Pole piece, pole piece belt, battery cell, energy storage device and electric equipment

Abstract

The utility model discloses a pole piece, pole piece belt, battery cell, energy storage device and electric equipment, pole piece includes: the body, the body has a plurality of apex angles, at least one apex angle is formed by the cooperation of first edge, second edge and third edge, at least one of first edge and second edge is the linear edge, and the third edge is the linear edge. One end of the third edge is connected with the edge of the first edge, the other end of the third edge is connected with the edge of the second edge, the third edge sinks towards the interior of the body, and the included angle between the third edge and the linear edge at the combination position is not smaller than 90 degrees. According to the pole piece disclosed by the embodiment of the utility model, the body is adopted, the body is provided with the vertex angles, and at least one vertex angle comprises the linear edge and the opening structure which is sunken inwards, so that the problems of pole piece tearing, corner folding and the like possibly caused in the slitting process of a pole piece belt can be solved at least, and the pole piece has the advantages of convenience in manufacturing, low manufacturing cost, stable structure and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and more specifically, to a pole piece, a pole piece belt, a battery cell, an energy storage device and an electrical equipment. Background Art

[0002] Nowadays, with the wide popularization of new energy vehicles, the demand for lithium-ion and sodium-ion batteries is increasing year by year. The existing battery manufacturing processes can be divided into two types: one is the winding process, which means that the positive and negative pole pieces on both sides of the separator are wound to form a cylindrical or elliptical battery cell; the other is the stacking process, in which multiple layers of positive electrode sheets and negative electrode sheets are stacked to form a stacked core structure. Compared with the winding process, the space utilization rate of the stacked core is often higher and the structure is more stable.

[0003] Currently, the most commonly used stacking process in the market is the Z-shaped stacking. After the positive and negative pole pieces are grabbed on both sides of the separator, they are stacked layer by layer, and after hot pressing and compaction, a stacked core is formed; however, during this process, there is a risk of folding at the corners around the pole piece, resulting in the separator being pierced after hot pressing and causing the stacked core to short circuit, greatly reducing the yield and performance of the battery.

[0004] In order to solve the short-circuit risk, it is usually necessary to design the size and the periphery of the pole piece. It is usually required that the active material area of the negative pole piece can completely cover the active material area of the positive pole piece, and the outer round corners are designed around the pole piece to prevent the chamfer from folding. The force at the connection of the two round corners is unstable, so there is a greater risk of tearing and breaking the belt during the production process. Summary of the Utility Model

[0005] An object of the utility model is to provide a pole piece, which can at least solve the technical problem of pole piece slitting in the prior art.

[0006] Another object of the utility model is to provide a pole piece belt, which includes the above-mentioned pole piece.

[0007] Another object of the utility model is to provide a battery cell, which includes the above-mentioned pole piece.

[0008] Another object of the utility model is to provide an energy storage device, which includes the above-mentioned battery cell.

[0009] Another object of the utility model is to provide an electrical equipment, which includes the above-mentioned energy storage device.

[0010] In order to achieve the above objects, the utility model provides the following technical solutions.

[0011] The pole piece according to the first aspect embodiment of the present utility model includes: a body having a plurality of top corners, at least one of which is formed by the cooperation of a first side, a second side, and a third side. Wherein, at least one of the first side and the second side is a straight side, one end of the third side is connected to the edge of the first side, the other end of the third side is connected to the edge of the second side, the third side is recessed towards the inside of the body and forms an opening, and the angle between the third side and the straight side at the joint position is not less than 90°.

[0012] Optionally, the first side is a straight side, and the third side includes: a first section, one end of the first section is connected to one end of the second side, and the first section is a straight section; a second section, one end of the second section is connected to the other end of the first section, the other end of the second section is connected to one end of the first side, and the second section is an arc section; wherein, the angle between the second section and the first section at the joint position is not less than 90°; and / or, the angle between the first section and the second side at the joint position is not less than 90°.

[0013] The pole piece belt according to the second aspect embodiment of the present utility model includes: a belt body, after being cut along a straight cutting line on the belt body, at least two pole pieces are formed, and each pole piece is any one of the above-mentioned pole pieces.

[0014] The battery cell according to the third aspect embodiment of the present utility model includes: a first pole piece, a separator, and a second pole piece. The first pole piece and the second pole piece are stacked along a first direction, the separator is located between the first pole piece and the second pole piece, one of the first pole piece and the second pole piece is a positive pole piece, the other of the first pole piece and the second pole piece is a negative pole piece, the positive pole piece includes a positive electrode substrate, a positive electrode tab, and a positive electrode active material provided on the positive electrode substrate, the negative pole piece includes a negative electrode substrate, a negative electrode tab, and a negative electrode active material provided on the negative electrode substrate, and the first pole piece and / or the second pole piece is any one of the above-mentioned pole pieces; wherein, the battery cell has a corner portion, and one corner portion corresponds to one top corner of the first pole piece and one top corner of the second pole piece at the same time.

[0015] Optionally, along the first direction, the orthographic projection of the negative pole piece covers the orthographic projection of the positive pole piece; wherein, in the length direction of the battery cell, on the same side of the battery cell, the negative pole piece extends beyond the positive pole piece; and / or, in the width direction of the battery cell, on the same side of the battery cell, the negative pole piece extends beyond the positive pole piece; and / or, the depth of the opening of the positive pole piece corresponding to one corner portion is greater than the depth of the opening of the negative pole piece.

[0016] Optionally, in the length direction of the battery cell, on the same side of the battery cell, the negative electrode active material extends beyond the positive electrode active material; and / or, in the width direction of the battery cell, on the same side of the battery cell, the negative electrode active material extends beyond the positive electrode active material.

[0017] Optionally, the positive electrode tab further includes: ceramics, the ceramics are disposed on one side of the positive electrode substrate close to the positive electrode tab, and in the length direction of the battery cell, the separator extends beyond the ceramics.

[0018] Optionally, the positive electrode tab is located at one end of the battery cell, and the negative electrode tab is located at the other end of the battery cell.

[0019] The energy storage device according to the fourth aspect embodiment of the present invention includes any one of the above-mentioned battery cells.

[0020] The electrical device according to the fifth aspect embodiment of the present invention includes any one of the above-mentioned energy storage devices.

[0021] According to the embodiment of the present invention, the tab adopts a body, the body has a vertex angle, and at least one vertex angle includes a straight-line side and an inwardly concave opening structure, which can at least solve problems such as tab tearing and corner folding that may occur during the slitting process of the tab, and has advantages such as being easy to manufacture, reducing manufacturing costs, and having a stable structure.

[0022] Other features and advantages of the present invention will become clear from the following detailed description of the exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention.

[0024] Figure 1 The tab structure of the prior art;

[0025] Figure 2 Schematic diagram of chamfering of the tab according to an embodiment of the present invention;

[0026] Figure 3 Detail view of the chamfer of adjacent tabs to be slit according to an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the negative electrode tab according to an embodiment of the present invention;

[0028] Figure 5 Schematic diagram of the positive electrode tab according to an embodiment of the present invention;

[0029] Figure 6 Schematic diagram of laminated core coating for an embodiment of the present utility model;

[0030] Figure 7 is Figure 4 Schematic diagram of area A circled in

[0031] Reference numerals in the drawings

[0032] Pole piece tape 100; Cutting line 101;

[0033] Body 1; First side 11; Second side 12; Third side 13; First section 131; Second section 132;

[0034] Positive pole piece 2; Positive pole tab 21; Ceramic 22;

[0035] Negative pole piece 3; Negative pole tab 31;

[0036] Pole piece tape structure 100'. Detailed implementation manners

[0037] Various exemplary embodiments of the present utility model will now be described in detail with reference to the accompanying drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present utility model.

[0038] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way a limitation on the present utility model or its application or use.

[0039] Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be regarded as part of the specification.

[0040] In all the examples shown and discussed herein, any specific values should be construed as merely exemplary and not as a limitation. Accordingly, other examples of the exemplary embodiments may have different values.

[0041] It should be noted that: Like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0042] The pole piece according to an embodiment of the present utility model will be specifically described below with reference to the accompanying drawings.

[0043] As Figures 2 to 7 shown, the pole piece according to an embodiment of the present utility model includes a body 1, and the body 1 has a plurality of apex angles.

[0044] Specifically, at least one vertex angle is formed by the cooperation of a first side 11, a second side 12, and a third side 13. Among them, at least one of the first side 11 and the second side 12 is a straight-line side. One end of the third side 13 is connected to the edge of the first side 11, the other end of the third side 13 is connected to the edge of the second side 12, and the third side 13 is recessed into the interior of the body 1 and forms an opening; the included angle between the third side 13 and the straight-line side at the joint position is not less than 90°.

[0045] In other words, the pole piece according to the embodiment of the present invention mainly consists of a body 1, where the body 1 has a plurality of vertex angles. For example, the body 1 is in the shape of a cuboid-like or cube-like, etc. When the body 1 is in the shape of a cuboid-like or cube-like, the body 1 has four vertex angles.

[0046] Among them, at least one vertex angle is formed by the cooperation of a first side 11, a second side 12, and a third side 13. For example, all four vertex angles are respectively formed by the cooperation of a first side 11, a second side 12, and a third side 13. At least one of the first side 11 and the second side 12 is a straight-line side. That is to say, it can be that the first side 11 is a straight-line side and the second side 12 has other shapes; or the second side 12 is a straight-line side and the first side 11 has other shapes; or both the first side 11 and the second side 12 are straight-line sides at the same time. It should be noted that by adopting a straight-line side, it is beneficial to cut the pole piece tape 100, so as to realize the splitting of the pole piece tape 100 to obtain pole pieces. That is to say, the connection part between the two pole pieces before splitting is a flat angle, which can be used as a cutting platform for pole piece splitting and has the advantage of better recognition for splitting.

[0047] Moreover, one end of the third side 13 is connected to the edge of the first side 11, the other end of the third side 13 is connected to the edge of the second side 12, the third side 13 is bent inwardly into the body 1 and has an opening. For example, the third side 13 is an inner rounded corner, or V-shaped, etc. Among them, the third side 13 can also be one of an oblique angle d2, an inner rounded corner r1, a flat angle d3 or a combination thereof. And, the included angle between the straight-line side and the third side at the joint position is not less than 90°. For example, the first side 11 is a straight-line side and extends in the left-right direction, the second side 12 extends in the up-down direction and is also a straight-line side, the left upper end of the third side 13 is connected to the right end of the first side 11, and the right lower end of the third side 13 is connected to the upper end of the second side 12. Among them, the included angle between the extension line of the left upper end of the third side 13 and the extension line of the right end of the first side 11 is ≥90°, and the included angle between the extension line of the right upper end of the third side 13 and the extension line of the right end of the second side 12 is ≥90°. Another example is that the third side 13, the second side 12, and the first side 11 form a V-shaped angle, and the overall angle of the V-shaped angle is greater than 90°.

[0048] It should be noted that, in this embodiment, the outer edge of the body 1 adopts an opening structure that is recessed inward along the outer edge, and the angle between the third side 13 and the straight edge at the combined position is not less than 90°, so that the top angle of the pole piece is not easy to fold during cutting, and the diaphragm is not easy to be punctured after hot pressing when the pole piece of this embodiment is used in the battery cell, avoiding the occurrence of stacked core short circuit. In addition, the angle between the third side 13 and the straight edge at the combined position is not less than 90°, so that the connection position between the third side 13 and the straight edge is stable, and there is no risk of tearing the belt during the production process. It can be understood that the straight edge here can be cut along the cutting line 101 of the pole piece belt 100.

[0049] Therefore, the pole piece according to the embodiment of the utility model adopts a main body 1, and the main body 1 has a vertex, at least one vertex includes a straight edge and an inwardly recessed opening structure, which can at least solve the problems of pole piece tearing, corner folding, etc. that may be caused by the pole piece strip 100 during the slitting process, and has the advantages of easy production, reduced production cost, and stable structure.

[0050] In some specific embodiments of the present invention, the first side is a straight side, and the third side 13 includes a first segment 131 and a second segment 132. Specifically, one end of the first segment 131 is connected to one end of the second side, and the first segment 131 is a straight segment. For example, the first segment 131 is a straight segment, and the first segment 131 can play a transition role. The first segment 131 can realize the connection between the first side 11 and the second segment 132, or realize the connection between the second side 12 and the second segment 132.

[0051] In addition, one end of the second segment 132 is connected to the other end of the first segment 131, and the other end of the second segment 132 is connected to one end of the first side 11, and the second segment 132 is an arc segment. The angle between the second segment 132 and the first segment 131 at the combined position is not less than 90°; and / or the angle between the first segment 131 and the second side 12 at the combined position is not less than 90°.

[0052] It can be understood that since the second section body 132 is an arc-shaped section body, it is not only convenient for manufacturing, but also avoids the folding at the corners during the slitting process of the pole piece tape 100, and the pole piece tape 100 is more stable in force during the slitting process. Moreover, through the mutual cooperation of the second section body 132 and the first section body 131, it is beneficial to control the angle between the second section body 132 and the straight edge to be not less than 90°. For example, the right lower end of the first section body 131 is connected to the left upper end of the second section body 132, and the angle between the extension line of the right lower end of the first section body 131 and the extension line of the left upper end of the second section body 132 is ≥90°, such as the angle being 90°, 95°, 100°, 120°, 150°, etc. In this embodiment, by controlling the angle between the second section body 132 and the first section body 131 at the joint position to be not less than 90°; and / or, the angle between the first section body 131 and the second side 12 at the joint position to be not less than 90°, it further avoids the easy folding of the four sides of the pole piece and the risk of piercing the diaphragm during hot pressing, and the adjacent two pole pieces to be slit are more stable in force during the conveying process, and the connection part is not easy to tear and break the tape.

[0053] That is to say, in this embodiment, by making the second section body 132 cooperate with the first section body 131, it can make the pole piece tape 100 more stable in force during the process of slitting to form pole pieces, the connection part of adjacent pole pieces is not easy to produce tearing phenomenon, and the production quality is high; and it avoids the folding of the corners of the pole piece, which causes the diaphragm to be pierced after hot pressing.

[0054] The present utility model also discloses a pole piece tape 100, which includes: a tape body. After the tape body is slit along a straight slitting line 101, at least two pole pieces are formed, and each pole piece is the pole piece of any one of the above embodiments. That is to say, when manufacturing the pole piece, the pole piece tape 100 is slit along the slitting line 101, and the pole pieces of any one of the above embodiments are obtained by slitting. Among them, the slitting line 101 is located between the adjacent straight edges of two pole pieces. That is to say, the straight edge can be formed by cutting the pole piece tape 100 along the slitting line 101, and the slitting line 101 can be a virtual line, etc. The edge of the tape body has a notch, and the notch can be divided into two openings along the slitting line 101, and each pole piece has one opening. In addition, it should be noted that the structure 100' of the pole piece tape in the prior art is as Figure 1 shown, the angle between two adjacent outer rounded corners is significantly less than 90°, and the force at the connection of the two rounded corners is unstable. Therefore, there is a greater risk of tearing and breaking the tape during the production process. In contrast, in this embodiment, the angle at the connection position of the openings of the two pole pieces before slitting is not less than 90°, which can make the pole piece tape 100 more stable in force during the process of slitting to form pole pieces, the connection part of adjacent pole pieces is not easy to produce tearing phenomenon, and the production quality is high.

[0055] Optionally, the notch can be formed by punching and cutting with a hardware mold, and the production is relatively simple.

[0056] Optionally, the depth of the notch is less than or equal to 10 mm. At this time, when using a metal mold to impact and cut, the cutting depth d1 can be controlled within the range of 0 < d1 ≤ 10 mm. In this embodiment, by adopting this depth range, not only can corner folding be avoided, but also the effective utilization rate of the electrode sheet can be ensured.

[0057] The present invention also discloses an electric core, which includes a first electrode sheet, a separator, and a second electrode sheet.

[0058] Specifically, the first electrode sheet and the second electrode sheet are stacked along a first direction, the separator is located between the first electrode sheet and the second electrode sheet, one of the first electrode sheet and the second electrode sheet is a positive electrode sheet 2, the other of the first electrode sheet and the second electrode sheet is a negative electrode sheet 3. The positive electrode sheet 2 includes a positive electrode substrate, a positive electrode tab, and a positive electrode active material provided on the positive electrode substrate. The negative electrode sheet 3 includes a negative electrode substrate, a negative electrode tab, and a negative electrode active material provided on the negative electrode substrate, and the first electrode sheet and / or the second electrode sheet is the electrode sheet of any of the above embodiments. Wherein, the electric core has a corner portion, and one corner portion corresponds to a vertex angle of the first electrode sheet and a vertex angle of the second electrode sheet at the same time.

[0059] In other words, the first electrode sheet, the separator, and the second electrode sheet are stacked along the first direction. For example, the first electrode sheet, the separator, and the second electrode sheet are stacked along the up-down direction. Wherein, the electric core has four corner portions, and at least one corner portion corresponds to a vertex angle of the first electrode sheet and a vertex angle of the second electrode sheet at the same time. For example, the first electrode sheet and the second electrode sheet respectively have a cuboid shape. The upper left end of the first electrode sheet and the upper left end of the second electrode sheet cooperate to correspond to the corner portion at the upper left position of the electric core. The upper right end of the first electrode sheet and the upper right end of the second electrode sheet cooperate to correspond to the corner portion at the upper right position of the electric core. The lower left end of the first electrode sheet and the lower left end of the second electrode sheet cooperate to correspond to the corner portion at the lower left position of the electric core. The lower right end of the first electrode sheet and the lower right end of the second electrode sheet cooperate to correspond to the corner portion at the lower right position of the electric core.

[0060] It should be noted that since the first electrode sheet and / or the second electrode sheet is the electrode sheet of any of the above embodiments, and the electrode sheet of any of the above embodiments has the advantages of being easy to manufacture and being able to effectively prevent vertex angle folding, etc., the electric core of the embodiment of the present invention has at least the advantages of reduced manufacturing cost, high yield and performance of the electric core, etc.

[0061] According to an embodiment of the present invention, along the first direction, the orthographic projection of the negative electrode sheet 3 covers the orthographic projection of the positive electrode sheet 2, which can reduce the short-circuit risk.

[0062] In some specific embodiments of the present utility model, in the length direction of the battery cell, on the same side of the battery cell, the negative electrode tab 3 extends beyond the positive electrode tab 2; and / or, in the width direction of the battery cell, on the same side of the battery cell, the negative electrode tab 3 extends beyond the positive electrode tab 2; and / or, the depth of the opening of the positive electrode tab 2 corresponding to a corner portion is greater than the depth of the opening of the negative electrode tab 3.

[0063] That is to say, by designing the size and covering relationship between the positive electrode tab 2 and the negative electrode tab 3, the short - circuit risk can be reduced, and the safety of the battery cell can be improved. For example, by designing the negative electrode tab 3 to be larger than the positive electrode tab 2 in the length direction and / or width direction, the short - circuit risk is reduced.

[0064] In addition, the depth of the opening of the positive electrode tab 2 corresponding to a corner portion is greater than the depth of the opening of the negative electrode tab 3. For example, the chamfer designs around the negative electrode tab 3 and the positive electrode tab 2 are different. The depth of the V - angle can be different. The depth of the V - angle on the side of the positive electrode tab 2 close to the positive electrode ear 21 is 3 mm deeper than the depth of the V - angle on the side of the negative electrode tab 3 far from the positive electrode ear 21, which is beneficial to ensuring that the negative electrode tab 3 can completely cover the positive electrode tab 2 during the lamination process and can effectively avoid short - circuits.

[0065] In some specific embodiments of the present utility model, in the length direction of the battery cell, on the same side of the battery cell, the negative active material extends beyond the positive active material; and / or, in the width direction of the battery cell, on the same side of the battery cell, the negative active material extends beyond the positive active material. That is to say, a positive - electrode - sheet active - material area is defined on the positive - electrode substrate, and a negative - electrode - sheet active - material area is defined on the negative - electrode substrate. For example, the difference X1 (0 ≤ X1 ≤ 10 mm) between the negative - electrode - sheet active - material area L1 (300 mm ≤ L1 ≤ 660 mm) and the positive - electrode - sheet active - material area L2 (300 mm ≤ L2 ≤ 660 mm) in the length direction of the battery cell; the difference X2 (0 ≤ X2 ≤ 10 mm) between the negative - electrode - sheet active - material area W1 (50 mm ≤ W1 ≤ 250 mm) and the positive - electrode - sheet active - material area W2 (50 mm ≤ W2 ≤ 250 mm) in the width direction of the battery cell.

[0066] In this embodiment, by making the negative - electrode - sheet active - material area of the negative electrode tab 3 completely cover the positive - electrode - sheet active - material area of the positive electrode tab 2, the technical problem of short - circuits in the battery cell can be effectively solved.

[0067] In some specific embodiments of the present utility model, the positive electrode tab 21 of the positive electrode plate 2 is located at one end of the battery cell, and the negative electrode tab 31 of the negative electrode plate 3 is located at the other end of the battery cell. That is to say, in a certain direction, the battery cell has two opposite ends, which can be defined as one end of the battery cell and the other end of the battery cell for the convenience of description. Optionally, one end of the battery cell here can be one end along the length direction of the battery cell, and the other end of the battery cell can be the other end along the length direction of the battery cell. This is only an example for illustration and is not limited thereto. That is to say, during the lamination process, the positive electrode tab 21 and the negative electrode tab 31 are respectively located at two ends of the battery cell. For example, in the length direction, the negative electrode active material area on the side of the negative electrode plate 3 close to the negative electrode tab 31 exceeds the positive electrode active material area by a distance of X3 (0 ≤ X3 ≤ 10 mm), and on the side of the positive electrode plate 2 close to the positive electrode tab 21, the negative electrode plate 3 exceeds the positive electrode plate 2 by a distance of X4, and X4 = X1 - X3. In the width direction, one side of the negative electrode active material area exceeds the positive electrode active material area by a distance of X5, and the other side exceeds by a distance of X6 = W1 - W2 - X5, which is beneficial to realizing the complete coating of the negative electrode plate 3 on the positive electrode plate 2.

[0068] According to an embodiment of the present utility model, the positive electrode plate 2 further includes: a ceramic 22, and the ceramic 22 is disposed on the side of the positive electrode substrate close to the positive electrode tab 21. In the length direction of the battery cell, the separator exceeds the ceramic 22. That is to say, in this embodiment, the positive electrode plate 2 includes a positive electrode substrate, a positive electrode active material, and a ceramic 22. For example, by providing a section of ceramic 22 material area L3 on the positive electrode tab 21 side, L3 > X4. In this embodiment, by providing the ceramic 22 area, contact between the negative electrode active material area and the positive electrode tab 21 can be avoided. In addition, the separator exceeds the ceramic 22. For example, on the side of the negative electrode tab 31, the distance by which the separator exceeds the negative electrode active material area is X7, and on the side of the positive electrode tab 21, the distance by which the separator exceeds the ceramic 22 material area on the positive electrode plate 2 is X8. The length of the separator is L4 = X7 + X8 + L1 + L3 - X4. In the width direction, the distance by which one edge of the separator exceeds the negative electrode active material area is X9, and the distance by which the other side exceeds is X10. The width of the stacked core is W3 = L1 + X9 + X10. In this embodiment, by the separator exceeding the ceramic 22 in the length direction of the battery cell, it is beneficial to realize the complete coating of the separator on the positive electrode plate 2 and the negative electrode plate 3.

[0069] Optionally, the substrate material of the positive electrode plate can be aluminum foil.

[0070] Optionally, the negative electrode plate includes a substrate and an active material, and the substrate material thereof is copper or aluminum foil, which can be specifically determined according to the type of positive electrode cation.

[0071] The present utility model also discloses an energy storage device, which includes the battery cell of any one of the above embodiments. The energy storage device can be a battery or the like, and has the advantage of high safety performance.

[0072] The present utility model also discloses an electrical equipment, which includes the energy storage device of any one of the above embodiments, improving the safety performance.

[0073] Embodiment 1

[0074] During manufacturing, a chamfer design as shown in Figure 3 is adopted. After the electrode roll is laser die-cut, the tab is cut out, and then the chamfer is cut out by a hardware die-cut, and then the electrode sheet is cut out by a slitting knife.

[0075] As shown in Figure 3 , it specifically shows the dimensions of the chamfers cut on adjacent electrode sheets. The designed V angle is composed of an inclined angle d2, an inner fillet r1, and a flat angle d3. The inclined angle d2 cuts inwards at 40° from the edge of the material area, and the cutting depth d2 is within 0 - 10 mm. Adjacent to the inclined angle d2 is the inner fillet r1 with a radius r1 of 4 mm. The last part of the flat angle d3 is tangent to the inner fillet r1, and the overall width d3 is within 0 - 10 mm.

[0076] As shown in Figure 4 , the negative electrode sheet 3 includes a negative electrode substrate and a negative electrode active material. The designed length L1 of the material area is 563 mm, the width W1 is 116 mm, and the depth d1 of the chamfers around is 4 mm.

[0077] As shown in Figure 5 , the positive electrode sheet 2 includes a positive electrode substrate, a positive electrode active material, and a ceramic 22. The designed difference x1 between the length of the positive electrode sheet active material area and the negative electrode sheet active material area is 4 mm. The width of the positive electrode sheet active material area is L2 = L1 - X1 = 563 - 4 = 559 mm. The width of the positive electrode sheet active material area is W2 = W1 - x2 = 116 - 3 mm. The length L3 of the ceramic 22 is 4 mm. The chamfer depth on the side of the positive electrode sheet 2 close to the positive electrode tab 21 is 7 mm, and the chamfer depth on the side of the negative electrode sheet 3 far from the positive electrode tab 21 is 4 mm, avoiding the positive electrode sheet active material area on the side of the positive electrode sheet 2 close to the positive electrode tab 21 exceeding the negative electrode sheet active material area during the lamination process.

[0078] As shown in Figure 6As shown, during the lamination process, in the length direction, the separator near the negative tab 31 extends beyond the negative electrode active material area by X8 = 1.5 mm, the negative electrode active material area extends beyond the positive electrode active material area by X3 = 2.5 mm, and the length of the separator is L4 = X7 + X8 + L1 + L3 - X4 = 569 mm; in the width direction, one side of the separator extends beyond the negative electrode active material area by X9 = 0.5 mm, X10 = 0.5 mm, the width of the stacked core W3 = L1 + X9 + X10 = 117 mm, the negative electrode active material area extends beyond the positive electrode active material area by X5 = 1.5 mm, and X6 = W1 - W2 - X5 = 1.5 mm.

[0079] In summary, the electrode sheet according to the embodiment of the present invention uses the body 1. The body 1 has a vertex angle, and at least one vertex angle includes a straight side and an inwardly recessed opening structure, which can at least solve problems such as electrode sheet tearing and corner folding that may occur during the slitting process of the electrode sheet 100, and has the advantages of being easy to manufacture, reducing manufacturing costs, and having a stable structure.

[0080] Although some specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A pole piece, characterized in that: include: A body (1), the body (1) having a plurality of vertex angles, at least one of which is formed by the cooperation of a first side (11), a second side (12) and a third side (13), wherein at least one of the first side (11) and the second side (12) is a straight side, one end of the third side (13) is connected to the edge of the first side (11), and the other end of the third side (13) is connected to the edge of the second side (12), the third side (13) is recessed into the interior of the body (1) and forms an opening, and the angle between the third side (13) and the straight side at the combined position is not less than 90°.

2. The pole piece according to claim 1, characterized in that: The first side (11) is a straight side, and the third side (13) comprises: A first segment (131), one end of the first segment (131) being connected to one end of the second side (12), and the first segment (131) being a straight segment; a second segment (132), one end of the second segment (132) being connected to the other end of the first segment (131), the other end of the second segment (132) being connected to one end of the first edge (11), and the second segment (132) being an arc segment; Wherein, the angle between the second segment (132) and the first segment (131) at the combined position is not less than 90°; and / or the angle between the first segment (131) and the second edge (12) at the combined position is not less than 90°.

3. A pole piece strip (100), characterized in that: include: A strip body, wherein the strip body is cut along a straight cutting line (101) to form at least two pole pieces, each of which is the pole piece according to claim 1 or 2.

4. A battery cell, characterized in that: include: A first pole sheet, a diaphragm and a second pole sheet, wherein the first pole sheet and the second pole sheet are stacked along a first direction, the diaphragm is located between the first pole sheet and the second pole sheet, one of the first pole sheet and the second pole sheet is a positive pole sheet (2), and the other of the first pole sheet and the second pole sheet is a negative pole sheet (3), the positive pole sheet (2) comprises a positive electrode substrate, a positive electrode tab (21) and a positive electrode active material provided on the positive electrode substrate, the negative electrode sheet (3) comprises a negative electrode substrate, a negative electrode tab (31) and a negative electrode active material provided on the negative electrode substrate, and the first pole sheet and / or the second pole sheet is the pole sheet according to claim 1 or 2; The battery cell has a corner portion, and one of the corner portions corresponds to a vertex angle of the first pole piece and a vertex angle of the second pole piece at the same time.

5. The battery cell according to claim 4, characterized in that: Along the first direction, the orthographic projection of the negative electrode sheet (3) covers the orthographic projection of the positive electrode sheet (2); wherein, In the length direction of the battery cell, on the same side of the battery cell, the negative electrode sheet (3) exceeds the positive electrode sheet (2); and / or, In the width direction of the battery cell, on the same side of the battery cell, the negative electrode sheet (3) exceeds the positive electrode sheet (2); and / or, The depth of the opening of the positive electrode sheet (2) corresponding to one of the corner portions is greater than the depth of the opening of the negative electrode sheet (3).

6. The battery cell according to claim 5, characterized in that: In the length direction of the battery core, on the same side of the battery core, the negative electrode active material exceeds the positive electrode active material; and / or, In the width direction of the battery cell, the negative electrode active material exceeds the positive electrode active material on the same side of the battery cell.

7. The battery cell according to claim 4, characterized in that: The positive electrode plate (2) further comprises: A ceramic (22), wherein the ceramic (22) is arranged on a side of the positive electrode substrate close to the positive electrode tab (21), and in the length direction of the battery cell, the diaphragm exceeds the ceramic (22).

8. The battery cell according to any one of claims 4 to 7, characterized in that: The positive electrode tab (21) is located at one end of the battery cell, and the negative electrode tab (31) is located at the other end of the battery cell.

9. An energy storage device, characterized in that: A battery cell comprising any one of claims 4 to 8.

10. An electrical device, characterized in that: Includes the energy storage device as described in claim 9.

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