segment 222 along the second direction y is the fourth preset length L2, where L2 = E * T, 1 ≤ E ≤ 20.

[0116] In this embodiment, each of the two solder stamp groups includes a solder stamp segment extending along the second direction y, which can reduce the pre-soldering processing cost of the tab. By setting the range of values ​​of the solder stamp segment along the first direction x and the second direction y according to the cumulative thickness of the foil 20, the length and width of the solder stamp segment are appropriate. It is neither too long or too wide, which would affect the crack compatibility of the foil 20 and increase the size of the tab 2, nor too short or too narrow, which would affect the pre-soldering quality or cause the stress at the edge of the solder stamp to be too concentrated, thereby aggravating the cracking of the tab 2.

[0117] In some embodiments, the cumulative thickness T ranges from 0.8 to 1.2 mm.

[0118] In this embodiment, by setting the range of T, the range of the soldering segment along the first direction x and the second direction y can be further limited, so that the length and width of the soldering segment are appropriate. It will not be too long or too wide, which will affect the crack compatibility of the foil 20 and increase the size of the tab 2. Nor will it be too short or too narrow, which will affect the pre-welding quality or cause the stress at the edge of the soldering to be too concentrated, thereby aggravating the cracking of the tab 2.

[0119] As an example, the first preset length W1 ranges from 4 to 8 mm, the second preset length W2 ranges from 4 to 8 mm, the third preset length L1 ranges from 4 to 10 mm, and the fourth preset length L2 ranges from 4 to 20 mm.

[0120] In some embodiments, the length of the first solder mark segment 211 along the second direction y is a third preset length L1, and the length of the second solder mark segment 222 along the second direction y is a fourth preset length L2, wherein the fourth preset length L2 is greater than the third preset length L1.

[0121] In this embodiment, by setting the fourth preset length L2 to be greater than the third preset length L1, the length of the second soldering segment 222, which is closer to the free side of the foil, can be made longer, thereby avoiding loosening of the free side of the foil, optimizing the pre-soldering effect, and reducing the pre-soldering processing cost of the electrode tab.

[0122] In some embodiments, the distance between the second soldering segment 222 and the two sides of the foil 20 along the second direction y is a first preset distance D2 and a second preset distance D3, respectively, where the first preset distance D2 is equal to the second preset distance D3.

[0123] In this embodiment, by setting the first preset distance D2 on both sides of the second soldering segment 222 along the second direction y to be equal to the second preset distance D3, the second soldering segment 222 is positioned in the center of the foil 20 along the second direction y, which can improve the reliability of the pre-soldering of the tab 2.

[0124] In some embodiments, D2 = D3 = F, and 1mm ≤ F ≤ 5mm.

[0125] In this embodiment, by setting the value range of the second soldering segment 222 on both sides of the second direction y, a sufficient safety distance can be reserved to improve the crack compatibility of the foil 20 and improve the reliability of the tab 2.

[0126] Figure 6 This is a top view of some other embodiments of the battery cell 100 of this disclosure with the foil in an unfolded state.

[0127] refer to Figure 4 The first solder group 21 may include a first solder segment 211, and the second solder group 22 may include a second solder segment 222; Reference Figure 6 The first solder group 21 may include a first solder segment 211, and the second solder group 22 may include a third solder segment 223 and a fourth solder segment 224.

[0128] refer to Figures 4-6 In some embodiments, the first solder group 21 and the second solder group 22 are spaced apart along a first direction x; and / or the first solder group 21 and the second solder group 22 are spaced apart along a second direction y.

[0129] When the multilayer foil 20 is in a folded state, the first solder group 21 and the second solder group 22 are spaced apart along the first direction x, and / or the first solder group 21 and the second solder group 22 are spaced apart along the second direction y.

[0130] By setting the first solder mark group 21 and the second solder mark group 22 to be spaced apart along the first direction x, the overlap of the two solder mark groups can be avoided, which helps to reduce the space occupied by the electrode tab 2 in the third direction z, which is perpendicular to the first direction x and the second direction y.

[0131] refer to Figure 6 By setting the first solder group 21 and the second solder group 22 to be spaced apart along the second direction y, even if the first solder group 21 and the second solder group 22 overlap along the first direction x in the folded state, the overlap of the two solder groups can be avoided, which also helps to reduce the space occupied by the tab 2 in the third direction z.

[0132] In this embodiment, by setting two solder pads at intervals along the first direction x and / or along the second direction y, the solder pads can be staggered in space, avoiding all solder pad edges from overlapping in space. This improves the overcurrent reliability of the tab 2 while reducing the thickness of the tab 2 along the third direction z, thus reducing the space occupied by the tab 2.

[0133] As an example, when the first solder group 21 and the second solder group 22 are spaced apart along the second direction y, there can be various combinations. For example, both the first solder group 21 and the second solder group 22 may include a solder segment, but they are staggered along the second direction y; the first solder group 21 may include a solder segment, and the second solder group 22 may include two solder segments, with the two solder segments of the second solder group 22 located on both sides of the solder segment of the first solder group 21 along the second direction y in the folded state; or the first solder group 21 may include two solder segments, and the second solder group 22 may include a solder segment, with the two solder segments of the first solder group 21 located on both sides of the solder segment of the second solder group 22 along the second direction y in the folded state, and so on.

[0134] refer to Figure 4 and Figure 6 In some embodiments, the thickness of the multilayer foil 20 is the sum of the thicknesses T, or the thickness of the connecting portion 202 is T. When the free end of the foil 20 is in the unfolded state, the distance between the first solder group 21 and the second solder group 22 along the first direction x is D1 = πT + A, where 1mm ≤ A ≤ 4mm.

[0135] The tab portion 2 includes N layers of foil 20, each layer of foil 20 having a thickness of t, so the cumulative thickness T = nt. The spacing distance D1 is the distance between the inner edges of the first solder group 21 and the second solder group 22.

[0136] In this embodiment, by making the interval distance D1 1 to 4 mm larger than the length of the semicircle arc, it is possible to better ensure that the second soldering group 22 can be spatially staggered with the edge of the first soldering group 21 when the foil 20 is folded; at the same time, it can improve the utilization rate of the length and width of the tab 2 and reduce the production cost of the battery cell 100.

[0137] In some embodiments, the cumulative thickness T ranges from 0.8 to 1.2 mm.

[0138] In this embodiment, by further limiting the range of the interval distance, it is possible to better ensure that the second soldering group 22 can be spatially staggered with the edge of the first soldering group 21 when the foil 20 is folded.

[0139] As an example, the interval distance D1 ranges from 4 to 6 mm.

[0140] Figure 7 This is a schematic diagram of the foil in an unfolded state, representing some other embodiments of the battery cell 100 disclosed herein. Figure 8 for Figure 7 A schematic diagram of the structure of the foil sheet in a folded state.

[0141] refer to Figure 7 and Figure 8In some embodiments, the free ends of the multilayer foil 20 are at different distances from the first solder group 21 to form a misalignment area, and the bent portion 201 is located in the misalignment area.

[0142] The multilayer foil 20 is gathered toward the top or bottom foil. The free ends of the multilayer foil are at different distances from the first solder group 21 to form a misalignment area. The bent portion 201 is located in the misalignment area, so that the overlapping portion 203 of the misalignment area is connected to the connecting portion 202 of the misalignment area, which enables the reuse of the redundant tab portion 2 misaligned in the thickness direction.

[0143] In this embodiment, the multilayer foil 20 is folded up on one side to form a misalignment area at the free end. The second solder group 22 is located in the misalignment area at the end of the tab, which enables the reuse of the redundant tab 2 misaligned in the thickness direction, thereby improving the utilization rate of the tab 2. The overlapping portion 203 located in the misalignment area can also reduce the overall thickness of the bent tab 2, thereby improving the manufacturability of the power battery manufacturing process.

[0144] refer to Figure 2 and Figure 3 In contrast, the multilayer foil 20 is centered and gathered to form a misalignment area at the free end, the bent portion 201 is located in the non-misalignment area, and the second solder group 22 is located in the non-misalignment area.

[0145] Figure 9 for Figure 3 A schematic diagram of the structure with added conductive protection components. Figure 10 for Figure 8 A schematic diagram of the structure with added conductive protection components.

[0146] refer to Figure 9 and Figure 10 In some embodiments, the battery cell 100 further includes:

[0147] The conductive protective element 3 is welded to the foil 20, and the conductive protective element 3 and the foil 20 are welded to form a third solder group 30. The third solder group 30 is located on the side of the first solder group 21 and the second solder group 22 close to the main body 1 along the first direction x. The conductive protective element 3 is configured to protect the end of the electrode tab 2 away from the main body 1.

[0148] In this embodiment, the battery cell 100 protects the end of the tab 2 away from the main body 1 by providing a conductive protective element 3, which can prevent the foil 20 with cracked solder edges from being exposed, improve the reliability of the tab 2, and extend the service life of the tab 2.

[0149] As an example, the third solder joint between the conductive protective element 3 and the foil 20 can be achieved by ultrasonic welding or laser welding.

[0150] As an example, the conductive protective element 3 can be configured as a clip structure or a single piece structure, and the conductive protective element 3 can be made of metal.

[0151] In some embodiments, the conductive protective member 3 is configured to cover the overlapping portion 203, the bent portion 201, and at least a portion of the connecting portion 202.

[0152] In this embodiment, by covering the overlapping portion 203, the bent portion 201 and at least part of the connecting portion 202 with the conductive protective member 3, the bent portion 201, which is more prone to cracking, can be adequately protected, while preventing the foil 20 from being exposed due to cracking at the solder edges of the overlapping portion 203 and the connecting portion 202.

[0153] refer to Figure 9 and Figure 10 In some embodiments, the conductive protective element 3 includes a first part 31, a second part 32 and a third part 33. The first part 31 and the second part 32 are arranged at a relative interval along the second direction y. The third part 33 is connected between the first part 31 and the second part 32. The first part 31, the multilayer foil 20 and the second part 32 are connected by a third solder group 30.

[0154] In this embodiment, by providing a U-shaped conductive protective element 3, the reliability of the protection of the tab 2 can be improved and the service life of the tab 2 can be extended.

[0155] Figure 11 for Figure 9 A partial structural dimension diagram.

[0156] refer to Figure 5 and Figure 11 In some embodiments, the first solder group 21 includes a first solder segment 211 extending along the second direction y, the length of the first solder segment 211 along the first direction x is a first preset length W1, and the contact length between the conductive protective member 3 and the electrode tab 2 along the first direction x is a fifth preset length W3, the fifth preset length W3 = G*W1, 2≤G≤5.

[0157] In this embodiment, by setting the contact length between the conductive protective member 3 and the tab 2 along the first direction x, the conductive protective member 3 can fully cover the end of the tab 2 away from the main body 1, thereby improving the reliability of the welding between the conductive protective member 3 and the foil 20.

[0158] In some embodiments, the first preset length W1 = H, where 4mm ≤ H ≤ 8mm.

[0159] In this embodiment, by setting the range of the first preset length W1 and further setting the range of the fifth preset length W3, the conductive protective component 3 can fully cover the end of the electrode tab 2 away from the main body 1, thereby improving the reliability of the welding between the conductive protective component 3 and the foil 20.

[0160] As an example, the fifth preset length W3 ranges from 10 to 16 mm.

[0161] In some specific embodiments, such as Figure 10 As shown, the battery cell 100 includes a main body 1 and a tab 2 extending from the main body 1. The tab 2 extends along a first direction x and includes: a multilayer foil 20, a first solder group 21 provided in the connecting portion 202 and a second solder group 22 provided in the overlapping portion 203. The first solder group 21 and the second solder group 22 are spaced apart along the first direction x and spaced apart along the second direction y. The multilayer foil 20 is gathered toward the top or bottom layer. The free end of the multilayer foil 20 is at a different distance from the first solder group 21 to form a misalignment area. The bending portion 201 is located in the misalignment area.

[0162] In this embodiment, the battery cell 100 reduces the space occupied by the tab 2 in the first direction x by folding the foil 20 and providing a first solder group 21 and a second solder group 22 at the connecting portion 202 and the overlapping portion 203, respectively. The first solder group 21 and the second solder group 22 are spaced apart from the edge of the foil 20 along the second direction y, which can prevent the foil 20 from cracking continuously along the second direction y, improve the crack compatibility of the foil 20, and improve the reliability of the tab 2 and the battery cell 100. The first solder group 21 and the second solder group 22 are arranged at intervals with the edge of the foil 20 along the second direction y. The second solder group 22 can achieve spatial staggered arrangement of solder groups, avoid all solder edges overlapping in space, and reduce the thickness of the tab 2 along the third direction z; the second solder group 22 is located in the staggered area at the end of the tab, which can realize the reuse of the redundant tab 2 that is staggered in the thickness direction, and improve the utilization rate of the tab 2; the bending part 201 is located in the staggered area, which can also reduce the overall thickness of the bent tab 2; the first solder group 21 and the second solder group 22 extend along the second direction y, which can reduce the pre-welding processing cost of the tab.

[0163] Figure 12 This is a flowchart illustrating the method for manufacturing a battery cell 100 according to this disclosure. The various embodiments of the battery cell 100 described above can be manufactured using the battery cell 100 manufacturing method. Therefore, in one aspect of this disclosure, a method for manufacturing a battery cell 100 based on the above embodiments is provided, such as... Figure 12 As shown, it includes:

[0164] S01. With the free end of the tab 2 in an unfolded state, the connecting part 202 is welded to form a first solder mark group 21 on the connecting part 202, and the overlapping part 203 is welded to form a second solder mark group 22 on the overlapping part 203.

[0165] S02, Fold the free end of the tab 2 toward the main body 1 to form a bent part 201;

[0166] S03, fix the overlapping part 203 and the connecting part 202 together.

[0167] S01 to S03 are executed sequentially.

[0168] In the manufacturing method of this embodiment, by welding the first solder group 21 and the second solder group 22 to the connecting part 202 and the overlapping part 203 respectively, and then folding the tab 2, the first solder group 21 and the second solder group 22 can be spaced apart along the length direction of the foil 20, reducing the space occupied by the tab 2 in the first direction x; the first solder group 21 and the second solder group 22 are spaced apart from the edge of the foil 20 along the second direction y, which can prevent the foil 20 from cracking continuously along the second direction y. Even if the foil 20 at individual solder edges cracks, the foil 20 near it can still play an effective current-carrying role, which can improve the crack compatibility of the foil 20, improve the reliability of the tab 2, and thus improve the reliability of the battery cell 100.

[0169] In some embodiments, when the free end of the tab 2 is folded toward the main body 1 to form the bend 201, the first solder group 21 and the second solder group 22 are spaced apart along the first direction x; and / or the first solder group 21 and the second solder group 22 are spaced apart along the second direction y.

[0170] In this embodiment, by arranging the two solder pads at intervals along the first direction x and / or along the second direction y, the solder pads can be staggered in space, avoiding all solder pad edges from overlapping in space. This improves the overcurrent reliability of the tab 2 while reducing the thickness of the tab 2 along the third direction z, thus reducing the space occupied by the tab 2.

[0171] In some embodiments, the step of fixing the overlapping portion 203 and the connecting portion 202 together includes:

[0172] Weld the overlapping portion 203 and the connecting portion 202.

[0173] In this embodiment, by welding the overlapping portion 203 and the connecting portion 202 to achieve a fixed connection between the overlapping portion 203 and the connecting portion 202, the detachment of the overlapping portion 203 and the connecting portion 202 can be avoided, thereby improving the reliability of the tab portion 2.

[0174] In some embodiments, the free end of the tab 2 is at a different distance from the first solder group 21 to form a misalignment area, and folding the free end of the tab 2 toward the main body 1 to form a bent portion 201 includes:

[0175] The bent portion 201 is positioned in the misalignment zone.

[0176] In this embodiment, by placing the bent portion 201 in the misalignment area, the redundant tab portion 2 that is misaligned in the thickness direction can be reused, thereby improving the utilization rate of the tab portion 2.

[0177] In some embodiments, the step of fixing the overlapping portion 203 and the connecting portion 202 together includes:

[0178] The overlapping portion 203, the bent portion 201 and at least part of the connecting portion 202 are covered by the conductive protective element 3;

[0179] On the side of the first solder group 21 and the second solder group 22 near the main body 1, the conductive protective element 3, the overlapping part 203 and the connecting part 202 are welded to form a third solder group 30 that fixes and connects the conductive protective element 3, the overlapping part 203 and the connecting part 202.

[0180] In this embodiment, by welding the conductive protective member 3 to the tab portion 2 to form a third solder group 30, the more easily cracked bent portion 201 can be adequately protected, while avoiding exposure of the foil 20 with cracked edges of the overlapping portion 203 and the connecting portion 202 solder marks.

[0181] Figure 13 This is a schematic diagram of the structure of some embodiments of the battery device disclosed herein.

[0182] The various embodiments of the battery cell 100 described above can be used in various battery devices 300. Therefore, in one aspect of this disclosure, a battery device 300 is provided, including the battery cell 100 of any of the foregoing embodiments.

[0183] The battery device 300 using the battery cell 100 of the aforementioned embodiment has good reliability.

[0184] refer to Figure 13 In some embodiments, the battery device 300 includes a housing 302, a cover 303 covering the opening side of the housing 302, and one or more battery cells 100 disposed in the housing 302. For ease of display of the battery cells 100 inside the housing 302, Figure 13 The enclosure 302 and the cover 303 conceal a portion of the casing. The casing 302 and the cover 303 provide storage space for the battery cell 100 and offer functions such as cooling, sealing, and impact protection. They also prevent liquids or other foreign objects from adversely affecting the charging, discharging, or safety of the battery cell.

[0185] The box body 302 and the lid 303 can be in various shapes, such as cuboids or cylinders. The box body 302 can be a hollow structure open on one side, and the lid 303 can be a plate-like structure. When the lid 303 closes onto the open side of the box body 302, it forms an internal storage space. In another embodiment, the box body 302 is a hollow structure open on one side, and the lid 303 is also a hollow structure open on one side. When the open side of the lid 303 closes onto the open side of the box body 302, it forms an internal storage space.

[0186] Figure 13 The individual battery cells 100 are electrically connected, such as in series, parallel, or mixed connection, to achieve the required electrical performance parameters of the battery device 300. Mixed connection refers to a combination of series and parallel connections among multiple battery cells 100. Adjacent battery cells 100 can be electrically connected via busbars. Multiple battery cells 100 are arranged in rows; one or more rows of battery cells 100 can be arranged within the housing 302 as needed.

[0187] In some embodiments, the individual battery cells 100 of the battery device 300 may be arranged along at least one of the length and width directions of the housing 302. At least one row or column of battery cells 100 may be provided as needed. Alternatively, one or more layers of battery cells 100 may be provided along the height direction of the battery device 300 as required.

[0188] In some embodiments, multiple battery cells 100 may first be connected in series, parallel, or in a mixed manner to form a battery module, and then the multiple battery modules may be connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 302. In other embodiments, all battery cells 100 are directly connected in series, parallel, or in a mixed manner, and then the whole composed of all battery cells 100 is housed within the housing.

[0189] Figure 14 This is a schematic diagram of the structure of some embodiments of the electrical device disclosed herein.

[0190] The various embodiments of the battery device 300 described above can be used in various electrical devices. Therefore, in one aspect of this disclosure, an electrical device is provided that includes the battery device 300 of any of the foregoing embodiments.

[0191] The power supply device using the battery device 300 of the aforementioned embodiment has good reliability.

[0192] Electrical devices can include mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools, etc. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. This disclosure does not impose any particular limitations on the aforementioned electrical devices. Batteries can be used to power electrical devices such as vehicles, for example, to provide power for vehicle operation or driving.

[0193] For simplicity, we will use vehicle 400 as an example for explanation. Vehicle 400 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles or hybrid vehicles, etc. Battery device 300 can be installed at the bottom, front, or rear of vehicle 400.

[0194] The battery device 300 can be used to power the vehicle 400. For example, the battery device 300 can serve as the operating power source for the vehicle 400's electrical system, such as meeting the power requirements for starting, navigation, and operation of the vehicle 400. The battery device 300 can not only serve as the operating power source for the vehicle 400, but also as the driving power source, replacing or partially replacing fuel or natural gas to provide propulsion for the vehicle 400.

[0195] The vehicle 400 may also house an axle, wheels, a motor 402, and a controller 401. The controller 401 controls the power supply from the battery device 300 to the motor 402. For example, when the vehicle 400 uses the battery device 300 as its drive power source, the battery device 300 replaces or partially replaces fuel or natural gas to provide the motor 402 with the power required for constant speed and acceleration. The motor 402 drives the axle to rotate, thereby rotating the wheels.

[0196] The present disclosure provides a detailed description of a battery cell, its manufacturing method, battery assembly, and power consumption device. Specific embodiments have been used to illustrate the principles and implementation methods of the present disclosure. These embodiments are merely illustrative and are intended to aid in understanding the method and core concepts of the present disclosure. It should be noted that those skilled in the art can make various improvements and modifications to the present disclosure without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this disclosure.

Claims

1. A battery cell (100) comprising an electrode assembly (200), the electrode assembly (200) comprising a main body portion (1) and a tab portion (2) extending from the main body portion (1) along a first direction (x), wherein, The tab portion (2) includes a gathering area (11) and a bending area (12) located on the side of the gathering area (11) away from the main body portion (1). The bending area (12) includes a bending portion (201), a connecting portion (202), and an overlapping portion (203). The free end of the bending area (12) is folded toward the main body portion (1) to form the bending portion (201). The connecting portion (202) is located between the bending portion (201) and the gathering area (11). The overlapping portion (203) is located on the side of the bending portion (201) away from the connecting portion (202) and is fixedly connected to the connecting portion (202). The connecting portion (202) is provided with a first solder group (21), which is spaced apart from the edge of the tab portion (2) in the second direction (y), and the second direction (y) intersects the first direction (x); the overlapping portion (203) is provided with a second solder group (22), which is spaced apart from the edge of the tab portion (2) in the second direction (y).

2. The battery cell (100) according to claim 1, wherein, The first solder group (21) and the second solder group (22) are spaced apart along the first direction (x); and / or The first solder mark group (21) and the second solder mark group (22) are spaced apart along the second direction (y).

3. The battery cell (100) of claim 1, wherein, The free end of the tab (2) is at a different distance from the first solder group (21) to form a misalignment area, and the bent portion (201) is located in the misalignment area.

4. The battery cell (100) of claim 1, wherein, When the free end of the tab (2) is in the unfolded state, the distance between the first solder group (21) and the second solder group (22) along the first direction (x) is D1 = πT + A, where T is the thickness of the connecting part (202), and 1mm ≤ A ≤ 4mm.

5. The battery cell (100) according to claim 4, wherein, The value of T ranges from 0.8 to 1.2 mm.

6. The battery cell (100) of claim 1, wherein, The first solder group (21) includes a first solder segment (211), and the second solder group (22) includes a second solder segment (222). Both the first solder segment (211) and the second solder segment (222) extend along the second direction (y). The length of the first solder section (211) along the first direction (x) is a first preset length W1, where W1 = B * T, 1 ≤ B ≤ 10, and T is the thickness of the connecting part (202). The length of the first solder section (211) along the second direction (y) is a third preset length L1, where L1 = C * T, 1 ≤ C ≤ 20; and / or The length of the second soldering segment (222) along the first direction (x) is the second preset length W2, the second preset length W2 = D*T, 1≤D≤10, T is the thickness of the connecting part (202), and the length of the second soldering segment (222) along the second direction (y) is the fourth preset length L2, the fourth preset length L2 = E*T, 1≤E≤20.

7. The battery cell (100) according to claim 6, wherein The value of T ranges from 0.8 to 1.2 mm.

8. The battery cell (100) of claim 1, wherein, The first solder group (21) includes a first solder segment (211), and the second solder group (22) includes a second solder segment (222). Both the first solder segment (211) and the second solder segment (222) extend along the second direction (y). The length of the first solder segment (211) along the second direction (y) is a third preset length L1, and the length of the second solder segment (222) along the second direction (y) is a fourth preset length L2. The fourth preset length L2 is greater than the third preset length L1.

9. The battery cell (100) according to claim 8, wherein The distances between the second solder mark segment (222) along the second direction (y) and the two sides of the electrode tab (2) are a first preset distance D2 and a second preset distance D3, respectively, where the first preset distance D2 is equal to the second preset distance D3.

10. The battery cell (100) according to claim 9, wherein D2=D3=F, 1mm≤F≤5mm.

11. The battery cell (100) according to any one of claims 1 to 10, further comprising: A conductive protective element (3) is welded to the tab portion (2), and a third solder group (30) is formed between the conductive protective element (3) and the tab portion (2). The third solder group (30) is located along the first direction (x) on the side of the first solder group (21) and the second solder group (22) close to the main body portion (1). The conductive protective element (3) is configured to protect the end of the tab portion (2) away from the main body portion (1).

12. The battery cell (100) according to claim 11, wherein The conductive protective element (3) is configured to cover the overlapping portion (203), the bent portion (201), and at least a portion of the connecting portion (202).

13. The battery cell (100) according to claim 12, wherein The conductive protective component (3) includes a first part (31), a second part (32) and a third part (33). The first part (31) and the second part (32) are arranged at intervals relative to each other along the second direction (y). The third part (33) is connected between the first part (31) and the second part (32). The first part (31), the tab (2) and the second part (32) are connected by the third solder group (30).

14. The battery cell (100) of claim 11, wherein, The first solder group (21) includes a first solder segment (211) extending along the second direction (y), the length of the first solder segment (211) along the first direction (x) is a first preset length W1, and the contact length between the conductive protective member (3) and the electrode (2) along the first direction (x) is a fifth preset length W3, the fifth preset length W3 = G*W1, 2≤G≤5.

15. The battery cell (100) according to claim 14, wherein The first preset length W1 = H, 4mm ≤ H ≤ 8mm.

16. A method for manufacturing a battery cell (100) according to any one of claims 1 to 15, comprising: With the free end of the tab (2) in an unfolded state, the connecting part (202) is welded to form the first solder mark group (21) on the connecting part (202), and the overlapping part (203) is welded to form the second solder mark group (22) on the overlapping part (203). Fold the free end of the tab (2) toward the main body (1) to form the bent part (201); The overlapping portion (203) and the connecting portion (202) are fixedly connected.

17. The manufacturing method according to claim 16, wherein, When the free end of the tab (2) is folded toward the main body (1) to form the bent portion (201), the first solder group (21) and the second solder group (22) are spaced apart along the first direction (x); and / or The first solder mark group (21) and the second solder mark group (22) are arranged at intervals along the second direction (y).

18. The manufacturing method according to claim 16, wherein, The steps for fixing the overlapping portion (203) and the connecting portion (202) together include: The overlapping portion (203) and the connecting portion (202) are welded together.

19. The method of manufacturing according to claim 16, wherein, The steps for fixing the overlapping portion (203) and the connecting portion (202) together include: The overlapping portion (203), the bent portion (201), and at least part of the connecting portion (202) are covered by a conductive protective element (3); On the side of the first solder group (21) and the second solder group (22) near the main body (1), the conductive protective element (3), the overlapping part (203) and the connecting part (202) are welded to form a third solder group (30) that fixes the conductive protective element (3), the overlapping part (203) and the connecting part (202).

20. A battery device (300), comprising: The battery cell (100) according to any one of claims 1 to 15.

21. An electrical appliance, comprising: The battery device (300) according to claim 20.

Images