Battery

Abstract

A battery, comprising at least one battery cell (100), the battery cell (100) comprising an electrode sheet (10) and electrolyte sheets (130) which are stacked, wherein the electrode sheet (10) comprises a current collector (1), electrode material layers (2) and edge-coated structures (3), the electrode material layers (2) being disposed on the current collector (1) and falling within a region of the current collector (1), and the outer contour of the region where the electrode material layers (2) are located being at least partially spaced apart from the outer contour of the region where the current collector (1) is located and forming a support region (20); the edge-coated structures (3) are disposed in the support region (20); and the electrolyte sheets (130) cover at least part of the electrode material layers (2) and at least part of the edge-coated structures (3).

Description

Battery

[0001] This application claims priority to Chinese patent applications No. 202411845166.3 and 202423091391.0, filed on December 13, 2024, to the Chinese Patent Office, the contents of which are incorporated herein by reference in their entirety.

[0002] TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, for example to a battery.

[0004] BACKGROUND

[0005] The cell of the solid-state lithium battery includes an electrode sheet and an electrolyte sheet, the electrode sheet includes a positive electrode sheet and a negative electrode sheet, and the electrolyte sheet is arranged between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer arranged on the positive electrode current collector, and the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer arranged 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 and is used for transmitting 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. The sizes of the positive electrode sheet and the negative electrode sheet are usually inconsistent. For example, the size of the positive electrode active material layer is smaller than the size of the negative electrode sheet, or the size of the negative electrode active material layer is smaller than the size of the positive electrode sheet. The electrolyte sheet is usually adapted to the one with the larger size to ensure that the energy of one of the positive electrode active material layer and the negative electrode active material layer can be fully utilized.

[0006] The electrode material layer (which is the positive electrode active material layer or the negative electrode active material layer) is arranged on the current collector, the size of the electrode material layer is smaller than the size of the current collector, and the edge coating structure is arranged on the outer periphery of the electrode material layer. The current collector, the electrode material layer and the edge coating structure constitute the electrode sheet. The electrolyte sheet needs to be arranged on one side of the electrode material layer, and the edge region of the electrolyte sheet falls on the edge coating structure.

[0007] TECHNICAL PROBLEM

[0008] In the electrode sheet of the battery in the related art, the electrode material layer and the edge coating structure have a large difference in material composition. When the pressure is applied to stack the electrolyte sheet and the electrode sheet, the thickness reduction of the electrode material layer and the edge coating structure under the pressure is difficult to keep consistent, and the surfaces of the electrode material layer and the edge coating structure are uneven, which causes cracks in the edge region of the electrolyte sheet and the edge region of the current collector, thereby affecting the quality of the finished product of the solid-state lithium battery.

[0009] TECHNICAL SOLUTION

[0010] The application provides a battery, comprising at least one battery cell, the battery cell comprising an electrode sheet and an electrolyte sheet, the electrode sheet and the electrolyte sheet being stacked, the electrode sheet comprising:

[0011] a current collector;

[0012] an electrode material layer, provided on the current collector and falling within a region where the current collector is located, an outer contour of a region where the electrode material layer is located being at least partially spaced apart from an outer contour of the region where the current collector is located, so that a support region is formed between the outer contour of the region where the electrode material layer is located and the outer contour of the region where the current collector is located;

[0013] an edge coating structure, provided in the support region; the electrolyte sheet covering at least part of the electrode material layer and at least part of the edge coating structure;

[0014] a material component of the edge coating structure comprising a solid-state electrolyte.

[0015] As some implementations of the battery provided by the application, a material component of the electrode material layer comprises a solid-state electrolyte.

[0016] As some implementations of the battery provided by the application, a percentage of a mass of the solid-state electrolyte in the electrode material layer to a total mass of the electrode material layer is a, and a percentage of a mass of the solid-state electrolyte in the edge coating structure to a total mass of the edge coating structure is b.

[0017] An absolute value of a difference between a and b is greater than or equal to 0 and less than or equal to 5%.

[0018] As some implementations of the battery provided by the application, a percentage of a mass of the solid-state electrolyte in the electrode material layer to a total mass of the electrode material layer is a, and a is greater than or equal to 5% and less than or equal to 35%.

[0019] As some implementations of the battery provided by the application, a percentage of a mass of the solid-state electrolyte in the edge coating structure to a total mass of the edge coating structure is b; and b is greater than or equal to 5% and less than or equal to 35%.

[0020] As some implementations of the battery provided by the application, a material component of the edge coating structure further comprises an insulating oxide and a binder.

[0021] As some implementations of the battery provided by the application, a percentage of a mass of the insulating oxide in the edge coating structure to a total mass of the edge coating structure is c; and c is greater than or equal to 65% and less than or equal to 90%.

[0022] As some implementations of the battery provided by the application, a percentage of a mass of the binder in the edge coating structure to a total mass of the edge coating structure is d; and d is greater than or equal to 1% and less than or equal to 5%.

[0023] As some implementations of the battery provided in the present application, the insulating oxide includes any one or a combination of at least two of aluminum oxide, silicon oxide, lithium aluminum titanium phosphate, lithium lanthanum zirconium oxide, an aluminum oxide homolog, a silicon oxide homolog, a lithium aluminum titanium phosphate homolog, and a lithium lanthanum zirconium oxide homolog.

[0024] As some implementations of the battery provided in the present application, the adhesive includes any one or a combination of at least two of polyisobutylene, hydrogenated nitrile rubber, nitrile rubber, hydrogenated styrene-butadiene block copolymer, a derivative of polyisobutylene, a derivative of hydrogenated nitrile rubber, a derivative of nitrile rubber, and a derivative of hydrogenated styrene-butadiene block copolymer.

[0025] As some implementations of the battery provided in the present application, the solid-state electrolyte in the edge coating structure is the same as the solid-state electrolyte in the electrode material layer.

[0026] As some implementations of the battery provided in the present application, the electrode material layer is surrounded by the edge coating structure in the circumferential direction.

[0027] As some implementations of the battery provided in the present application, the edge coating structure is attached to or connected to the electrode material layer.

[0028] As some implementations of the battery provided in the present application, the edge coating structure is adhesively connected to at least one of the current collector or the electrode material layer.

[0029] As some implementations of the battery provided in the present application, 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 10 μm.

[0030] As some implementations of the battery provided in the present application, the difference between the thickness of the edge coating structure and the thickness of the electrode material layer is less than or equal to 5 μm.

[0031] As some implementations of the battery provided in the present application, the edge of the current collector falls within the projection area of the edge coating structure.

[0032] As some implementations of the battery provided in the present application, the electrode material layer and the edge coating structure are arranged on both sides of the current collector.

[0033] As some implementations of the battery provided in the present application, 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.

[0034] As some implementations of the battery provided in the present application, the maximum dimension of the edge coating structure in a first direction is L1, the maximum dimension of the edge coating structure in a second direction is L2, and there is an included angle between the first direction and the second direction.

[0035] 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.

[0036] As some implementations of the battery provided in the present application, the maximum dimension 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.

[0037] As some implementations of the battery provided in the present application, the maximum dimension 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.

[0038] As some implementations of the battery provided in the present application, the electrode material layer is formed by cutting.

[0039] Advantages

[0040] The battery provided in the present application, since the material composition of the edge coating structure includes a solid-state electrolyte, and the material composition of the electrode material layer also includes a solid-state electrolyte, the material composition of the electrode material layer and the material composition of the edge coating structure are as similar as possible. In the process of stacking the electrolyte sheet and the electrode sheet, the thickness of the electrode material layer and the thickness of the edge coating structure will gradually decrease under the action of pressure. Since the material composition of the electrode material layer and the material composition of the edge coating structure are similar, the degree of thickness reduction of the electrode material layer and the edge coating structure under the action of pressure is almost the same. That is, after pressure is simultaneously applied to the electrode material layer and the edge coating structure, the thickness of the electrode material layer and the thickness of the edge coating structure at each moment are almost the same. The side of the electrode material layer facing the current collector and the side of the edge coating structure facing the current collector are almost flush. The side of the electrode material layer facing the electrolyte sheet and the side of the edge coating structure facing the electrolyte sheet are almost flush. Therefore, cracks in the electrolyte sheet and the current collector can be avoided, and the finished product quality of the battery cell and the battery is improved.

[0041] BRIEF DESCRIPTION OF DRAWINGS

[0042] FIG. 1 is a schematic view of the inside of a battery according to some implementations of the present application.

[0043] FIG. 2 is a schematic view of the stacking of an electrode sheet and an electrolyte sheet according to some implementations of the present application.

[0044] FIG. 3 is a schematic view of an electrode material layer on a current collector according to some implementations of the present application.

[0045] FIG. 4 is a side view of an electrode sheet according to some implementations of the present application.

[0046] FIG. 5 is a schematic view of an electrode material layer and an edge coating structure according to some implementations of the present application.

[0047] Figure 6 is a schematic diagram of a positive electrode material layer on a positive current collector according to some embodiments of the present application.

[0048] Figure 7 is a schematic diagram of a first structure of an electric core according to some embodiments of the present application.

[0049] Figure 8 is a schematic diagram of a negative electrode material layer on a negative current collector according to some embodiments of the present application.

[0050] Figure 9 is a schematic diagram of a second structure of an electric core according to some embodiments of the present application.

[0051] Figure 10 is a schematic diagram of a battery according to some embodiments of the present application.

[0052] In the drawings:

[0053] 1, current collector; 2, electrode material layer; 10, electrode sheet; 20, support area; 3, edge coating structure;

[0054] 11, first edge; 12, second edge;

[0055] 21, fifth edge; 22, sixth edge;

[0056] 31, third edge; 32, fourth edge;

[0057] 100, electric core; 200, packaging structure; 300, connecting sheet; 400, heat-conducting layer; 500, battery positive electrode tab; 600, battery negative electrode tab;

[0058] 110, positive electrode sheet; 120, negative electrode sheet; 130, electrolyte sheet;

[0059] 111, positive current collector; 112, positive electrode material layer; 1110, positive electrode tab;

[0060] 121, negative current collector; 122, negative electrode material layer; 1210, negative electrode tab.

[0061] Embodiments of the present application

[0062] As shown in Figure 1, the present application provides a battery, which includes at least one electric core 100. As shown in Figure 2, the electric core 100 includes an electrode sheet 10 and an electrolyte sheet 130 arranged in a stack.

[0063] As shown in FIG. 3 and FIG. 4, the electrode sheet 10 comprises the current collector 1, the electrode material layer 2, and the edge coating structure 3. The electrode material layer 2 is arranged on the current collector 1 and falls within the area where the current collector 1 is located. The outer contour of the area where the electrode material layer 2 is located is at least partially spaced apart from the outer contour of the area where the current collector 1 is located, so that the outer contour of the area where the electrode material layer 2 is located and the outer contour of the area where the current collector 1 is located form a support area 20. The edge coating structure 3 is arranged in the support area 20. In the battery cell 100, the electrolyte sheet 130 covers at least part of the electrode material layer 2 and at least part of the edge coating structure 3. For example, as shown in FIG. 2, when the electrolyte sheet 130 is arranged on the side of the electrode material layer 2 away from the current collector 1, part of the electrolyte sheet 130 falls on the electrode material layer 2 and the other part falls on the edge coating structure 3.

[0064] After the electrolyte sheet 130 and the electrode sheet 10 are arranged in layers, pressure is applied to the electrolyte sheet 130 and the electrode sheet 10. During the application of pressure, the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 gradually decrease under the action of pressure. If the difference between the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 is large during the application of pressure, the surfaces of the electrode material layer 2 and the edge coating structure 3 facing the current collector 1 and the surfaces of the electrode material layer 2 and the edge coating structure 3 facing the electrolyte sheet 130 will not be flush, which may cause cracks in the current collector 1 and the electrolyte sheet 130 during the pressing process, for example, cracks may occur in the edge area of the current collector 1 and the electrolyte sheet 130. If cracks occur in the edge area of the current collector 1, the effective contact area between the electrode material layer 2 and the current collector 1 may be reduced, which may affect the charge transfer efficiency. If cracks occur in the edge area of the electrolyte sheet 130, the lithium ion transport channel may be damaged, the lithium ion conduction efficiency may be reduced, the battery internal resistance may be increased, and the charge and discharge performance may be poor.

[0065] In the embodiments of the present application, the difference between the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 is greater than or equal to 0 and less than or equal to 10 μm, so that the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 are almost equal before pressure is applied to the electrode material layer 2 and the edge coating structure 3. During the application of pressure to the electrolyte sheet 130 and the electrode sheet 10 after the electrolyte sheet 130 and the electrode sheet 10 are arranged in layers, the difference between the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 is small, the surface of the side of the edge coating structure 3 away from the current collector 1 is almost flush with the surface of the side of the electrode material layer 2 away from the current collector 1, which can ensure the flatness of the electrolyte sheet 130 and is conducive to avoiding cracks in the current collector 1 and the electrolyte sheet 130.

[0066] In some implementations, the difference between the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 is less than or equal to 5 μm, so that the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 are closer, which can ensure that the electrode material layer 2 and the edge coating structure 3 are flush after being arranged in layers.

[0067] In the embodiments of the present application, the material component of the electrode material layer 2 and the material component of the edge coating structure 3 both include solid-state electrolyte, so that the material component of the electrode material layer 2 and the material component of the edge coating structure 3 are as similar as possible. In the process of stacking the electrolyte sheet 130 and the electrode sheet 10, the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 will gradually decrease under the action of pressure. Since the material component of the electrode material layer 2 and the material component of the edge coating structure 3 are similar, the thickness reduction degree of the electrode material layer 2 and the edge coating structure 3 under the action of pressure is almost the same. That is, after the pressure is applied to the electrode material layer 2 and the edge coating structure 3 at the same time, the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 at each moment are almost the same, the side of the electrode material layer 2 facing the current collector 1 and the side of the edge coating structure 3 facing the current collector 1 are almost flush, and the side of the electrode material layer 2 facing the electrolyte sheet 130 and the side of the edge coating structure 3 facing the electrolyte sheet 130 are almost flush, thereby avoiding cracks in the electrolyte sheet 130 and the current collector 1, and improving the finished product quality of the battery cell 100 and the battery.

[0068] In some implementations, the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 are equal, that is, the difference between the thicknesses of the two is 0, and when the electrolyte sheet 130 and the electrode sheet 10 are stacked, the thickness consistency of the electrode material layer 2 and the edge coating structure 3 can be improved.

[0069] In some implementations, the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 can be different, but the difference between the thicknesses of the two is less than or equal to 10 μm. For example, the difference between the thickness of the electrode material layer 2 and the thickness of the edge coating structure 3 is 1 μm, 1.3 mm, 1.8 mm, 2 μm, 2.5 mm, 3 μm, 4 μm, 4.7 mm, 5 μm, 5.3 mm, 6 μm, 6.5 mm, 7 μm, 8 μm, 8.2 mm, 9 μm, 10 μm.

[0070] In the embodiments of the present application, the mass percentage of the solid-state electrolyte in the electrode material layer 2 in the total mass of the electrode material layer 2 is a, and the mass percentage of the solid-state electrolyte in the edge coating structure 3 in the total mass of the edge coating structure 3 is b. For ease of description, the "mass percentage of the solid-state electrolyte in the electrode material layer 2 in the total mass of the electrode material layer 2" is simplified to "mass percentage of the solid-state electrolyte in the electrode material layer 2", and the "mass percentage of the solid-state electrolyte in the edge coating structure 3 in the total mass of the edge coating structure 3" is simplified to "mass percentage of the solid-state electrolyte in the edge coating structure 3".

[0071] In some implementations, the mass percentage a of the solid-state electrolyte in the electrode material layer 2 is greater than or equal to 5% and less than or equal to 35%, so that the electrode material layer 2 has a relatively high electrical conductivity, which is conducive to reducing the internal resistance of the electrode sheet 10. Moreover, the mass percentage of the solid-state electrolyte in the electrode material layer 2 is less than or equal to 35%, so that the solid-state electrolyte does not excessively occupy the proportion of other material components in the electrode material layer 2.

[0072] For example, the mass percentage a of the solid-state electrolyte in the electrode material layer 2 is 5%, 7.5%, 10%, 12%, 12.8%, 15%, 20%, 22.4%, 25%, 27%, 30%, 33.6%, 35%, etc.

[0073] In some implementations, the mass percentage b of the solid-state electrolyte in the edge coating structure 3 is greater than or equal to 5% and less than or equal to 35%. That is, the value range of b is the same as that of a, so that the mass percentage of the solid-state electrolyte in the edge coating structure 3 is similar to that in the electrode material layer 2, thereby improving the similarity of the material components of the two.

[0074] In some implementations, the absolute value of the difference between a and b is greater than or equal to 0 and less than or equal to 5%.

[0075] In some implementations, a and b can be equal (i.e., the difference between a and b is 0), so that the mass percentage of the solid-state electrolyte in the edge coating structure 3 and the electrode material layer 2 is consistent, thereby making the similarity of the material components of the two higher. In the process of stacking the electrolyte sheet 130 and the electrode sheet 10, the consistency of the thickness change of the edge coating structure 3 and the electrode material layer 2 is improved, thereby achieving a better effect of preventing cracks in the electrolyte sheet 130 and the current collector 1.

[0076] For example, a and b are 5%, 7.5%, 9.2%, 10%, 12.5%, 15%, 16.8%, 17.5%, 20%, 22.5%, 24%, 25%, 27.5%, 30%, 31.4%, 32.5%, 33%, 35%, etc.

[0077] In other implementations, a and b can also be different, but the absolute value of the difference between a and b is less than or equal to 5%, so that the mass percentage of the solid-state electrolyte in the edge coating structure 3 and the electrode material layer 2 is as close as possible, thereby improving the similarity of the material components of the two. In the process of stacking the electrolyte sheet 130 and the electrode sheet 10, the possibility of cracks in the electrolyte sheet 130 and the current collector 1 is reduced.

[0078] Exemplarily, the absolute value of the difference between a and b can be 0.5%, 1%, 1.2%, 1.5%, 2%, 2.3%, 2.5%, 3%, 3.5%, 3.8%, 4%, 4.5%, 4.6%, 5%. For example, a is 10%, b is 12.5%, and the difference between a and b is 2.5%.

[0079] In the embodiments of the present application, the optional range of the solid-state electrolyte material is: sulfide electrolyte, halide electrolyte, oxide electrolyte, and polymer electrolyte, and any one or a combination of at least two of them can be used as the solid-state electrolyte in the electrode material layer 2 and the edge coating structure 3. The solid-state electrolyte material is convenient to obtain and low in cost, and when added to the electrode material layer 2, it can make the electrode material layer 2 have higher electrical conductivity and smaller internal resistance.

[0080] Exemplarily, the sulfide electrolyte includes lithium phosphate sulfate chloride (LPSCl), lithium germanium phosphorus sulfur (LGPS) (germanium phosphorus sulfur lithium ion solid-state electrolyte), and derivatives thereof. The halide electrolyte includes Li3YCl6, Li3InCl6, and derivatives thereof. The oxide electrolyte includes lithium lanthanum zirconium oxygen (LLZO), lithium aluminum titanium phosphate (LATP), lanthanum titanate lithium (LLTO), and derivatives thereof.

[0081] In the embodiments of the present application, the type of the solid-state electrolyte in the edge coating structure 3 is the same as that in the electrode material layer 2, which improves the similarity of the material components of the edge coating structure 3 and the electrode material layer 2. In the process of stacking the electrolyte sheet 130 and the electrode sheet 10, the thickness reduction of the edge coating structure 3 and the electrode material layer 2 in a unit time can be effectively ensured to be almost consistent, thereby ensuring that no cracks are generated on the electrolyte sheet 130 and the current collector 1. The thickness reduction of the edge coating structure 3 refers to the difference between the thicknesses of the edge coating structure 3 at two time points, and the thickness reduction of the electrode material layer 2 refers to the difference between the thicknesses of the electrode material layer 2 at two time points.

[0082] In the embodiments of the present application, the material components of the edge coating structure 3 further include insulating oxides and adhesives. If the edge coating structure 3 is conductive, when the edge region of the electrolyte sheet 130 is cracked, it can cause the electrode material layer 2 of the positive electrode sheet and the electrode material layer 2 of the negative electrode sheet to be in conductive contact through the edge coating structure 3, resulting in short circuit. The presence of insulating oxides can make the edge coating structure 3 have certain insulation performance, avoiding short circuit between the positive electrode sheet and the negative electrode sheet. The presence of adhesives can make the edge coating structure 3 connected to any one of the current collector 1, the electrode material layer 2 and the electrolyte sheet 130 through adhesion to the other two, ensuring the stability of the edge coating structure 3 and preventing it from falling off.

[0083] In some implementations, the mass percentage of the insulating oxides in the edge coating structure 3 in the total mass of the edge coating structure 3 is c. Wherein, c is greater than or equal to 65% and less than or equal to 90%, so that the edge coating structure 3 has good insulation performance. For ease of description, the "mass percentage of the insulating oxides in the edge coating structure 3 in the total mass of the edge coating structure 3" is simplified as "mass percentage of the insulating oxides in the edge coating structure 3".

[0084] Exemplarily, the mass percentage of the insulating oxides in the edge coating structure 3 is 65%, 66.5%, 70%, 73%, 75%, 76.2%, 78.6%, 80%, 82.7%, 85%, 88.3%, 90%, etc.

[0085] The mass percentage of the adhesives in the edge coating structure 3 in the total mass of the edge coating structure 3 is d. Wherein, d is greater than or equal to 1% and less than or equal to 5%. Adding adhesives with a mass percentage of 1% to 5% in the edge coating structure 3 can ensure that the edge coating structure 3 is firmly adhered to the current collector 1, the electrode material layer 2 and the electrolyte sheet 130. Moreover, since the mass percentage of the adhesives is less than or equal to 5%, it can avoid reducing the mass percentage of the solid-state electrolyte and the mass percentage of the insulating oxides in the edge coating structure 3. For ease of description, the "mass percentage of the adhesives in the edge coating structure 3 in the total mass of the edge coating structure 3" is simplified as "mass percentage of the adhesives in the edge coating structure 3".

[0086] Exemplarily, the mass percentage of the adhesives in the edge coating structure 3 is 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0087] In the embodiments of the present application, the optional range of the insulating oxide material includes: aluminum oxide, silicon oxide, lithium aluminum titanium phosphate, lithium lanthanum zirconium oxide, aluminum oxide homologues, silicon oxide homologues, lithium aluminum titanium phosphate homologues, lithium lanthanum zirconium oxide homologues. Any one or a combination of at least two of them can be used as the insulating oxide in the edge coating structure 3. The insulating oxide material is convenient to obtain and has low cost, and has good insulation performance.

[0088] In the embodiments of the present application, the optional range of the adhesive material includes polyisobutylene, hydrogenated nitrile rubber, nitrile rubber, hydrogenated styrene-butadiene block copolymer, derivatives of polyisobutylene, derivatives of hydrogenated nitrile rubber, derivatives of nitrile rubber, and derivatives of hydrogenated styrene-butadiene block copolymer. Any one or a combination of at least two of them can be used as the adhesive in the edge coating structure 3. The adhesive material is easy to obtain, low in cost, and has high adhesion.

[0089] In some implementations, the electrode material layer 2 of the electrode sheet 10 is cut to shape. After the electrode material layer 2 is cut to shape, it can be arranged on the current collector 1 without waiting for drying, thereby improving the production speed of the electrode sheet 10 and further improving the production efficiency of the battery. Moreover, the electrode material layer 2 cut to shape is easy to control the thickness and 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 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 electrode material layer 2 cut to shape has a certain roughness relative to the plane formed by flow, thereby being able to increase the adhesion strength between the electrode material layer 2 and the electrolyte sheet 130. Furthermore, compared with the electrode material layer formed on the current collector 1 by coating slurry, the electrode material layer 2 cut to shape 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 10 and the capacity of the battery from being affected.

[0090] In some implementations, the electrode material layer 2 is circumferentially surrounded by the edge coating structure 3. Referring to FIG. 3, 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 shown in FIG. 2, 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 is able to support a circle of edge regions of the electrolyte sheet 130.

[0091] 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 apart from the edges of the current collector 1, without the need to align part of the edges of the electrode material layer 2 with the edges of the current collector 1, thereby being higher in production efficiency.

[0092] The shapes of the electrode material layer 2 and the current collector 1 can be circular, oval, polygonal, or the like. 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 that of the current collector 1. The electrode material layer 2 and the current collector 1 can be concentrically arranged, so that the area between the outer contours of the electrode material layer 2 and the current collector 1 forms a circular annular support area 20. At this time, the edge coating structure 3 arranged in the support area 20 is also circular annular.

[0093] If the electrode material layer 2 and the current collector 1 are polygonal, the electrode material layer 2 has N edges, N being a positive integer greater than or equal to 3. The electrode material layer 2 in a rectangular shape has four edges, and the electrode material layer 2 in a pentagonal shape has five edges. When the electrode material layer 2 is arranged on the current collector 1, if M (0≤M

[0094] In some implementations, the edges of the current collector 1 are arranged to be spaced apart from the edges of the electrode material layer 2, that is, the N edges of the electrode material layer 2 are all arranged to be 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.

[0095] Exemplarily, referring to FIG. 3, the electrode material layer 2 is rectangular and has four sides (N=4). The four edges of the electrode material layer 2 shown in FIG. 3 are all spaced apart from the edges of the current collector 1. That is, 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 is arranged to surround 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 other three edges are all spaced apart from the edges of the current collector 1. At this time, the edge coating structure 3 can be arranged on one side of the three edges. Alternatively, one edge or two edges of the electrode material layer 2 are spaced apart from the edges of the current collector 1. At this time, the edge coating structure 3 can be arranged on one side of the one edge or the two edges.

[0096] In some embodiments, the edge coating structure 3 can be attached to the electrode material layer 2 without a gap therebetween. For example, the edge coating structure 3 can be attached to the current collector 1 by an adhesive on one side of the edge coating structure 3, and the edge coating structure 3 can be attached to the electrode material layer 2 without a gap therebetween. In this way, the gap between the edge coating structure 3 and the electrode material layer 2 can be avoided, and the electrolyte sheet 130 can be prevented from having a gap below the electrolyte sheet 130 after the electrolyte sheet 130 is stacked on the electrode material layer 2. In this way, the edge coating structure 3 can provide better support to the edge region of the electrolyte sheet 130, and the electrolyte sheet 130 can be prevented from having cracks in the edge region.

[0097] In some other embodiments, the edge coating structure 3 can be attached to the electrode material layer 2. In this way, the edge coating structure 3 can be more stable after being arranged, and the edge coating structure 3 can be less likely to fall off.

[0098] In some embodiments, the edge coating structure 3 can be attached to the current collector 1 and the electrode material layer 2. In this way, the edge coating structure 3 can be more stable after being arranged.

[0099] In some embodiments, the edge coating structure 3 can be an insulating adhesive tape that is attached to the current collector 1 and attached to the electrode material layer 2. Alternatively, the edge coating structure 3 can include an adhesive component that can be attached to the current collector 1 and the electrode material layer 2. In this way, the edge coating structure 3 can be attached to the current collector 1 and the electrode material layer 2 without a gap therebetween, and the edge coating structure 3 can be more stable on the current collector 1 and less likely to fall off.

[0100] In some embodiments, the edge of the current collector 1 can fall within the projection area of the edge coating structure 3. In other words, the edge of the edge coating structure 3 can be flush with or beyond the edge of the current collector 1. In this way, the edge region of the electrolyte sheet 130 can fall on the edge coating structure 3 when the electrolyte sheet 130 is stacked on the electrode material layer 2, and the electrolyte sheet 130 can be prevented from having cracks in the edge region during the pressure forming process of the battery cell.

[0101] The current collector 1 can have the electrode material layer 2 and the edge coating structure 3 on one side or both sides. In some embodiments, the current collector 1 can have the electrode material layer 2 and the edge coating structure 3 on one side. In this case, the electrolyte sheet 130 and the electrode sheet can be stacked on the side of the current collector 1 where the electrode material layer 2 is arranged. In some other embodiments, the current collector 1 can have the electrode material layer 2 and the edge coating structure 3 on both sides, as shown in FIG. 2. In this case, the electrolyte sheet 130 and the electrode sheet can be stacked on both sides of the current collector 1, and a sandwich structure can be formed to improve the energy density of the battery.

[0102] In the embodiments of the present application, the area of the edge coating structure 3 is S1, the area of the electrode material layer 2 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. When the inner side edge of the edge coating structure 3 is in contact with the electrode material layer 2, and the outer side edge 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. The area ratio relationship between the edge coating structure 3 and the electrode material layer 2 in the present application prevents the area of the edge coating structure 3 from being 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 resulting in 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, and it is easy to fall off after being coated on the current collector 1.

[0103] As shown in FIG. 5, 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, the edge coating structure 3 has a rectangular shape, the width direction of the edge coating structure 3 is the first direction, and the length direction 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.

[0104] As shown in FIG. 3 and FIG. 5, in the embodiments of the present application, 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. The maximum dimension 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 set on the current collector 1, and is also easy to fall off after being set. If L3 is too short, it will result in a decrease in the size of the electrode material layer 2, and further result in a decrease in the capacity of the battery.

[0105] In the embodiments of the present application, 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. The maximum dimension 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 too small size of the edge coating structure 3, 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 the size reduction of the electrode material layer 2, thereby reducing the capacity of the battery.

[0106] As shown in FIGS. 3 and 5, the current collector 1 has a first edge 11 and a second edge 12 arranged at an 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.

[0107] 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.

[0108] The ratio of L3 to L1 is limited to 0.984 to 0.998, so that the length of the fifth edge 21 relative to the third edge 31 is in a suitable range, and the length of the fifth edge 21 relative to the third edge 31 is not too long or too short. If the length of the fifth edge 21 relative to the length of the third edge 31 is too long, it will result in too small spacing between the sixth edge 22 of the electrode material layer 2 and the second edge 12 of the current collector 1, so that it is difficult to coat the edge coating structure 3 in the region between the sixth edge 22 and the second edge 12, and even if the edge coating structure 3 is coated, it is easy to fall off. If the length of the fifth edge 21 relative to the length of the third edge 31 is too short, it will result in too large spacing between the sixth edge 22 of the electrode material layer 2 and the second edge 12 of the current collector 1, so that the space for arranging the electrode material layer 2 on the current collector 1 is reduced, which is not conducive to improving the capacity of the battery.

[0109] The ratio of L4 to L2 is limited to 0.988 to 0.9984, so that the length of the sixth edge 22 relative to the fourth edge 32 is within a suitable range, and the sixth edge 22 is not too long or too short relative to the fourth edge 32. If the length of the sixth edge 22 is too long relative to the length of the fourth edge 32, the distance between the fifth edge 21 of the electrode material layer 2 and the first edge 11 of the current collector 1 is too small, and it is difficult to apply the edge coating structure 3 to the area between the fifth edge 21 and the first edge 11, and even if the edge coating structure 3 is applied, it is easy to fall off. If the length of the sixth edge 22 is too short relative to the length of the fourth edge 32, the distance between the fifth edge 21 of the electrode material layer 2 and the first edge 11 of the current collector 1 is too large, and the space on the current collector 1 for arranging the electrode material layer 2 is reduced, which is not conducive to improving the capacity of the battery.

[0110] In the embodiments of the present application, the current collector 1 is rectangular, and the first edge 11 and the second edge 12 are arranged vertically. Correspondingly, 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.

[0111] In some implementations, the edge coating structure 3 can be attached to the periphery of the electrode material layer 2 by spraying. A slurry for preparing the edge coating structure 3 is prepared, and then the prepared slurry is sprayed around the electrode material layer 2 by a spraying device. When spraying, a mask is used to cover the electrode material layer 2, and the mask has a shielding area and a hollow area, the shielding area is consistent with the size of the electrode material layer 2 and completely covers the electrode material layer 2 to prevent the slurry from being sprayed on the electrode material layer 2, and the hollow area is consistent with the size of the support area 20 to expose the support area 20 around the electrode material layer 2. After the mask is arranged, the spraying device sprays the edge coating structure 3 slurry on the current collector 1 through the hollow area of the mask. When spraying, the thickness of the edge coating structure 3 can be controlled to be consistent with the thickness of the electrode material layer 2 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 electrode material layer 2, and does not exceed the edge of the current collector 1, so that the edge of the sprayed edge coating structure 3 is flush with the edge of the positive current collector 111.

[0112] For example, the spraying device is an ultrasonic atomization spraying device, which can spray more uniformly, improve the density of the edge coating structure 3 formed by spraying, and ensure the strength of the edge coating structure 3.

[0113] The step of preparing the slurry of the edge coating structure 3 includes: taking the insulating oxide powder and the solid electrolyte into a mixer, and mixing at high speed until uniform. Then, the uniformly mixed material is added into a double planetary mixer, and then the binder is added, and an appropriate amount of solvent is added to prepare a slurry with appropriate viscosity and stability. The solvent added in the double planetary mixer can be non-polar solvents such as p-xylene, anisole, tetralin, butyl butyrate, isobutyl isobutyrate, etc.

[0114] As shown in FIGS. 7 and 9, the battery cell 100 provided by the embodiments of the present application includes 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 includes the edge coating structure 3. The electrode material layer 2 includes both the positive electrode material layer 112 and the negative electrode material layer 122.

[0115] The structures of two battery cells provided by the embodiments of the present application are described below with reference to FIGS. 6-9.

[0116] As shown in FIGS. 6 and 7, the positive electrode sheet 110 includes a positive electrode current collector 111 and a positive electrode material layer 112. The positive electrode material layer 112 is cut and formed, and is 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 correspond to less than those of the positive electrode current collector 111, respectively. The four edges of the positive electrode material layer 112 are 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. The edge coating structure 3 is annular and surrounds the positive electrode material layer 112. As shown in FIG. 6, the positive electrode current collector 111 is provided with a positive electrode tab 1110.

[0117] Referring to FIG. 7, the negative electrode sheet 120 includes a negative electrode current collector 121 and a negative electrode material layer 122. The negative electrode material layer 122 can be a coating layer formed by coating a slurry of negative electrode active material on the negative electrode current collector 121, or a cut layer formed by cutting.

[0118] The electrolyte sheet 130 is arranged on the side of the positive electrode material layer 112 away from the positive electrode current collector 111, the negative electrode sheet 120 is arranged on the side of the electrolyte sheet 130 away from the positive electrode sheet 110, and the electrolyte sheet 130 is located between the negative electrode material layer 122 and the positive electrode material layer 112.

[0119] After the negative electrode sheet 120, the electrolyte sheet 130 and the positive electrode sheet 110 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 process, the positive electrode material layer 112 and the edge coating structure 3 have a high similarity in material components, so the thickness reduction of the positive electrode material layer 112 and the edge coating structure 3 per unit time is almost consistent, and the thickness of the positive electrode material layer 112 and the thickness of the edge coating structure 3 are approximately equal at any time. That is, the positive electrode material layer 112 is substantially flush with the edge coating structure 3, which can avoid the electrolyte sheet 130, the positive current collector 111, the negative current collector 121 and the negative electrode material layer 122 from being cracked seriously during the lamination process.

[0120] The area of the negative current collector 121, the area of the negative electrode material layer 122 and the area of the electrolyte sheet 130 are all greater than the area of the positive electrode material layer 112, and the negative current collector 121, the negative electrode material layer 122 and the electrolyte sheet 130 all completely cover the positive electrode material layer 112. After the negative electrode sheet 120, the electrolyte sheet 130 and the positive electrode sheet 110 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. If the edge coating structure 3 is not arranged on the positive current collector 111, the edge region of the electrolyte sheet 130 is in a suspended state, and during the pressure forming of the battery cell 100, the edge region of the electrolyte sheet 130 is not supported, which causes the electrolyte sheet 130 and the negative electrode sheet 120 to be cracked. By arranging the edge coating structure 3 on the positive current collector 111, the edge region of the electrolyte sheet 130 is avoided from being suspended, and the edge region of the electrolyte sheet 130 and the edge region of the negative electrode sheet 120 are supported. During the pressure application process, the electrolyte sheet 130, the positive current collector 111, the negative current collector 121 and the negative electrode material layer 122 are avoided from being cracked seriously, and the yield of the battery cell 100 and the battery is improved.

[0121] In some implementations, the edges of the negative current collector 121, the edges of the negative electrode 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. 7.

[0122] For example, the size of the positive electrode material layer 112 is 500mm×1000mm, and the size of the negative electrode material layer 122 is 502mm×1002mm. The size of the positive current collector 111 and the size of the negative current collector 121 are both 502mm×1002mm. The edge coating structure 3 can be attached to the positive electrode material layer 112 without being connected to the positive electrode material layer 112. The edge coating structure 3 can also be connected to the positive electrode material layer 112, so that there is no gap between the edge coating structure 3 and the positive electrode material layer 112.

[0123] The battery cell 100 shown in FIG. 7 is provided with the positive material layer 112 and the edge coating structure 3 on both sides of the positive current collector 111. Correspondingly, the battery cell 100 includes two electrolyte sheets 130 and two negative electrode sheets 120. The battery cell 100 is sequentially provided with the negative electrode sheet 120, the electrolyte sheet 130, the positive electrode sheet 110, the electrolyte sheet 130, and the negative electrode sheet 120 from top to bottom.

[0124] As shown in FIGS. 8 and 9, the negative electrode sheet 120 includes the negative current collector 121 and the negative material layer 122, which is cut and formed and overlaid 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 those of the negative current collector 121. 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 annular support areas 20. The edge coating structure 3 is annular and surrounds the negative material layer 122. As shown in FIG. 8, the negative current collector 121 is provided with the negative tab 1210.

[0125] Referring to FIG. 9, the positive electrode sheet 110 includes the positive current collector 111 and the positive material layer 112. The positive material layer 112 can be a slice layer, which is cut and formed and overlaid on the positive current collector 111. The positive material layer 112 can also be a coating layer coated on the positive current collector 111.

[0126] The electrolyte sheet 130 is stacked on the side of the negative material layer 122 away from the negative current collector 121, and the positive electrode sheet 110 is stacked on the side of the electrolyte sheet 130 away from the negative electrode sheet 120, and the electrolyte sheet 130 is located between the negative material layer 122 and the positive material layer 112.

[0127] 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 pressure application process, the thickness reduction of the negative material layer 122 and the edge coating structure 3 per unit time is almost consistent due to the high similarity of the material components, and the thickness of the negative material layer 122 and the thickness of the edge coating structure 3 are approximately equal at any time. That is, the negative material layer 122 is substantially flush with the edge coating structure 3, which can avoid the electrolyte sheet 130, the negative current collector 121, the positive current collector 111, and the positive material layer 112 from being severely cracked during the stacking and pressing process.

[0128] 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. After the negative electrode sheet 120, the electrolyte sheet 130, and the positive electrode sheet 110 are laminated, pressure is applied to make the negative electrode sheet 120, the electrolyte sheet 130, and the positive electrode sheet 110 tightly adhere to each other. If the edge coating structure 3 is not arranged on the negative current collector 121, the edge region of the electrolyte sheet 130 is in a suspended state, and during the pressure forming of the battery cell 100, due to the lack of support under the edge region of the electrolyte sheet 130, cracks are generated on the electrolyte sheet 130 and the positive electrode sheet 110. By arranging the edge coating structure 3 on the negative current collector 121, the suspended state of the edge region of the electrolyte sheet 130 is avoided, and support is provided for the edge region of the electrolyte sheet 130 and the edge region of the positive electrode sheet 110. During the pressing process, due to the supporting effect of the edge coating structure 3, the electrolyte sheet 130, the negative current collector 121, the positive current collector 111, and the positive material layer 112 can be prevented from generating serious cracks during the pressing process, thereby improving the yield of the battery cell 100 and the battery.

[0129] As shown in FIG. 9, in some implementations, 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.

[0130] As shown in FIG. 9, the battery cell 100 is provided with the negative material layer 122 and the edge coating structure 3 on both sides of the negative current collector 121. Correspondingly, the battery cell 100 includes two electrolyte sheets 130 and two positive electrode sheets 110. The battery cell 100 is sequentially provided with the positive electrode sheet 110, the electrolyte sheet 130, the negative electrode sheet 120, the electrolyte sheet 130, and the positive electrode sheet 110 from top to bottom.

[0131] As shown in FIG. 1 and FIG. 10, the battery provided by the embodiments of the present application further includes a packaging structure 200. At least one battery cell 100 is arranged in the packaging structure 200. In the battery provided by the embodiments of the present application, the possibility of cracks generated on the electrolyte sheet 130 and the current collector 1 is small, and thus the yield of the battery is high. When the edge coating structure 3 contains an adhesive in the material composition, the electrolyte sheet 130 is not easy to separate from the electrode sheet 10 after long-term use of the battery, which effectively prevents the phenomenon of increased interface impedance from occurring.

[0132] Exemplarily, the plurality of battery cells 100 are arranged along the thickness direction, for example, 2-50 battery cells 100 are arranged. The positive tab 1110 of one of the two adjacent battery cells 100 and the negative tab 1210 of the other of the two adjacent battery cells 100 are electrically connected by the connecting sheet 300. The thermally conductive layer 400 is arranged between the two adjacent battery cells 100, so as to facilitate the temperature consistency of the plurality of battery cells 100 inside the battery.

[0133] Referring to FIG. 1, the positive tab 1110 of the uppermost battery cell 100 is electrically connected with the battery positive tab 500, and the negative tab 1210 of the lowermost battery cell 100 is electrically connected with the battery negative tab 600. The battery positive tab 500 and the battery negative tab 600 are both partially arranged outside the packaging structure 200.

[0134] In some implementations, the packaging structure 200 can include an aluminum plastic film structure. The aluminum plastic film structure includes oppositely arranged upper and lower aluminum plastic films, and the battery cell 100 is arranged between the upper and lower aluminum plastic films. The edge region of the upper aluminum plastic film and the edge region of the lower aluminum plastic film are arranged in a stacked manner and bonded together, so as to seal and wrap the battery cell 100 by the upper and lower aluminum plastic films.

[0135] The battery provided by the present application is described below in the manner of specific embodiments. Embodiment 1

[0136] The battery provided by the present application is described below in the manner of specific embodiments.

[0137] In the electrode material layer 2, the percentage of the mass of each material in the total mass of the electrode material layer 2 is: 85% of the electrode material (positive electrode material or negative electrode material), 12% of the solid-state electrolyte (i.e., a is 12%), 1.5% of the binder, and 1.5% of the conductive agent.

[0138] The positive electrode material can be nickel-cobalt-manganese ternary material, lithium iron phosphate, lithium manganate, lithium cobaltate, nickel-cobalt-aluminum lithium acid, etc. The negative electrode material can be silicon-oxygen negative electrode material, silicon-carbon negative electrode material, tin-carbon negative electrode material, lithium titanate, graphite, etc.

[0139] The percentage of the mass of each material in the edge coating structure 3 in the total mass of the edge coating structure 3 is as follows: the mass percentage c of the insulating oxide is 86%, the mass percentage b of the solid-state electrolyte is 12%, and the mass percentage d of the binder is 2%. In this embodiment, the mass percentage b of the solid-state electrolyte in the edge coating structure 3 is the same as the mass percentage a of the solid-state electrolyte in the electrode material layer 2.

[0140] The electrolyte sheet 130 is stacked on the side of the electrode material layer 2 opposite to the current collector 1, so that a part of the electrolyte sheet 130 falls on the electrode material layer 2 and another part falls on the edge coating structure 3.

[0141] The electrolyte sheet 130 and the electrode sheet 10 are stacked and pressure is applied, the pressure being 400 MPa and the pressure maintaining time being 10 min. Embodiment 2

[0142] The battery of this embodiment is different from that of Embodiment 1 in that the electrode sheet 10 of the battery cell is as follows:

[0143] The percentage of the mass of each material in the edge coating structure 3 is as follows: the mass percentage c of the insulating oxide is 88.5%, the mass percentage b of the solid-state electrolyte is 10%, and the mass percentage d of the binder is 1.5%. Embodiment 3

[0144] The battery of this embodiment is different from that of Embodiment 1 in that the electrode sheet 10 of the battery cell is as follows:

[0145] The percentage of the mass of each material in the electrode material layer 2 in the total mass of the electrode material layer 2 is as follows: the electrode material (positive electrode material or negative electrode material) is 77%, the solid-state electrolyte is 20% (i.e., a is 20%), the binder is 1.5%, and the conductive agent is 1.5%.

[0146] The percentage of the mass of each material in the edge coating structure 3 is as follows: the mass percentage c of the insulating oxide is 78.5%, the mass percentage b of the solid-state electrolyte is 20%, and the mass percentage d of the binder is 1.5%.

[0147] In this embodiment, the mass percentage b of the solid-state electrolyte in the edge coating structure 3 is the same as the mass percentage a of the solid-state electrolyte in the electrode material layer 2. Embodiment 4

[0148] The battery of this embodiment is different from that of Embodiment 3 in that the electrode sheet 10 of the battery cell is as follows:

[0149] The mass percentage of each material in the edge coating structure 3 is as follows: the mass percentage c of the insulating oxide is 75.5%, the mass percentage b of the solid-state electrolyte is 23%, and the mass percentage d of the binder is 1.5%. In this embodiment, the mass percentage b of the solid-state electrolyte in the edge coating structure 3 differs from the mass percentage a of the solid-state electrolyte in the electrode material layer 2 in Embodiment 1 by 3%. Embodiment 5

[0150] This embodiment provides a battery, and the electrode sheet 10 of the battery cell is different from that of Embodiment 1 in that:

[0151] The mass percentage of each material in the electrode material layer 2 is as follows: the mass percentage of the electrode material (positive electrode material or negative electrode material) is 67.5%, the mass percentage of the solid-state electrolyte is 30% (i.e., a is 30%), the mass percentage of the binder is 1%, and the mass percentage of the conductive agent is 1.5%.

[0152] The mass percentage of each material in the edge coating structure 3 is as follows: the mass percentage c of the insulating oxide is 68.5%, the mass percentage b of the solid-state electrolyte is 30%, and the mass percentage d of the binder is 1.5%.

[0153] In this embodiment, the mass percentage b of the solid-state electrolyte in the edge coating structure 3 is the same as the mass percentage a of the solid-state electrolyte in the electrode material layer 2. Embodiment 6

[0154] This embodiment provides a battery, and the electrode sheet 10 of the battery cell is different from that of Embodiment 5 in that:

[0155] The mass percentage of each material in the edge coating structure 3 is as follows: the mass percentage c of the insulating oxide is 72%, the mass percentage b of the solid-state electrolyte is 26%, and the mass percentage d of the binder is 2%. In this embodiment, the mass percentage b of the solid-state electrolyte in the edge coating structure 3 differs from the mass percentage a of the solid-state electrolyte in the electrode material layer 2 in Embodiment 1 by 4%. Embodiment 7

[0156] This embodiment is different from Embodiment 1 in that the pressure applied to the electrolyte sheet 130 and the electrode sheet 10 is 400 Mpa, and the pressure maintaining time is 40 min. Embodiment 8

[0157] This embodiment is different from Embodiment 1 in that the pressure applied to the electrolyte sheet 130 and the electrode sheet 10 is 300 Mpa, and the pressure maintaining time is 40 min.

[0158] Comparative Example 1

[0159] This comparative example provides a battery, and the electrode sheet 10 of the battery cell is different from that of Embodiment 1 in that:

[0160] The mass ratio of each material in the edge coating structure 3 is as follows: the mass percentage of the insulating oxide in the total mass of the edge coating structure 3 is 98.5%, and the mass percentage of the binder in the total mass of the edge coating structure 3 is 1.5%.

[0161] The edge coating structure 3 in Comparative Example 1 does not contain a solid-state electrolyte.

[0162] The electrolyte sheet 130 is stacked on the electrode material layer 2 of the electrode sheet 10 provided in Examples 1 to 8 and Comparative Example 1, and is pressed at the pressure set in each example and comparative example. After the pressure is maintained for the set time, the cracks on the electrolyte sheet 130 and the current collector 1 are observed using an electron microscope, and the results are shown in the following table:

[0163] As can be seen from the above table, compared with Comparative Example 1, the edge coating structure 3 and the electrode material layer 2 in Examples 1 to 8 both contain a solid-state electrolyte material, and the number of cracks generated on the electrolyte sheet 130 and the current collector 1 during the stacking and pressing of the electrolyte sheet 130 and the electrode sheet 10 is significantly reduced or even no cracks are generated. Moreover, the closer the mass percentage b of the solid-state electrolyte in the edge coating structure 3 to the mass percentage a of the solid-state electrolyte in the electrode material layer 2, the fewer the cracks generated. The greater the mass percentage b of the solid-state electrolyte in the edge coating structure 3 and the mass percentage a of the solid-state electrolyte in the electrode material layer 2, the greater the number of cracks generated on the electrolyte sheet 130 and the current collector 1. The smaller the mass percentage d of the binder in the edge coating structure 3, the greater the number of cracks generated on the electrolyte sheet 130 and the current collector 1.

Claims

1. A battery comprising at least one cell (100), the cell (100) comprising an electrode sheet (10) and an electrolyte sheet (130), the electrode sheet (10) and the electrolyte sheet (130) being stacked, the electrode sheet (10) comprising: a current collector (1) ; an electrode material layer (2) on the current collector (1) and falling within the area where the current collector (1) is located, the outer contour of the area where the electrode material layer (2) is located being at least partially spaced from the outer contour of the area where the current collector (1) is located, so that a support area (20) is formed between the outer contour of the area where the electrode material layer (2) is located and the outer contour of the area where the current collector (1) is located; and an edge coating structure (3) in the support area (20), the electrolyte sheet (130) covering at least part of the electrode material layer (2) and at least part of the edge coating structure (3), wherein the material composition of the edge coating structure (3) comprises a solid-state electrolyte, and the material composition of the electrode material layer (2) comprises a solid-state electrolyte, and the percentage of the mass of the solid-state electrolyte in the electrode material layer (2) to the total mass of the electrode material layer (2) is a, and the percentage of the mass of the solid-state electrolyte in the edge coating structure (3) to the total mass of the edge coating structure (3) is b, and the absolute value of the difference between a and b is greater than or equal to 0 and less than or equal to 5%, and the percentage of the mass of the solid-state electrolyte in the electrode material layer (2) to the total mass of the electrode material layer (2) is a, and a is greater than or equal to 5% and less than or equal to 35%, and the percentage of the mass of the solid-state electrolyte in the edge coating structure (3) to the total mass of the edge coating structure (3) is b, and b is greater than or equal to 5% and less than or equal to 35%, and the material composition of the edge coating structure (3) further comprises an insulating oxide and a binder, and the percentage of the mass of the insulating oxide in the edge coating structure (3) to the total mass of the edge coating structure (3) is c, and c is greater than or equal to 65% and less than or equal to 90%, and the percentage of the mass of the binder in the edge coating structure (3) to the total mass of the edge coating structure (3) is d, and d is greater than or equal to 1% and less than or equal to 5%, and the insulating oxide comprises any one or a combination of at least two of aluminum oxide, silicon oxide, lithium aluminum titanium phosphate, lithium lanthanum zirconium oxide, an aluminum oxide homolog, a silicon oxide homolog, a lithium aluminum titanium phosphate homolog, and a lithium lanthanum zirconium oxide homolog, and the binder comprises any one or a combination of at least two of polyisobutylene, hydrogenated nitrile rubber, nitrile rubber, hydrogenated styrene-butadiene block copolymer, a derivative of polyisobutylene, a derivative of hydrogenated nitrile rubber, a derivative of nitrile rubber, and a derivative of hydrogenated styrene-butadiene block copolymer, and the kind of the solid-state electrolyte in the edge coating structure (3) is the same as the kind of the solid-state electrolyte in the electrode material layer (2), and the electrode material layer (2) is surrounded by the edge coating structure (3) in the circumferential direction, and the edge coating structure (3) is in contact with or connected to the electrode material layer (2), and the edge coating structure (3) is adhesively connected to at least one of the current collector (1) or the electrode material layer (2). ​ ​ ​ ​ 2. The battery of claim 1, wherein, ​ 3. The battery of claim 2, wherein, ​ ​ 4. The battery of claim 2, wherein, ​ 5. The battery of any one of claims 1-4, wherein, ​ 6. The battery of any one of claims 1-5, wherein, ​ 7. The battery of claim 6, wherein, ​ 8. The battery of claim 6 or 7, wherein, ​ 9. The battery of any one of claims 6-8, wherein, ​ 10. The battery of any one of claims 6-9, wherein, ​ 11. The battery of any one of claims 1-10, wherein, ​ 12. The battery of any one of claims 1-11, wherein, ​ 13. The battery of any one of claims 1-12, wherein, ​ 14. The battery of claim 13, wherein, ​ 15. The battery of any one of claims 1-14, wherein, 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 10 μm.

16. The battery of claim 15, wherein, The difference between the thickness of the edge coating structure (3) and the thickness of the electrode material layer (2) is less than or equal to 5 μm.

17. The battery of any one of claims 1-16, wherein, The edge of the current collector (1) falls within the projection area of the edge coating structure (3).

18. The battery of any one of claims 1-17, wherein, Both sides of the current collector (1) are provided with the electrode material layer (2) and the edge coating structure (3).

19. The battery of any one of claims 1-18, wherein, The area of the edge coating structure (3) is S1, the area of the electrode material layer (2) 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.

20. The battery of any one of claims 1-19, wherein, 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.

21. The battery of claim 20, 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.

22. The battery of claim 20, 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.

23. The battery of any one of claims 1-22, wherein, The electrode material layer (2) is formed by cutting.

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