Pole piece, battery cell, battery and electric device

Abstract

The utility model relates to a pole piece, a battery cell, a battery and a power utilization device, and the pole piece comprises an active layer which comprises a nick region and a plurality of convex surface regions, and the nick region separates the convex surface regions. The nick region is recessed along the thickness direction of the active layer relative to the convex surface region. The total length L of the nick region, the length L1 of the active layer and the width L2 of the active layer meet the condition that L / (L1 + L2) is greater than 0 and less than L1 / L2. According to the technical scheme, the battery capacity can be considered while the electrode liquid permeation effect and the exhaust effect of the pole piece are improved so as to improve the cycle performance of the battery.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to pole pieces, battery cells, battery packs and electrical devices. Background Art

[0002] The capacity of power cells is generally high, and there are many pole pieces inside a single cell. In order to improve the production efficiency of the cell, the pole pieces of the single cell tend to be longer and larger. For larger and longer pole pieces, the pole piece area is large, and it is difficult for the electrolyte to infiltrate the central area of ​​the pole piece. The electrolyte infiltration effect in the central area is poor. It is difficult for lithium ions to be embedded in the fully charged state, which will cause the center of the pole piece to turn black. After long-term circulation, it will cause lithium precipitation in this area, causing the cell cycle to plunge. Moreover, after the size of the pole piece is increased, the small amount of gas generated inside the cell during the formation stage is easy to remain between the pole pieces, and form spots in the local area of ​​the pole piece. The location of the spots will accelerate lithium precipitation, resulting in a poor pole piece interface, which is not conducive to the stability of the cell cycle. Utility Model Content

[0003] Based on this, the present application provides an electrode, a battery cell, a battery and an electrical device, which can not only accelerate the infiltration of the electrolyte into the electrode, but also facilitate the discharge of gas between the electrode pieces, alleviate lithium plating in the battery cell, and improve the cycle stability performance of the battery cell.

[0004] A pole piece, comprising:

[0005] An active layer, the active layer comprising a notched area and a plurality of convex areas, the notched area separating the convex areas; the notched area being recessed relative to the convex area along a thickness direction of the active layer;

[0006] The total length L of the notched area, the length L1 of the active layer, and the width L2 of the active layer satisfy: 0<L / (L1+L2)<L1 / L2.

[0007] In some embodiments, the notched area at least penetrates the end surface of the active layer, and the end surface includes at least one end surface of the active layer in its width direction and / or at least one end surface of the active layer in its length direction.

[0008] In some embodiments, the score area includes at least one score segment, all of the score segments together separate all of the convex areas, and each of the score segments extends in a straight line or in a zigzag manner.

[0009] In some embodiments, the at least one scoring segment includes a first scoring segment, a plurality of the first scoring segments are arranged at intervals in the length direction of the active layer, and the first scoring segments are separated between adjacent convex regions;

[0010] Each of the first notch segments extends from one end to the other end in the width direction of the active layer.

[0011] In some embodiments, the at least one score segment includes a second score segment, wherein the second score segment extends from one end to the other end in the width direction of the active layer and intersects with all of the first score segments.

[0012] In some embodiments, the score area includes a plurality of score groups, each of the score groups includes a plurality of first score segments spaced apart and arranged in parallel along the length direction; the first score segments of each score group are arranged to intersect.

[0013] In some embodiments, at least some of the score segments are staggered with at least one other score segment.

[0014] In some embodiments, the width w of the notched area, the depth h of the notched area, and the thickness H of the active layer satisfy:

[0015] w≤h; and / or, 0.15≤(h / H)≤0.75.

[0016] In some embodiments, the w satisfies: 1 μm≤w≤500 μm; and / or, the h satisfies: 1 μm≤h≤500 μm.

[0017] A battery cell comprises the pole piece as described in the above embodiment.

[0018] A battery comprises the battery cell as described in the above embodiment.

[0019] An electrical device comprises the battery as described in the above embodiment, wherein the battery is used to provide electrical energy.

[0020] In actual application, the notched area on the above-mentioned pole piece, battery cell, battery and power-consuming device can be used as a channel for electrolyte penetration during the injection stage, at least guiding the electrolyte to flow to the middle area of ​​the pole piece, so as to alleviate the problem of lithium deposition on the pole piece caused by poor electrolyte penetration in the middle area of ​​the pole piece, which helps to improve the cycle stability of the battery cell. Moreover, the notched area on it can also be used as a channel for gas discharge during the formation stage, at least guiding the gas generated in the middle area of ​​the pole piece to be discharged outside the pole piece, alleviating the problem of accelerated lithium deposition caused by spots formed by residual gas, which helps to improve the cycle stability of the battery cell.

[0021] In addition, L, L1, and L2 satisfy: 0<L / (L1+L2)<L1 / L2, and the total length of the notched area can take a larger value as the ratio of L1 / L2 increases, so that the active layer area passed by the notched area can be wider, and a longer channel for electrolyte infiltration and exhaust can be set on the pole piece, which helps to improve the electrolyte infiltration effect and exhaust effect. Moreover, within the above range, the notched area occupies an appropriate area of ​​the active layer, has little effect on the active material of the active layer, and has little effect on the battery capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0023] Figure 1 Schematic diagram of the structure of pole pieces in some embodiments.

[0024] Figure 2 Schematic diagrams of the structures of pole pieces in other embodiments.

[0025] Figure 3 Schematic diagrams of the structures of pole pieces in other embodiments.

[0026] Figure 4 Schematic diagrams of the structures of pole pieces in other embodiments.

[0027] Figure 5 Schematic diagrams of the structures of pole pieces in other embodiments.

[0028] The reference numerals in the specific implementation manner are as follows:

[0029] 10. Pole piece; 11. Active layer; 12. Notched area; 12a. Notched segment; a1. First notched segment; a2. Second notched segment; 13. Pole ear. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] In the description of the present application, it should be understood that terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships, if any, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In addition, if present, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In this application, unless otherwise clearly specified and limited, if any, the terms "installed", "connected", "connected", "fixed" and the like 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, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] In the present application, if it appears, unless otherwise clearly specified and limited, a first feature “above” or “below” a 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, a first feature “above”, “above” and “above” a 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. A first feature “below”, “below” and “below” a 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.

[0035] It should be noted that, if present, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0036] In view of the problems mentioned in the background technology, the embodiments of the present application propose a pole piece.

[0037] Reference Figure 1The pole piece 10 provided in the embodiment of the present application includes an active layer 11, and the active layer 11 includes a notched area 12 and a plurality of convex areas 14, and the notched area 12 separates the convex areas 14. The notched area 12 is recessed relative to the convex area 14 along the thickness direction of the active layer 11. The total length L of the notched area 12, the length L1 of the active layer 11, and the width L2 of the active layer 11 satisfy: 0<L / (L1+L2)<L1 / L2.

[0038] The active layer 11 is the surface structure of the pole piece 10, which is formed by the electrode active material. In addition to the active layer 11, the pole piece 10 also includes a current collector, and the active layer 11 is arranged on one side or both sides in the thickness direction of the current collector. The active layer 11 is usually obtained by coating the electrode active slurry on the current collector. The current collector is used to collect current and can be a metal current collector, a composite current collector, etc. The portion of the current collector that is not coated with the active layer 11 can be used as the pole ear 13 of the pole piece 10 for connecting to an external circuit.

[0039] The active layer 11 may be a positive electrode active layer 11 or a negative electrode active layer 11. The positive electrode active layer 11 contains a positive electrode active material, which includes but is not limited to lithium cobalt oxide, lithium nickel oxide, nickel cobalt manganese ternary material, nickel cobalt aluminum oxide, lithium manganese oxide, lithium iron phosphate, lithium iron titanate, cobalt trifluoride, etc. The negative electrode active layer 11 contains a negative electrode active material, which includes but is not limited to graphite, soft carbon, hard carbon, lithium titanate, metallic lithium, tin-based materials, silicon-based materials, etc.

[0040] It can be understood that the width direction of the active layer 11 is consistent with the width direction of the pole piece 10, the length direction of the active layer 11 is consistent with the length direction of the pole piece 10, and the thickness direction of the active layer 11 is consistent with the thickness direction of the pole piece 10. The notched area 12 is recessed relative to the convex area 14 along the thickness direction of the active layer 11.

[0041] It is understandable that the scored area 12 is generally arranged in a thin strip shape, that is, its width dimension is smaller than its dimension in the extension direction. Specifically, the scored area 12 can be processed on the active layer 11 by laser cutting, gravure coating and gravure rolling, and the remaining area is used as the convex area 14. It is understandable that the area of ​​the convex area 14 is larger than the area of ​​the scored area 12, providing the main reaction interface of the active layer. The specific layout between the multiple convex areas 14 is flexibly set according to the specific structure of the scored area 12.

[0042] The notched area 12 separates the convex areas 14. Specifically, the notched area 12 may completely separate two adjacent convex areas 14, or may partially separate two adjacent convex areas 14. Since the convex areas 14 are separated by the notched area 12, the notched area 12 penetrates deep into the inner area of ​​the active layer 11, and the channel formed by the notched area 12 can accelerate the penetration of the electrolyte into the electrode 10, and accelerate the flow of gas in the electrode 10 to discharge the gas.

[0043] The total length L of the notched area 12 is its total extended length. Generally, the length L1 of the active layer 11 is not less than the width L2 of the active layer 11. For a long strip-shaped pole piece 10, the length L1 of the active layer 11 is generally much greater than the width L2 of the active layer 11. At this time, the pole piece 10 is suitable for winding a battery cell.

[0044] In the embodiment of the present application, L, L1, and L2 satisfy: 0<L / (L1+L2)<L1 / L2. As the pole piece 10 is longer, that is, the ratio of L1 / L2 is larger, the value of L is often designed to be larger to meet the electrode liquid penetration effect and exhaust effect of the longer pole piece 10. However, the value of L should not be too large, otherwise the notched area 12 occupies too much area of ​​the active layer 11, reducing the active material content of the active layer 11, which is not conducive to the battery capacity.

[0045] In actual application, the notched area 12 of the above-mentioned pole piece 10 can be used as a channel for electrolyte penetration during the injection stage to guide the electrolyte to flow to the middle area of ​​the pole piece 10, so as to alleviate the problem of lithium deposition in the pole piece 10 caused by poor electrolyte penetration in the middle area of ​​the pole piece 10, which helps to improve the cycle stability of the battery cell. Moreover, the notched area 12 can also be used as a channel for gas discharge during the formation stage, at least to guide the gas generated in the middle area of ​​the pole piece 10 to be discharged outside the pole piece 10, so as to alleviate the problem of accelerated lithium deposition caused by spots formed by residual gas, which helps to improve the cycle stability of the battery cell.

[0046] In addition, L, L1, and L2 satisfy: 0<L / (L1+L2)<L1 / L2, and the total length of the notched area 12 can take a larger value as the ratio of L1 / L2 increases, so that the area of ​​the active layer 11 through which the notched area 12 passes can be wider, and a longer channel for electrolyte infiltration and exhaust can be set on the pole piece 10, which helps to improve the electrolyte infiltration effect and exhaust effect. Moreover, within the above range, the notched area 12 occupies an appropriate area of ​​the active layer 11, has little effect on the active material of the active layer 11, and has little effect on the battery capacity.

[0047] It is understandable that in the final stage of the battery cell cycle, the notched area 12 can also be used to release the expansion force of the pole piece 10 .

[0048] In some embodiments, the width w of the notched region 12, the depth h of the notched region 12, and the thickness H of the active layer 11 satisfy: w≤h; and / or, 0.15≤(h / H)≤0.75.

[0049] The width w of the scored area 12 refers to the average width of the scored area 12 in the horizontal direction on a cross section perpendicular to its extension direction. Usually, on the cross section, the width of the scored area 12 is equal everywhere, so the width w of the scored area 12 can be taken as the width of the notch of the scored area 12.

[0050] The depth h of the score area 12 refers to the average depth of the score area 12 in the vertical direction on a cross section perpendicular to its extension direction. Usually, the depth of the score area 12 is equal at each place on the cross section.

[0051] The thickness H of the active layer 11 refers to its dimension in the thickness direction of the pole piece 10. The thickness of the active layer 11 is usually uniform everywhere.

[0052] The width w of the notched area 12 does not exceed its depth h. Under the condition of the same cross-sectional area (i.e., under the condition of the same active material loss), the depth h is larger than the width w. The electrolyte can penetrate deeply into the interior of the active layer 11 through the notched area 12, thereby enhancing the migration ability of lithium ions in the active layer 11 and helping to improve the performance of the battery cell.

[0053] The thickness H of the active layer 11 and the depth h of the notched area 12, the greater the ratio of h / H, the more active material is consumed, which is not conducive to the battery cell capacity, and the smaller the ratio of h / H, the worse the electrolyte infiltration effect, the more serious lithium precipitation of the pole piece 10, which is not conducive to the battery cell cycle performance. When h / H is within the range of 0.15 to 0.75, the pole piece 10 has a better electrolyte infiltration effect, which can take into account both good battery cell capacity and battery cell cycle performance.

[0054] Specifically, h / H can be selected as 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 and any value between adjacent selected values.

[0055] In some embodiments, w satisfies: 1 μm ≤ w ≤ 500 μm. Specifically, w is 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 50 μm, 80 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, etc. When w is within the above range, the electrolyte wetting effect and the exhaust effect are both good, and the battery cell capacity and cycle performance are good.

[0056] In some embodiments, h satisfies: 1 μm ≤ h ≤ 500 μm. Specifically, h is 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 50 μm, 80 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, etc. When h is within the above range, the electrolyte infiltration effect and the exhaust effect are both good, and the battery cell capacity and cycle performance are good.

[0057] In some embodiments, the notched area 12 runs through the end surface of the active layer 11 , and the end surface includes at least one end surface of the active layer 11 in its width direction and / or at least one end surface of the active layer 11 in its length direction.

[0058] When the notched area 12 extends to the end surface of the active layer 11, the notched area 12 is connected to the outside of the active layer 11 through the end surface, so that the electrolyte can penetrate into the middle area of ​​the active layer 11 through the notched area 12, and the gas generated in the middle area of ​​the active layer 11 during the formation stage can be smoothly discharged from the pole piece 10 through the notched area 12. In this way, the exhaust efficiency and the penetration efficiency can be improved.

[0059] In specific applications, the notched area 12 may extend only to the two end surfaces of the active layer 11 in the width direction or only to the two end surfaces of the active layer 11 in the length direction, or partially extend to the end surfaces of the active layer 11 in the width direction and partially extend to the end surfaces of the active layer 11 in the length direction.

[0060] Specifically in some embodiments, the notched area 12 at least penetrates the end of the active layer 11 in the width direction.

[0061] It should be noted that for the long strip-shaped electrode 10, most of them are formed into a battery cell by winding. For the wound battery cell, the electrolyte is easier to infiltrate into the interior of the battery cell from the width direction of the electrode 10. Therefore, in the embodiment of the present application, the notched area 12 at least passes through one or both ends in the width direction of the active layer 11. The electrolyte infiltration path and the gas discharge path are both shorter, which helps the electrolyte to infiltrate into the interior of the electrode 10 and also helps the gas inside the electrode 10 to be discharged quickly.

[0062] In some embodiments, reference Figures 1 to 5 The scored area 12 includes at least one scored segment 12a, and all the scored segments 12a together separate all the convex areas 14. Each scored segment 12a extends in a straight line or in a zigzag manner.

[0063] The notched section 12a is generally in the shape of a thin strip. Specifically, it can be extended in a straight line or a curve. The notched section 12a in the shape of a thin strip will not occupy too much area of ​​the active layer 11, and can increase the active material content of the active layer 11, which is beneficial to the improvement of the battery capacity.

[0064] Generally, there are multiple scored segments 12a, and when the multiple scored segments 12a are evenly distributed on the active layer 11, the scored area 12 can guide the electrolyte to more evenly penetrate into the interior of the active layer 11. When there is only one scored segment 12a, the scored segment 12a can extend in a meandering manner like a river to expand the area of ​​the active layer 11 through which it passes, thereby improving the penetration effect.

[0065] In some embodiments, reference Figure 1 and Figure 2At least one scoring segment 12a includes a first scoring segment a1, and a plurality of first scoring segments a1 are arranged at intervals in the length direction of the active layer 11, and the first scoring segments a1 are separated between adjacent convex areas 14. Each first scoring segment a1 extends from one end to the other end in the width direction of the active layer 11.

[0066] like Figure 1 As shown, the first notch segment a1 extends in a straight line, and the first notch segment a1 is easier to process. Figure 2 As shown, the first notch segment a1 extends in a curved shape. The longer the first notch segment a1 extends, the wider the area of ​​the active layer 11 it passes through, and the better the electrolyte infiltration effect and the exhaust effect.

[0067] At this time, the first notch segment a1 can guide the electrolyte to extend from both ends of the active layer 11 in the width direction to the middle area thereof, and guide the gas to be discharged from the middle area of ​​the active layer 11 to both ends in the width direction thereof, and both the electrolyte penetration efficiency and the exhaust efficiency are relatively high.

[0068] In a further embodiment, referring to Figure 3 At least one scoring segment 12a includes a second scoring segment a2, which extends from one end to the other end of the active layer 11 in the width direction and intersects with all the first scoring segments a1.

[0069] Specifically, the second notch segment a2 can extend in a straight line or a curve, and the specific extension is not limited. The second notch segment a2 intersects with all the first notch segments a1, and the two are staggered and connected, so that the electrolyte can infiltrate into the inside of the pole piece 10 from both ends in the length direction and both ends in the width direction of the active layer 11, and the gas can be discharged from the inside of the pole piece 10 from both ends in the length direction and both ends in the width direction of the active layer 11, which increases the electrolyte infiltration path and gas exhaust path, and improves the electrolyte infiltration efficiency and exhaust efficiency of the pole piece 10.

[0070] For some specific embodiments, refer to Figure 4 The scoring area 12 includes a plurality of scoring groups, each scoring group includes a plurality of first scoring segments a1 spaced apart and arranged in parallel along the length direction, and the first scoring segments a1 of each scoring group are arranged to intersect.

[0071] by Figure 4 For example, Figure 4 The first score segment a1 in the middle extends in a straight line along the width direction of the active layer 11, and serves as the first score segment a1 of one score group. The first score segment a1 in another score group extends in a straight line along a direction intersecting the width direction of the active layer 11. Of course, in other embodiments, each first score segment a1 in a score group may also extend in a curve, and is not limited to Figure 4 The scheme shown.

[0072] At this time, the two first notch segments a1 of the two notch groups intersect and communicate with each other, which increases the probability of the electrolyte infiltrating into the middle area of ​​the active layer 11 and also increases the probability of gas discharge from the middle area of ​​the active layer 11 .

[0073] In some other embodiments, referring to Figure 5 , at least part of the scoring segments 12a are alternately arranged with at least one remaining scoring segment 12a.

[0074] The plurality of notched segments 12a may be staggered to form a notched area 12 in a tree-like, radial, grid-like, etc. When the notched area 12 passes through the end surface of the active layer 11 , at least part of the notched segments 12a extend to the end surface of the active layer 11 .

[0075] At this time, the staggered notched segments 12a increase the infiltration path and exhaust path of the electrode liquid, which helps to improve the uniformity of electrolyte infiltration, thereby improving the infiltration efficiency and exhaust efficiency, and helps to improve the cycle performance of the battery cell.

[0076] In addition, the embodiment of the present application further provides a battery cell, including the pole piece 10 in the above embodiment. The battery cell has all the beneficial effects of the above embodiment. The pole piece 10 can be used as a positive pole piece or a negative pole piece.

[0077] In a specific example, the battery cell includes a shell, an end cap and an electrode assembly, and the shell and the end cap cooperate to form an internal space of the battery cell, and the electrode assembly is contained in the internal space. The electrode assembly is a unit for electrochemical reaction in the battery cell, usually including a positive electrode sheet, a negative electrode sheet and a separator, which is arranged between the positive electrode sheet and the negative electrode sheet, plays the role of insulating and isolating the positive electrode sheet and the negative electrode sheet, and can allow ions to pass through itself. The separator can be a diaphragm. The electrode assembly can be a winding type or a laminated type. Generally, a pole, an explosion-proof structure, an injection hole, etc. can be arranged on the end cap. The pole is electrically connected to the electrode assembly for connection with an external circuit. The explosion-proof structure can break and release pressure when the internal air pressure of the battery cell exceeds a threshold value, which can be an explosion-proof valve, a thinning notch area, etc. The injection hole is used to inject electrolyte into the battery cell. The battery cell can be a primary battery cell, a secondary battery cell, etc. The specific shape can be a cylindrical battery cell, a square battery cell, etc.

[0078] Regarding the specific structure of the battery cell, those skilled in the art can make routine settings.

[0079] In addition, the present application also provides a battery, which includes the above-mentioned battery cell. In addition to the battery cell, in some embodiments, the battery also includes a box. Multiple battery cells are arranged side by side in the box. A battery pipeline system for managing the battery cells and a liquid cooling structure for dissipating heat from the battery cells can also be arranged in the box. Those skilled in the art can make conventional settings regarding the specific structure of the battery.

[0080] In addition, the embodiment of the present application also provides an electric device, including the above-mentioned battery, which is used to provide electric energy. The electric device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, etc. Taking the electric device as a vehicle as an example, the battery can be set at the rear, front or bottom of the vehicle, and the battery can provide electric energy for the drive of the vehicle, and can also provide electric energy for the control system of the vehicle.

[0081] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A pole piece, characterized in that: The pole piece comprises: An active layer (11), the active layer (11) comprising a notched area (12) and a plurality of convex areas (14), the notched area (12) separating the convex areas (14); the notched area (12) being arranged concave relative to the convex area (14) along the thickness direction of the active layer (11); The total length L of the notched area (12), the length L1 of the active layer (11), and the width L2 of the active layer (11) satisfy the following relationship: 0<L / (L1+L2)<L1 / L2.

2. The pole piece according to claim 1, characterized in that: The notched area (12) runs through the end surface of the active layer (11), and the end surface includes at least one end surface of the active layer (11) in its width direction and / or at least one end surface of the active layer (11) in its length direction.

3. The pole piece according to any one of claims 1 to 2, characterized in that: The scored area (12) includes at least one scored segment (12a), all of the scored segments (12a) jointly separate all of the convex areas (14), and each of the scored segments (12a) extends in a straight line or in a zigzag manner.

4. The pole piece according to claim 3, characterized in that: The at least one scored segment (12a) comprises a first scored segment (a1), a plurality of the first scored segments (a1) are arranged at intervals in the length direction of the active layer (11), and the first scored segments (a1) are separated between adjacent convex areas (14); Each of the first notch segments (a1) extends from one end to the other end of the active layer (11) in the width direction.

5. The pole piece according to claim 4, characterized in that: The at least one scoring segment (12a) includes a second scoring segment (a2), wherein the second scoring segment (a2) extends from one end to the other end in the width direction of the active layer (11) and intersects with all of the first scoring segments (a1); and / or, The scoring area (12) includes a plurality of scoring groups, each of which includes a plurality of first scoring segments (a1) spaced apart and arranged in parallel along the length direction; the first scoring segments (a1) of each of the scoring groups are arranged to intersect with each other.

6. The pole piece according to any one of claims 1 to 2, characterized in that: The width w of the notched area (12), the depth h of the notched area (12), and the thickness H of the active layer (11) satisfy: w≤h; and / or, 0.15≤(h / H)≤0.

75.

7. The pole piece according to claim 6, characterized in that: The w satisfies: 1 μm≤w≤500 μm; and / or, the h satisfies: 1 μm≤h≤500 μm.

8. A battery cell, characterized in that: Comprising a pole piece as claimed in any one of claims 1 to 7.

9. A battery, characterized in that: Comprising the battery cell as claimed in claim 8.

10. An electrical device, characterized in that: Comprising a battery as claimed in claim 9, the battery is used to provide electrical energy.

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