CN115832605B

CN115832605B - Separator, battery module, battery pack, and electricity-using device

Info

Publication number: CN115832605B
Application number: CN202111466802.8A
Authority: CN
Inventors: 常雯; 付成华
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2023-10-10
Anticipated expiration: 2041-12-01
Also published as: CN115832605A; CN117080682A; WO2023098461A1

Abstract

The application provides a separator, a battery module, a battery pack and an electric device. The separator includes a first separator portion and a second separator portion alternately disposed, and when the separator is disposed in a laminated battery having first and second electrode sheets alternately laminated in a first direction, the first separator portion overlaps the second separator portion in the first direction, and bottom surfaces of the first and second electrode sheets are disposed at the first and second separator portions, respectively, the first separator portion has a first ceramic layer having a plurality of first portions corresponding to a peripheral edge of the first electrode sheet, the plurality of first portions surrounding the first electrode sheet along the peripheral edge of the first electrode sheet in a manner in which any one of the first portions is connected, the second separator portion has a second ceramic layer having a plurality of second portions corresponding to a peripheral edge of the second electrode sheet, the plurality of second portions surrounding the second electrode sheet along the peripheral edge of the second electrode sheet in a manner in which any one of the second portions is connected.

Description

Separator, battery module, battery pack, and electricity-using device

Technical Field

The application relates to the technical field of batteries, in particular to a diaphragm, a battery module, a battery pack and an electric device.

Background

In recent years, with the continuous development of lithium ion battery technology, lithium ion batteries are widely used in energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, and in various fields such as electric tools, electric bicycles, electric motorcycles, electric automobiles, military equipment, aerospace and the like. As lithium ion batteries have been greatly developed, higher demands are also being made on their safety performance and the like.

In a laminated lithium ion battery, electrode sheets are obtained by cutting, and positive electrode sheets and negative electrode sheets are alternately laminated with separators interposed therebetween. Therefore, in the process of manufacturing and transporting the laminated lithium ion battery, the pole pieces are easy to misplace, so that the risk of lithium precipitation exists on one side of the positive pole piece, which exceeds the negative pole piece, and under the serious misplacement, the positive pole piece and the negative pole piece can be in contact, so that short circuit is caused. In addition, when the pole piece is cut in the process of manufacturing the laminated lithium ion battery, burrs are easily generated on the cut peripheral surfaces of the pole piece (especially the positive pole piece), and the burrs possibly pierce the diaphragm, so that short circuit is caused, and the safety performance of the battery is affected.

Disclosure of Invention

Technical problem to be solved by the application

The present application has been made in view of the above-described problems, and an object of the present application is to provide a separator, a battery module, a battery pack, and an electric device, which can prevent dislocation of pole pieces, prevent short circuit due to burrs, and improve safety performance of the battery with a simple structure and without increasing the size.

Technical scheme for solving technical problems

In order to achieve the above object, the present application provides a separator, a battery module, a battery pack, and an electric device.

A first aspect of the present application provides a separator including first and second separator portions alternately arranged, wherein when the separator is arranged in a laminated battery having first and second electrode sheets alternately laminated in a first direction, the first separator portion overlaps the second separator portion in the first direction, and a bottom surface of the first electrode sheet and a bottom surface of the second electrode sheet are respectively arranged in the first separator portion and the second separator portion, the first separator portion has a first ceramic layer having a plurality of first portions corresponding to a peripheral edge of the first electrode sheet, the plurality of first portions surround the first electrode sheet along the peripheral edge of the first electrode sheet in a manner that any one of the first portions is connected, the second separator portion has a second ceramic layer having a plurality of second portions corresponding to the peripheral edge of the second electrode sheet, and the plurality of second portions surround the second electrode sheet along the peripheral edge of the second electrode sheet in a manner that any one of the second portions is connected.

The first diaphragm part of the diaphragm, which can be provided with the first pole piece, is provided with the first parts corresponding to the periphery of the first pole piece, the first parts surround the first pole piece in a mode that any one of the first parts is connected with the periphery of the first pole piece, the second diaphragm part of the diaphragm, which can be provided with the second pole piece, is provided with the second parts corresponding to the periphery of the second pole piece, and the second parts surround the second pole piece in a mode that any one of the second parts is connected with the periphery of the second pole piece, so that the first pole piece and the second pole piece can be limited by the ceramic layer, and dislocation of the first pole piece and the second pole piece in the laminated battery assembled by the first pole piece, the second pole piece and the diaphragm is prevented. Therefore, lithium precipitation or short circuit caused by dislocation of the first pole piece and the second pole piece can be prevented, and the safety performance of the battery can be improved. Moreover, since the first ceramic layer and the second ceramic layer are disposed on the separator, no additional space is required for arrangement, and the original structure is not affected, the structure is simple and the size is not increased, and the energy density of the battery is not reduced.

In addition, since any one of the plurality of first portions of the first ceramic layer provided to the separator is connected, that is, the plurality of first portions may be connected to each other, disconnected from each other, or some of the first portions are connected and the remaining first portions are disconnected, the amount of material for manufacturing the ceramic layer can be reduced as much as possible, and the cost can be reduced. Similarly, since any of the plurality of second portions of the second ceramic layer disposed on the separator may be connected to each other, that is, the plurality of second portions may be connected to each other, or some of the second portions may be connected and the remaining second portions may be disconnected, the length of the ceramic layer along the periphery of the pole piece may be reduced as much as possible, the amount of material for manufacturing the ceramic layer may be reduced, and the cost may be reduced.

In some embodiments, the first electrode sheet and the second electrode sheet are rectangular parallelepiped, the first ceramic layer has 4 first portions corresponding to 4 side surfaces of the first electrode sheet, the 4 first portions and the 4 side surfaces of the first electrode sheet have lengths along the corresponding side surfaces of the first electrode sheet that are not longer than the lengths of the side surfaces when viewed in the first direction, the second ceramic layer has 4 second portions corresponding to 4 side surfaces of the second electrode sheet, the 4 second portions and the 4 side surfaces of the second electrode sheet are parallel, and the lengths of the second portions along the corresponding side surfaces of the second electrode sheet that are not longer than the lengths of the side surfaces when viewed in the first direction.

The first pole piece and the second pole piece are cuboid, the periphery of the first pole piece and the second pole piece are respectively provided with 4 side faces, and the side faces are cutting faces. By arranging 4 first portions of the first ceramic layer corresponding to 4 sides of the first pole piece and 4 second portions of the second ceramic layer corresponding to 4 sides of the second pole piece, 4 cutting surfaces of the first pole piece, namely 4 sides, and 4 cutting surfaces of the second pole piece, namely 4 sides, can be limited by the first portions of the first ceramic layer and the second portions of the second ceramic layer respectively. Thus, in the laminated battery in which the first electrode sheet, the second electrode sheet, and the separator are assembled, the first electrode sheet and the second electrode sheet can be prevented from being displaced. Therefore, lithium precipitation or short circuit caused by dislocation of the first pole piece and the second pole piece can be prevented, and the safety performance of the battery can be improved.

In some embodiments, the first electrode sheet is formed by stacking a first electrode active material layer and a first current collector, wherein when the first electrode sheet is disposed in the first separator, a stacking direction of the first electrode active material layer and the first current collector is the first direction, a length of the first portion along a side surface of the corresponding first electrode sheet when viewed from the first direction is equal to a length of the side surface, and a height of the first ceramic layer in the first direction is greater than a height from a bottom surface of the first electrode sheet to a surface of the first current collector away from the bottom surface in the first direction, and is not greater than a height of the first electrode sheet in the first direction.

Since the current collector of the positive electrode sheet is composed of a metal foil (typically, aluminum foil), burrs are easily generated in the positive electrode current collector when cutting is performed in the lamination direction. Therefore, by providing the first ceramic layer at the first separator portion where the first electrode sheet as the positive electrode sheet can be provided, and making the length of the first portion along the side face of the corresponding first electrode sheet equal to the length of the side face when viewed from the first direction, and making the height of the first ceramic layer in the first direction larger than the height from the bottom face of the first electrode sheet to the face of the first current collector away from the bottom face in the first direction and not larger than the height of the first electrode sheet in the first direction, burrs formed on the 4 side faces of the first electrode sheet can be shielded (wrapped) in addition to restricting the first electrode sheet with the first ceramic layer to prevent misalignment of the first electrode sheet and the second electrode sheet. Therefore, the dislocation is prevented, and meanwhile, burrs can be prevented from penetrating through the diaphragm, so that short circuits caused by the burrs are prevented, and the safety performance of the battery is further improved.

In some embodiments, the second electrode sheet is formed by stacking a second electrode active material layer and a second current collector, wherein when the second electrode sheet is provided in the second separator, a stacking direction of the second electrode active material layer and the second current collector is the first direction, a length of the second portion along a side surface of the corresponding second electrode sheet when viewed from the first direction is equal to a length of the side surface, and a height of the second ceramic layer in the first direction is greater than a height of a surface from a bottom surface of the second electrode sheet to a surface of the second current collector away from the bottom surface in the first direction, and is not greater than a height of the second electrode sheet in the first direction.

Since the current collector of the negative electrode tab is made of a metal foil (typically, copper foil), burrs are not likely to be generated in the negative electrode current collector as in the positive electrode tab when the current collector is cut in the stacking direction. Therefore, by providing the second ceramic layer at the second separator portion where the second electrode sheet can be provided as the negative electrode sheet, and making the length of the second portion along the side face of the corresponding second electrode sheet equal to the length of the side face when viewed from the first direction, and making the height of the second ceramic layer in the first direction larger than the height from the bottom face of the second electrode sheet to the face of the second current collector away from the bottom face in the first direction and not larger than the height of the second electrode sheet in the first direction, burrs formed on 4 side faces of the second electrode sheet can be shielded (wrapped) in addition to restricting the second electrode sheet with the second ceramic layer to prevent misalignment of the first electrode sheet and the second electrode sheet. Therefore, the dislocation is prevented, and meanwhile, burrs can be prevented from penetrating through the diaphragm, so that short circuits caused by the burrs are prevented, and the safety performance of the battery is further improved.

In some embodiments, the first portion is spaced from a side of the corresponding first pole piece and the second portion is spaced from a side of the corresponding second pole piece when viewed in the first direction.

By spacing the first portion from the side face of the corresponding first pole piece and spacing the second portion from the side face of the corresponding second pole piece, it is possible to prevent the first pole piece and the second pole piece from being larger in size than the surrounding areas of the first ceramic layer and the second ceramic layer due to manufacturing errors or the like and from being unable to be assembled to the separator, and to improve the yield of products. In addition, the situation that the first pole piece and the second pole piece are damaged due to extrusion of the first ceramic layer and the second ceramic layer caused by expansion caused by temperature change during transportation or use can be prevented, and the safety performance of the battery is further improved.

In some embodiments, the first electrode sheet has a first tab formed by extending the first current collector from the 1 side surface of the first electrode sheet to the outside, the first ceramic layer is not in contact with the first tab when the first electrode sheet is disposed on the first separator portion, and the second electrode sheet has a second tab formed by extending the second current collector from the 1 side surface of the second electrode sheet to the outside, and the second ceramic layer is not in contact with the second tab when the second electrode sheet is disposed on the second separator portion.

Through making first ceramic layer and second ceramic layer respectively with first utmost point ear and second utmost point ear contact, can prevent that first ceramic layer and second ceramic layer from extrudeing and damaging the condition of first utmost point ear and second utmost point ear, further improve the security performance of battery.

In some embodiments, the ceramic slurries used to make the first ceramic layer and the second ceramic layer are the same. The ceramic slurry contains ceramic material, binder, thickener, dispersant and defoamer. The ceramic material accounts for 20 to 70 weight percent.

Thus, the first ceramic layer and the second ceramic layer are manufactured by using the ceramic slurry containing the ceramic material, the binder, the thickener, the dispersant and the defoamer, and the ceramic material accounts for 20 to 70 weight percent, so that the stability, the insulativity and the adhesiveness of the first ceramic layer and the second ceramic layer can be ensured, and the ceramic material is not too little to cause the stability and the insulativity to be insufficient, and is not too much to cause the insulation layer to fall off.

In some embodiments, the ceramic material is one of hydrated alumina, magnesia, silicon carbide, and silicon nitride, preferably hydrated alumina. The adhesive is one or more of polyacrylate, methyl acrylate, ethyl acrylate, 2-methyl methacrylate and 2-ethyl methacrylate, the thickener is one of sodium carboxymethyl cellulose, methyl cellulose and sodium polyacrylate, the dispersing agent is one or more of polyvinyl alcohol, polyacrylamide and polyvinylpyrrolidone, and the defoaming agent is one or more of n-butanol and ethanol.

Therefore, the ceramic material, the binder, the thickener, the dispersant and the defoamer are prepared from the materials which are low in cost and easy to obtain, so that the manufacturing cost can be reduced, and the industrial production is facilitated.

In some embodiments, the base film of the separator is one of a base film made of PP, a base film made of PE, and a base film made of PP or PE having a ceramic coating layer on one or both surfaces.

Therefore, the base film of the diaphragm adopts the material which is low in cost and easy to obtain, can reduce the manufacturing cost and is beneficial to industrial production.

A second aspect of the present application provides a battery including a first electrode sheet, a second electrode sheet, and the separator of the first aspect, the first electrode sheet and the second electrode sheet being alternately laminated in the first direction, the separator being sandwiched between the first electrode sheet and the second electrode sheet.

A third aspect of the application provides a battery module comprising the battery of the second aspect.

A fourth aspect of the application provides a battery pack comprising the battery module of the third aspect.

A fifth aspect of the present application provides an electric device including at least one selected from the battery of the above second aspect, the battery module of the above third aspect, and the battery pack of the above fourth aspect.

Effects of the application

The application provides a diaphragm, a battery module, a battery pack and an electric device, which can prevent dislocation of pole pieces with a simple structure and without increasing the size, prevent short circuit caused by burrs and improve the safety performance of the battery.

Drawings

Fig. 1 is a schematic view of a separator of the present application.

Fig. 2 is a front view of the laminated battery of the present application.

Fig. 3A is a sectional view of the laminated battery according to the first embodiment of the present application taken along the line A-A of fig. 2.

Fig. 3B is a sectional view of the laminated battery according to the first embodiment of the present application taken along the line B-B of fig. 2.

Fig. 3C is a sectional view of a laminated battery according to a modification of the first embodiment of the present application taken along the line A-A of fig. 2.

Fig. 3D is a sectional view of a laminated battery according to a modification of the first embodiment of the present application, taken along the line B-B of fig. 2.

Fig. 4A is a sectional view of a laminated battery according to a second embodiment of the present application taken along the line A-A of fig. 2.

Fig. 4B is a sectional view of a laminated battery according to a second embodiment of the present application taken along line B-B of fig. 2.

Fig. 5A is a combined view of sectional views of a laminated battery according to a third embodiment of the present application, taken along the line A-A and the line B-B of fig. 2.

Fig. 5B is a combined view of sectional views taken along the line A-A and the line B-B of fig. 2 of a laminated battery according to a modification of the third embodiment of the present application.

Fig. 6 is a partial perspective view of the first pole piece of fig. 5A disposed on a first diaphragm portion of the diaphragm.

Fig. 7 is a partial perspective view of fig. 6 with the first ceramic layer removed.

Fig. 8A is a combined view of sectional views of a laminated battery according to a fourth embodiment of the present application, taken along the line A-A and the line B-B of fig. 2.

Fig. 8B is a combined view of sectional views taken along the line A-A and the line B-B of fig. 2 of a laminated battery according to a modification of the fourth embodiment of the present application.

Fig. 9 is a partial perspective view of the second pole piece of fig. 8A disposed on the second diaphragm portion of the diaphragm.

Fig. 10 is a partial perspective view of fig. 9 with the second ceramic layer removed.

Fig. 11 is a schematic view of an electric device according to an embodiment of the present application.

Description of the reference numerals

A 1-stack battery (cell), 10 separator, 11 first separator part, 110 first ceramic layer, 111 first part, 12 second separator part, 120 second ceramic layer, 121 second part, 20 first electrode tab, 21 first tab, 22 first current collector, 23 first electrode active material layer 23, 20a bottom surface, 20b side surface, 30 second tab, 31 second tab, 32 second current collector, 33 second electrode active material layer, 30a bottom surface, 30b side surface.

Detailed Description

Hereinafter, embodiments of the positive electrode tab and the battery of the present application are specifically disclosed with reference to the drawings as appropriate. However, unnecessary detailed description may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of the actual same structure may be omitted. This is to avoid that the following description becomes unnecessarily lengthy, facilitating the understanding of those skilled in the art. Furthermore, the drawings and the following description are provided for a full understanding of the present application by those skilled in the art, and are not intended to limit the subject matter recited in the claims.

The "range" disclosed herein is defined in terms of lower and upper limits, with a given range being defined by 1 lower limit and 1 upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges that are defined in this way can be inclusive or exclusive of the endpoints, and any combination is possible, i.e., any lower limit may be combined with any upper limit to form 1 range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if the minimum range values 1 and 2 are listed, and if the maximum range values 3,4 and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise indicated, the numerical ranges "a-b" represent a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed throughout, and "0-5" is only a shorthand representation of a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is disclosed that the parameter is, for example, an integer of 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12 or the like.

All embodiments of the application and alternative embodiments may be combined with each other to form new solutions, unless otherwise specified.

All technical features and optional technical features of the application may be combined with each other to form new technical solutions, unless specified otherwise.

All the steps of the present application may be performed sequentially or randomly, preferably sequentially, unless otherwise specified. For example, the method may include steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, it is mentioned that the above method may further include step (c), meaning that step (c) may be added to the above method in any order, for example, the above method may include steps (a), (b) and (c), may include steps (a), (c) and (b), may include steps (c), (a) and (b), and the like.

The terms "comprising" and "including" as used herein mean open ended or closed ended, unless otherwise noted. For example, the foregoing "comprising" and "including" may mean that other components not listed may be included or included, or that only listed components may be included or included.

The term "or" is inclusive in this application, unless otherwise specified. For example, the phrase "a or B" means "a, B, or both a and B. More specifically, either of the following conditions satisfies the condition "a or B": a is true (or present) and B is false (or absent); a is false (or absent) and B is true (or present); or both A and B are true (or present).

The inventors have noted that, in a laminated lithium ion battery, the electrode sheets are obtained by cutting, and the positive electrode sheets and the negative electrode sheets are alternately laminated with a separator interposed therebetween. Therefore, in the process of manufacturing and transporting the laminated lithium ion battery, the pole pieces are easy to misplace, so that the risk of lithium precipitation exists on one side of the positive pole piece, which exceeds the negative pole piece, and under the serious misplacement, the positive pole piece and the negative pole piece can be in contact, so that short circuit is caused. In addition, when the pole piece is cut in the process of manufacturing the laminated lithium ion battery, burrs are easily generated on the periphery of the cut positive pole piece, and the burrs possibly pierce through a diaphragm, so that short circuit is caused, and the safety performance of the battery is affected.

In the prior art, the blocking parts which are separated from the pole pieces and the diaphragms are arranged to prevent the pole pieces from being misplaced, but due to the fact that the blocking parts are large in size, the size of the battery can be increased through the design, and then loss is caused to energy density, and the infiltration of electrolyte is affected.

Accordingly, a first aspect of the present application provides a separator including first and second separator portions alternately arranged, wherein when the separator is arranged in a laminated battery having first and second electrode sheets alternately laminated in a first direction, the first separator portion overlaps the second separator portion in the first direction, and a bottom surface of the first electrode sheet and a bottom surface of the second electrode sheet are respectively arranged in the first separator portion and the second separator portion, the first separator portion has a first ceramic layer having a plurality of first portions corresponding to a peripheral edge of the first electrode sheet, the plurality of first portions surround the first electrode sheet along the peripheral edge of the first electrode sheet in a manner that any one of the first portions is connected, and the second separator portion has a second ceramic layer having a plurality of second portions corresponding to the peripheral edge of the second electrode sheet, the plurality of second portions surrounding the peripheral edge of the second electrode sheet in a manner that any one of the second portions is connected.

In addition, since any one of the plurality of first portions of the first ceramic layer provided to the separator is connected, that is, the plurality of first portions may be connected to each other, disconnected from each other, or some of the first portions are connected and the remaining first portions are disconnected, the amount of material for manufacturing the ceramic layer can be reduced as much as possible, and the cost can be reduced. Also, since any one of the plurality of second portions of the second ceramic layer provided to the separator is connected, that is, the plurality of second portions may be connected to each other, disconnected from each other, or some of the second portions are connected and the remaining second portions are disconnected, it is possible to reduce the amount of material for manufacturing the ceramic layer as much as possible, and to reduce the cost.

The present application will be specifically described below with reference to the drawings.

Fig. 1 is a schematic view of a diaphragm 10 of the present application. As shown in fig. 1, the separator 10 is assembled to the laminated battery in a state of being folded in a zigzag shape. The diaphragm 10 includes first diaphragm portions 11 and second diaphragm portions 12 alternately arranged.

Fig. 2 is a front view of the laminated battery 1 of the present application. When the separator 10 is provided in the laminated battery 1 having the first electrode sheets 20 and the second electrode sheets 30 alternately laminated in the first direction Z, as shown in fig. 2, the first separator 11 overlaps the second separator 12 in the first direction Z, the bottom surface 20a of the first electrode sheet 20 is provided at the first separator 11, and the bottom surface 30a of the second electrode sheet 30 is provided at the second separator 12. The diaphragm 10 in fig. 1 and 2 is a Z-folded continuous diaphragm, but the diaphragm 10 may be a diaphragm composed of a first diaphragm portion 11 and a second diaphragm portion 12 that are separate.

Fig. 3A is a sectional view of the laminated battery 1 according to the first embodiment of the present application taken along the line A-A of fig. 2, showing a view of the first pole piece 20 from a first direction. As shown in fig. 3A, the first separator 11 has a first ceramic layer 110, and the first ceramic layer 110 has a plurality of first portions 111 (3 in fig. 3) corresponding to the peripheral edges of the first pole piece 20. Optionally, the first ceramic layer 110 corresponding to 1 first pole piece 20 has at least 3 first portions 111 to surround the first pole piece 20. Optionally, more than 1 first portion 111 is provided on each of at least any 3 sides 20b of the first pole piece 20.

In fig. 3A, a plurality (3) of first portions 111 surround the first pole piece 20 along the periphery of the first pole piece 20 and are not connected to each other. Fig. 3C is a sectional view of the laminated battery 1 of the modification of the first embodiment of the present application taken along the line A-A of fig. 2. As shown in fig. 3C, 2 first portions 111 of the 3 first portions 111 are connected at 1 corner of the periphery of the first pole piece 20. Alternatively, although not shown, 4 first portions 111 in fig. 4A described later surround the first pole piece 20 along the periphery of the first pole piece 20 in such a manner that any one thereof is connected. Alternatively, as shown in fig. 5B described later, a plurality (4) of first portions 111 surround the first pole piece 20 in such a manner as to be connected to each other along the periphery of the first pole piece 20. That is, the plurality of first portions 111 surrounds the first pole piece 20 along the circumference of the first pole piece 20 in such a manner that any one thereof is connected.

Fig. 3B is a cross-sectional view of the laminated battery 1 according to the first embodiment of the present application taken along line B-B of fig. 2, showing a view of the second electrode sheet 30 seen from the first direction. As shown in fig. 3B, the second diaphragm portion 12 has a second ceramic layer 120, and the second ceramic layer 120 has a plurality of second portions 121 corresponding to the peripheral edges of the second pole pieces 30. Optionally, the second ceramic layer 120 corresponding to 1 second surrounding sheet 30 has at least 3 second portions 121 to surround the second surrounding sheet 30. More than 1 second portion 121 may be provided around at least any 3 sides 30b of the second pole piece 30.

In fig. 3B, a plurality (3) of second portions 121 surround the second pole piece 30 along the periphery of the second pole piece 30 in a manner not connected to each other. Fig. 3D is a sectional view of the laminated battery 1 of the modification of the first embodiment of the present application taken along the line B-B of fig. 2. As shown in fig. 3D, 2 second portions 121 of the 3 second portions 121 are connected at 1 corner of the periphery of the second pole piece 30. Alternatively, although not shown, 4 second portions 121 in fig. 4B described later surround the second pole piece 30 along the periphery of the second pole piece 30 in such a manner that any one of them is connected. Alternatively, as shown in fig. 8B described later, a plurality of second portions 121 surround the second pole piece 30 in such a manner as to be connected to each other along the periphery of the second pole piece 30. That is, the plurality of second portions 121 surrounds the second pole piece 30 along the periphery of the second pole piece 30 in such a manner that any one thereof is connected.

By providing the first membrane portion 11 of the membrane 10, in which the first pole piece 20 can be provided, with the plurality of first portions 111 corresponding to the peripheral edge of the first pole piece 20, the plurality of first portions 111 surround the first pole piece 20 along the peripheral edge of the first pole piece 20 so as to connect to each other, and providing the second membrane portion 12 of the membrane, in which the second pole piece 30 can be provided, with the plurality of second portions 121 corresponding to the peripheral edge of the second pole piece 30, and the plurality of second portions 121 surround the second pole piece 30 along the peripheral edge of the second pole piece 30 so as to connect to each other, the first pole piece 20 and the second pole piece 30 can be restrained by the ceramic layer, and dislocation of the first pole piece 20 and the second pole piece 30 in the laminated battery 1 in which the first pole piece 20, the second pole piece 30, and the membrane are assembled can be prevented. Therefore, lithium precipitation and short circuit due to misalignment between the first electrode sheet 20 and the second electrode sheet 30 can be prevented, and the safety performance of the battery can be improved. Moreover, since the first ceramic layer 110 and the second ceramic layer 120 are disposed on the separator, additional space is not required for disposition, and the original structure is not affected, the structure is simple and the size is not increased, and at the same time, the energy density of the battery is not reduced.

In addition, since any one of the plurality of first portions 111 of the first ceramic layer 110 provided to the separator 10 is connected, that is, the plurality of first portions 111 may be connected to each other, disconnected from each other, or some of the first portions 111 are connected and the remaining first portions 111 are disconnected, it is possible to reduce the amount of material for manufacturing the ceramic layer as much as possible, and to reduce the cost. Also, since any one of the plurality of second portions 121 of the second ceramic layer 120 provided to the separator 10 is connected, that is, the plurality of second portions 121 may be connected to each other, disconnected from each other, or some of the second portions 121 are connected and the remaining second portions 121 are disconnected, the length of the ceramic layer along the circumference of the pole piece can be reduced as much as possible, the amount of material for manufacturing the ceramic layer can be reduced, and the cost can be reduced.

Fig. 4A is a cross-sectional view of the laminated battery 1 according to the second embodiment of the present application taken along the line A-A of fig. 2, and is a view showing the first pole piece 20 seen from the first direction. Fig. 4B is a cross-sectional view of the laminated battery 1 according to the second embodiment of the present application taken along line B-B of fig. 2, and is a view showing the second electrode sheet 30 seen from the first direction. In some embodiments, as shown in fig. 2, 4A and 4B, the first and second pole pieces 20 and 30 are rectangular parallelepiped-shaped.

As shown in fig. 4A, the first ceramic layer 110 has 4 first portions 111 corresponding to the 4 side surfaces 20b of the first pole piece 20, the 4 first portions 111 being respectively parallel to the 4 side surfaces 20b of the first pole piece 20, and a length of the first portions 111 along the corresponding side surfaces 20b of the first pole piece 20 is not greater than a length of the side surfaces 20b when viewed from the first direction Z. As shown in fig. 4B, the second ceramic layer 120 has 4 second portions 121,4 of the second portions 121 corresponding to the 4 side surfaces 30B of the second pole piece 30, respectively, parallel to the 4 side surfaces 30B of the second pole piece 30, and the length of the second portions 121 along the corresponding side surfaces 30B of the second pole piece 30 is not greater than the length of the side surfaces 30B when viewed from the first direction Z. The 4 first portions 111 shown in fig. 4A are not connected to each other, but any one of the 4 first portions 111 may be connected at a corner of the periphery of the first pole piece 20 (where the two side surfaces 20b are connected). The 4 second portions 121 shown in fig. 4B are not connected to each other, but any one of the 4 second portions 121 may be connected at a corner of the periphery of the second pole piece 30 (where the two side faces 30B are connected).

The peripheries of the rectangular first pole piece 20 and the second pole piece 30 have 4 side surfaces 20b and 30b, respectively, and the side surfaces 20b and 30b are cut surfaces. By providing 4 first portions 111 of the first ceramic layer 110 corresponding to the 4 side surfaces 20b of the first pole piece 20 and providing 4 second portions 121 of the second ceramic layer 120 corresponding to the 4 side surfaces 20b of the second pole piece 30, the 4 cut surfaces of the first pole piece 20, i.e., the 4 side surfaces 20b and the 4 cut surfaces of the second pole piece 30, i.e., the 4 side surfaces 30b, can be respectively limited by the first portions 111 of the first ceramic layer 110 and the second portions 121 of the second ceramic layer 120. In this way, in the laminated battery 1 in which the first electrode sheet 20, the second electrode sheet 30, and the separator are assembled, the first electrode sheet 20 and the second electrode sheet 30 can be prevented from being displaced. Therefore, lithium precipitation and short circuit due to misalignment between the first electrode sheet 20 and the second electrode sheet 30 can be prevented, and the safety performance of the battery can be improved.

Fig. 5A is a combined view of sectional views taken along the line A-A and the line B-B of fig. 2 of the laminated battery 1 according to the third embodiment of the present application, and is a view showing the first electrode sheet 20 and the second electrode sheet 30 viewed from the first direction. Fig. 5B is a combined view of sectional views taken along the line A-A and the line B-B of fig. 2 of a laminated battery 1 of a modification of the third embodiment of the present application. Fig. 6 is a partial perspective view of the first pole piece 20 of fig. 5A disposed on the first diaphragm portion 11 of the diaphragm 10. Fig. 7 is a partial perspective view of fig. 6 with the first ceramic layer 110 removed.

In some embodiments, as shown in fig. 7, the first electrode sheet 20 is formed by stacking a first electrode active material layer 23 and a first current collector 22. As shown in fig. 5A and 6, when the first electrode sheet 20 is disposed on the first separator 11, the lamination direction of the first electrode active material layer 23 and the first current collector 22 is the first direction Z, and the length of the first portion 111 along the side surface 20b of the corresponding first electrode sheet 20 is equal to the length of the side surface 20b as viewed from the first direction Z. Also, the height H1 of the first ceramic layer 110 in the first direction Z is greater than the height H2 from the bottom surface 20a of the first electrode sheet 20 to the surface of the first current collector 22 away from the bottom surface 20a in the first direction Z, and is not greater than the height H3 of the first electrode sheet 20 in the first direction Z.

In addition, as shown in fig. 5A, the second ceramic layer 120 surrounding the second pole piece 30 is provided in the same manner as in fig. 4B.

As shown in fig. 7, the first electrode active material layer 23 in the first electrode sheet 20 is two layers, sandwiching the first current collector 22. However, the first electrode active material layer 23 may be a single layer.

In fig. 5A, the length of the 4 first portions 111 along the side 20b of the corresponding first pole piece 20 is equal to the length of the side 20b, i.e. the 4 first portions 111 are not connected to each other, as seen from the first direction Z. However, since the thickness of the first ceramic layer 110 is extremely thin, and considering the ease of the coating process, it is also possible that 4 first portions 111 are connected to each other at corners of the circumference of the first pole piece 20 as shown in fig. 5B.

Since the current collector of the positive electrode sheet is composed of a metal foil (typically, aluminum foil), burrs are easily generated in the positive electrode current collector when cutting is performed in the lamination direction. Therefore, by providing the first ceramic layer 110 at the first separator portion 11 where the first electrode sheet 20 as the positive electrode sheet can be provided, and making the length of the first portion 111 along the side surface 20b of the corresponding first electrode sheet 20 equal to the length of the side surface 20b when the first ceramic layer 110 is viewed from the first direction Z, and making the height of the first ceramic layer 110 in the first direction Z larger than the height from the bottom surface 20a of the first electrode sheet 20 to the surface of the first current collector 22 away from the bottom surface 20a in the first direction Z and not larger than the height of the first electrode sheet 20 in the first direction Z, burrs formed on the 4 side surfaces 20b of the first electrode sheet 20 can be blocked (wrapped) in addition to restricting the first electrode sheet 20 with the first ceramic layer 110 to prevent misalignment of the first electrode sheet 20 with the second electrode sheet 30. Therefore, the dislocation is prevented, and meanwhile, burrs can be prevented from penetrating through the diaphragm, so that short circuits caused by the burrs are prevented, and the safety performance of the battery is further improved.

Fig. 8A is a combined view of sectional views taken along the line A-A and the line B-B of fig. 2 of the laminated battery 1 according to the fourth embodiment of the present application, and is a view showing the first electrode sheet 20 and the second electrode sheet 30 viewed from the first direction. Fig. 8B is a combined view of sectional views taken along the line A-A and the line B-B of fig. 2 of a laminated battery according to a modification of the fourth embodiment of the present application. Fig. 9 is a partial perspective view of the second pole piece 30 in fig. 8A provided on the second diaphragm portion 12 of the diaphragm 10. Fig. 10 is a partial perspective view of fig. 9 with the second ceramic layer 120 removed.

In some embodiments, as shown in fig. 10, the second electrode sheet 30 is laminated by a second electrode active material layer 33 and a second current collector 32. As shown in fig. 8A and 9, when the second electrode sheet 30 is provided on the second separator 12, the lamination direction of the second electrode active material layer 33 and the second current collector 32 is the first direction Z, and the length of the second portion 121 along the side surface 30b of the corresponding second electrode sheet 30 is equal to the length of the side surface 30b when viewed from the first direction Z. Also, the height H4 of the second ceramic layer 120 in the first direction Z is greater than the height H5 from the bottom surface 30a of the second electrode sheet 30 to the surface of the second current collector 32 away from the bottom surface 30a in the first direction Z, and is not greater than the height H6 of the second electrode sheet 30 in the first direction Z.

In addition, as shown in fig. 8A, the first ceramic layer 110 surrounding the first pole piece 20 is the same as the arrangement of fig. 5A.

As shown in fig. 10, the second electrode active material layer 33 in the second electrode sheet 30 is two layers, sandwiching the second current collector 32. However, the second electrode active material layer 33 may be one layer.

In fig. 8A, the length of the 4 second portions 121 along the side 30b of the corresponding second pole piece 30 is equal to the length of the side 30b, i.e., the 4 first portions 111 are not connected to each other, as viewed from the first direction Z. However, since the thickness of the second ceramic layer 120 is extremely thin, and considering the ease of the coating process, it is also possible that 4 first portions 111 are connected to each other at corners of the periphery of the second electrode sheet 30 as shown in fig. 8B.

Since the current collector of the negative electrode tab is made of a metal foil (typically, copper foil), burrs are not likely to be generated in the negative electrode current collector as in the positive electrode tab when the current collector is cut in the stacking direction. Therefore, by providing the second ceramic layer 120 at the second separator portion 12 where the second electrode sheet 30 as the negative electrode sheet can be provided, and making the length of the second portion 121 along the side face 30b of the corresponding second electrode sheet 30 equal to the length of the side face 30b when the second ceramic layer 120 is viewed from the first direction Z, and making the height of the second ceramic layer 120 in the first direction Z larger than the height from the bottom face 30a of the second electrode sheet 30 to the face of the second current collector 32 away from the bottom face 30a in the first direction Z and not larger than the height of the second electrode sheet 30 in the first direction Z, burrs formed on the 4 side faces 30b of the second electrode sheet 30 can be shielded (wrapped) in addition to restricting the second electrode sheet 30 with the second ceramic layer 120 to prevent misalignment of the first electrode sheet 20 and the second electrode sheet 30. Therefore, the dislocation is prevented, and meanwhile, burrs can be prevented from penetrating through the diaphragm, so that short circuits caused by the burrs are prevented, and the safety performance of the battery is further improved.

In some embodiments, although not illustrated, the first portion 111 is spaced apart from the side surface of the corresponding first pole piece 20 and the second portion 121 is spaced apart from the side surface of the corresponding second pole piece 30 when viewed from the first direction Z.

By properly spacing the first portion 111 from the side surface of the corresponding first electrode sheet 20 and properly spacing the second portion 121 from the side surface of the corresponding second electrode sheet 30, it is possible to prevent the first electrode sheet 20 and the second electrode sheet 30 from being larger in size than the surrounding areas of the first ceramic layer 110 and the second ceramic layer 120 due to manufacturing errors or the like and from being unable to be assembled to the separator, and to improve the yield of products. In addition, it is possible to prevent the first and second electrode tabs 20 and 30 from being damaged by being pressed by the first and second ceramic layers 110 and 120 due to expansion with heat and contraction with cold caused by isothermal changes during transportation or use, and further improve the safety performance of the battery.

In some embodiments, the first electrode tab 20 has a first tab 21 formed by the first current collector 22 extending from the 1 side 20b of the first electrode tab 20 to the outside, the first ceramic layer 110 is not in contact with the first tab 21 when the first electrode tab 20 is disposed on the first separator portion 11, the second electrode tab 30 has a second tab 31 formed by the second current collector 32 extending from the 1 side 30b of the second electrode tab 30 to the outside, and the second ceramic layer 120 is not in contact with the second tab 31 when the second electrode tab 30 is disposed on the second separator portion 12.

By preventing the first and second ceramic layers 110 and 120 from contacting the first and second tabs 21 and 31, respectively, the first and second ceramic layers 110 and 120 can be prevented from being pressed to damage the first and second tabs 21 and 31, thereby further improving the safety performance of the battery. The points that the first ceramic layer 110 is not in contact with the first tab 21 and the second ceramic layer 120 is not in contact with the second tab 31 are not shown in the drawings, but only if there is a space between the first ceramic layer 110 and the first tab 21 and a space between the second ceramic layer 120 and the second tab 31, the space can prevent the deformation due to expansion by heat and contraction by cold or the like from being pressed.

In some embodiments, the ceramic slurries making the first ceramic layer 110 and the second ceramic layer 120 are the same. The ceramic slurry comprises a ceramic material, a binder, a thickener, a dispersant, and a defoamer. The ceramic material accounts for 20 to 70 weight percent.

Thus, the first ceramic layer 110 and the second ceramic layer 120 are manufactured using a ceramic slurry including a ceramic material, a binder, a thickener, a dispersant, and a defoamer, and the ceramic material accounts for 20 to 70wt%, so that the stability, insulation, and adhesion of the first ceramic layer 110 and the second ceramic layer 120 can be ensured, and neither the insufficient stability and insulation of the ceramic material nor the insufficient adhesion of the ceramic material cause the insulation layer to be detached.

In some embodiments, the base film of the separator 10 is a base film composed of PP or a base film composed of PE.

Fig. 2 is a schematic view of a battery (laminated battery 1) according to an embodiment of the present application. The battery (laminated battery 1) includes the first electrode sheet 20, the second electrode sheet 30, and the separator of the first aspect described above, the first electrode sheet 20 and the second electrode sheet 30 being alternately laminated in the first direction Z, the separator 10 being sandwiched between the first electrode sheet 20 and the second electrode sheet 30.

In some embodiments, the cells may be assembled into a battery module, and the number of cells contained in the battery module may be one or more, with the specific number being selectable by one of ordinary skill in the art based on the application and capacity of the battery module.

In the battery module, a plurality of batteries (laminated batteries) may be arranged in order along the length direction of the battery module. Of course, the arrangement may be performed in any other way. The plurality of batteries may further be secured by fasteners. Alternatively, the battery module may further include a case having an accommodating space in which the plurality of batteries are accommodated.

In some embodiments, the above battery modules may be further assembled into a battery pack, and the number of battery modules included in the battery pack may be one or more, and a specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.

A battery case and a plurality of battery modules disposed in the battery case may be included in the battery pack. The battery box comprises an upper box body and a lower box body, wherein the upper box body can be covered on the lower box body, and a closed space for accommodating the battery module is formed. The plurality of battery modules may be arranged in the battery case in any manner.

In addition, the application also provides an electric device which comprises at least one of the battery, the battery module or the battery pack. The battery, the battery module, or the battery pack may be used as a power source of the power consumption device, and may also be used as an energy storage unit of the power consumption device. The power utilization device may include mobile devices (e.g., cell phones, notebook computers, etc.), electric vehicles (e.g., electric-only vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but is not limited thereto.

As the electricity consumption device, a battery module, or a battery pack may be selected according to the use requirements thereof.

Fig. 11 is a schematic view of an electric device according to an embodiment of the present application. The electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or the like. To meet the high power and high energy density requirements of the power device for the battery, a battery pack or battery module may be employed.

As another example, the device may be a cell phone, tablet computer, notebook computer, or the like. The device is generally required to be light and thin, and a battery can be used as a power source.

Examples (example)

Hereinafter, embodiments of the present application are described. The following examples are illustrative only and are not to be construed as limiting the application. The examples are not to be construed as limiting the specific techniques or conditions described in the literature in this field or as per the specifications of the product. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

Example 1

1. Preparation of the first Pole piece

And (3) coating a first electrode active material on two sides of a first current collector, and carrying out cold pressing and cutting to obtain a first pole piece (namely, a positive pole piece).

2. Preparation of the second Pole piece

And (3) coating a second electrode active material on two sides of a second current collector, and carrying out cold pressing and cutting to obtain a second electrode plate (namely, a negative electrode plate).

3. Preparation of separator

(1) A base film made of PP was produced.

(2) The lengths of the first ceramic layer and the second ceramic layer are set to 1/4 of the length of the side surfaces corresponding thereto according to the positions and lengths of the side surfaces of the first pole piece and the second pole piece as viewed from the first direction, and the positions where the first ceramic layer and the second ceramic layer are to be disposed are determined.

(3) While moving the diaphragm in the horizontal direction, ceramic slurry is sprayed on the first diaphragm portion of the diaphragm by a spray head of a spraying apparatus. The ceramic slurry is sprayed by moving the spray head back and forth and left and right to correspond to any 3 sides of the first pole piece. And controlling the spraying time of the spraying equipment at the same position, and adjusting the height of the first ceramic layer in the first direction to be 1/2 of the height of the first pole piece, wherein the height is lower than the surface, far away from the bottom surface of the first pole piece, of the first current collector. And drying in an oven at 80-120 ℃ while spraying.

(4) While moving the diaphragm in the horizontal direction, ceramic slurry is sprayed on the second diaphragm portion of the diaphragm by a spray head of a spraying apparatus. The spray head is moved back and forth and left and right to spray ceramic slurry corresponding to any 3 sides of the second pole piece. And controlling the spraying time of the spraying equipment at the same position, and adjusting the height of the second ceramic layer in the first direction to be 1/2 of the height of the second pole piece, wherein the height is lower than the surface, far away from the bottom surface of the second pole piece, of the second current collector. And drying in an oven at 80-120 ℃ while spraying.

The diaphragm obtained through the steps is provided with the first ceramic layer on one surface and the second ceramic layer on the other surface, and the first ceramic layer and the second ceramic layer are distributed in a staggered manner, namely, when the first ceramic layer is positioned on the front surface, the second ceramic layer is not positioned on the opposite surface of the corresponding position.

4. Assembly

And (3) placing the cut second pole piece into a region surrounded by the second ceramic layer on the diaphragm by using an assembly fixture, then Z-folding the diaphragm, placing the cut first pole piece into a region surrounded by the first ceramic layer on the diaphragm, Z-folding the diaphragm again, and assembling according to the sequence of 'diaphragm-second pole piece-diaphragm-first pole piece-diaphragm-second pole piece … …', thereby obtaining the laminated battery of the embodiment 1.

Example 2

In the same manner as in example 1 except that the first ceramic layer and the second ceramic layer were provided corresponding to all sides (4 sides) of the first and second electrode sheets, respectively, a laminated battery of example 2 was obtained.

Example 3

A first ceramic layer or a second ceramic layer is respectively arranged corresponding to all side surfaces (4 side surfaces) of the first pole piece and the second pole piece; the length of the first portion of the first ceramic layer is equal to the length of the side face of the corresponding first pole piece when viewed from the first direction, and the height of the first portion in the first direction is higher than the face, away from the bottom face of the first pole piece, of the first current collector. Except for this, in the same manner as in example 1, a laminated battery of example 3 was obtained.

Example 4

A first ceramic layer or a second ceramic layer is respectively arranged corresponding to all side surfaces (4 side surfaces) of the first pole piece and the second pole piece; the length of the first part of the first ceramic layer is equal to the length of the side surface of the corresponding first pole piece when being observed from the first direction, and the height of the first part in the first direction is higher than the surface of the first current collector, which is far away from the bottom surface of the first pole piece; the length of the second portion of the second ceramic layer is equal to the length of the side face of the corresponding second pole piece when viewed from the first direction, and the height of the second portion in the first direction is higher than the face, away from the bottom face of the second pole piece, of the second current collector. Except for this, in the same manner as in example 1, a laminated battery of example 4 was obtained.

Comparative example 1

In the same manner as in example 1 except that the first ceramic layer and the second ceramic layer were not provided on the separator, a laminated battery of comparative example 1 was obtained.

Comparative example 2

In the same manner as in example 1 except that the first ceramic layer and the second ceramic layer were provided corresponding to any two side surfaces of the first and second electrode sheets, respectively, a laminated battery of comparative example 2 was obtained.

200 laminated batteries of examples 1 to 4, comparative examples 1 and comparative example 2 were each produced. 100 laminated batteries of examples 1 to 4, comparative examples 1 and 2 were selected, and the first and second electrode sheets were checked for misalignment by an X-Ray detector. The percentage of the number of the dislocation of the pole pieces to the total number is calculated and recorded in a pole piece dislocation probability column in table 1. In addition, the remaining 100 laminated batteries of examples 1 to 4, comparative examples 1 and 2 were selected, and these laminated batteries were subjected to a dielectric withstand voltage test (Hi-point test) to detect whether burrs penetrated the separator. The number of cells that failed the withstand voltage test was counted, and the percentage thereof to the total number was calculated and recorded in the burr-penetration membrane probability column in table 1.

Table 1 shows the evaluation results of the laminated battery. As can be seen from table 1, when the first ceramic layer and the second ceramic layer are not provided (as in comparative example 1), the pole piece dislocation probability is highest; when the first ceramic layer and the second ceramic layer on the diaphragm are distributed on any 2 sides of the first pole piece and the second pole piece (as in comparative example 2), the displacement of the pole piece to the side without the ceramic layer and the dislocation of the pole piece are also unavoidable; when the first ceramic layer and the second ceramic layer on the diaphragm are distributed on any 3 sides of the first pole piece and the second pole piece (in the embodiment 1), the dislocation probability of the pole pieces is greatly reduced; when the first and second ceramic layers on the separator are distributed on all sides, i.e., 4 sides, of the first and second pole pieces (as in example 2), the probability of pole piece misalignment can be reduced to a very low level.

In example 1, example 2, comparative example 1 and comparative example 2, the lengths of the first ceramic layer and the second ceramic layer were smaller than the lengths of the corresponding sides, and the heights were lower than the sides of the current collector, which were far away from the bottom surface of the pole piece, which had little effect on the dislocation probability of the pole piece, but still within a proper range, had a great effect on the probability of the burr piercing the separator. When the first ceramic layers are distributed on 4 side surfaces of the first pole piece and the length of the first ceramic layers is equal to that of the corresponding side surfaces, and the height of the first ceramic layers is higher than that of the surface, far away from the bottom surface, of the first current collector (as in example 3), burrs of the first pole piece serving as the positive pole piece on the 4 side surfaces (namely cutting surfaces) can be wrapped, so that the probability of the burrs penetrating through the diaphragm is greatly reduced; when the first pole piece is arranged like this, and also the second pole piece is arranged, the second ceramic layer is distributed on 4 side surfaces of the first pole piece, the length of the second ceramic layer is equal to that of the corresponding side surface, and the height of the second ceramic layer is higher than that of the surface (such as embodiment 4) of the second current collector, which is far away from the bottom surface, burrs of the second pole piece, which is used as the negative pole piece, on the 4 side surfaces (namely cutting surfaces) are further wrapped, and the probability of the burrs penetrating the diaphragm can be greatly reduced.

Therefore, on the premise of not increasing the size of the battery and not weakening the volume energy density of the battery core, the lithium precipitation risk caused by the dislocation of the pole pieces of the laminated battery and the situation is greatly reduced or even avoided, and on the other hand, the internal short circuit risk caused by the piercing of the diaphragm by the burr of the edge cutting of the pole pieces is greatly reduced or even avoided.

The present application is not limited to the above embodiment. The above embodiments are merely examples, and embodiments having substantially the same configuration and the same effects as those of the technical idea within the scope of the present application are included in the technical scope of the present application. Further, various modifications that can be made to the embodiments and other modes of combining some of the constituent elements in the embodiments, which are conceivable to those skilled in the art, are also included in the scope of the present application within the scope not departing from the gist of the present application.

Claims

1. A diaphragm, characterized in that:

comprises a first diaphragm part and a second diaphragm part which are alternately arranged, wherein when the diaphragm is arranged in a laminated battery with a first pole piece and a second pole piece which are alternately laminated along a first direction, the first diaphragm part and the second diaphragm part are overlapped along the first direction, and the bottom surface of the first pole piece and the bottom surface of the second pole piece are respectively arranged on the first diaphragm part and the second diaphragm part,

The first diaphragm portion has a first ceramic layer having a plurality of first portions corresponding to the peripheral edges of the first pole pieces, the plurality of first portions surrounding the first pole pieces along the peripheral edges of the first pole pieces in such a manner that any one of the first portions is connected,

the second diaphragm part has a second ceramic layer having a plurality of second portions corresponding to the peripheral edges of the second pole pieces, the plurality of second portions surrounding the second pole pieces along the peripheral edges of the second pole pieces in a manner in which any one of the second portions is connected, wherein

The first pole piece is formed by laminating a first electrode active material layer and a first current collector, when the first pole piece is arranged on the first diaphragm part, the lamination direction of the first electrode active material layer and the first current collector is the first direction,

the height of the first ceramic layer in the first direction is greater than the height from the bottom surface of the first pole piece to the surface of the first current collector away from the bottom surface in the first direction, and is not greater than the height of the first pole piece in the first direction.

2. A diaphragm according to claim 1, characterized in that:

The first pole piece and the second pole piece are cuboid,

the first ceramic layer has 4 first portions corresponding to 4 sides of the first pole piece, the 4 first portions are respectively parallel to the 4 sides of the first pole piece, the length of the first portions along the corresponding sides of the first pole piece is not greater than the length of the sides when viewed from the first direction,

the second ceramic layer is provided with 4 second parts corresponding to 4 side surfaces of the second pole piece, the 4 second parts are respectively parallel to the 4 side surfaces of the second pole piece, and the length of the second parts along the corresponding side surfaces of the second pole piece is not greater than the length of the side surfaces when the second ceramic layer is observed from the first direction.

3. A diaphragm according to claim 2, characterized in that:

the length of the first portion along the side of the corresponding first pole piece as viewed from the first direction is equal to the length of the side.

4. A diaphragm according to claim 3, characterized in that:

the second electrode sheet is formed by laminating a second electrode active material layer and a second current collector, and when the second electrode sheet is arranged on the second diaphragm part, the lamination direction of the second electrode active material layer and the second current collector is the first direction,

The length of the second portion along the side of the corresponding second pole piece as seen from the first direction is equal to the length of the side,

the height of the second ceramic layer in the first direction is greater than the height from the bottom surface of the second pole piece to the surface of the second current collector away from the bottom surface in the first direction, and is not greater than the height of the second pole piece in the first direction.

5. The membrane of any one of claims 1 to 4, wherein:

the first portion is spaced from the side of the corresponding first pole piece and the second portion is spaced from the side of the corresponding second pole piece when viewed from the first direction.

6. A separator according to any one of claims 1 to 3, wherein:

the first pole piece is provided with a first pole lug formed by extending the first current collector from 1 side face of the first pole piece to the outside, when the first pole piece is arranged on the first diaphragm part, the first ceramic layer is not contacted with the first pole lug,

the second electrode sheet is formed by stacking a second electrode active material layer and a second current collector, the second electrode sheet has a second tab formed by extending the second current collector from 1 side surface of the second electrode sheet to the outside, and the second ceramic layer is not in contact with the second tab when the second electrode sheet is provided on the second separator portion.

7. The membrane of any one of claims 1 to 4, wherein:

the ceramic slurry for manufacturing the first ceramic layer and the second ceramic layer is the same, the ceramic slurry comprises ceramic materials, binding agents, thickening agents, dispersing agents and defoaming agents, and the proportion of the ceramic materials is 20-70wt%.

8. A diaphragm according to claim 7, characterized in that:

the ceramic material is one of hydrated alumina, magnesia, silicon carbide and silicon nitride, the binder is one or a combination of more of polyacrylate, methyl acrylate, ethyl acrylate, 2-methyl methacrylate and 2-ethyl methacrylate, the thickener is one of sodium carboxymethyl cellulose, methyl cellulose and sodium polyacrylate, the dispersing agent is one or a combination of more of polyvinyl alcohol, polyacrylamide and polyvinylpyrrolidone, and the defoamer is one or a combination of more of n-butyl alcohol and ethanol.

9. A diaphragm according to claim 8, characterized in that:

the ceramic material is hydrated alumina.

10. The membrane of any one of claims 1 to 4, wherein:

the base film of the diaphragm is a base film formed by PP or PE.

11. A battery, characterized in that:

comprising a first pole piece, a second pole piece and a diaphragm as claimed in any one of claims 1 to 10,

the first pole pieces and the second pole pieces are alternately laminated in the first direction,

the diaphragm is sandwiched between the first pole piece and the second pole piece.

12. A battery module, characterized in that:

comprising the battery of claim 11.

13. A battery pack, characterized in that:

comprising the battery module of claim 12.

14. An electrical device, characterized in that:

comprising at least one selected from the group consisting of the battery of claim 11, the battery module of claim 12, and the battery pack of claim 13.