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

Abstract

The application relates to the technical field of battery processing, and relates to a battery cell pole piece, a battery cell, a battery and an electric device. 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 along a first direction, and there is a cutting part extending along a second direction between two adjacent single pole pieces. The first direction intersects the second direction. The connecting piece is connected to the two adjacent single pole pieces on the two sides of the cutting part before the battery cell pole piece is wound. The pole piece body expands, so that the two adjacent single pole pieces are disconnected from the cutting part. In the battery cell pole piece, the cutting part is formed by cutting on the pole piece body, and then the two adjacent single pole pieces are connected by the connecting piece. Compared with the technical solution of the battery cell pole piece formed by punching to form a fracture hole, the waste generated in the pole piece processing process can be effectively reduced, special tools do not need to be additionally arranged, and the manufacturing cost can be effectively reduced.

Description

Battery electrode, battery cell, battery and electrical equipment Technical Field

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

[0002] In the field of battery technology, the structural design of cell electrodes has a significant impact on battery performance and manufacturing processes. In some existing technologies, by incorporating fracture holes, the cell electrode can be broken into multiple individual electrode pieces along the fracture holes after formation, which can effectively improve the processing efficiency of the cell electrode.

[0003] However, fracture holes on battery cell electrodes are often created using a punching process, which generates a significant amount of electrode waste, leading to unnecessary resource waste. Furthermore, this method requires a corresponding waste recycling system and specially shaped punching tools, significantly increasing production costs.

[0004] Therefore, it is necessary to address the aforementioned issues in order to improve the current situation. Summary of the Invention

[0005] This application provides a battery electrode sheet, a battery cell, a battery, and an electrical device to solve the problem of excessive waste and high production costs caused by the use of punching to form fracture holes in the existing battery electrode sheet processing.

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

[0007] An electrode body includes multiple individual electrode sheets arranged along a first direction, and adjacent individual electrode sheets have a cut portion extending along a second direction, wherein the first direction intersects the second direction; and

[0008] A connector is provided, which is respectively connected to two adjacent single electrode sheets on both sides of the cut portion; the electrode body expands to disconnect the two adjacent single electrode sheets from the cut portion.

[0009] In one possible implementation, each of the individual electrode sheets includes an electrode portion and at least one tab portion, the tab portion being connected to at least one side of the electrode portion and located outside the cut portion;

[0010] The cutting portion is located between at least two adjacent electrode portions, and the two adjacent electrode portions are separated from the cutting portion.

[0011] In one possible implementation, the dimension of the cut portion in the second direction is not greater than the dimension of the electrode portion in the second direction.

[0012] In one possible implementation, the electrode portion includes a current collector and an active material layer, the active material layer being disposed on at least one side surface of the current collector, and the current collectors of two adjacent electrode portions being spaced apart to form the cut portion.

[0013] In one possible implementation, the connector is attached to the active material layer.

[0014] In one 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, satisfying the following relationship:

[0015] 1 / 3H3≤H1≤H3;

[0016] And / or 1 / 3H3≤H4≤H3;

[0017] And / or H2≤H3.

[0018] In one possible implementation, at least a portion of the orthographic projection of the connector toward the electrode portion is located outside the active material layer.

[0019] In one possible implementation, the edge of the connector projecting orthogonally toward the electrode portion in the second direction is located between the edge of the active material layer and the edge of the current collector.

[0020] In one possible implementation, the edge of the connector on the side near the tab is located inside the current collector; the edge of the connector on the side away from the tab is at least partially located outside the electrode portion.

[0021] In one possible implementation, on the side of the connector away from the tab, the distance between the edge of the connector and the edge of the single electrode is W2, and W2 < 5 mm.

[0022] In one 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 connector and the edge of the cut portion inside the connector is K2, and 1mm. <K2<20mm。

[0024] In one possible implementation, the connector is an adhesive layer having an adhesive surface and a non-adhesive surface, the adhesive surface facing the single electrode.

[0025] In one possible implementation, the cutting portion is constructed as any one of a straight line, a serrated line, a wavy line, or a curved line.

[0026] In one possible implementation, the length dimension of the plurality of said individual electrodes gradually decreases along the first direction.

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

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

[0029] In one possible implementation, the length dimensions of the plurality of said individual electrodes are equal along the first direction.

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

[0031] Diaphragm;

[0032] A first electrode is disposed on one side of the diaphragm; and

[0033] The second electrode is disposed on the side of the diaphragm opposite to the first electrode;

[0034] Wherein, the first electrode and / or the second electrode include the cell electrode as described in any of the above.

[0035] In one possible implementation, the diaphragm, the first electrode, and the second electrode are wound to form the battery cell, wherein, in the extending direction of the battery cell electrode, the size of the individual electrode located inside the battery cell is not less than the size of the individual electrode located outside the battery cell.

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

[0037] The cell electrode sheet as described in any of the above claims, or the cell as described in any of the above claims; wherein, the plurality of said individual electrode sheets expand and break off from the cut portion after being formed and sized.

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

[0039] The fourth aspect of this application provides an electrical device, including an electrical device and a battery or a battery cell as described in any of the preceding claims, wherein the battery cell or the battery is connected to the electrical device and is used to supply power to the electrical device.

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

[0041] In the battery cell electrode sheet of this embodiment, by forming a cutting portion on the electrode sheet body and then connecting two adjacent individual electrode sheets through a connector, the electrode sheet body can be broken at the cutting portion after fractionation to form multiple individual electrode sheets. Compared with the traditional battery cell electrode sheet technology that uses punching to form fracture holes, this can effectively reduce the waste generated during the electrode sheet processing. In addition, no special cutting tools are required, which can also effectively reduce manufacturing costs. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0044] Figure 2 shows a top view of the electrode structure of the battery cell in an embodiment of the present invention;

[0045] Figure 3 shows a schematic cross-sectional view of the battery cell in an embodiment of the present invention;

[0046] Figure 4 shows a schematic cross-sectional view of the electrode sheet of the battery cell in an embodiment of the present invention;

[0047] Figure 5 shows a cross-sectional schematic diagram of the battery cell electrode sheet during transportation in an embodiment of the present invention;

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

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

[0050] Figure label:

[0051] 1-Battery cell;

[0052] 10-Cell electrode; 10-1-First electrode; 10-2-Second electrode;

[0053] 100 - Monomer electrode; 110 - Electrode section; 111 - Cutting section; 112 - Current collector; 113 - Active material layer; 120 - Tab section;

[0054] 200-Connector;

[0055] 20-Diaphragm;

[0056] 2-Conveyor rollers. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0058] For ease of description, referring to Figure 1, 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. In the embodiment shown in Figure 1, the X direction is perpendicular to the Y direction. In this case, the first direction can be the length direction of the entire cell electrode 10, and the second direction can be the width direction of the cell electrode 10. Of course, in some embodiments, the first direction and the second direction can also intersect and be set at an angle, specifically 0-90°. The angle between the first direction and the second direction is specifically determined according to the design requirements of the cell electrode 10, and is not uniquely limited here.

[0059] Referring to Figures 1 to 7, an embodiment of the present invention provides a battery cell electrode 10, which includes an electrode body and a connector 200. The electrode body includes a plurality of individual electrode sheets 100 arranged along a first direction (e.g., the X direction), and there is a cut portion 111 extending along a second direction (e.g., the Y direction) between two adjacent individual electrode sheets 100. For example, as shown in Figure 1, the cut portion 111 extends along the Y direction to two edges in the width direction of the individual electrode sheet 100.

[0060] Before the cell electrode 10 is formed and tested, the connector 200 connects to two adjacent single electrode sheets 100 on both sides of the cutting section 111. After the cell electrode 10 is formed and tested, the electrode body expands, and the two adjacent single electrode sheets 100 break off from the cutting section 111. For example, before winding, the cell electrode 10 has two states: a connected state and a disconnected state. In the connected state, two adjacent single electrode sheets 100 on both sides of the cutting section 111 are partially connected. Before winding, multiple single electrode sheets 100 are connected by the connector 200 to form a continuous electrode body. Before winding, the connector 200 mainly serves to strengthen the connection between adjacent single electrode sheets 100 to ensure that the winding is continuous. When the cell electrode is applied to the battery, after the battery is formed and tested, the electrode 10 breaks off at the cutting section 111 due to expansion. In the open state, adjacent individual electrode sheets 100 cannot be electrically connected at the cutting section 111; in the open state, the electrode sheet 10 has been completely broken at the cutting section 111 before winding to form multiple individual electrode sheets 100. The two adjacent individual electrode sheets 100 connected by the connector 200 ensure the continuity of the electrode sheet 10 before winding. After winding, the two adjacent individual electrode sheets 100 have a gap along the extension direction of the individual electrode sheet 100. After the separation and formulation, the gap is further expanded, and the adjacent individual electrode sheets 100 cannot be electrically connected at the cutting section 111.

[0061] It should be noted that the capacity grading process refers to determining the battery capacity by charging and discharging the battery and detecting the discharge capacity when fully charged; the formation process refers to the process of charging the battery with a small current after electrolyte injection; during the formation and capacity grading stage, the cell electrode 10 can be expanded and the cell electrode 10 can be broken at the cutting part 111 to separate two adjacent single cell electrodes 100.

[0062] In the battery cell electrode 10 of this embodiment, by forming a cutting portion 111 on the electrode body and then connecting two adjacent individual electrode cells 100 through a connector 200, the electrode body can be broken at the cutting portion 111 after separation and capacity formation to form multiple individual electrode cells 100. Compared with the traditional battery cell electrode 10 technology that uses punching to form fracture holes, this can effectively avoid the waste generated during the electrode cell fracture hole processing. In addition, no additional specific cutting tools are required, which can also effectively reduce manufacturing costs.

[0063] Specifically, in some embodiments, the electrode body can be cut into cut portions 111 during the slitting stage by means of mechanical cutting or laser die cutting. However, for the prior art electrode solution that uses punching to form fracture holes with multiple spaced material discharges, a large amount of waste is generated during the punching process, and special punching tools are usually required to ensure fracture quality, which significantly increases manufacturing costs. In the embodiments of this application, cutting can be used to form cut portions 111 on the electrode 10, and two adjacent individual electrode 100s can be fixed by connectors 200. This can fix two adjacent individual electrode 100s to ensure the continuity of the electrode 10, facilitate die cutting of the electrode 10 to form tabs, and facilitate subsequent winding and conveying of the electrode 10.

[0064] It should be noted that, in this embodiment, the cut portion 111 between two adjacent individual electrode sheets 100 can be a completely severed seam, for example, after two adjacent individual electrode sheets 100 are cut, they are pulled apart by a certain distance, and the two adjacent individual electrode sheets 100 cannot be electrically connected by the cut end face. Alternatively, the cut portion 111 between two adjacent individual electrode sheets 100 can also be partially connected, for example, the two segments of the electrode sheets after being cut can be electrically connected by the cut end face or the partially cut position. During capacity formation, due to the expansion and fracture displacement of the electrode sheets, the adjacent electrode sheets are completely disconnected. In some embodiments, the connector 200 has a certain elasticity. This configuration ensures that during the winding or bending of the cell electrode sheet 10, the connector 200 can remain connected to the adjacent individual electrode sheet 100 inside the cell 1, so as to facilitate the processing of the cell electrode sheet 10 into the cell 1.

[0065] Specifically, referring to Figure 1, each individual electrode 100 includes an electrode portion 110 and at least one tab portion 120. The tab portion 120 is connected to at least one side of the electrode portion 110 and is located outside the cut portion 111.

[0066] Understandably, in the cell electrode 10, since the positive and negative electrodes need to be arranged correspondingly, the tabs 120 are usually located on one side of the electrode portion 110. This allows the positive and negative electrodes, after being separated by a separator, to have their tabs 120 located in different directions within the cell 1, thus preventing short circuits. When both sides of the cell electrode 10 have tabs 120, the positive and negative tabs 120 can be alternately arranged to avoid short circuits during the cell 1 process.

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

[0068] Furthermore, when the cell electrode 10 is used in a cylindrical battery, if the tab 120 has the same length as the electrode portion 110 (i.e., the tab 120 is a single piece), it becomes inconvenient to bend the tab 120 towards the central axis of the cylindrical battery during the winding process of the cell electrode 10. Therefore, in this embodiment, by forming multiple spaced tabs 120 on the electrode portion 110, the cell electrode 10 can be easily wound and applied to a cylindrical battery. Of course, in some embodiments, when the cell electrode 10 is used in a sheet battery, since the tabs 120 do not need to be wound and stacked, the tabs 120 can also be a single piece corresponding to the electrode portion 110; this will not be elaborated upon here.

[0069] Furthermore, at least some of the adjacent two electrode portions 110 have a cutting portion 111 between them, and the adjacent two electrode portions 110 are separated from the cutting portion 111.

[0070] In the battery cell electrode 10 of this embodiment, the processing location of the cutting portion 111 generally needs to avoid the tab portion 120 to prevent cutting off the tab portion 120 during the cutting process and to avoid damaging the tab portion 120. In the specific processing, 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 tabless area. The specific location is determined according to the design requirements of the battery cell electrode 10 and is not limited here. Of course, in some embodiments, the cutting portion 111 can be omitted between two adjacent electrode portions 110 to keep them tightly connected.

[0071] In one specific embodiment, the dimension of the cutting portion 111 in the second direction is not greater than the dimension of the electrode portion 110 in the second direction.

[0072] Referring to Figure 1, the dimension of the cutting portion 111 in the second direction is H1, and the dimension of the electrode portion 110 in the second direction is H3. H1 and H3 satisfy the following relationship: H1 ≤ H3. During the specific processing of the electrode 10, the cutting portion 111 may or may not penetrate the electrode 10 in the second direction. When the cutting portion 111 does not penetrate the electrode 10 in the second direction, two adjacent individual electrode pieces 100 can maintain a micro-connection at the cutting portion 111. This arrangement ensures that even if the individual electrode pieces 100 are not separated at the cutting portion 111, they can still be disconnected at the cutting portion 111 after capacity formation. When the cutting portion 111 of the electrode 10 is disconnected in the second direction, the two separated adjacent individual electrode pieces 100 can also be connected by the connector 200 to ensure the continuity of the electrode 10.

[0073] Referring to Figures 1 and 2, in one embodiment, the electrode portion 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 electrode portions 110 are spaced apart to form a cut portion 111.

[0074] Specifically, in some embodiments, the connector 200 can be disposed on one side of the current collector 112, or simultaneously on both sides of the current collector 112, and corresponds to at least one layer of active material 113. The specific arrangement is determined according to the design requirements of the cell electrode 10, and is not limited here. By forming a cut portion 111 between two adjacent individual electrode sheets 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 break of the cut portion 111. The micro-connection of the two adjacent active material layers 113 means that after the individual electrode sheet 100 is cut, the two adjacent individual electrode sheets 100 are directly connected through the connector 200. The two cut segments of the individual electrode sheet 100 can be electrically connected by the break end face or the incompletely cut position, and the expansion of the cell electrode sheet 10 during the formation process can achieve fracture displacement, so that the two adjacent individual electrode sheets 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 individual electrode plates 100 respectively, if the electrode portions 110 of the two individual electrode plates 100 are provided with active material layers 113 on the same side, the connector 200 can contact the active material layers 113 on the two current collectors 112 respectively on the same side. In some embodiments, when the two adjacent electrode portions 110 are not provided with active material layers 113 on the same side, the connector 200 can also be connected to the current collector 112 of one electrode portion 110 and the active material layer 113 of the other electrode portion 110 respectively. Of course, when the two adjacent electrode portions 110 are not provided with active material layers 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 unique limitation here.

[0077] Further, referring to Figure 1, in the second direction, the size of the cutting part 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 they satisfy the following relationships: 1 / 3H3≤H1≤H3; and / or 1 / 3H3≤H4≤H3; and / or H2≤H3.

[0078] In this embodiment, by setting the length of the cutting portion 111 in the second direction to between 1 / 3H3 and H3, it is ensured that the cell electrode 10 can be broken and displaced through expansion after being broken down and sized, so that two adjacent individual electrode pieces 100 can be separated to form multiple individual electrode pieces 100. Furthermore, the active material layer 113 is preferably disposed within the range of the current collector 112 in the second direction. In this case, the connector 200 can extend beyond 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 between 1 / 3H3 and H3, it is ensured that the individual electrode pieces 100 can be connected by the connector 200, thus ensuring continuity during winding.

[0079] Specifically, at least a portion of the orthographic projection of the connector 200 toward the electrode portion 110 is located on the outer side of the active material layer 113.

[0080] In some embodiments, when the width H2 of the active material layer 113 in the second direction is less than the width H3 of the current collector 112, the connector 200 can simultaneously cover the current collector 112 and the tab 120 in the second direction, so that the connector 200 and the single electrode 100 have a larger contact range, thereby improving the connection strength of the connector 200.

[0081] In one embodiment, the edge of the connector 200 projecting toward the electrode portion 110 in the second direction is located between the edge of the active material layer 113 and the edge of the current collector 112.

[0082] This configuration ensures the connection strength between the connector 200 and the single electrode 100 while preventing the end of the connector 200 from extending beyond the current collector 112, thus preventing the connector 200 from contacting the tab 120 and affecting the welding quality of the tab 120.

[0083] In the specific embodiment shown in FIG1, the edge of the connector 200 on the side near the tab 120 is located inside the current collector 112; the edge of the connector 200 on the side away from the tab 120 is at least partially located outside the electrode portion 110.

[0084] As shown in Figure 1, in this embodiment, the upper edge of the connector 200 (located on the side closer to the tab 120) extends beyond the active material layer 113 by a distance of W1, and the lower edge of the connector 200 (located on the side away from the tab 120) extends beyond the single electrode 100 by a distance of W2. In this embodiment, W2 < 5 mm and satisfies the following relationship: W1 < H3 - H2, 1 / 3 H3 < H4 ≤ H3.

[0085] By setting W1 < H3 - H2, when H3 > H2 (i.e., the edge of the active material layer 113 near the tab 120 is located inside the current collector 112), it can be ensured that the connector 200 can maintain connection with the single electrode 100 while shielding the cut section 111 after the battery cell electrode 10 is cut into segments and glued. At the same time, since the edge of the connector 200 near the tab 120 is located inside the current collector 112, it can also avoid cutting the connector 200 when the tab 120 is die-cut, ensuring the quality of the tab die-cutting and avoiding the waste material sticking when cutting the connector 200.

[0086] After the cell electrode 10 is die-cut to form the tab 120, the connector 200 is prevented from extending beyond the electrode portion 110 (i.e., the root of the tab 120). This prevents the connector 200 from being trapped in the tab 120 after the cell electrode 10 is wound and formed, thus affecting the welding quality of the current collector and effectively improving the electrical connection performance of the cell electrode 10. Simultaneously, by setting W2 < 5mm, it is ensured that the lower side of the connector 200 (the side away from the tab 120) does not extend beyond the lower side of the electrode portion 110 (the side away from the tab 120). After the cell electrode 10 is wound and formed, the connector 200 is prevented from being trapped in the tab of another electrode and affecting the welding of the current collector, thus effectively improving the overall electrical connection performance of the cell 1.

[0087] Specifically, as shown in FIGS. 1 and 2, in the first direction, the size of the cutting portion 111 is K1, and 0 < K1 < 200 mm; 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 < K < 20 mm.

[0088] In a specific embodiment, after the single cell electrode 100 is cut and disconnected, the two adjacent single cell electrodes 100 can be pulled apart by a distance of K1 in a direction away from each other and then connected by the connecting member 200. At this time, the connecting member 200 can be provided on the active material layer 113 on at least one side to ensure the overall continuity of the cell electrode 10. As shown in FIG. 4, in one embodiment, the connecting member 200 can be equal to the circumference of the wound cell 1. In the schematic diagram of the cell electrode 10 after winding as shown in FIG. 4, at this time, since the connecting member 200 winds around the circumference of the cell 1 and connects the two single cell electrodes 100 respectively, it is possible to prevent the single cell electrodes 100 from intersecting each other and generating thickness accumulation in one direction in the radial direction of the cell 1, so that the thickness in the circumferential direction of the cell 1 is more uniform, and the stress concentration effect caused by the thickness difference accumulation inside the cell 1 is minimized as much as possible, improving the cycle performance of the cell 1. The length K1 of the cutting portion 111 can be specifically determined according to the design requirements of the cell 1, and can be the circumference of the cell 1 or multiple circumferences, and is not uniquely limited herein.

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

[0090] At the same time, by setting 1 mm < K2 < 20 mm, the contact range of the connecting member 200 with the single cell electrode 100 in the first direction can be ensured, thereby further improving the overall connection strength of the cell electrode 10. The specific setting of K2 needs to ensure that the single cell electrode 100 does not break during winding. When K2 is too small, the cell electrode 10 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, affecting the electrical performance of the cell 1.

[0091] In one embodiment, the connecting member 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 cell electrode 100.

[0092] Referring to Figure 5, in this 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 adhesive surface on the connector 200 is in contact with the single electrode 100. By removing the adhesive from the connector 200, a non-adhesive surface is formed on the connector 200. At this time, the non-adhesive surface is located at the cut portion 111 between two adjacent single electrode 100s. The range of the adhesive removal process is within the range D in Figure 5. With this setting, when the cell electrode 10 is conveyed by the conveying roller 2, the part of the connector 200 facing the conveying roller 2 and located within the cut portion 111 is a non-adhesive surface. When the connector 200 at this point contacts the conveying roller 2, adhesion between the connector 200 and the conveying roller 2 can be avoided. Thus, the conveying quality of the cell electrode 10 can be guaranteed while reducing the overall thickness of the cell electrode 10.

[0093] Of course, when both sides of the active material layer 113 are provided with connectors 200, the portions of the connectors 200 on both sides of the cell electrode 10 located within the cutting portion 111 can contact and adhere to each other regardless of whether they have adhesive surfaces, so as to avoid contact between the adhesive surfaces of the connectors 200 and external components such as the conveyor roller 2. In other embodiments, the connectors 200 can also be connected and fixed to the individual electrode 100 by means of pressing, fusion welding, etc., which is not the only limitation here.

[0094] As shown in Figure 6, the cutting section 111 can be constructed in any of the following shapes: straight, sawtooth (as shown in Figures 6(a) and 6(b)), wavy (as shown in Figure 6(c)), or curved. The specific shape is determined according to the design requirements of the cell electrode 10, and no single limitation is made here.

[0095] In this embodiment, the length of the plurality of individual electrode sheets 100 gradually decreases along the first direction.

[0096] Referring to Figure 7(a), the overall length of the cell electrode 10 is L. After the cell electrode 10 is cut, the lengths of the individual electrode pieces 100 are L1, L2, ..., Ln, where L1 + L2 + ... + Ln = L, and L1 > L2 > ... > Ln. The individual electrode piece 100 of length L1 is located inside the cell 1, and the individual electrode pieces 100 of lengths L2, ..., Ln are arranged sequentially along the spiral direction of the cell 1 towards the outer ring. This arrangement ensures that the capacity of the small electrode pieces in the outer ring of the cell 1 is minimized. When an external force causes a short circuit failure in the outer ring of the cell 1, the failed electrode piece can be limited to the outermost small electrode piece or the second outermost electrode piece, reducing the overall failure risk of the cell 1 and thus effectively improving the safety performance of the cell 1. Specifically, the dimensions of L1, L2, ..., Ln gradually decrease, optionally by a fixed proportion of the piece length, or by a fixed proportion of the capacity of the individual electrode piece 100, or by a fixed proportion of the number of turns, etc. To improve the overall safety performance of cell 1, the single electrode 100 of the last Ln preferably meets the following requirements: the specific energy of the small electrode core where Ln is located is ≤400Wh / L, or the specific energy of the electrode core is ≤200Wh / kg.

[0097] Referring to Figure 7(b), in some other embodiments of this application, after the cell electrode 10 is cut, the lengths of the segments of the individual electrode 100 are L1, L2, ..., Ln, etc., where L1 + L2 + ... + Ln = L0, L1 = L2 = ... = Ln. In other embodiments, L1 ≠ L2 ≠ ... ≠ Ln or a combination of multiple cases. L1, L2, ..., Ln, etc., can be set according to the electrode length, capacity, number of turns, etc.

[0098] In this embodiment, the length of the cell electrode 10 is L, and the length of the nth individual electrode 100 is Ln, satisfying the following relationship: 3%L≤L1≤50%L, where n is an integer and 2≤n. Along the first direction, the dimensions of the multiple individual electrode 100s are L1, L2, ..., Ln, satisfying the following relationship: 0≤Ln-1-Ln≤1 / 2Ln-1, where n is an integer and 2≤n.

[0099] Referring to Figure 3, this application also provides a battery cell 1, which includes a first electrode 10-1, a second electrode 10-2, and a separator 20; the first electrode 10-1 is disposed on one side of the separator 20; the second electrode 10-2 is disposed on the side of the separator 20 opposite to the first electrode 10-1; wherein the first electrode 10-1 and / or the second electrode 10-2 include the battery cell electrode 10 in any of the above embodiments, and either the first electrode 10-1 or the second electrode 10-2 can be a positive electrode and the other can be a negative electrode.

[0100] It is understood that in the battery cell 1 of this embodiment, by setting the battery cell electrode 10 in any of the above embodiments, the battery cell electrode 10 of this embodiment forms a cutting portion 111 by cutting on the electrode body, and then two adjacent individual electrode sheets 100 are connected by the connector 200. After the electrode body is divided and tested, it can be broken at the cutting portion 111 to form multiple individual electrode sheets 100. Compared with the traditional battery cell electrode 10 technology that uses punching to form a fracture hole, it can effectively reduce the waste generated during the electrode processing, and at the same time, it does not require additional specific tools, and can also effectively reduce manufacturing costs, thereby reducing the overall manufacturing cost of battery cell 1.

[0101] Specifically, when the battery cell 1 has a wound structure, during the cycling process, the battery cell 1 will generate an expansion force that diffuses from the inside out. When the expansion force is too large, the brittleness of the battery cell electrode 10 may cause the battery cell electrode 10 to tear. In this embodiment, the battery cell electrode 10, through the above-mentioned arrangement, allows the battery cell 1 to completely break apart during the subsequent formation and capacity testing stage when the battery cell electrode 10 is cut with micro-connectors, as the battery cell electrode 10 can be displaced at the cutting part 111 under the expansion force. Each segment of the battery cell electrode 10 has at least one effective tab 120, which allows the battery cell electrode 10 to maintain electrical connection after breakage, ensuring the electrochemical performance of the battery cell 1 and improving the service life of the battery cell 1. When the battery cell electrode 10 is completely cut and pulled apart, the segmented individual electrode 100 is connected by the connector 200, ensuring the continuity of the battery cell electrode 10 before winding and maintaining the multi-segment characteristics of the battery cell electrode 10 in the battery cell 1.

[0102] In some embodiments, the positive electrode can be the cell electrode 10 of any of the above embodiments. Similarly, in some embodiments, the negative electrode can also be the cell electrode 10 of any of the above embodiments, and is segmented corresponding to the positive electrode. Each segment of the negative electrode has at least one tab 120. Alternatively, the negative electrode can be a continuous structure corresponding to the positive electrode, and preferably, the negative electrode covers the positive electrode. In this embodiment, the connector 200 can separate the outer ring small electrode core from the inner ring small electrode core. The flame-retardant material can reduce the risk of short circuits caused by the outer ring affecting the inner ring small electrode core, thus improving the safety performance of the cell 1.

[0103] In the embodiment, the diaphragm 20, the first electrode 10-1 and the second electrode 10-2 are wound to form the battery cell 1. In the extending direction of the battery cell electrode 10, the size of the single electrode 100 located inside the battery cell 1 is not less than the size of the single electrode 100 located outside the battery cell 1.

[0104] This configuration ensures that the capacity of the outermost small electrode core of cell 1 is minimized. In the event of a short circuit failure of the outer ring of cell 1 due to external forces, the failed electrode core can be limited to the outermost small electrode core or the second outermost electrode core, reducing the overall failure risk of cell 1 and effectively improving its safety performance. Specifically, the dimensions of L1, L2, ..., Ln gradually decrease, optionally by a fixed ratio based on the sheet length, a fixed ratio based on the capacity of a single electrode 100, or a fixed ratio based on the number of turns, etc. To improve the overall safety performance of cell 1, the single electrode 100 at the very end Ln preferably satisfies a specific energy of ≤400Wh / L for the small electrode core containing Ln, or a specific energy of ≤200Wh / kg for the electrode core.

[0105] This application also provides a battery comprising the cell electrode 10 in any of the above embodiments, or the cell 1 in any of the above embodiments; wherein, a plurality of individual electrode sheets 100 expand and break off from the cut portion 111 after being formed and tested for capacity.

[0106] It is understood that in the battery of this embodiment, by setting the cell electrode 10 in any of the above embodiments, the cell electrode 10 of this embodiment is formed by cutting a cutting portion 111 on the electrode body, and then two adjacent single electrode pieces 100 are connected by a connector 200. After the formation and capacity testing, the electrode body can be broken at the cutting portion 111 to form multiple single electrode pieces 100. Compared with the traditional technical solution of cell electrode 10 that uses punching to form a fracture hole, it can effectively reduce the waste generated during the electrode processing, and at the same time, it does not require additional specific tools, and can also effectively reduce the manufacturing cost, 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, cylindrical batteries generate an expansion force that diffuses from the inside out during cycling. When the expansion force is too large, the brittleness of the positive electrode sheet may cause it to tear. By using the cell electrode sheet 10 in any of the above embodiments, the positive electrode sheet can be displaced at the cut point and completely broken when subjected to the expansion force during the subsequent formation and capacity testing stage. Each segment of the positive electrode sheet has at least one effective tab 120, which allows the positive electrode sheet to maintain electrical connection after breakage, ensuring the electrochemical performance of the battery and improving its lifespan. When the positive electrode sheet is completely cut and pulled apart, the segmented electrode sheets are connected by the connector 200, ensuring the continuity of the positive electrode sheet before winding and maintaining the multi-segment characteristics of the positive electrode sheet in the cell 1. The cylindrical battery uses a continuous winding method during winding, which can avoid misalignment caused by adhesive bonding of multi-segment electrode sheets and improve production efficiency. Of course, in some embodiments, the battery can also be a flat battery, which is not the only limitation.

[0109] This 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, wherein 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 this embodiment, the electrical equipment can be a vehicle, which can be a new energy vehicle, such as a pure electric vehicle (PEV / BEV), a range-extended electric vehicle (REEV), a hybrid electric vehicle (HEV), or a fuel cell electric vehicle. The vehicle can also be any vehicle equipped with a battery. The electrical equipment can also be an energy storage station.

[0111] It is understood that, in the electrical equipment of this embodiment, by using a battery or cell 1 having the cell electrode 10 of 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," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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 device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0113] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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 mechanical connection or an electrical 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 the embodiments of the present invention based on the specific circumstances.

[0114] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0115] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate 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: The electrode body includes a plurality of individual electrode sheets (100) arranged along a first direction, and a cut portion (111) extending along a second direction is provided between two adjacent individual electrode sheets (100), wherein the first direction intersects the second direction; each individual electrode sheet (100) includes an electrode portion (110) and at least one tab portion (120), the tab portion (120) being connected to at least one side of the electrode portion (110) and located outside the cut portion (111); the electrode portion (110) includes an active material layer (113); and a connector (200). The connector (200) is connected to two adjacent single electrode sheets (100) on both sides of the cut portion (111); the electrode body expands to disconnect the two adjacent single electrode sheets (100) from the cut portion (111); the connector (200) is connected to the active material layer (113), at least a portion of the orthographic projection of the connector (200) toward the electrode portion (110) is located on the outer side of the active material layer (113), and the distance between the edge of the connector (200) and the edge of the cut portion (111) on the inner side of the connector (200) is K2, and 1 mm. <K2<20mm。 2. The cell electrode (10) according to claim 1, characterized in that, At least some of the adjacent two electrode portions (110) have the cutting portion (111) between them, and the adjacent two electrode portions (110) are disconnected from the cutting portion (111).

3. The cell electrode (10) according to claim 2, characterized in that, The size of the cut portion (111) in the second direction is not greater than the size of the electrode portion (110) in the second direction.

4. The cell electrode (10) according to any one of claims 1-3, characterized in that, The electrode portion (110) further includes a current collector (112), 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 electrode portions (110) are spaced apart to form the cut portion (111).

5. The cell electrode (10) according to claim 4, 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 they satisfy the following relationships: 1 / 3H3≤H1≤H3; and / or 1 / 3H3≤H4≤H3; and / or H2≤H3.

6. The cell electrode (10) according to claim 4, characterized in that, The edge of the connector (200) projecting toward the electrode portion (110) in the second direction is located between the edge of the active material layer (113) and the edge of the current collector (112).

7. The cell electrode (10) according to claim 6, characterized in that, The edge of the connector (200) on the side near the tab (120) is located inside the current collector (112); the edge of the connector (200) on the side away from the tab (120) is at least partially located outside the electrode portion (110).

8. The cell electrode (10) according to claim 7, characterized in that, On the side of the connector (200) away from the tab (120), the distance between the edge of the connector (200) and the edge of the single electrode (100) is W2, and W2 < 5 mm.

9. The cell electrode (10) according to any one of claims 1-3, characterized in that, In the first direction, the size of the cutting portion (111) is K1, and 0 <K1<200mm。 10. The cell electrode (10) according to any one of claims 1-3, characterized in that, The connector (200) is an adhesive layer having an adhesive surface and a non-adhesive surface, the adhesive surface facing the single electrode (100).

11. The cell electrode (10) according to any one of claims 1-3, characterized in that, The cutting section (111) is constructed as any one of the following: straight, sawtooth, wavy, or curved.

12. The cell electrode (10) according to any one of claims 1-3, characterized in that, Along the first direction, the length of the plurality of individual electrode sheets (100) gradually decreases.

13. The cell electrode (10) according to claim 12, characterized in that, The length of the cell electrode (10) is L, and the length of the nth individual electrode (100) is L. n And satisfy the following relationship: 3%L≤L1≤50%L.

14. The cell electrode (10) according to claim 12, characterized in that, Along the first direction, the dimensions of the plurality of individual electrode sheets (100) are L1, L2, ..., L n And satisfy the following relationship: 0≤L n-1 - L n ≤1 / 2L n-1 n is an integer, 2≤n.

15. The cell electrode (10) according to any one of claims 1-3, characterized in that, Along the first direction, the lengths of the plurality of individual electrode sheets (100) are equal.

16. A battery cell (1), characterized in that, include: Diaphragm (20); First electrode (10-1), disposed on one side of the diaphragm (20); And a second electrode (10-2) is disposed on the side of the diaphragm (20) opposite to the first electrode (10-1); wherein the first electrode (10-1) and / or the second electrode (10-2) includes the cell electrode (10) as described in any one of claims 1-15.

17. The battery cell (1) according to claim 16, characterized in that, The diaphragm (20), the first electrode (10-1) and the second electrode (10-2) are wound to form the battery cell (1). In the extension direction of the battery cell electrode (10), the size of the single electrode (100) located inside the battery cell (1) is not less than the size of the single electrode (100) located outside the battery cell (1).

18. A battery, characterized in that, include: The cell electrode (10) as described in any one of claims 1-15, or the cell (1) as described in claim 16 or 17; wherein the plurality of said individual electrode sheets (100) expand after being formed and broken off from the cut portion (111).

19. The battery according to claim 18, characterized in that, The battery is a cylindrical battery.

20. An electrical appliance, characterized in that, It includes an electrical device, and a battery as described in claim 18 or 19, or a battery cell (1) as described in claim 16 or 17, 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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