Electrode plate, battery cell and battery

Abstract

The utility model belongs to the technical field of batteries, and discloses an electrode plate, a battery cell and a battery, the electrode plate comprises a current collector, an electrode material layer and an edge coating structure, the electrode material layer is arranged on the current collector and falls in the area of the current collector, and at least part of the edge of the electrode material layer and the edge of the current collector are arranged at intervals; a supporting region is formed in a region between the edge of the electrode material layer and the edge of the current collector; the edge coating structure is arranged in the supporting area. The electrode material layer is formed by cutting and can be arranged on the current collector after being formed without waiting for drying, so that the production efficiency of the electrode plate and the battery is improved; the thickness of the cut electrode material layer is easy to control, the thickness uniformity of the electrode material layer is also easy to ensure, the fitting compactness between the electrode material layer and the electrolyte sheet is improved, in addition, the flatness of the edge of the electrode material layer can also be improved, when the edge coating structure is arranged, the edge coating structure is prevented from covering the edge area of the electrode material layer, and the service life of the electrode material layer is prolonged. The performance of the electrode plate and the capacity of the battery are prevented from being influenced.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a kind of electrode sheet, battery cell and battery. BACKGROUND

[0002] The battery cell of solid-state lithium battery includes electrode sheet and electrolyte sheet, and the electrode sheet includes positive electrode sheet and negative electrode sheet. The electrolyte sheet is arranged between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes positive electrode current collector and positive electrode active material layer coated on the positive electrode current collector, and the negative electrode sheet includes negative electrode current collector and negative electrode active material layer coated on the negative electrode current collector. The electrolyte sheet is arranged between the positive electrode active material layer and the negative electrode active material layer to transmit lithium ions. During the manufacturing process of the solid-state battery, a pressure of hundreds of megapascals needs to be added to make the positive electrode sheet, the negative electrode sheet and the electrolyte sheet tightly adhere to each other.

[0003] The size of the positive electrode active material layer is usually inconsistent with the size of the negative electrode active material layer. For example, the size of the positive electrode active material layer is smaller than the size of the negative electrode active material layer. In this case, the positive electrode current collector has a first area and a second area, and the second area is arranged outside the first area. The second area is used to arrange the positive electrode active material layer, and the second area is provided with an edge coating structure. Alternatively, the size of the negative electrode active material layer is smaller than the size of the positive electrode active material layer. In this case, the negative electrode current collector has a first area and a second area, and the second area is arranged outside the first area. The second area is used to arrange the negative electrode active material layer, and the second area is provided with an edge coating structure.

[0004] In the prior art, the electrode material layer (positive electrode active material layer or negative electrode active material layer) is formed by coating slurry on the current collector. First, the slurry needs to be dried after being coated on the current collector. After waiting for the slurry to dry, the edge coating structure can be arranged on the current collector. This results in a slow production speed of the electrode sheet, which in turn slows down the production efficiency of the battery. Second, the thickness of the electrode material layer formed by coating the slurry is difficult to control, and the uniformity of the thickness of the entire electrode material layer is difficult to guarantee. If the uniformity of the thickness of the electrode material layer is poor, the adhesion between the electrode material layer and the electrolyte sheet will not be tight enough. Third, when the slurry is coated on the current collector, the flatness of the edge of the slurry is poor, which results in poor flatness of the edge of the electrode material layer. When the edge coating structure is arranged between the edge of the electrode material layer and the edge of the current collector, the edge coating structure is likely to fall on the edge area of the electrode material layer, which affects the performance of the electrode sheet and even reduces the capacity of the battery. SUMMARY

[0005] The utility model aims to provide an electrode sheet, a battery cell and a battery, which can avoid defects such as cracking or micro-cracks of the electrolyte sheet and the electrode sheet under the action of pressure, and improve the yield of the solid-state lithium battery.

[0006] To achieve the above object, the utility model adopts the following technical scheme:

[0007] In a first aspect, an electrode sheet is provided, comprising:

[0008] A current collector;

[0009] An electrode material layer is provided on the current collector and falls within the area where the current collector is located, and the edge of the electrode material layer is spaced apart from the edge of the current collector to form a support area between the edge of the electrode material layer and the edge of the current collector; the electrode material layer is formed by cutting;

[0010] An edge coating structure is provided in the support area.

[0011] As a preferred electrode sheet provided by the utility model, the electrode material layer is surrounded by the edge coating structure in the circumferential direction.

[0012] As a preferred electrode sheet provided by the utility model, the edge coating structure is in contact with or connected to the electrode material layer.

[0013] As a preferred electrode sheet provided by the utility model, the edge coating structure is connected to the current collector by adhesion; and / or, the edge coating structure is connected to the electrode material layer by adhesion.

[0014] As a preferred electrode sheet provided by the utility model, the difference between the thickness of the edge coating structure and the thickness of the electrode material layer is greater than or equal to 0 μm and less than or equal to 5 μm.

[0015] As a preferred electrode sheet provided by the utility model, the edge of the current collector falls within the projection area of the edge coating structure.

[0016] As a preferred electrode sheet provided by the utility model, the electrode material layer and the edge coating structure are provided on both sides of the current collector.

[0017] As a preferred electrode sheet provided by the utility model, the area of the edge coating structure is S1, the area of the electrode material layer is S2, and the ratio of S1 to S2 is greater than or equal to 0.0036 and less than or equal to 0.0296.

[0018] As a preferred electrode sheet provided by the utility model, the maximum dimension of the edge coating structure in the first direction is L1, the maximum dimension of the edge coating structure in the second direction is L2, and there is an included angle between the first direction and the second direction.

[0019] L1 is greater than or equal to 500 mm and less than or equal to 1500 mm, and L2 is greater than or equal to 1000 mm and less than or equal to 2500 mm.

[0020] As a preferred scheme of the electrode sheet provided by the utility model, the maximum size of the electrode material layer in the first direction is L3, and the ratio of L3 to L1 is greater than or equal to 0.984 and less than or equal to 0.998.

[0021] As a preferred scheme of the electrode sheet provided by the utility model, the maximum size of the electrode material layer in the second direction is L4, and the ratio of L4 to L2 is greater than or equal to 0.988 and less than or equal to 0.9984.

[0022] In a second aspect, an electrode sheet is provided, including a current collector, an electrode material layer and an electrolyte sheet, the electrode material layer is arranged on the current collector, and the electrolyte sheet is arranged on the electrode material layer.

[0023] The second current collector, the second electrode material layer, the electrolyte sheet, the first electrode material layer and the first current collector are sequentially stacked, and the second current collector, the second electrode material layer and the electrolyte sheet all completely cover the first electrode material layer.

[0024] In a third aspect, a battery is provided, including a packaging structure and at least one electrode sheet as described above, and the electrode sheet is located in the packaging structure.

[0025] The utility model has the advantages of:

[0026] The utility model provides a kind of electrode sheet, electric core and battery, wherein the electrode material layer of electrode sheet is shaped by cutting, can be set on current collector after cutting, without waiting for drying, improve the production speed of electrode sheet, to further can improve the production efficiency of battery;Moreover, the thickness of the electrode material layer shaped by cutting is easy to control, and the thickness uniformity of the electrode material layer is also easy to ensure, to improve the adhesion density between the electrode material layer and the electrolyte sheet.In addition, the surface of the electrode material layer shaped by coating slurry on the current collector is formed by liquid spontaneous casting, which is very smooth.Compared with the electrode material layer shaped by coating slurry on the current collector, the cutting surface of the electrode material layer shaped by cutting has a certain roughness relative to the plane formed by casting, so as to increase the bonding strength between the electrode material layer and the electrolyte sheet.In addition, compared with the electrode material layer shaped by coating slurry on the current collector, the edge flatness of the electrode material layer shaped by cutting is higher, and when the edge coating structure is arranged, the edge coating structure can be prevented from covering the edge area of the electrode material layer, to prevent affecting the performance of the electrode sheet and the capacity of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced the drawings needed to be used in the embodiments of the utility model, obviously, the drawings described below are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to the drawings without creating labor.

[0028] Figure 1 is the schematic diagram of the electrode material layer on the current collector provided by the specific embodiment of the utility model;

[0029] Figure 2 is the side view of the electrode sheet provided by the specific embodiment of the utility model;

[0030] Figure 3 is the schematic diagram of the electrode material layer and the edge coating structure provided by the specific embodiment of the utility model;

[0031] Figure 4 is the schematic diagram of the positive electrode material layer on the positive electrode current collector provided by the specific embodiment of the utility model;

[0032] Figure 5 is the side view of one of the electric cores provided by the specific embodiment of the utility model;

[0033] Figure 6 is the schematic diagram of the negative electrode material layer on the negative electrode current collector provided by the specific embodiment of the utility model;

[0034] Figure 7 is the side view of another electric core provided by the specific embodiment of the utility model;

[0035] Figure 8 is the internal schematic diagram of the battery provided by the embodiment of the utility model;

[0036] Figure 9 is the external schematic diagram of the battery provided by the embodiment of the utility model.

[0037] In the figure:

[0038] 1, current collector; 2, electrode material layer; 20, support area; 3, edge coating structure;

[0039] 11, first edge; 12, second edge;

[0040] 21, fifth edge; 22, sixth edge;

[0041] 31, third edge; 32, fourth edge;

[0042] 100, battery cell; 200, packaging structure; 300, connecting piece; 400, heat conduction layer; 500, battery positive tab; 600, battery negative tab;

[0043] 110, positive pole piece; 120, negative pole piece; 130, electrolyte sheet;

[0044] 111, positive current collector; 112, positive material layer; 1110, positive tab;

[0045] 121, negative current collector; 122, negative material layer; 1210, negative tab. DETAILED DESCRIPTION

[0046] The utility model will be further described in detail below in combination with the drawings and examples. It can be understood that the specific examples described herein are only used to explain the utility model, and not limited to the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.

[0047] In the description of the utility model, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0048] In the utility model, unless another definite provision and limitation, first feature is "on" or "under" second feature can include that first and second features are in direct contact, also can include that first and second features are not in direct contact but contact through another feature between them. Moreover, first feature "on", "above" and "upper surface" of second feature includes that first feature is directly above and obliquely above second feature, or only indicates that horizontal height of first feature is higher than second feature. First feature "under", "below" and "under surface" of second feature includes that first feature is directly below and obliquely below second feature, or only indicates that horizontal height of first feature is less than second feature.

[0049] In the description of the embodiment, the terms "upper", "lower", "left", "right" and other orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0050] In the embodiment, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the utility model generally represents an "or" relationship between the front and rear associated objects.

[0051] In the embodiments of the utility model, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments.

[0052] As shown in Figure 1 and Figure 2 The utility model provides an electrode sheet, including current collector 1, electrode material layer 2 and edge coating structure 3. The size of electrode material layer 2 is less than the size of current collector 1, and electrode material layer 2 is stacked on current collector 1 and falls in the area where current collector 1 is located, and electrode material layer 2 is at least partially spaced from the edge of current collector 1, so that the area between the edge of electrode material layer 2 and the edge of current collector 1 forms a support area 20. The edge coating structure 3 is arranged in the support area 20. That is, the vacancy of current collector 1 where electrode material layer 2 is not arranged can be provided with edge coating structure 3.

[0053] In the production of the battery, the electrolyte sheet 130 is stacked on the side of the electrode material layer 2 away from the current collector 1, and another electrode sheet is stacked on the side of the electrolyte sheet 130 away from the electrode material layer 2, and pressure is applied to make the two electrode sheets and the intermediate electrolyte sheet 130 tightly pressed together. Exemplarily, seeFigure 4 and Figure 5 The positive electrode tab 110 of the battery cell 100 is an electrode tab provided in the embodiments of the present application, the current collector 1 of the positive electrode tab 110 is a positive electrode current collector 111, the electrode material layer 2 of the positive electrode tab 110 is a positive electrode material layer 112, and the edge coating structure 3 is arranged on one side of the positive electrode material layer 112. An electrolyte sheet 130 is stacked on the side of the positive electrode material layer 112 away from the positive electrode current collector 111, and a negative electrode tab 120 is stacked on the side of the electrolyte sheet 130 away from the positive electrode material layer 112. The area of the electrolyte sheet 130 and the area of the negative electrode tab 120 are both greater than the area of the positive electrode material layer 112, and the positive electrode material layer 112 is within the projection area of the electrolyte sheet 130 and the negative electrode tab 120, so that a part of the electrolyte sheet 130 falls on the positive electrode material layer 112, and the other part (the edge area of the electrolyte sheet 130) can fall on the edge coating structure 3. When the battery cell 100 is formed, the positive electrode tab 110, the electrolyte sheet 130, and the negative electrode tab 120 are tightly attached together by applying pressure.

[0054] If the edge coating structure 3 is not arranged on the positive electrode current collector 111, the edge area of the electrolyte sheet 130 is in a suspended state, and during the pressure forming of the battery cell 100, the edge area of the electrolyte sheet 130 has no support, which causes cracking on the electrolyte sheet 130 and the negative electrode tab 120.

[0055] In the embodiments, by arranging the edge coating structure 3 on the positive electrode current collector 111, the edge area of the electrolyte sheet 130 is supported, the edge area of the electrolyte sheet 130 and the edge area of the negative electrode tab 120 are supported, and further, during the pressure forming of the battery cell 100, the edge area of the electrolyte sheet 130 and the edge area of the negative electrode tab 120 are prevented from cracking.

[0056] It can be understood that when the negative electrode tab 120 of the battery cell 100 is an electrode tab provided in the embodiments of the present application, the edge coating structure 3 can support the edge area of the electrolyte sheet 130 and the edge area of the positive electrode tab 110, and prevent the edge area of the electrolyte sheet 130 and the edge area of the positive electrode tab 110 from cracking.

[0057] In this embodiment, the electrode material layer 2 of the electrode sheet is cut into shape, and can be arranged on the current collector 1 after cutting into shape, without waiting for drying, thereby improving the production speed of the electrode sheet, and further improving the production efficiency of the battery. Moreover, the cut-to-shape electrode material layer 2 is easy to control the thickness, and is also easy to ensure the thickness uniformity of the electrode material layer 2, thereby improving the close contact degree between the electrode material layer 2 and the electrolyte sheet 130. In addition, the surface of the electrode material layer formed on the current collector 1 by coating slurry is formed by spontaneous flow casting of liquid, and is very smooth. Compared with the electrode material layer formed on the current collector 1 by coating slurry, the cut surface of the cut-to-shape electrode material layer 2 has a certain roughness relative to the plane formed by flow casting, thereby being able to increase the bonding strength between the electrode material layer 2 and the electrolyte sheet 130. In addition, compared with the electrode material layer formed on the current collector 1 by coating slurry, the cut-to-shape electrode material layer 2 has higher edge flatness, and when the edge coating structure 3 is arranged, the edge coating structure 3 can be prevented from covering the edge region of the electrode material layer 2, thereby preventing the performance of the electrode sheet and the capacity of the battery from being affected.

[0058] In some embodiments, the electrode material layer 2 is circumferentially surrounded by the edge coating structure 3. Referring to Figure 1 , the support region 20 formed between the edge of the electrode material layer 2 and the edge of the current collector 1 is an annular region, and the edge coating structure 3 arranged in the annular region is also annular. As described above, when the electrode core 100 is formed, a part of the electrolyte sheet 130 falls on the electrode material layer 2, and another part falls on the edge coating structure 3. The annular edge coating structure 3 can support a circle of edge regions of the electrolyte sheet 130.

[0059] Moreover, when the electrode material layer 2 is arranged on the current collector 1, the electrode material layer 2 is arranged on the middle part of the current collector 1, and all the edges of the electrode material layer 2 are arranged to be spaced from the edges of the current collector 1, without the need to align a part of the edges of the electrode material layer 2 with the edges of the current collector 1, thereby being higher in production efficiency.

[0060] The shapes of the electrode material layer 2 and the current collector 1 can be circular, oval, polygonal, etc. Exemplarily, the shapes of the electrode material layer 2 and the current collector 1 are both circular, and the diameter of the electrode material layer 2 is smaller than the diameter of the current collector 1, and the two can be concentrically arranged, so that the region between the edges of the two forms an annular support region. At this time, the edge coating structure 3 arranged in the support region is also annular.

[0061] If the electrode material layer 2 and the current collector 1 are polygonal, the electrode material layer 2 is provided with N edges, N being a positive integer greater than or equal to 3. For example, for a rectangular electrode material layer 2, it has four edges, and for a pentagonal electrode material layer 2, it has five edges. When the electrode material layer 2 is arranged on the current collector 1, it is assumed that M edges of the electrode material layer 2 are flush with the edges of the current collector 1, 0≤M<N, and the remaining N-M edges are arranged spaced apart from the edges of the current collector 1, and the area between the N-M edges and the edges of the current collector 1 forms a support area 20, and the edge coating structure 3 is arranged in the support area 20.

[0062] In some embodiments, the edges of the current collector 1 are arranged spaced apart from the edges of the electrode material layer 2, i.e. all N edges of the electrode material layer 2 are arranged spaced apart from the edges of the current collector 1, and the support area 20 formed is annular, and the edge coating structure 3 is arranged in the annular area to surround the electrode material layer 2 along the circumferential direction.

[0063] For example, referring to Figure 1 and Figure 2 , the electrode material layer 2 is rectangular and has four sides (N=4). Figure 1 As shown in the figure, the four edges of the electrode material layer 2 are spaced apart from the edges of the current collector 1, i.e. the length dimension of the electrode material layer 2 is smaller than the length dimension of the current collector 1, and the width dimension of the electrode material layer 2 is smaller than the width dimension of the current collector 1, so that the support area 20 is an annular area. Correspondingly, the edge coating structure 3 surrounds the four sides of the electrode material layer 2. Alternatively, one edge of the electrode material layer 2 is flush with one edge of the current collector 1, and the remaining three edges are spaced apart from the edges of the current collector 1, and the edge coating structure 3 can be arranged on one side of the three edges. Alternatively, only one edge or only two edges of the electrode material layer 2 are spaced apart from the edges of the current collector 1, and the edge coating structure 3 can be arranged on one side of the one edge or the two edges.

[0064] In some embodiments, the edge coating structure 3 can be in contact with the electrode material layer 2 but not connected, so that there is no gap between the edge coating structure 3 and the electrode material layer 2. For example, an adhesive is arranged on one side of the edge coating structure 3, and the edge coating structure 3 is adhered to the current collector 1 by the adhesive and is in contact with the electrode material layer 2, so that a gap between the edge coating structure 3 and the electrode material layer 2 is avoided, and after the electrolyte sheet 130 is arranged on the electrode material layer 2, a gap under the electrolyte sheet 130 is prevented, the support effect of the edge coating structure 3 on the edge area of the electrolyte sheet 130 is improved, and cracking of the edge area of the electrolyte sheet 130 is prevented.

[0065] In some embodiments, the edge coating structure 3 is connected to the electrode material layer 2, and the connection ensures that there is no gap between the edge coating structure 3 and the electrode material layer 2, and improves the stability of the edge coating structure 3 after being arranged.

[0066] In some embodiments, the edge coating structure 3 is connected to the current collector 1 by adhesion, and / or the edge coating structure 3 is connected to the electrode material layer 2 by adhesion, which ensures the stability of the edge coating structure 3 after being arranged. For example, the edge coating structure 3 is an insulating adhesive tape, which is adhered to the current collector 1 and can be in contact with the electrode material layer 2. Alternatively, the edge coating structure 3 contains an adhesive in its material composition, which can be adhered to both the current collector 1 and the electrode material layer 2. On the one hand, the adhesive ensures that there is no gap between the edge coating structure 3 and the electrode material layer 2. On the other hand, the adhesive improves the firmness of the edge coating structure 3 on the current collector 1 and prevents the edge coating structure 3 from falling off.

[0067] In some embodiments, the thickness of the edge coating structure 3 is greater than or equal to 0 μm and less than or equal to 5 μm than the thickness of the electrode material layer 2. The thickness difference ensures that the thickness of the edge coating structure 3 is approximately equal to the thickness of the electrode material layer 2, and thus the side surfaces of the edge coating structure 3 and the electrode material layer 2, which are away from the current collector 1, are almost flush. During the pressure forming of the battery cell, the flatness of the electrolyte sheet 130 can be ensured, and the electrolyte sheet 130 can be prevented from cracking.

[0068] For example, the thickness of the edge coating structure 3 is 0 μm, i.e., the thickness of the edge coating structure 3 is equal to the thickness of the electrode material layer 2, which ensures that the side surfaces of the edge coating structure 3 and the electrode material layer 2, which are away from the current collector 1, are flush. When the electrolyte sheet 130 is stacked on the electrode material layer 2 and pressure is applied to the electrolyte sheet 130, the flatness of the electrolyte sheet 130 during the pressure application can be ensured, and the electrolyte sheet 130 can be prevented from cracking or having micro-cracks.

[0069] In other embodiments, the thickness of the edge coating structure 3 can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, etc., as long as the thickness difference between the edge coating structure 3 and the electrode material layer 2 is controlled to be 0 μm to 5 μm. In some embodiments, the edge of the current collector 1 falls within the projection area of the edge coating structure 3, i.e., the edge of the edge coating structure 3 is flush with or exceeds the edge of the current collector 1. When the electrolyte sheet 130 is stacked on the electrode material layer 2, the edge area of the electrolyte sheet 130 can fall entirely on the edge coating structure 3, and during the pressure forming of the battery cell, the electrolyte sheet 130 can be completely prevented from cracking or having micro-cracks in the edge area.

[0070] The electrode material layer 2 and the edge coating structure 3 can be laminated on one side or both sides of the current collector 1. In some embodiments, the electrode material layer 2 and the edge coating structure 3 are arranged on only one side of the current collector 1. At this time, the electrolyte sheet 130 and the electrode sheet are laminated on the side of the current collector 1 on which the electrode material layer 2 is arranged. In another embodiment, as shown in FIG. 1B, the electrode material layer 2 and the edge coating structure 3 are arranged on both sides of the current collector 1. At this time, the electrolyte sheet 130 and the electrode sheet are laminated on both sides of the current collector 1 to form a sandwich structure, which can improve the energy density of the battery. Figure 2

[0071] The area of the edge coating structure 3 is S1, and the area of the electrode material layer 2 is S2. The ratio of S1 to S2 is greater than or equal to 0.0036 and less than or equal to 0.0296. When the inner edge of the edge coating structure 3 abuts against the electrode material layer 2, and the outer edge of the edge coating structure 3 is flush with the current collector 1, the sum of the area S1 of the edge coating structure 3 and the area S2 of the electrode material layer 2 is equal to the area S3 of the current collector 1. The above area ratio relationship between the edge coating structure 3 and the electrode material layer 2 ensures that the area of the edge coating structure 3 is not too large. If the area of the edge coating structure 3 is too large, it will occupy more space on the current collector 1, resulting in a decrease in the space reserved for the electrode material layer 2 on the current collector 1, and further leading to a decrease in the capacity of the battery. Moreover, the area ratio relationship between the edge coating structure 3 and the electrode material layer 2 also limits the area of the edge coating structure 3 from being too small. If the area of the edge coating structure 3 is too small, it is difficult to operate when coating the edge coating structure 3 on the current collector 1, and the strength of the edge coating structure 3 is difficult to guarantee, which is easy to fall off after being coated on the current collector 1.

[0072] In the embodiments of the present application, the maximum dimension of the edge coating structure 3 in the first direction is L1, the maximum dimension of the edge coating structure 3 in the second direction is L2, and there is an included angle between the first direction and the second direction. L1 is greater than or equal to 500 mm and less than or equal to 1500 mm, and L2 is greater than or equal to 1000 mm and less than or equal to 2500 mm. The edge coating structure 3 meeting the size can be applied in the battery of a new energy vehicle. Exemplarily, the first direction is perpendicular to the second direction, the battery has a cuboid structure, and the edge coating structure 3 has a rectangular shape, the width direction of which is the first direction, and the length direction of which is the second direction. For the battery in the vehicle, the length dimension is usually greater than or equal to 1000 mm and less than or equal to 2500 mm, and the width dimension is usually greater than or equal to 500 mm and less than or equal to 1500 mm. Therefore, by setting the length dimension of the edge coating structure 3 to be greater than or equal to 1000 mm and less than or equal to 2500 mm, and the width dimension to be greater than or equal to 500 mm and less than or equal to 1500 mm, the battery applied in the vehicle can be adapted.

[0073] ​In the embodiment of the present application, the maximum size of the electrode material layer 2 in the first direction is L3, and the ratio of L3 to L1 is greater than or equal to 0.984 and less than or equal to 0.998. The maximum size L3 of the electrode material layer 2 in the first direction should not be too long or too short. If L3 is too long, it will occupy too much space of the edge coating structure 3, resulting in that the size of the edge coating structure 3 is too small, so that the edge coating structure 3 is difficult to be arranged on the current collector 1, and is easy to fall off after being arranged. If L3 is too short, it will result in that the size of the electrode material layer 2 is reduced, so that the capacity of the battery is reduced.

[0074] In the embodiment of the present application, the maximum size of the electrode material layer 2 in the second direction is L4, and the ratio of L4 to L2 is greater than or equal to 0.988 and less than or equal to 0.9984. The maximum size L4 of the electrode material layer 2 in the second direction should not be too long or too short. If L4 is too long, it will occupy too much space of the edge coating structure 3, resulting in that the size of the edge coating structure 3 is too small, so that the edge coating structure 3 is difficult to be arranged on the current collector 1, and is easy to fall off after being arranged. If L4 is too short, it will result in that the size of the electrode material layer 2 is reduced, so that the capacity of the battery is reduced.

[0075] More specifically, as shown in Figure 1 and Figure 3 The current collector 1 has a first edge 11 and a second edge 12 arranged at an included angle. The first edge 11 is parallel to the first direction, and the second edge 12 is parallel to the second direction. The edge coating structure 3 has a third edge 31 and a fourth edge 32, the third edge 31 is parallel to the first edge 11, and the fourth edge 32 is parallel to the second edge 12. The length of the third edge 31 is L1, and the length of the fourth edge 32 is L2. The electrode material layer 2 has a fifth edge 21 and a sixth edge 22, the fifth edge 21 is parallel to the first edge 11, and the sixth edge 22 is parallel to the second edge 12. The length of the fifth edge 21 is L3, and the length of the sixth edge 22 is L4.

[0076] L1 is greater than or equal to 500 mm and less than or equal to 1500 mm, and L2 is greater than or equal to 1000 mm and less than or equal to 2500 mm. The ratio of L3 to L1 is greater than or equal to 0.984 and less than or equal to 0.998, and the ratio of L4 to L2 is greater than or equal to 0.988 and less than or equal to 0.9984.

[0077] The ratio of L3 to L1 limits the length of the fifth edge 21 relative to the third edge 31 to an appropriate range. If the length of the fifth edge 21 is too long relative to the length of the third edge 31, the spacing between the sixth edge 22 of the electrode material layer 2 and the second edge 12 of the current collector 1 will be too small, making it difficult to apply the edge coating structure 3 in the area between the sixth edge 22 and the second edge 12, and even if the edge coating structure 3 is applied, it will easily fall off. If the length of the fifth edge 21 is too short relative to the length of the third edge 31, the spacing between the sixth edge 22 of the electrode material layer 2 and the second edge 12 of the current collector 1 will be too large, reducing the space on the current collector 1 for the electrode material layer 2, which is not conducive to improving the capacity of the battery.

[0078] The ratio of L4 to L2 limits the length of the sixth edge 22 relative to the fourth edge 32 to an appropriate range. If the length of the sixth edge 22 is too long relative to the length of the fourth edge 32, the spacing between the fifth edge 21 of the electrode material layer 2 and the first edge 11 of the current collector 1 will be too small, making it difficult to apply the edge coating structure 3 in the area between the fifth edge 21 and the first edge 11, and even if the edge coating structure 3 is applied, it will easily fall off. If the length of the sixth edge 22 is too short relative to the length of the fourth edge 32, the spacing between the fifth edge 21 of the electrode material layer 2 and the first edge 11 of the current collector 1 will be too large, reducing the space on the current collector 1 for the electrode material layer 2, which is not conducive to improving the capacity of the battery. In the present embodiment, the current collector is rectangular, and the first edge 11 and the second edge 12 are arranged vertically. Accordingly, the third edge 31 and the fourth edge 32 of the edge coating structure 3 are arranged vertically, and the fifth edge 21 and the sixth edge 22 of the electrode material layer 2 are arranged vertically.

[0079] The embodiment also provides an electric core 100, comprising a positive electrode sheet 110, a negative electrode sheet 120, and an electrolyte sheet 130, the electrolyte sheet 130 is located between the positive electrode sheet 110 and the negative electrode sheet 120, and one of the positive electrode sheet 110 and the negative electrode sheet 120 adopts the electrode sheet as described above. That is, the electrode sheet provided by the embodiment can be the positive electrode sheet 110 or the negative electrode sheet 120. One of the positive electrode sheet 110 and the negative electrode sheet 120 adopts the electrode sheet as described above, and the current collector 1 of the electrode sheet is defined as a first current collector 1, and the electrode material layer 2 is defined as a first electrode material layer. The other of the positive electrode sheet 110 and the negative electrode sheet 120 comprises a second current collector 1 and a second electrode material layer arranged on the second current collector 1. The second current collector 1, the second electrode material layer, the electrolyte sheet 130, the first electrode material layer, and the first current collector 1 are sequentially stacked, the area of the second current collector 1, the area of the second electrode material layer, and the area of the electrolyte sheet 130 are all greater than the area of the first electrode material layer, and the second current collector 1, the second electrode material layer, and the electrolyte sheet 130 can all completely cover the first electrode material layer.

[0080] The structure of the electrode sheet and the electric core 100 provided by the embodiment will be described below with reference to two specific embodiments.

[0081] The first embodiment is shown in Figure 4 and Figure 5 . In the first embodiment, the positive electrode sheet 110 of the electric core 100 is the electrode sheet provided by the embodiment.

[0082] Specifically, the positive electrode sheet 110 comprises a positive electrode current collector 111 and a positive electrode material layer 112 (i.e., the first current collector is the positive electrode current collector 111, and the first electrode material layer is the positive electrode material layer 112). The positive electrode material layer 112 is a slice layer, which is formed by cutting and arranged on the positive electrode current collector 111. The positive electrode current collector 111 and the positive electrode material layer 112 are both rectangular, and the length and width of the positive electrode material layer 112 correspondingly are less than those of the positive electrode current collector 111. The four edges of the positive electrode material layer 112 are all spaced apart from the edges of the positive electrode current collector 111, so that the edges of the positive electrode material layer 112 and the edges of the positive electrode current collector 111 form annular support areas 20, and the edge coating structure 3 is annular and arranged outside the positive electrode material layer 112. Figure 4 As shown in

[0083] Referring to Figure 5The negative electrode sheet 120 includes a negative current collector 121 and a negative material layer 122 (i.e., the aforementioned second current collector is the negative current collector 121, and the aforementioned second electrode material layer is the negative material layer 122). The negative material layer 122 can be a coating layer formed by coating a slurry of a negative active material on the negative current collector 121, or a cut sheet layer formed by cutting.

[0084] The electrolyte sheet 130 is stacked on the side of the positive material layer 112 away from the positive current collector 111, and the negative electrode sheet 120 is stacked on the side of the electrolyte sheet 130 away from the positive electrode sheet 110. The electrolyte sheet 130 is located between the negative material layer 122 and the positive material layer 112. The area of the negative current collector 121, the area of the negative material layer 122, and the area of the electrolyte sheet 130 are all greater than the area of the positive material layer 112, and the negative current collector 121, the negative material layer 122, and the electrolyte sheet 130 all completely cover the positive material layer 112. When the battery cell 100 is press-formed, the edge coating structure 3 can support the edge regions of the electrolyte sheet 130, the negative material layer 122, and the negative current collector 121.

[0085] In some embodiments, the edges of the negative current collector 121, the edges of the negative material layer 122, the edges of the electrolyte sheet 130, the edges of the edge coating structure 3, and the edges of the positive current collector 111 are flush, as shown in FIG. 1B. Figure 5 Alternatively, the edges of the edge coating structure 3 extend beyond the edges of the positive current collector 111 and the edges of the electrolyte sheet 130. After the negative electrode sheet 120, the electrolyte sheet 130, and the positive electrode sheet 110 are stacked, pressure is applied to tightly adhere the negative electrode sheet 120, the electrolyte sheet 130, and the positive electrode sheet 110 together. During the pressing process, the support of the edge coating structure 3 ensures that the electrolyte sheet 130, the positive current collector 111, the negative current collector 121, and the negative material layer 122 do not crack during the pressing process, thereby improving the yield of the battery cell 100 and the battery.

[0086] For example, the size of the positive material layer 112 is 500 mm x 1000 mm, and the size of the negative material layer 122 is 502 mm x 1002 mm. The size of the positive current collector 111 and the size of the negative current collector 121 are both 502 mm x 1002 mm. In other embodiments, other sizes can also be used, which are not limited here.

[0087] As described above, the edge coating structure 3 is attached or connected to the positive material layer 112, so that there is no gap between the edge coating structure 3 and the positive material layer 112.

[0088] As described above, the thickness of the edge coating structure 3 is greater than or equal to 0 μm and less than or equal to 5 μm than the thickness of the positive electrode material layer 112, so that the side of the edge coating structure 3 facing away from the positive electrode current collector 111 and the side of the positive electrode material layer 112 facing away from the positive electrode current collector 111 are flush or almost flush, so as to ensure that the electrolyte sheet 130 and the negative electrode sheet 120 remain flat during the press forming process, and prevent the edge region of the electrolyte sheet 130 and the edge region of the negative electrode sheet 120 from cracking or cracking.

[0089] With reference to the drawings again, Figure 5 The positive electrode current collector 111 is provided with the positive electrode material layer 112 and the edge coating structure 3 on both upper and lower sides, so that the electrolyte sheet 130 and the negative electrode sheet 120 are respectively stacked on both upper and lower sides of the positive electrode sheet 110. Of course, the positive electrode material layer 112 and the edge coating structure 3 can be provided on only one side of the positive electrode current collector 111, and the electrolyte sheet 130 and the negative electrode sheet 120 can be stacked on only one side of the positive electrode sheet 110.

[0090] Exemplarily, the edge coating structure 3 is attached to the periphery of the positive electrode material layer 112 by spraying. First, a slurry of the edge coating structure 3 is prepared, and then the prepared slurry is sprayed on the periphery of the positive electrode material layer 112 by a spraying device. When spraying, a mask plate is used to cover the positive electrode material layer 112, wherein the mask plate has a shielding area and a hollow area, the shielding area is consistent with the size of the positive electrode material layer 112 and completely covers the positive electrode material layer 112 to prevent the slurry from being sprayed on the positive electrode material layer 112, and the hollow area is consistent with the size of the support area 20 to expose the support area 20 around the positive electrode material layer 112. After the mask plate is arranged, the spraying device sprays the slurry of the edge coating structure 3 on the positive electrode current collector 111 through the hollow area of the mask plate. When spraying, the thickness of the edge coating structure 3 can be controlled to be consistent with the thickness of the positive electrode material layer 112 by controlling the discharge amount of the spraying device per unit time and the spraying time. The sprayed slurry falls into the space surrounded by the inner wall of the hollow area and the edge of the positive electrode material layer 112, and does not exceed the edge of the positive electrode current collector 111, so that the edge of the sprayed edge coating structure 3 is flush with the edge of the positive electrode current collector 111.

[0091] Exemplarily, the spraying device is an ultrasonic atomizing spraying device, which can spray more uniformly, improve the compactness of the edge coating structure 3 formed by spraying, and ensure the support strength of the edge coating structure 3.

[0092] Figure 5The structure shown is stacked from bottom to top in the order of the negative electrode tab 120, the electrolyte tab 130, the positive electrode tab 110, the electrolyte tab 130, and the negative electrode tab 120, and the edges of all the negative electrode tab 120, the electrolyte tab 130, and the positive electrode tab 110 are controlled to be flush during the stacking, thereby preventing the edges of the negative electrode tab 120 and the electrolyte tab 130 from cracking or generating cracks during the press forming process.

[0093] Exemplarily, the material components of the edge coating structure 3 include an insulating oxide powder, a solid electrolyte, and a binder. The steps of preparing the slurry of the edge coating structure 3 include: taking the insulating oxide powder and the solid electrolyte into a mixer, and mixing at high speed until uniform. Then, the mixed materials are added into a double planetary mixer, the binder is added, and an appropriate amount of solvent is added to prepare a slurry with appropriate viscosity and stability.

[0094] The binder contained in the edge coating structure 3 can be tightly bonded with the positive electrode material layer 112, the positive electrode current collector 111, and the electrolyte tab 130 after the hot pressing process, so that the electrolyte tab 130 and the positive electrode tab 110 are tightly and firmly attached, preventing the separation of the two during the battery operation to form an interface cavity and cause the phenomenon of hindering ion transmission.

[0095] The insulating oxide powder described above can be one or more of alumina, silica, lithium aluminum titanium phosphate, lithium lanthanum zirconium oxide electronic insulating oxide material, and respective homologues.

[0096] The solid electrolyte described above can be one or more of sulfide electrolyte (such as LPSCl, LGPS and derivatives thereof), halide electrolyte (such as Li3YCl6, Li3InCl6 and derivatives thereof), oxide electrolyte (such as LLZO, LATP, LLTO and derivatives thereof), and polymer electrolyte.

[0097] The binder described above includes polyisobutylene, hydrogenated nitrile rubber, nitrile rubber, hydrogenated styrene-butadiene block copolymer, and derivatives of the above materials. One or more of the above materials can be used in combination.

[0098] The solvent described above includes non-polar solvents such as p-xylene, anisole, tetralin, butyl butyrate, and isobutyl isobutyrate.

[0099] The second embodiment is shown in Figure 6 and Figure 7 The negative electrode tab 120 of the battery cell 100 is the electrode tab provided in the embodiments of the present application.

[0100] Specifically, the negative electrode tab 120 includes a negative current collector 121 and a negative material layer 122 (i.e., the aforementioned first current collector is the negative current collector 121, and the aforementioned first electrode material layer is the negative material layer 122), and the negative material layer 122 is a cut piece layer that is formed by cutting and then stacked on the negative current collector 121. The negative current collector 121 and the negative material layer 122 are both rectangular, and the length and width of the negative material layer 122 are both less than the length and width of the negative current collector 121, respectively. The four edges of the negative material layer 122 are spaced apart from the edges of the negative current collector 121, so that the edges of the negative material layer 122 and the edges of the negative current collector 121 form an annular support area 20, and the edge coating structure 3 is annular and surrounds the negative material layer 122. As shown in Figure 6 The negative current collector 121 is provided with a negative tab 1210.

[0101] Referring to Figure 7 , the positive electrode tab 110 includes a positive current collector 111 and a positive material layer 112 (i.e., the aforementioned second current collector is the positive current collector 111, and the aforementioned second electrode material layer is the positive material layer 112). The positive material layer 112 can be a cut piece layer that is formed by cutting and then stacked on the positive current collector 111; or the positive material layer 112 can be a coating layer that is coated on the positive current collector 111.

[0102] The electrolyte sheet 130 is stacked on the side of the negative material layer 122 away from the negative current collector 121, the positive electrode tab 110 is stacked on the side of the electrolyte sheet 130 away from the negative electrode tab 120, and the electrolyte sheet 130 is located between the negative material layer 122 and the positive material layer 112. The area of the positive current collector 111, the area of the positive material layer 112, and the area of the electrolyte sheet 130 are all greater than the area of the negative material layer 122, and the positive current collector 111, the positive material layer 112, and the electrolyte sheet 130 all completely cover the negative material layer 122. When the battery cell 100 is press-formed, the edge coating structure 3 can support the edge area of the electrolyte sheet 130, the edge area of the positive material layer 112, and the edge area of the positive current collector 111.

[0103] In some embodiments, the edges of the positive current collector 111, the edges of the positive material layer 112, the edges of the electrolyte sheet 130, the edges of the edge coating structure 3, and the edges of the negative current collector 121 are flush, as shown in Figure 7Alternatively, the edge of the edge-coating structure 3 extends beyond the edge of the negative current collector 121 and the edge of the electrolyte sheet 130. After the positive electrode sheet 110, the electrolyte sheet 130 and the negative electrode sheet 120 are laminated, pressure is applied to make the negative electrode sheet 120, the electrolyte sheet 130 and the positive electrode sheet 110 closely adhere to each other. During the pressure application, the electrolyte sheet 130, the negative current collector 121, the positive current collector 111 and the positive material layer 112 will not crack due to the support of the edge-coating structure 3, thereby improving the yield of the battery cell 100 and the battery.

[0104] With reference to Figure 7 , the upper and lower sides of the negative current collector 121 are provided with the negative material layer 122 and the edge-coating structure 3, so that the upper and lower sides of the negative electrode sheet 120 are respectively laminated with the electrolyte sheet 130 and the positive electrode sheet 110. Of course, the negative material layer 122 and the edge-coating structure 3 can be provided on one side of the negative current collector 121, and the electrolyte sheet 130 and the positive electrode sheet 110 can be laminated on one side of the negative current collector 121.

[0105] The difference between the thickness of the edge-coating structure 3 and the thickness of the negative material layer 122 is greater than or equal to 0 μm and less than or equal to 5 μm, so that the side of the edge-coating structure 3 away from the negative current collector 121 and the side of the negative material layer 122 away from the negative current collector 121 are flush or almost flush, thereby avoiding cracking of the electrolyte sheet 130 and the positive electrode sheet 110.

[0106] The material and preparation method of the edge-coating structure 3 are as shown in the embodiments of Figure 4 and Figure 5 , which will not be repeated here.

[0107] As shown in Figure 8 and Figure 9 , the present embodiment also provides a battery comprising the packaging structure 200 and at least one battery cell 100 as described above, and the battery cell 100 is located in the packaging structure 200. The battery with the battery cell 100 described above has high production efficiency, high yield and guaranteed battery capacity. When the edge-coating structure 3 contains an adhesive, the electrolyte sheet 130 is not easy to separate from the electrode sheet after long-term use of the battery, which effectively prevents the phenomenon of increased interface impedance.

[0108] Exemplarily, the battery cell 100 is provided with a plurality of, for example, 2-50, in the thickness direction. The positive tab 1110 of one of the two adjacent battery cells 100 and the negative tab 1210 of the other are conductively connected by the connecting sheet 300. A heat-conducting layer 400 is arranged between the two adjacent battery cells 100, which facilitates the temperature consistency of the plurality of battery cells 100 inside the battery.

[0109] With reference to Figure 8The positive electrode tab 1110 of the uppermost battery cell 100 is electrically connected to the battery positive electrode tab 500, and the negative electrode tab 1210 of the lowermost battery cell 100 is electrically connected to the battery negative electrode tab 600. The battery positive electrode tab 500 and the battery negative electrode tab 600 are both partially arranged outside the packaging structure 200.

[0110] Further, the packaging structure 200 can comprise an aluminum-plastic film structure, wherein the aluminum-plastic film structure comprises oppositely arranged upper and lower aluminum-plastic films, the battery cells 100 are arranged between the upper and lower aluminum-plastic films, the edge regions of the upper and lower aluminum-plastic films are laminated and bonded together to seal the battery cells 100.

[0111] Obviously, the above embodiments of the present application are merely exemplary and are not intended to limit the embodiments of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the scope of the present application. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. An electrode tab, characterized by include: current collector(1); An electrode material layer (2) is disposed on the current collector (1) and falls within the area where the current collector (1) is located. The electrode material layer (2) has at least a portion of its edges spaced apart from the edge of the current collector (1) so that the area between the edge of the electrode material layer (2) and the edge of the current collector (1) forms a support area (20). The electrode material layer (2) is formed by cutting. The edge coating structure (3) is disposed in the support area (20).

2. The electrode pad of claim 1, wherein The electrode material layer (2) is circumferentially surrounded by the edge coating structure (3).

3. The electrode pad of claim 1, wherein The edge coating structure (3) is attached to or connected to the electrode material layer (2).

4. The electrode pad of claim 3, wherein The edge coating structure (3) is bonded to the current collector (1); and / or, the edge coating structure (3) is bonded to the electrode material layer (2).

5. The electrode sheet according to any one of claims 1 to 4, characterized by The difference between the thickness of the edge coating structure (3) and the thickness of the electrode material layer (2) is greater than or equal to 0 μm and less than or equal to 5 μm.

6. The electrode sheet according to any one of claims 1 to 4, characterized by The edge of the current collector (1) falls within the projection area of ​​the edge coating structure (3).

7. The electrode sheet according to any one of claims 1 to 4, characterized by The current collector (1) has an electrode material layer (2) and a side coating structure (3) on both sides.

8. The electrode sheet according to any one of claims 1 to 4, characterized by The area of ​​the edge coating structure (3) is S1, and the area of ​​the electrode material layer (2) is S2. The ratio of S1 to S2 is greater than or equal to 0.0036 and less than or equal to 0.0296.

9. The electrode sheet according to any one of claims 1 to 4, characterized by The maximum dimension of the edge coating structure (3) in the first direction is L1, and the maximum dimension of the edge coating structure (3) in the second direction is L2. There is an angle between the first direction and the second direction. L1 is greater than or equal to 500mm and less than or equal to 1500mm, and L2 is greater than or equal to 1000mm and less than or equal to 2500mm.

10. The electrode pad of claim 9, wherein The maximum dimension of the electrode material layer (2) in the first direction is L3, and the ratio of L3 to L1 is greater than or equal to 0.984 and less than or equal to 0.

998.

11. The electrode pad of claim 9, wherein The maximum dimension of the electrode material layer (2) in the second direction is L4, and the ratio of L4 to L2 is greater than or equal to 0.988 and less than or equal to 0.9984.

12. An electric cell characterized by It includes a positive electrode (110), a negative electrode (120), and an electrolyte sheet (130); one of the positive electrode (110) and the negative electrode (120) is an electrode sheet as described in any one of claims 1-11, and the current collector (1) of the electrode sheet is a first current collector, the electrode material layer (2) is a first electrode material layer, and the other of the positive electrode (110) and the negative electrode (120) includes a second current collector and a second electrode material layer disposed on the second current collector; The second current collector, the second electrode material layer, the electrolyte sheet (130), the first electrode material layer, and the first current collector are stacked in sequence, and the second current collector, the second electrode material layer, and the electrolyte sheet (130) completely cover the first electrode material layer.

13. A battery characterized by An electric battery (1) comprising a packaging structure (200) and at least one electric cell (100) as claimed in claim 12, said electric cell (100) being located inside said packaging structure (200).

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