Battery cell pole piece, battery cell, battery and electric equipment

Abstract

The invention relates to the technical field of battery processing, and relates to a battery cell pole piece, a battery cell, a battery and electric equipment. The battery cell pole piece comprises a pole piece body and a connecting piece, the pole piece body comprises a plurality of single pole pieces arranged in the first direction, a cutting part extending in the second direction is arranged between every two adjacent single pole pieces, and the first direction intersects with the second direction; the connecting pieces are respectively connected to two adjacent single pole pieces on the two sides of the cutting part before the battery cell pole pieces are wound; and the pole piece body expands, so that the two adjacent single pole pieces are disconnected from the cutting part. According to the battery cell pole piece disclosed by the embodiment of the invention, the cutting part is formed on the pole piece body through cutting, and the two adjacent single pole pieces are connected through the connecting piece, so that compared with the traditional technical scheme of forming a fracture hole through punching, the battery cell pole piece disclosed by the invention has the advantages that waste materials generated in a pole piece processing process can be effectively reduced; meanwhile, a specific cutter does not need to be additionally arranged, and the manufacturing cost can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell pole piece, a battery cell, a battery and an electrical device. Background Art

[0002] In the field of battery technology, the structural design of the battery cell pole piece has an important impact on the performance and manufacturing process of the battery. In some prior arts, the battery cell pole piece is provided with a fracture hole so that the battery cell pole piece can be fractured into multiple single pole pieces along the fracture hole after formation, which can effectively improve the processing efficiency of the battery cell pole piece.

[0003] However, the broken holes on the battery cell pole pieces are often punched, but a considerable amount of pole piece waste is generated during the punching process, resulting in unnecessary waste of resources. In addition, this method also requires the corresponding waste recycling system and special-shaped punching tools, which significantly increases production costs.

[0004] Therefore, it is necessary to make improvements to the above problems in order to improve the current situation. Summary of the invention

[0005] The present application provides a battery cell pole piece, a battery cell, a battery and an electrical device, which are used to solve the problem that in the existing battery cell pole piece processing process, a punching process is used to form a fracture hole, resulting in excessive processing waste and high production costs.

[0006] The first aspect of the present application provides a battery cell electrode sheet, comprising:

[0007] A pole piece body, comprising a plurality of single pole pieces arranged along a first direction, and a cutting portion extending along a second direction is provided between two adjacent single pole pieces, wherein the first direction intersects with the second direction; and

[0008] A connecting piece is respectively connected to two adjacent monomer pole pieces on both sides of the cutting portion; the pole piece body expands to disconnect the two adjacent monomer pole pieces from the cutting portion.

[0009] In a possible implementation, each of the single pole pieces includes a pole piece portion and at least one pole ear portion, the pole ear portion is connected to at least one side of the pole piece portion, and the pole ear portion is located outside the cutting portion;

[0010] The cutting portion is provided between at least some of the adjacent two pole pieces, and the adjacent two pole pieces are disconnected from the cutting portion.

[0011] In a possible implementation, a size of the cut portion in the second direction is not greater than a size of the pole piece in the second direction.

[0012] In one possible implementation, the pole piece includes a current collector and an active material layer, the active material layer is disposed on at least one side surface of the current collector, and the current collectors of two adjacent pole pieces are spaced apart to form the cutting portion.

[0013] In a possible implementation manner, the connecting element is connected to the active material layer.

[0014] In a possible implementation, in the second direction, the size of the cut portion is H1, the size of the active material layer is H2, the size of the current collector is H3, and the size of the connector is H4, and the following relationship is satisfied:

[0015] 1 / 3H3≤H1≤H3;

[0016] and / or 1 / 3H3≤H4≤H3;

[0017] And / or H2≤H3.

[0018] In a possible implementation, at least part of the orthographic projection of the connecting member toward the pole piece is located outside the active material layer.

[0019] In a possible implementation, an edge of an orthographic projection of the connecting member toward the pole piece in the second direction is located between an edge of the active material layer and an edge of the current collector.

[0020] In a possible implementation, an edge of the connector on a side close to the pole ear portion is located inside the current collector; an edge of the connector on a side away from the pole ear portion is at least partially located outside the pole piece portion.

[0021] In a possible implementation, at a side of the connector away from the pole ear portion, a distance between an edge of the connector and an edge of the single pole piece is W2, and W2<5 mm.

[0022] In a possible implementation, in the first direction, the size of the cut portion is K1, and 0 <K1<200mm;

[0023] and / or the distance between the edge of the connecting piece and the edge of the cut portion inside the connecting piece is K2, and 1mm <K2<20mm。

[0024] In a possible implementation, the connecting member is an adhesive layer, the adhesive layer has an adhesive surface and a non-adhesive surface, and the adhesive surface faces the monomer pole piece.

[0025] In a possible implementation, the cutting portion is configured to be any one of a straight line, a zigzag, a wave, and a curve.

[0026] In a possible implementation, along the first direction, the length dimensions of the plurality of single pole pieces gradually decrease.

[0027] In a possible implementation, the length of the battery cell electrode piece is L, the length of the nth single electrode piece is Ln, and the following relationship is satisfied: 3%L≤L1≤50%L.

[0028] In one possible implementation, along the first direction, the sizes of the plurality of single pole pieces are L1, L2, ..., Ln, respectively, and satisfy the following relationship: 0≤Ln-1-Ln≤1 / 2Ln-1, where n is an integer, 2≤n.

[0029] In a possible implementation, along the first direction, the lengths of the plurality of single pole pieces are equal.

[0030] A second aspect of the present application provides a battery cell, comprising:

[0031] Diaphragm;

[0032] a first pole piece, disposed on one side of the diaphragm; and

[0033] A second pole piece, disposed on a side of the diaphragm facing away from the first pole piece;

[0034] Wherein, the first pole piece and / or the second pole piece comprises a battery cell pole piece as described in any one of the above items.

[0035] In one possible implementation, the diaphragm, the first pole sheet and the second pole sheet are wound to form the battery cell, and in the extension direction of the battery cell pole sheets, the size of the single pole sheet located inside the battery cell is not smaller than the size of the single pole sheet located outside the battery cell.

[0036] A third aspect of the present application provides a battery, comprising:

[0037] A battery cell pole piece as described in any one of the above items, or a battery cell as described in any one of the above items; wherein the plurality of said single pole pieces expand after being converted into capacity and are disconnected at the cutting portion.

[0038] In one possible implementation, the battery is a cylindrical battery.

[0039] A fourth aspect of the present application provides an electrical device, comprising an electrical device, and a battery as described in any one of the above items, or a battery cell as described in any one of the above items, wherein the battery cell or the battery is connected to the electrical device and is used to power the electrical device.

[0040] Implementing the embodiments of the present application has the following beneficial effects:

[0041] In the battery cell pole piece of the present embodiment, a cutting portion is formed on the pole piece body, and two adjacent single pole pieces are connected by a connecting piece. After the capacity is divided, the pole piece body can be disconnected at the cutting portion to form a plurality of single pole pieces. Compared with the traditional technical solution of using punching processing to form a breaking hole in the battery cell pole piece, the waste generated in the pole piece processing process can be effectively reduced. In addition, there is no need to additionally equip specific tools, and the manufacturing cost can be effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 A schematic diagram of the unfolded structure of a battery cell electrode sheet in an embodiment of the present invention is shown;

[0044] Figure 2 A schematic diagram of the top view of the battery cell electrode sheet in an embodiment of the present invention is shown;

[0045] Figure 3 A schematic diagram of the cross-sectional structure of a battery cell in an embodiment of the present invention is shown;

[0046] Figure 4 A schematic diagram of the cross-sectional structure of a battery cell electrode sheet in an embodiment of the present invention is shown;

[0047] Figure 5 A schematic cross-sectional view of a cell electrode sheet during transportation in an embodiment of the present invention is shown;

[0048] Figure 6 A schematic diagram of the unfolded structure of a battery cell electrode sheet in some embodiments of the present invention is shown;

[0049] Figure 7 A schematic diagram of the unfolded structure of a battery cell electrode sheet in some embodiments of the present invention is shown.

[0050] Reference numerals:

[0051] 1-Battery cell;

[0052] 10-battery cell pole piece; 10-1-first pole piece; 10-2-second pole piece;

[0053] 100-single pole piece; 110-pole piece portion; 111-cutting portion; 112-current collector; 113-active material layer; 120-pole ear portion;

[0054] 200-connecting piece;

[0055] 20 - diaphragm;

[0056] 2-Conveyor roller. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0058] For ease of description, refer to Figure 1 As shown, the X direction in the figure is defined as the first direction, and the Y direction in the figure is defined as the second direction, such as Figure 1 In the embodiment shown, the X direction is perpendicular to the Y direction. In this case, the first direction may be the length direction of the entire battery cell electrode sheet 10, and the second direction may be the width direction of the battery cell electrode sheet 10. Of course, in some embodiments, the first direction and the second direction may also intersect and be set at an angle of 0-90°. The angle between the first direction and the second direction is determined by the design requirements of the battery cell electrode sheet 10 and is not limited here.

[0059] See also Figures 1 to 7 As shown, an embodiment of the present invention provides a battery cell pole piece 10, which includes a pole piece body and a connector 200, wherein the pole piece body includes a plurality of single pole pieces 100 arranged along a first direction (e.g., X direction), and a cutting portion 111 extending along a second direction (e.g., Y direction) is provided between two adjacent single pole pieces 100, for example Figure 1 As shown, the cutting portion 111 extends along the Y direction toward two edges of the single pole piece 100 in the width direction.

[0060] The connector 200 is respectively connected to two adjacent single pole pieces 100 on both sides of the cutting portion 111 before the battery cell pole piece 10 is converted into capacity. After the battery cell pole piece 10 is converted into capacity, the pole piece body expands, and the two adjacent single pole pieces 100 are disconnected from the cutting portion 111. For example, before winding, the battery cell pole piece 10 has two states, a connected state and a disconnected state. The connected state is to partially connect two adjacent single pole pieces 100 on both sides of the cutting portion 111. Before winding, multiple single pole pieces 100 are connected by the connector 200 to form a continuous pole piece body. Before winding, the connector 200 mainly plays the role of strengthening the connection between adjacent single pole pieces 100 to ensure that there is no break in the winding process. When the battery cell pole piece is applied to the battery and the battery is converted into capacity, the pole piece 10 is disconnected at the cutting portion 111 due to expansion. The disconnected state is that the pole piece 10 has been completely disconnected at the cutting portion 111 before winding to form a plurality of pole pieces 100, and the continuity of the pole piece 10 is ensured before winding for two adjacent pole pieces 100 connected by the connecting piece 200. After winding, there is a gap between the two adjacent pole pieces 100 along the extension direction of the pole piece 100, and the gap is further enlarged after the capacitance is generated, and the adjacent pole pieces 100 cannot be electrically connected at the cutting portion 111.

[0061] It should be noted that the capacity division process refers to determining the capacity of the battery by charging and discharging the battery and detecting the discharge capacity when the capacity division is fully charged; the formation process refers to the process of charging the battery with a small current after liquid injection; in the formation and capacity division stage, the battery cell pole piece 10 can be expanded and the battery cell pole piece 10 can be broken at the cutting portion 111 to separate two adjacent single pole pieces 100.

[0062] In the battery cell pole piece 10 of the present embodiment, a cutting portion 111 is formed on the pole piece body, and two adjacent single pole pieces 100 are connected by a connector 200. After the capacity is divided, the pole piece body can be disconnected at the cutting portion 111 to form a plurality of single pole pieces 100. Compared with the traditional technical solution of the battery cell pole piece 10 in which a breaking hole is formed by punching, the waste generated during the pole piece processing breaking hole can be effectively avoided. In addition, there is no need to additionally equip specific tools, and the manufacturing cost can be effectively reduced.

[0063] Specifically in some embodiments, the pole piece body can be cut in the slitting stage by, for example, mechanical cutting or laser die cutting to form a cutting portion 111. However, for the prior art battery cell pole piece solution that uses punching processing to form a plurality of spaced-out fracture holes, a large amount of waste will be generated during the punching process, and in order to ensure the fracture quality, a special punching tool is usually required, and the manufacturing cost is also significantly increased. In the embodiment of the present application, a cutting process can be used to form a cutting portion 111 on the battery cell pole piece 10, and two adjacent single-unit pole pieces 100 can be fixed by a connector 200, thereby fixing the two adjacent single-unit pole pieces 100 to ensure the continuity of the battery cell pole piece 10, facilitating the die cutting of the battery cell pole piece 10 to form the pole ear, and facilitating the subsequent winding and transportation of the battery cell pole piece 10.

[0064] It should be noted that, in the embodiment of the present application, the cut portion 111 between two adjacent monomer pole pieces 100 can be a completely cut seam, for example, after the two adjacent monomer pole pieces 100 are cut, they are pulled apart by a certain distance, and the two adjacent monomer pole pieces 100 cannot be electrically connected by the end face of the cut. Alternatively, the cut portion 111 between two adjacent monomer pole pieces 100 can also be incompletely disconnected and slightly connected, for example, after the two adjacent monomer pole pieces 100 are cut, the two sections of the pole pieces can be electrically connected by relying on the end face of the cut or the incompletely cut position, and the adjacent pole pieces are completely disconnected due to the expansion, fracture and displacement of the pole pieces during the conversion into capacity. In some embodiments, the connector 200 has a certain elasticity. In this way, during the winding or bending process of the battery cell pole piece 10, it can be ensured that the connector 200 can remain connected to the adjacent monomer pole piece 100 inside the battery cell 1, so as to facilitate the processing of the battery cell pole piece 10 to form the battery cell 1.

[0065] Specifically, see Figure 1 As shown, each single pole piece 100 includes a pole piece portion 110 and at least one pole ear portion 120 . The pole ear portion 120 is connected to at least one side of the pole piece portion 110 , and the pole ear portion 120 is located outside the cutting portion 111 .

[0066] It is understandable that, in the battery cell pole piece 10, since the positive pole piece and the negative pole piece need to be arranged correspondingly, the pole ear portion 120 is usually arranged on one side of the pole piece portion 110, so that after the positive pole piece and the negative pole piece are separated by the diaphragm, the pole ear portion 120 of the positive pole piece and the pole ear portion 120 of the negative pole piece can be respectively located in different directions of the battery cell 1 to avoid short circuit. When the pole ear portions 120 are provided on both sides of the battery cell pole piece 10, when the battery cell pole piece 10 is processed to form the battery cell 1, the pole ear portions 120 of the positive and negative poles can be arranged alternately to avoid short circuit.

[0067] Therefore, in a possible implementation, a plurality of pole ears 120 may be provided on one side of the pole piece 110. When the cell pole piece 10 is applied to a full-pole ear battery, after the cell pole piece 10 is wound and formed, the plurality of pole ears 120 may be stacked on the same end of the battery (similar to the positive and negative poles). At this time, since the plurality of pole ears 120 are stacked on each other, during the welding process, it can be ensured that as many pole ears 120 as possible can be welded to the collector disk to achieve electrical conduction. In addition, when there are some pole ears 120 that are not welded to the collector disk, these pole ears 120 may also contact each other or contact the pole ears 120 that have been welded to the collector disk, and electrical conduction may also be achieved. When the cell pole piece 10 is broken by the cutting portion 111 to form a plurality of monomer pole pieces 100, it is ensured that there is at least one effective pole ear 120 on the intermittently disconnected cell pole piece 10 for electrical connection, thereby ensuring the circuit conduction performance of the battery.

[0068] In addition, when the battery cell pole piece 10 is applied to a cylindrical battery, if the pole ear portion 120 has the same length as the pole piece portion 110 (that is, the pole ear portion 120 is a whole-piece structure), it is inconvenient to bend the pole ear portion 120 toward the central axis of the cylindrical battery during the winding process of the battery cell pole piece 10. Therefore, the battery cell pole piece 10 in this embodiment can be easily wound by forming a plurality of pole ear portions 120 spaced apart on the pole piece portion 110, so that it is easy to be applied to a cylindrical battery. Of course, in some embodiments, when the battery cell pole piece 10 is applied to a sheet battery, since the pole ear portion 120 does not need to be wound and stacked, the pole ear portion 120 can also adopt a whole-piece structure and correspond to the pole piece portion 110, which will not be elaborated here.

[0069] Furthermore, at least a portion of two adjacent pole pieces 110 have a cutting portion 111 between them, and the two adjacent pole pieces 110 are cut off from the cutting portion 111 .

[0070] In the battery cell pole piece 10 of the present embodiment, the processing position of the cutting portion 111 is usually selected to avoid the pole ear portion 120, so as to avoid cutting the pole ear portion 120 during the cutting process, so as to avoid damaging the pole ear portion 120. In the specific processing process, the processing position of the cutting portion 111 can be set by high-precision processing control, or the processing position of the cutting portion 111 can be reserved in the non-pole ear area, which is specifically determined according to the design requirements of the battery cell pole piece 10, and is not limited here. Of course, in some embodiments, the cutting portion 111 can be removed between some adjacent pole pieces 110 to keep the two closely connected.

[0071] Specifically in one embodiment, the size of the cutting portion 111 in the second direction is not greater than the size of the pole piece portion 110 in the second direction.

[0072] See also Figure 1As shown, the size of the cutting portion 111 in the second direction is H1 in the figure, and the size of the pole piece portion 110 in the second direction is H3, then H1 and H3 satisfy the following relationship: H1≤H3; in the specific processing process of the battery cell pole piece 10, the cutting portion 111 may or may not penetrate the battery cell pole piece 10 in the second direction. When the cutting portion 111 does not penetrate the battery cell pole piece 10 in the second direction, the two adjacent monomer pole pieces 100 can maintain a micro-connection at the cutting portion 111. In this way, although the monomer pole piece 100 is not separated at the cutting portion 111, the monomer pole piece 100 can be disconnected at the cutting portion 111 after the cell pole piece 10 is divided into different volumes. When the cutting portion 111 of the battery cell pole piece 10 is disconnected in the second direction, the two separated adjacent monomer pole pieces 100 can also be connected by the connector 200 to ensure the continuity of the battery cell pole piece 10.

[0073] See also Figure 1 and Figure 2 As shown, in one embodiment, the pole piece 110 includes a current collector 112 and an active material layer 113 , the active material layer 113 is disposed on at least one side surface of the current collector 112 , and the current collectors 112 of two adjacent pole pieces 110 are spaced apart to form a cutting portion 111 .

[0074] Specifically, in some embodiments, the connector 200 can be arranged on one side of the current collector 112, or on both sides of the current collector 112, and corresponds to at least one layer of active material layer 113, which is determined according to the design requirements of the battery cell pole piece 10, and is not limited here. By forming a cutting portion 111 between two adjacent monomer pole pieces 100, the active material layers 113 on the two adjacent current collectors 112 can be completely disconnected or micro-connected. When the active material layer 113 is completely disconnected, the two adjacent active material layers 113 cannot be electrically connected through the cut of the cutting portion 111; the micro-connection of the two adjacent active material layers 113 means that after the monomer pole piece 100 is cut, the two adjacent monomer pole pieces 100 are directly connected through the connector 200, and the two sections of the cut monomer pole piece 100 can be electrically connected by relying on the end face of the cut or the position that is not completely cut, and the fracture displacement is achieved due to the expansion of the battery cell pole piece 10 during the formation process, so that the two adjacent monomer pole pieces 100 can be completely disconnected.

[0075] In some embodiments, the connector 200 is connected to the active material layer 113 .

[0076] In this embodiment, when the connector 200 is connected to two single pole pieces 100 respectively, when the active material layer 113 is provided on the same side of the pole piece parts 110 of the two single pole pieces 100, the connector 200 can be in contact with the active material layers 113 on the two current collectors 112 on the same side; in some embodiments, when the two adjacent pole pieces 110 are not provided with the active material layer 113 on the same side, the connector 200 can also be respectively connected to the current collector 112 of one of the pole pieces 110 and the active material layer 113 of the other pole piece part 110; of course, when the two adjacent pole pieces 110 are not provided with the active material layer 113 on the same side, the connector 200 can also be connected to the two current collectors 112 at the same time, which is not a sole limitation here.

[0077] Further, see Figure 1 As shown, in the second direction, the size of the cut portion 111 is H1, the size of the active material layer 113 is H2, the size of the current collector 112 is H3, and the size of the connector 200 is H4, and the following relationship is satisfied: 1 / 3H3≤H1≤H3; and / or 1 / 3H3≤H4≤H3; and / or H2≤H3.

[0078] In this embodiment, the length of the cutting portion 111 in the second direction is set to between 1 / 3 H3 and H3 to ensure that the battery cell pole piece 10 can be broken and displaced by expansion after being reduced to capacity, so that two adjacent monomer pole pieces 100 can be separated to form multiple sections of monomer pole pieces 100. In addition, the active material layer 113 is preferably arranged within the range of the current collector 112 in the second direction. At this time, the connector 200 can exceed the range of the active material layer 113 in the second direction and contact the current collector 112. By setting the length H4 of the connector 200 in the second direction to 1 / 3 H3 and H3, it can be ensured that the monomer pole piece 100 can be connected by the connector 200 to ensure continuity during winding.

[0079] Specifically, at least a portion of the orthographic projection of the connecting member 200 toward the pole piece 110 is located outside the active material layer 113 .

[0080] In some embodiments, when the width H2 of the active material layer 113 in the second direction is smaller than the width H3 of the current collector 112 , the connector 200 can simultaneously cover the current collector 112 and the pole ear portion 120 in the second direction, so that there is a larger contact range between the connector 200 and the monomer pole piece 100 , thereby improving the connection strength of the connector 200 .

[0081] In one embodiment, an edge of the orthographic projection of the connecting member 200 toward the pole piece 110 in the second direction is located between an edge of the active material layer 113 and an edge of the current collector 112 .

[0082] With this arrangement, under the premise of ensuring the connection strength between the connector 200 and the single pole piece 100 , the end of the connector 200 can be prevented from exceeding the range of the current collector 112 to prevent the connector 200 from contacting the pole ear 120 and affecting the welding quality of the pole ear 120 .

[0083] Specific as Figure 1 In the illustrated embodiment, the edge of the connector 200 close to the pole ear 120 is located inside the current collector 112 ; the edge of the connector 200 away from the pole ear 120 is at least partially located outside the pole piece 110 .

[0084] like Figure 1 As shown in the placement direction, in the present embodiment, the distance that the upper edge of the connector 200 in the second direction (located on the side close to the pole ear portion 120) exceeds the active material layer 113 is W1, and the distance that the lower edge of the connector 200 (located on the side away from the pole ear portion 120) exceeds the monomer pole piece 100 is W2. In the embodiment, W2 is less than 5 mm, and the following relationship is satisfied: W1 is less than H3-H2, 1 / 3H3 is less than H4≤H3.

[0085] Thus, by setting W1<H3-H2, when H3>H2 (that is, the edge of the active material layer 113 close to the pole ear 120 is located on the inner side of the current collector 112), it can be ensured that after the battery cell pole piece 10 is cut and glued in the cutting section, the connector 200 can remain connected to the single pole piece 100 while shielding the cutting portion 111. At the same time, since the edge of the connector 200 close to the pole ear 120 is located in the current collector 112, it can also avoid cutting the connector 200 when die-cutting the molded pole ear 120, thereby ensuring the quality of the pole ear die-cutting and avoiding the waste material adhesion caused by the connector 200 not being cut when cutting.

[0086] After the cell pole piece 10 is die-cut to form the pole ear portion 120, the connector 200 can be prevented from exceeding the pole piece portion 110 (i.e., the root of the pole ear portion 120), so that the connector 200 can be prevented from being mixed in the pole ear portion 120 after the cell pole piece 10 is wound and formed, thereby affecting the welding quality of the collector plate, thereby effectively improving the electrical connection performance of the cell pole piece 10. At the same time, by setting W2 < 5mm, it can be ensured that the lower side of the connector 200 (the side away from the pole ear portion 120) does not exceed the lower side of the pole piece portion 110 (the side away from the pole ear portion 120), and when the cell pole piece 10 is wound and formed, the connector 200 can be prevented from being mixed in the pole ear of another pole piece and affecting the welding of the collector plate, thereby effectively improving the overall electrical connection performance of the cell 1.

[0087] Specifically, see Figure 1 and Figure 2As shown, in the first direction, the size of the cutting part 111 is K1, and 0 < K1 < 200 mm; or the distance between the edge of the connecting piece 200 and the edge of the cutting part 111 inside the connecting piece 200 is K2, and 1 mm < K2 < 20 mm.

[0088] In a specific embodiment, after the single electrode sheet 100 is cut and disconnected, the two adjacent single electrode sheets 100 can be pulled apart by a distance of K1 in a direction away from each other and then connected by the connecting piece 200. At this time, the connecting piece 200 can be arranged on the active material layer 113 on at least one side to ensure the overall continuity of the connecting piece 200 and the electrode sheet 10 of the battery cell. Refer to Figure 4 As shown, in an embodiment, the connecting piece 200 can be equal to the circumference of the wound battery cell 1, such as Figure 4 In the schematic diagram of the electrode sheet 10 of the battery cell after winding as shown, at this time, since the connecting piece 200 winds around the circumference of the battery cell 1 and connects the two single electrode sheets 100 respectively, it is possible to prevent the single electrode sheets 100 from intersecting each other and generating thickness accumulation in one direction in the radial direction of the battery cell 1, so that the thickness in the circumferential direction of the battery cell 1 is more uniform, and as much as possible reduce the influence of stress concentration caused by thickness difference accumulation inside the battery cell 1, improve the cycle performance of the battery cell 1. The length K1 of the cutting part 111 can be specifically determined according to the design requirements of the battery cell 1, and can be the circumference or multiple circumferences of the battery cell 1, and no unique limitation is made here.

[0089] In some embodiments, when K1 is set closer to the upper limit. The connecting piece 200 can preferably be a tape made of materials such as polyethylene, polyvinyl chloride, and aluminum foil peeling fiber cloth with certain viscosity and better flame retardant effect. Optionally, the material of the connecting piece 200 can be a swelling tape containing polyurethane components, etc., to improve the infiltration of the electrolyte in the electrode core and enhance the liquid retention capacity of the battery cell.

[0090] At the same time, by setting 1 mm < K2 < 20 mm, the contact range between the connecting piece 200 and the single electrode sheet 100 in the first direction can be ensured, thereby further improving the overall connection strength of the electrode sheet 10 of the battery cell. The specific setting of K2 needs to ensure that the single electrode sheet 100 does not break during winding of the electrode sheet 10 of the battery cell. When K2 is too small, the electrode sheet 10 of the battery cell is prone to breakage, and when K2 is too large, too much active material layer 113 will be wasted due to covering too much active material layer 113, which will affect the electrical performance of the battery cell 1.

[0091] In an embodiment, the connecting piece 200 is an adhesive layer, and the adhesive layer has an adhesive surface and a non-adhesive surface, and the adhesive surface faces the single electrode sheet 100.

[0092] Refer to Figure 5As shown, in the embodiment, the connector 200 is an insulating tape. When the connector 200 is only located on one side of the active material layer 113, the bonding surface on the connector 200 is in contact with the monomer pole piece 100. The connector 200 is debonded to form a non-bonding surface on the connector 200. At this time, the non-bonding surface is provided at the cutting portion 111 between two adjacent monomer pole pieces 100. The range of the debonding treatment is as shown in FIG. Figure 5 Within the range of D in the figure, when the battery cell electrode sheet 10 is conveyed by the conveying roller 2, the portion of the connecting member 200 facing the conveying roller 2 and located in the cutting portion 111 is a non-adhesive surface. When the connecting member 200 here contacts the conveying roller 2, adhesion between the connecting member 200 and the conveying roller 2 can be avoided. Therefore, the conveying quality of the battery cell electrode sheet 10 can be guaranteed while reducing the overall thickness of the battery cell electrode sheet 10.

[0093] Of course, when the active material layers 113 on both sides are provided with connectors 200, the connectors 200 on both sides of the cell pole piece 10 located in the cutting portion 111 can be in contact with each other regardless of whether there is an adhesive surface, so as to avoid the adhesive surface of the connector 200 from contacting external components such as the conveying roller 2. In other embodiments, the connector 200 can also be connected and fixed to the monomer pole piece 100 by means of crimping, fusion, etc., which is not limited here.

[0094] Specific as Figure 6 As shown, the cutting portion 111 is configured as a straight line, a sawtooth ( Figure 6 (a) and Figure 6 (b)), wavy ( Figure 6 (c)), or any one of the curve types. The specific design is determined according to the design requirements of the battery cell electrode 10, and is not limited here.

[0095] In an embodiment, along the first direction, the length dimensions of the plurality of single pole pieces 100 gradually decrease.

[0096] See also Figure 7As shown in (a), the overall length of the cell pole piece 10 in the figure is L. After the cell pole piece 10 is cut, the lengths of the individual pole pieces 100 are L1, L2, ..., Ln, L1+L2+...+Ln=L, and L1>L2>...>Ln. The individual pole piece 100 of length L1 is located inside the cell 1, and the individual pole pieces 100 of length L2, ..., Ln are arranged in sequence along the spiral direction of the cell 1 toward the outer circle of the cell 1. With this arrangement, the capacity of the small pole core of the outer circle of the cell 1 can be guaranteed to be the smallest. When the external force causes the outer circle of the cell 1 to fail due to a short circuit, the failed pole core can be limited to the outermost small pole core or the secondary outer circle pole core, reducing the overall failure risk of the cell 1, thereby effectively improving the safety performance of the cell 1. Specifically, the sizes of L1, L2, ..., Ln gradually decrease, and can be optionally reduced by a fixed ratio of the length, or by a fixed ratio of the capacity of the individual pole piece 100, or by a fixed ratio of the number of turns, etc. In order to improve the overall safety performance of the battery cell 1, the single pole piece 100 at the tail end Ln preferably satisfies the small pole core specific energy of Ln ≤ 400Wh / L, or the pole core specific energy ≤ 200Wh / kg.

[0097] See also Figure 7 (b) shows, in other embodiments of the present application, after the cell electrode sheet 10 is cut, the lengths of the segments of the single electrode sheet 100 are L1, L2, ..., Ln, etc., L1 + L2 + ... + Ln = L0, L1 = L2 = ... = Ln. In other embodiments, L1 ≠ L2 ≠ ... ≠ Ln or a combination of multiple situations. L1, L2, ..., Ln, etc. can be set according to the length of the sheet, capacity, number of turns, etc.

[0098] In the embodiment, the length of the cell pole piece 10 is L, the length of the nth single pole piece 100 is Ln, and the following relationship is satisfied: 3% L≤L1≤50% L, n is an integer, 2≤n. Along the first direction, the sizes of the plurality of single pole pieces 100 are L1, L2, ..., Ln, and the following relationship is satisfied: 0≤Ln-1-Ln≤1 / 2Ln-1, n is an integer, 2≤n.

[0099] See also Figure 3 As shown, the present application also provides a battery cell 1, which includes a first electrode sheet 10-1, a second electrode sheet 10-2 and a diaphragm 20; the first electrode sheet 10-1 is arranged on one side of the diaphragm 20; the second electrode sheet 10-2 is arranged on the side of the diaphragm 20 facing away from the first electrode sheet 10-1; wherein the first electrode sheet 10-1 and / or the second electrode sheet 10-2 include the battery cell electrode sheet 10 in any of the above-mentioned embodiments, and any one of the first electrode sheet 10-1 and the second electrode sheet 10-2 can be a positive electrode sheet, and the other can be a negative electrode sheet.

[0100] It can be understood that, in the battery cell 1 of the present embodiment, by setting the battery cell pole piece 10 in any of the above-mentioned embodiments, the battery cell pole piece 10 of the present embodiment is formed by cutting on the pole piece body to form a cutting portion 111, and then two adjacent single pole pieces 100 are connected by a connecting piece 200. After the pole piece body is divided into volumes, the pole piece body can be disconnected at the cutting portion 111 to form a plurality of single pole pieces 100. Compared with the traditional technical solution of the battery cell pole piece 10 in which the breaking hole is formed by punching, the waste generated in the pole piece processing process can be effectively reduced. At the same time, there is no need to additionally equip specific cutting tools, and the manufacturing cost can also be effectively reduced, thereby reducing the overall manufacturing cost of the battery cell 1.

[0101] Specifically, when the battery cell 1 is a winding structure, the battery cell 1 will generate an expansion force that spreads from the inside to the outside during the cycle. When the expansion force is too large, the battery cell electrode sheet 10 may be torn due to the high brittleness of the battery cell electrode sheet 10. The battery cell electrode sheet 10 in this embodiment is configured as described above. When the battery cell electrode sheet 10 is cut and micro-connected, the battery cell 1 can be completely disconnected by displacement at the cutting portion 111 when subjected to the expansion force during the subsequent charge-discharge stage. At least one effective pole ear portion 120 on each segment of the battery cell electrode sheet 10 can maintain electrical connection after the battery cell electrode sheet 10 is broken, thereby ensuring the electrochemical performance of the battery cell 1 and increasing the service life of the battery cell 1. When the battery cell electrode sheet 10 is completely cut and pulled apart, the segmented monomer electrode sheets 100 are connected by means of the connector 200 to ensure the continuity of the battery cell electrode sheet 10 before winding while ensuring the multi-segment characteristics of the battery cell electrode sheet 10 in the battery cell 1.

[0102] In some embodiments, the positive electrode sheet can adopt the battery cell electrode sheet 10 in any of the above embodiments. Of course, in some embodiments, the negative electrode sheet can also adopt the battery cell electrode sheet 10 in any of the above embodiments, and is arranged in sections corresponding to the positive electrode sheet, and each section of the negative electrode sheet is provided with at least one pole ear portion 120. Of course, the negative electrode sheet can also be a continuous structure and correspond to the positive electrode sheet, and the negative electrode sheet is preferably arranged to cover the positive electrode sheet. In an embodiment, the connector 200 can separate the outer ring small pole core from the inner ring small pole core, and the flame retardant material can reduce the risk of the inner ring small pole core being affected by the outer ring and causing a short circuit, thereby improving the safety performance of the battery 1.

[0103] In the embodiment, the diaphragm 20, the first pole piece 10-1 and the second pole piece 10-2 are wound to form the battery cell 1. In the extension direction of the battery cell pole piece 10, the size of the single pole piece 100 located on the inner side of the battery cell 1 is not smaller than the size of the single pole piece 100 located on the outer side of the battery cell 1.

[0104] This arrangement can ensure that the capacity of the small pole core in the outer ring of the battery cell 1 is minimized. When the external force causes the outer ring of the battery cell 1 to fail due to a short circuit, the failed pole core can be limited to the outermost small pole core or the second outer ring pole core, reducing the overall failure risk of the battery cell 1, thereby effectively improving the safety performance of the battery cell 1. Specifically, the size of L1, L2, ..., Ln gradually decreases, optionally by a fixed ratio of the length of the piece, or by a fixed ratio of the capacity of the single pole piece 100, or by a fixed ratio of the number of turns, etc. In order to improve the overall safety performance of the battery cell 1, the single pole piece 100 at the tail end Ln preferably satisfies the small pole core specific energy of Ln ≤400Wh / L, or the pole core specific energy ≤200Wh / kg.

[0105] The present application also provides a battery, which includes the battery cell pole piece 10 in any of the above embodiments, or the battery cell 1 in any of the above embodiments; wherein the plurality of single pole pieces 100 expand after being converted into capacity and are disconnected at the cutting portion 111 .

[0106] It can be understood that, in the battery of the present embodiment, by setting the battery cell pole piece 10 in any of the above-mentioned embodiments, the battery cell pole piece 10 of the present embodiment forms a cutting portion 111 by cutting on the pole piece body, and then connects two adjacent single pole pieces 100 through a connecting piece 200. After the pole piece body is converted into capacity, the pole piece body can be disconnected at the cutting portion 111 to form a plurality of single pole pieces 100. Compared with the traditional technical solution of the battery cell pole piece 10 in which the breaking holes are formed by punching, the waste generated in the pole piece processing process can be effectively reduced. At the same time, no additional specific cutting tools are required, and the manufacturing cost can be effectively reduced, thereby reducing the manufacturing cost of the battery and improving the safety of the battery.

[0107] In one embodiment, the battery is a cylindrical battery.

[0108] Specifically, the cylindrical battery will generate an expansion force that spreads from the inside to the outside during the cycle. When the expansion force is too large, the positive electrode sheet may be torn due to the brittleness of the positive electrode sheet. By adopting the battery cell electrode sheet 10 in any of the above embodiments, the positive electrode sheet can be displaced at the cutting position when subjected to the expansion force in the subsequent stage of the battery capacity division, thereby being completely disconnected. At least one effective pole ear portion 120 on each section of the positive electrode sheet can keep the positive electrode sheet electrically connected after breaking, thereby ensuring the electrochemical performance of the battery and improving the service life of the battery. When the positive electrode sheet is completely cut and pulled apart, the segmented electrode sheets are connected by the connector 200 to ensure the continuity of the positive electrode sheet before winding and the multi-segment characteristics of the positive electrode sheet in the battery cell 1. The cylindrical battery adopts a continuous winding method when winding, which can avoid the dislocation caused by the multi-segment electrode sheet gluing, thereby improving production efficiency. Of course, in some embodiments, the battery can also be a flat battery, which is not the only limitation here.

[0109] The present application also provides an electrical device, which includes an electrical device and a battery in any of the above embodiments, or a battery cell 1 in any of the above embodiments, the battery cell 1 or the battery is connected to the electrical device, and the battery cell 1 and the battery are used to supply power to the electrical device.

[0110] In the embodiment of the present application, the electric device may be a vehicle, and the vehicle may be a new energy vehicle (New Energy Vehicle), such as a pure electric vehicle (Pure Electric Vehicle / Battery Electric Vehicle; referred to as PEV / BEV), a range extended electric vehicle (Range Extended Electric Vehicle; referred to as REEV), a hybrid electric vehicle (Hybrid Electric Vehicle; referred to as HEV), or a fuel cell electric vehicle. The vehicle may also be any vehicle with a battery. The electric device may also be an energy storage power station.

[0111] It can be understood that, in the electrical equipment of this embodiment, by adopting a battery or a battery cell 1 having a battery cell electrode sheet 10 in any of the above embodiments, higher electrical safety can be achieved while effectively reducing manufacturing costs.

[0112] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0113] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0114] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0115] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery cell electrode (10), characterized in that: include: A pole piece body, comprising a plurality of single pole pieces (100) arranged along a first direction, and a cutting portion (111) extending along a second direction is provided between two adjacent single pole pieces (100), wherein the first direction intersects with the second direction; as well as A connecting piece (200) is respectively connected to two adjacent monomer pole pieces (100) on both sides of the cutting portion (111); the pole piece body expands so that the two adjacent monomer pole pieces (100) are disconnected from the cutting portion (111).

2. The battery cell electrode (10) according to claim 1, characterized in that: Each of the single pole pieces (100) comprises a pole piece portion (110) and at least one pole ear portion (120), wherein the pole ear portion (120) is connected to at least one side of the pole piece portion (110), and the pole ear portion (120) is located outside the cutting portion (111); The cutting portion (111) is provided between at least a portion of two adjacent pole pieces (110), and the two adjacent pole pieces (110) are disconnected from the cutting portion (111).

3. The battery cell electrode (10) according to claim 2, characterized in that: The dimension of the cutting portion (111) in the second direction is not greater than the dimension of the pole piece portion (110) in the second direction.

4. The battery cell electrode (10) according to any one of claims 2 to 3, characterized in that: The pole piece (110) comprises a current collector (112) and an active material layer (113), wherein the active material layer (113) is disposed on at least one side surface of the current collector (112), and the current collectors (112) of two adjacent pole pieces (110) are spaced apart to form the cutting portion (111).

5. The battery cell electrode (10) according to claim 4, characterized in that: The connecting member (200) is connected to the active material layer (113).

6. The battery cell electrode (10) according to claim 5, characterized in that: In the second direction, the size of the cut portion (111) is H1, the size of the active material layer (113) is H2, the size of the current collector (112) is H3, and the size of the connector (200) is H4, and the following relationship is satisfied: 1 / 3H3≤H1≤H3; and / or 1 / 3H3≤H4≤H3; And / or H2≤H3.

7. The battery cell electrode (10) according to claim 5, characterized in that: At least part of the orthographic projection of the connecting member (200) toward the pole piece (110) is located outside the active material layer (113).

8. The battery cell electrode (10) according to claim 7, characterized in that: The edge of the orthographic projection of the connecting member (200) toward the pole piece (110) in the second direction is located between the edge of the active material layer (113) and the edge of the current collector (112).

9. The battery cell electrode (10) according to claim 8, characterized in that: The edge of the connecting member (200) on the side close to the pole ear portion (120) is located on the inner side of the current collector (112); and the edge of the connecting member (200) on the side away from the pole ear portion (120) is at least partially located on the outer side of the pole piece portion (110).

10. The battery cell electrode (10) according to claim 9, characterized in that: On the side of the connecting member (200) away from the pole ear portion (120), the distance between the edge of the connecting member (200) and the edge of the single pole piece (100) is W2, and W2 is less than 5 mm.

11. The battery cell electrode (10) according to any one of claims 1 to 3, characterized in that: In the first direction, the size of the cutting portion (111) is K1, and 0 <K1<200mm; and / or the distance between the edge of the connecting member (200) and the edge of the cutting portion (111) inside the connecting member (200) is K2, and 1 mm <K2<20mm。 12. The battery cell electrode (10) according to any one of claims 1 to 3, characterized in that: The connecting member (200) is an adhesive layer, the adhesive layer having an adhesive surface and a non-adhesive surface, the adhesive surface facing the monomer pole piece (100).

13. The battery cell electrode (10) according to any one of claims 1 to 3, characterized in that: The cutting portion (111) is configured in any one of a straight line shape, a sawtooth shape, a wave shape, and a curve shape.

14. The battery cell electrode (10) according to any one of claims 1 to 3, characterized in that: Along the first direction, the length dimensions of the plurality of single pole pieces (100) gradually decrease.

15. The battery cell electrode (10) according to claim 14, characterized in that: The length of the battery cell pole piece (10) is L, and the length of the nth single pole piece (100) is L n , and satisfies the following relationship: 3%L≤L1≤50%L.

16. The battery cell electrode (10) according to claim 14, characterized in that: Along the first direction, the sizes of the plurality of single pole pieces (100) are L1, L2, ..., L n , and satisfy the following relationship: 0≤L n-1 -L n ≤1 / 2L n-1 , wherein n is an integer, 2≤n.

17. The battery cell electrode (10) according to any one of claims 1 to 3, characterized in that: Along the first direction, the lengths of the plurality of single pole pieces (100) are equal.

18. A battery cell (1), characterized in that: include: Diaphragm (20); A first pole piece (10-1) is arranged on one side of the diaphragm (20); as well as A second pole piece (10-2) is arranged on a side of the diaphragm (20) facing away from the first pole piece (10-1); Wherein, the first pole piece (10-1) and / or the second pole piece (10-2) comprises the battery cell pole piece (10) according to any one of claims 1 to 17.

19. The battery cell (1) according to claim 18, characterized in that: The diaphragm (20), the first pole piece (10-1) and the second pole piece (10-2) are wound to form the battery cell (1); in the extension direction of the battery cell pole piece (10), the size of the single pole piece (100) located inside the battery cell (1) is not smaller than the size of the single pole piece (100) located outside the battery cell (1).

20. A battery, characterized in that: include: A battery cell pole piece (10) as claimed in any one of claims 1 to 17, or a battery cell (1) as claimed in claim 18 or 19; wherein the plurality of said single pole pieces (100) expand after being converted into capacities and are disconnected from the cutting portion (111).

21. The battery according to claim 20, characterized in that The battery is a cylindrical battery.

22. An electrical equipment, characterized in that: It comprises an electrical device, and the battery according to claim 20 or 21, or the battery cell (1) according to claim 18 or 19, wherein the battery cell (1) or the battery is connected to the electrical device and is used to supply power to the electrical device.

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