Pressing device

Abstract

The invention provides a pressing device, and relates to the field of batteries. The press-fit device comprises a press-fit piece, the press-fit piece is provided with a receding part and a press-fit face, the press-fit face is used for making contact with the electrode assembly and pressing the electrode assembly, and the receding part is used for receding the electrode assembly. The pressing face is arranged around the clearance part in a surrounding mode. When the pressing device works, the pressing piece can make contact with the electrode assembly and press the electrode assembly, and the receding part does not make contact with the electrode assembly, so that the electrode assembly is receded. The area, corresponding to the clearance part, of the electrode assembly is not pressed, and the area, corresponding to the pressing face, of the electrode assembly can be compacted. As the pressing surface is arranged around the clearance part, the area close to the center of the electrode assembly is not excessively extruded, and the gap between the positive plate and the negative plate in the area close to the center of the electrode assembly is large, so that the electrolyte can reach the area close to the center of the electrode assembly, the infiltration time of the electrode assembly can be shortened, and the service life of the electrode assembly is prolonged. The infiltration effect of the electrode assembly can be improved, and the service life of the electrode assembly is prolonged.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a pressing device. Background Art

[0002] Batteries are widely used in the field of new energy, such as electric vehicles and new energy vehicles. New energy vehicles and electric vehicles have become a new trend in the development of the automotive industry. The development of battery technology must consider many design factors at the same time, such as performance parameters such as energy density, discharge capacity, and charge and discharge rate. In addition, the battery life also needs to be considered. However, the current battery life is short. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a pressing device, which aims to improve the problem of short battery life in the related art.

[0004] An embodiment of the present application provides a pressing device, which includes a pressing piece, wherein the pressing piece has a gap-avoiding portion and a pressing surface, wherein the pressing surface is used to contact and press the electrode assembly, the gap-avoiding portion is used to avoid the electrode assembly, and the pressing surface is arranged around the gap-avoiding portion.

[0005] In the above technical solution, when the pressing device is working, the pressing piece can contact and press the electrode assembly, and the air-avoiding portion does not contact the electrode assembly, thereby avoiding the air-avoiding electrode assembly. The area on the electrode assembly corresponding to the air-avoiding portion will not be compressed, while the area corresponding to the pressing surface can be compacted. Since the pressing surface is arranged around the air-avoiding portion, the area near the center of the electrode assembly will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly, which can not only shorten the infiltration time of the electrode assembly, but also improve the infiltration effect of the electrode assembly and extend the life of the electrode assembly.

[0006] As an optional technical solution of an embodiment of the present application, the air avoidance portion is a groove arranged on the pressing piece, and the groove side surface of the groove is connected to the pressing surface.

[0007] In the above technical solution, the avoidance portion is a groove, and the groove side of the groove extends to the pressing surface. Setting the avoidance portion as a groove is not only easy to manufacture, but also the pressing piece has a higher strength.

[0008] As an optional technical solution of an embodiment of the present application, the air avoidance portion is a through hole provided in the pressing piece, and the hole wall surface of the through hole is connected to the pressing surface.

[0009] In the above technical solution, the air-avoiding part is a through hole, and the hole wall of the through hole extends to the pressing surface. Setting the air-avoiding part as a through hole is not only easy to manufacture, but also helps to reduce the weight of the pressing part, so that less energy is required to drive the pressing part to move.

[0010] As an optional technical solution of an embodiment of the present application, the outer edge of the pressed surface is a rectangle, and the outer edge includes a first long side, a second long side, a first short side and a second short side, and the first long side, the first short side, the second long side and the second short side are connected end to end in sequence; the minimum distance between the gap portion and the first long side is A1, and the minimum distance between the gap portion and the second long side is A2, satisfying: 0.8≤A1 / A2≤1.2; and / or the minimum distance between the gap portion and the first short side is B1, and the minimum distance between the gap portion and the second short side is B2, satisfying: 0.8≤B1 / B2≤1.2.

[0011] In the above technical solution, when the ratio of the minimum distance between the gap portion and the first long side and the minimum distance between the gap portion and the second long side is within the range of 0.8 to 1.2, it indicates that the minimum distance between the gap portion and the first long side and the minimum distance between the gap portion and the second long side are relatively close, and along the width direction of the outer edge of the pressed surface, the gap portion is approximately located in the middle of the pressed surface, so that along the width direction of the outer edge of the pressed surface, the parts of the pressed surface located on both sides of the gap portion have a relatively even stress on the electrode assembly. When the ratio of the minimum distance between the gap portion and the first short side and the minimum distance between the gap portion and the second short side is within the range of 0.8 to 1.2, it indicates that the minimum distance between the gap portion and the first short side and the minimum distance between the gap portion and the second short side are relatively close, and along the length direction of the outer edge of the pressed surface, the gap portion is approximately located in the middle of the pressed surface. In this way, along the length direction of the outer edge of the pressed surface, the parts of the pressed surface located on both sides of the gap portion have a relatively even stress on the electrode assembly.

[0012] As an optional technical solution of an embodiment of the present application, the air avoidance portion intersects with the pressing surface to form a contour line, and the distance between the geometric center of the contour line and the geometric center of the outer edge of the pressing surface is D, satisfying 0≤D≤5mm.

[0013] In the above technical solution, the distance between the geometric center of the contour line and the geometric center of the outer edge of the pressing surface is greater than or equal to 0 and less than or equal to 5 mm, so that the distance between the geometric center of the contour line and the geometric center of the outer edge of the pressing surface is small, and the avoidance portion is roughly located in the middle position of the pressing surface. In this way, the stress of the electrode assembly on the pressing surface around the avoidance portion is more uniform.

[0014] As an optional technical solution of an embodiment of the present application, the geometric center of the contour line coincides with the geometric center of the outer edge.

[0015] In the above technical solution, when the geometric center of the contour line coincides with the geometric center of the outer edge, the gap is located in the middle of the pressing surface, so that the stress of the pressing surface on the electrode assembly around the gap is more uniform.

[0016] As an optional technical solution of an embodiment of the present application, the pressing part is a pressing plate used for hot pressing or cold pressing the electrode assembly.

[0017] In the above technical scheme, when the pressing device is a hot pressing device, the pressing part is a hot pressing plate to achieve hot pressing of the electrode assembly. At this time, compared with the prior art, the present application adjusts the shape of the hot pressing plate so that the hot pressing plate avoids the area near the center of the electrode assembly when hot pressing the electrode assembly, so that the area near the center of the electrode assembly will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly, which can not only shorten the wetting time of the electrode assembly, but also improve the wetting effect of the electrode assembly and extend the life of the electrode assembly. When the pressing device is a cold pressing device, the pressing part is a cold pressing plate to achieve cold pressing of the electrode assembly. At this time, compared with the prior art, the present application adjusts the shape of the cold pressing plate so that the cold pressing plate avoids the area near the center of the electrode assembly when cold pressing the electrode assembly, so that the area near the center of the electrode assembly will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly, which can not only shorten the wetting time of the electrode assembly, but also improve the wetting effect of the electrode assembly and extend the life of the electrode assembly.

[0018] As an optional technical solution of an embodiment of the present application, the pressing device includes a pressing plate, the pressing member is connected to the pressing plate, and the pressing plate is a hot pressing plate or a cold pressing plate.

[0019] In the above technical solution, when the pressing device is a hot pressing device, the pressing plate is a hot pressing plate. In this case, compared with the prior art, the present application may not change the shape of the hot pressing plate, but additionally set a pressing piece on the basis of the hot pressing plate, and the hot pressing plate can transfer heat to the pressing piece to achieve hot pressing of the electrode assembly. When the pressing device is a cold pressing device, the pressing plate is a cold pressing plate. In this case, compared with the prior art, the present application may not change the shape of the cold pressing plate, but additionally set a pressing piece on the basis of the cold pressing plate to achieve hot pressing of the electrode assembly.

[0020] As an optional technical solution of the embodiment of the present application, the pressing part is made of insulating material.

[0021] In the above technical solution, by setting the pressing piece to be an insulating material, when the pressing piece presses the electrode assembly, the pressing plate can be insulated and isolated from the electrode assembly, and it is not easy to cause damage to the electrode assembly.

[0022] As an optional technical solution of the embodiment of the present application, the pressing piece is made of anti-sticking material.

[0023] In the above technical solution, by setting the pressing piece to be an anti-sticking material, the risk of the pressing piece sticking to the electrode assembly when pressing the electrode assembly is reduced.

[0024] As an optional technical solution of the embodiment of the present application, the material of the pressing part includes at least one of Teflon material and ceramic.

[0025] In the above technical solution, Teflon material and ceramics not only have insulating properties, but also have anti-sticking properties, and at the same time have low costs.

[0026] As an optional technical solution of an embodiment of the present application, the pressing part includes a connecting layer and an anti-sticking layer, the connecting layer connects the pressing plate and the anti-sticking layer, the pressing surface is located on the side of the anti-sticking layer away from the connecting layer, and the air avoidance portion is at least partially arranged on the anti-sticking layer.

[0027] In the above technical solution, the connecting layer can connect the pressing plate and the anti-sticking layer. The anti-sticking layer has an anti-sticking property and can reduce adhesion with the electrode assembly, thereby improving the pressing effect.

[0028] As an optional technical solution of an embodiment of the present application, the connecting layer is cardboard or an adhesive layer, and the anti-sticking layer is at least one of Teflon material and ceramic.

[0029] In the above technical solution, when the connecting layer is cardboard, the connecting layer has low cost and can increase the thickness of the entire pressed part to achieve padding. When the connecting layer is an adhesive layer, the connecting layer bonds the anti-sticking layer to the pressing plate. Teflon and ceramics not only have insulating properties, but also have anti-sticking properties, and are relatively low in cost.

[0030] As an optional technical solution of the embodiment of the present application, the pressing piece is bonded to the pressing plate.

[0031] In the above technical solution, by bonding the pressing piece to the pressing plate, the connection is stable and reliable. When the model of the electrode assembly to be pressed is changed, the pressing piece can be torn off and another pressing piece can be bonded to the pressing plate.

[0032] As an optional technical solution of the embodiment of the present application, the pressing piece is detachably connected to the pressing plate.

[0033] In the above technical solution, the pressing part can be disassembled, replaced, and repaired by detachably connecting the pressing part to the pressing plate. When the model of the electrode assembly to be pressed is changed, the pressing part can be disassembled and another pressing part can be installed on the pressing plate. The disassembled pressing part is not easily damaged and can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the structure of a pressing piece provided in some embodiments of the present application;

[0036] Figure 2 A schematic diagram of a pressed part pressing an electrode assembly provided in some embodiments of the present application;

[0037] Figure 3 A schematic diagram of the structure of a pressing piece provided in some other embodiments of the present application;

[0038] Figure 4 A schematic diagram of a pressing piece pressing an electrode assembly provided in some other embodiments of the present application;

[0039] Figure 5 A bottom view schematic diagram of a pressing member provided in some embodiments of the present application;

[0040] Figure 6 A schematic diagram of the structure of a pressing piece provided in some other embodiments of the present application;

[0041] Figure 7 A schematic diagram of a pressing piece pressing an electrode assembly provided in some other embodiments of the present application;

[0042] Figure 8 A schematic diagram of the structure of a pressing member provided in some other embodiments of the present application;

[0043] Fig. 9 A schematic diagram of a pressing piece pressing an electrode assembly provided in some further embodiments of the present application;

[0044] Fig.10 A schematic diagram of the structure of a pressing member provided in some other embodiments of the present application;

[0045] Fig.11 Schematic diagram of pressing parts to press electrode assemblies according to some other embodiments of the present application.

[0046] Icons: 10-pressing part; 110-air-avoiding part; 111-groove side; 112-hole wall; 120-pressing surface; 121-first long side; 122-second long side; 123-first short side; 124-second short side; 125-geometric center of outer edge; 130-connecting layer; 140-anti-sticking layer; 20-pressing plate; 30-electrode assembly. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0049] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0050] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0051] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0052] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0053] The term "plurality" used in the present application refers to two or more (including two).

[0054] In the present application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0055] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells to a certain extent.

[0056] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode ear. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode ear. The material of the negative electrode collector can be copper, and the negative electrode active material can be carbon or silicon. In order to ensure that a large current can be passed without melting, the number of positive pole ears is multiple and stacked together, and the number of negative pole ears is multiple and stacked together. The material of the isolation film can be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly can be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0057] At present, from the perspective of market development, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of battery application areas, its market demand is also constantly expanding.

[0058] The development of battery technology must consider many design factors at the same time, such as energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, the battery life must also be considered. However, the current battery life is short.

[0059] Liquid injection is an important step in the battery production process. Liquid injection refers to the process of controlling the amount and injection time of liquid electrolyte so that the liquid electrolyte is injected into the battery cell from the injection port. The electrolyte injected into the battery cell will gradually infiltrate the electrode assembly. However, the area near the center of the electrode assembly is difficult to be infiltrated, which will cause black spots and lithium precipitation problems in the electrode assembly during use, resulting in a shorter life of the battery cell.

[0060] Before liquid injection, the electrode assembly needs to go through a pressing step, which mainly presses the wound or stacked electrode assembly to compact the electrode assembly and control the size of the electrode assembly. However, when pressing the electrode assembly, the area near the center of the electrode assembly is subjected to greater force and is pressed too tightly. In this way, after liquid injection, it is difficult for the electrolyte to reach the area near the center of the electrode assembly, making it difficult for the area near the center of the electrode assembly to be infiltrated by the electrode assembly.

[0061] In view of this, an embodiment of the present application provides a pressing device, which includes a pressing piece, the pressing piece having a gap-avoiding portion and a pressing surface, the pressing surface is used to contact and press the electrode assembly, and the gap-avoiding portion is used to avoid the gap of the electrode assembly. The pressing surface is arranged around the gap-avoiding portion.

[0062] When the pressing device is working, the pressing piece can contact and press the electrode assembly, and the air-avoiding portion does not contact the electrode assembly, thereby avoiding the air-avoiding electrode assembly. The area on the electrode assembly corresponding to the air-avoiding portion will not be compressed, while the area corresponding to the pressing surface can be compacted. Since the pressing surface is arranged around the air-avoiding portion, the area near the center of the electrode assembly will not be over-compressed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly, which can not only shorten the infiltration time of the electrode assembly, but also improve the infiltration effect of the electrode assembly and extend the life of the electrode assembly.

[0063] The technical solution described in the embodiment of the present application is applicable to the compression of electrode assemblies, which can reduce the pressure on the area close to the center of the electrode assembly, so as to improve the wetting effect of the electrode assembly and extend the life of the battery cell.

[0064] Please refer to Figure 1 and Figure 2 , Figure 1 A schematic structural diagram of a pressing piece 10 provided in some embodiments of the present application. Figure 2 Schematic diagram of a pressing piece 10 provided in some embodiments of the present application pressing an electrode assembly 30. The present application provides a pressing device, which includes a pressing piece 10, the pressing piece 10 having a gap-avoiding portion 110 and a pressing surface 120, the pressing surface 120 is used to contact with the electrode assembly 30 and press the electrode assembly 30, and the gap-avoiding portion 110 is used to avoid the gap of the electrode assembly 30. The pressing surface 120 is arranged around the gap-avoiding portion 110.

[0065] The pressing piece 10 is a component used to directly contact and press the electrode assembly 30. The surface of the pressing piece 10 that directly contacts the electrode assembly 30 is a pressing surface 120. The pressing surface 120 can be a flat surface or a curved surface.

[0066] The press-fitting part 10 is also provided with a voiding portion 110, which is a structure for voiding the electrode assembly 30. When the press-fitting device presses the electrode assembly 30, the press-fitting surface 120 contacts and presses the electrode assembly 30, and the voiding portion 110 does not contact the electrode assembly 30, thereby voiding the electrode assembly 30. In this way, the area on the electrode assembly 30 corresponding to the voiding portion 110 will not be pressed.

[0067] “The pressing surface 120 is arranged around the gap-avoiding portion 110” means that the pressing surface 120 is arranged around the gap-avoiding portion 110. In this way, the area near the edge of the electrode assembly 30 can be compacted, while the area near the center is subjected to less pressure, so that the area near the center of the electrode assembly 30 is not over-compacted, thereby facilitating the electrode assembly 30 to infiltrate the area near the center of the electrode assembly 30.

[0068] When the pressing device is working, the pressing part 10 can contact and press the electrode assembly 30, and the air-avoiding portion 110 does not contact the electrode assembly 30, thereby avoiding the air of the electrode assembly 30. The area corresponding to the air-avoiding portion 110 on the electrode assembly 30 will not be compressed, while the area corresponding to the pressing surface 120 can be compacted. Since the pressing surface 120 is arranged around the air-avoiding portion 110, the area near the center of the electrode assembly 30 will not be over-compressed, and the gap between the positive and negative electrodes in the area near the center of the electrode assembly 30 is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly 30, which can not only shorten the infiltration time of the electrode assembly 30, but also improve the infiltration effect of the electrode assembly 30 and extend the life of the electrode assembly 30.

[0069] Please refer to Figure 1 and Figure 2 In some embodiments, the avoidance portion 110 is a groove provided in the pressing piece 10 , and a groove side surface 111 of the groove is connected to the pressing surface 120 .

[0070] Along the pressing direction of the pressing piece 10 , the groove is recessed from the pressing surface 120 toward the side away from the pressing surface 120 , and the groove does not penetrate the pressing piece 10 .

[0071] The shape of the groove can be square, circular, trapezoidal, etc.

[0072] The avoidance portion 110 is a groove, and the groove side surface 111 of the groove extends to the pressing surface 120. The avoidance portion 110 is set as a groove, which is not only easy to manufacture, but also has a higher strength of the pressing piece 10.

[0073] Please refer to Figure 3 and Figure 4 , Figure 3 Schematic diagram of the structure of the pressing piece 10 provided in other embodiments of the present application. Figure 4Schematic diagram of the pressing piece 10 pressing the electrode assembly 30 provided in other embodiments of the present application. In other embodiments, the air-avoiding portion 110 is a through hole provided in the pressing piece 10 , and the hole wall surface 112 of the through hole is connected to the pressing surface 120 .

[0074] Along the pressing direction of the pressing piece 10 , the through hole is recessed from the pressing surface 120 toward the side away from the pressing surface 120 and penetrates the pressing piece 10 .

[0075] The shape of the through hole can be square, circular, pentagonal, etc.

[0076] The avoidance portion 110 is a through hole, and the hole wall surface 112 of the through hole extends to the pressing surface 120. Setting the avoidance portion 110 as a through hole is not only easy to manufacture, but also helps to reduce the weight of the pressing piece 10, so that less energy is required to drive the pressing piece 10 to move.

[0077] Please refer to Figure 5 , Figure 5 A bottom view schematic diagram of a pressing part 10 provided for some embodiments of the present application. In some embodiments, the outer edge of the pressing surface 120 is a rectangle, and the outer edge includes a first long side 121, a second long side 122, a first short side 123, and a second short side 124, and the first long side 121, the first short side 123, the second long side 122, and the second short side 124 are connected end to end in sequence. The minimum distance between the air avoidance portion 110 and the first long side 121 is A1, and the minimum distance between the air avoidance portion 110 and the second long side 122 is A2, satisfying: 0.8≤A1 / A2≤1.2. And / or the minimum distance between the air avoidance portion 110 and the first short side 123 is B1, and the minimum distance between the air avoidance portion 110 and the second short side 124 is B2, satisfying: 0.8≤B1 / B2≤1.2.

[0078] The first long side 121 and the second long side 122 are respectively the two long sides of the outer edge of the rectangle. The first short side 123 and the second short side 124 are respectively the two short sides of the outer edge of the rectangle. The length of the first long side 121 is equal to the length of the second long side 122, the length of the first long side 121 is greater than the length of the first short side 123, and the length of the first short side 123 is equal to the length of the second short side 124.

[0079] A1 represents the minimum distance between the gap portion 110 and the first long side 121, that is, the spacing between the gap portion 110 and the first long side 121. During measurement, the minimum distance between the side wall surface of the gap portion 110 and the first long side 121 can be measured as A1.

[0080] A2 represents the minimum distance between the gap portion 110 and the second long side 122, that is, the spacing between the gap portion 110 and the second long side 122. During measurement, the minimum distance between the side wall surface of the gap portion 110 and the second long side 122 can be measured as A2.

[0081] The ratio of the minimum distance between the gap portion 110 and the first long side 121 to the minimum distance between the gap portion 110 and the second long side 122 can be: A1 / A2=0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, 1, 1.02, 1.05, 1.08, 1.1, 1.12, 1.15, 1.18, 1.2.

[0082] B1 represents the minimum distance between the gap portion 110 and the first short side 123, that is, the spacing between the gap portion 110 and the first short side 123. During measurement, the minimum distance between the side wall surface of the gap portion 110 and the first short side 123 can be measured as B1.

[0083] B2 represents the minimum distance between the gap portion 110 and the second short side 124, that is, the spacing between the gap portion 110 and the second short side 124. During measurement, the minimum distance between the side wall surface of the gap portion 110 and the second short side 124 can be measured as A2.

[0084] The ratio of the minimum distance between the gap portion 110 and the first short side 123 to the minimum distance between the gap portion 110 and the second short side 124 can be: B1 / B2=0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, 1, 1.02, 1.05, 1.08, 1.1, 1.12, 1.15, 1.18, 1.2.

[0085] When the ratio of the minimum distance between the gap portion 110 and the first long side 121 to the minimum distance between the gap portion 110 and the second long side 122 is in the range of 0.8 to 1.2, it indicates that the minimum distance between the gap portion 110 and the first long side 121 and the minimum distance between the gap portion 110 and the second long side 122 are relatively close, and along the width direction of the outer edge of the pressing surface 120, the gap portion 110 is approximately located in the middle position of the pressing surface 120. In this way, along the width direction of the outer edge of the pressing surface 120, the parts of the pressing surface 120 located on both sides of the gap portion 110 have a more even stress on the electrode assembly 30. When the ratio of the minimum distance between the gap portion 110 and the first short side 123 to the minimum distance between the gap portion 110 and the second short side 124 is in the range of 0.8 to 1.2, it indicates that the minimum distance between the gap portion 110 and the first short side 123 and the minimum distance between the gap portion 110 and the second short side 124 are relatively close, and along the length direction of the outer edge of the pressing surface 120, the gap portion 110 is approximately located in the middle of the pressing surface 120. In this way, along the length direction of the outer edge of the pressing surface 120, the stress of the portions of the pressing surface 120 located on both sides of the gap portion 110 on the electrode assembly 30 is relatively even.

[0086] Please refer to Figure 5In some embodiments, the air avoidance portion 110 intersects with the pressing surface 120 to form a contour line, and the distance between the geometric center of the contour line and the geometric center 125 of the outer edge of the pressing surface 120 is D, satisfying 0≤D≤5mm.

[0087] The contour line is the intersection line of the clearance portion 110 and the pressing surface 120. In the embodiment where the clearance portion 110 is a groove, the contour line is the intersection line of the groove side surface 111 of the groove and the pressing surface 120. In the embodiment where the clearance portion 110 is a through hole, the contour line is the intersection line of the hole wall surface 112 of the through hole and the pressing surface 120.

[0088] Please refer to Figure 5 , the figure shows the geometric center 125 of the outer edge of the pressing surface 120. The geometric center 125 of the outer edge is a circle, and a circle is drawn with a radius of 5 mm, and the geometric center of the contour line falls within the circle, which satisfies: the distance between the geometric center of the contour line and the geometric center 125 of the outer edge of the pressing surface 120 is within the range of 0 to 5 mm.

[0089] The distance between the geometric center of the contour line and the geometric center 125 of the outer edge of the pressing surface 120 can be: D=0, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0090] The distance between the geometric center of the contour line and the geometric center 125 of the outer edge of the pressing surface 120 is greater than or equal to 0 and less than or equal to 5 mm. In this way, the distance between the geometric center of the contour line and the geometric center 125 of the outer edge of the pressing surface 120 is small, and the avoidance portion 110 is roughly located in the middle position of the pressing surface 120. In this way, the stress of the pressing surface 120 on the electrode assembly 30 around the avoidance portion 110 is more uniform.

[0091] Please refer to Figure 5 In some embodiments, the geometric center of the contour line coincides with the geometric center 125 of the outer edge.

[0092] When the geometric center of the contour line coincides with the geometric center 125 of the outer edge, the clearance portion 110 is located in the middle of the pressing surface 120 , so that the stress of the pressing surface 120 on the electrode assembly 30 around the clearance portion 110 is more uniform.

[0093] Please refer to Figure 1 , Figure 2 , Figure 3 and Figure 4 In some embodiments, the press member 10 is a press plate 20 for hot pressing or cold pressing the electrode assembly 30 .

[0094] When the pressing device is a hot pressing device, the pressing part 10 is a hot pressing plate to realize hot pressing of the electrode assembly 30. At this time, compared with the prior art, the present application adjusts the shape of the hot pressing plate so that the hot pressing plate avoids the area near the center of the electrode assembly 30 when hot pressing the electrode assembly 30, so that the area near the center of the electrode assembly 30 will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly 30 is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly 30, which can not only shorten the wetting time of the electrode assembly 30, but also improve the wetting effect of the electrode assembly 30 and extend the life of the electrode assembly 30. When the pressing device is a cold pressing device, the pressing part 10 is a cold pressing plate to realize cold pressing of the electrode assembly 30. At this time, compared with the prior art, the present application adjusts the shape of the cold pressing plate so that the cold pressing plate avoids the area near the center of the electrode assembly 30 when cold pressing the electrode assembly 30, so that the area near the center of the electrode assembly 30 will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly 30 is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly 30, which can not only shorten the wetting time of the electrode assembly 30, but also improve the wetting effect of the electrode assembly 30 and extend the life of the electrode assembly 30.

[0095] Please refer to Figure 6 , Figure 7 , Figure 8 and Fig. 9 , Figure 6 Schematic diagram of the structure of the pressing piece 10 provided in some other embodiments of the present application. Figure 7 Schematic diagram of the pressing piece 10 pressing the electrode assembly 30 provided in some other embodiments of the present application. Figure 8 This is a schematic structural diagram of a pressing piece 10 provided in some further embodiments of the present application. Fig. 9 The schematic diagram of the pressing member 10 pressing the electrode assembly 30 provided in some other embodiments of the present application. The pressing device includes a pressing plate 20, and the pressing member 10 is connected to the pressing plate 20. The pressing plate 20 is a hot pressing plate or a cold pressing plate.

[0096] Please refer to Figure 6 and Figure 7 In some other embodiments, the avoidance portion is a groove provided on the pressing part 10, and the groove side surface 111 of the groove is connected to the pressing surface 120. The pressing plate 20 can be a hot pressing plate or a cold pressing plate. Compared with the cold pressing plate, the hot pressing plate is provided with a heating module, which can generate a higher temperature and transfer the heat to the pressing part 10, thereby achieving hot pressing.

[0097] Please refer to Figure 8 and Fig. 9In some other embodiments, the avoidance portion is a through hole provided in the pressing member 10, and the hole wall surface 112 of the through hole is connected to the pressing surface 120. The pressing plate 20 can be a hot pressing plate or a cold pressing plate. The pressing member 10 is connected to the side of the pressing plate 20 facing the electrode assembly 30.

[0098] When the pressing device is a hot pressing device, the pressing plate 20 is a hot pressing plate. In this case, compared with the prior art, the present application may not change the shape of the hot pressing plate, but additionally set a pressing piece 10 on the basis of the hot pressing plate, and the hot pressing plate can transfer heat to the pressing piece 10 to achieve hot pressing of the electrode assembly 30. When the pressing device is a cold pressing device, the pressing plate 20 is a cold pressing plate. In this case, compared with the prior art, the present application may not change the shape of the cold pressing plate, but additionally set a pressing piece 10 on the basis of the cold pressing plate to achieve hot pressing of the electrode assembly 30.

[0099] In some embodiments, the pressing member 10 is made of insulating material.

[0100] The insulating material has insulating properties and can insulate and isolate the pressing plate 20 from the electrode assembly 30. The insulating material can be plastic, rubber, etc.

[0101] By setting the pressing piece 10 to be made of insulating material, when the pressing piece 10 presses the electrode assembly 30 , the pressing plate 20 can be insulated and isolated from the electrode assembly 30 , and it is not easy to cause damage to the electrode assembly 30 .

[0102] In some embodiments, the pressing member 10 is made of a non-stick material.

[0103] Anti-stick material refers to a material that is not easy to adhere to other structures.

[0104] By setting the pressing piece 10 to be made of an anti-sticking material, the risk of the pressing piece 10 sticking to the electrode assembly 30 when pressing the electrode assembly 30 is reduced.

[0105] In some embodiments, the material of the pressing piece 10 includes at least one of Teflon material and ceramic.

[0106] Teflon and ceramics not only have insulating properties, but also have anti-stick properties and are relatively low in cost.

[0107] Please refer to Fig.10 and Fig.11 , Fig.10 Schematic diagram of the structure of the pressing piece 10 provided in some other embodiments of the present application. Fig.11Schematic diagram of a laminating member 10 laminating an electrode assembly 30 provided in some other embodiments of the present application. In some other embodiments, the laminating member 10 includes a connecting layer 130 and an anti-adhesion layer 140, and the connecting layer 130 connects the pressing plate 20 and the anti-adhesion layer 140. The laminating surface 120 is located on the side of the anti-adhesion layer 140 that is away from the connecting layer 130, and the air-avoiding portion 110 is at least partially disposed on the anti-adhesion layer 140.

[0108] The connecting layer 130 is mainly used to connect the pressing plate 20 and the anti-adhesive layer 140. The anti-adhesive layer 140 is mainly used to contact the electrode assembly 30. The pressing surface 120 is located on the side of the anti-adhesive layer 140 away from the connecting layer 130. The avoidance portion 110 can be only provided in the anti-adhesive layer 140, for example, the avoidance portion 110 is a groove provided in the anti-adhesive layer 140. For another example, the avoidance portion 110 is a through hole provided in the anti-adhesive layer 140. The avoidance portion 110 can also be provided with the anti-adhesive layer 140 and the connecting layer 130 at the same time, for example, the avoidance portion 110 is a through hole penetrating the anti-adhesive layer 140 and the connecting layer 130.

[0109] The connection layer 130 can connect the pressing plate 20 and the anti-sticking layer 140 . The anti-sticking layer 140 has an anti-sticking property and can reduce adhesion with the electrode assembly 30 , thereby improving the lamination effect.

[0110] In some embodiments, the connecting layer 130 is a cardboard or an adhesive layer, and the anti-sticking layer 140 is at least one of Teflon and ceramic.

[0111] When the connecting layer 130 is a cardboard, the connecting layer 130 is low in cost and can increase the overall thickness of the pressed piece 10 to achieve padding. When the connecting layer 130 is an adhesive layer, the connecting layer 130 bonds the anti-sticking layer 140 to the pressing plate 20. Teflon and ceramics not only have insulating properties, but also have anti-sticking properties, and are relatively low in cost.

[0112] In some embodiments, the pressing member 10 is bonded to the pressing plate 20 .

[0113] By bonding the pressing piece 10 to the pressing plate 20 , the connection is stable and reliable. When the type of the electrode assembly 30 to be pressed is changed, the pressing piece 10 can be torn off and another pressing piece 10 can be bonded to the pressing plate 20 .

[0114] In some other embodiments, the pressing member 10 is detachably connected to the pressing plate 20 .

[0115] "Removable connection" refers to a connection method in which the connecting member and the connected member are not damaged after thousands of repeated assembly and disassembly, and the original connection quality can be maintained. For example, the pressing member 10 can be bolted to the pressing plate 20, and the pressing member 10 can also be clamped to the pressing plate 20.

[0116] By detachably connecting the pressing part 10 to the pressing plate 20, the pressing part 10 can be disassembled, replaced, and repaired. When the model of the electrode assembly 30 to be pressed is changed, the pressing part 10 can be disassembled and another pressing part 10 can be installed on the pressing plate 20. The disassembled pressing part 10 is not easily damaged and can be reused.

[0117] According to some embodiments of this application, please refer to Figures 1 to 11 .

[0118] The embodiment of the present application provides a pressing device, which includes a pressing piece 10, and the pressing piece 10 has a gap-avoiding portion 110 and a pressing surface 120, the pressing surface 120 is used to contact and press the electrode assembly 30, and the gap-avoiding portion 110 is used to avoid the gap of the electrode assembly 30. The pressing surface 120 is arranged around the gap-avoiding portion 110. When the pressing device is working, the pressing piece 10 can contact and press the electrode assembly 30, and the gap-avoiding portion 110 does not contact the electrode assembly 30, thereby avoiding the gap of the electrode assembly 30. The area corresponding to the gap-avoiding portion 110 on the electrode assembly 30 will not be compressed, while the area corresponding to the pressing surface 120 can be compacted. Since the pressing surface 120 is arranged around the air avoidance portion 110, the area near the center of the electrode assembly 30 will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly 30 is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly 30, which can not only shorten the wetting time of the electrode assembly 30, but also improve the wetting effect of the electrode assembly 30, thereby extending the life of the electrode assembly 30.

[0119] The avoidance portion 110 is a groove or a through hole provided in the pressing member 10. The avoidance portion 110 is provided as a groove or a through hole, which is easy to manufacture.

[0120] The pressing part 10 is a pressing plate 20 for hot pressing or cold pressing the electrode assembly 30. When the pressing device is a hot pressing device, the pressing part 10 is a hot pressing plate to achieve hot pressing of the electrode assembly 30. At this time, compared with the prior art, the present application adjusts the shape of the hot pressing plate so that the hot pressing plate avoids the area near the center of the electrode assembly 30 when hot pressing the electrode assembly 30, so that the area near the center of the electrode assembly 30 will not be over-pressed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly 30 is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly 30, which can not only shorten the infiltration time of the electrode assembly 30, but also improve the infiltration effect of the electrode assembly 30 and extend the life of the electrode assembly 30. When the pressing device is a cold pressing device, the pressing part 10 is a cold pressing plate to realize cold pressing of the electrode assembly 30. At this time, compared with the prior art, the present application adjusts the shape of the cold pressing plate so that the cold pressing plate avoids the area near the center of the electrode assembly 30 when cold pressing the electrode assembly 30, so that the area near the center of the electrode assembly 30 will not be excessively squeezed, and the gap between the positive and negative electrode sheets in the area near the center of the electrode assembly 30 is larger, which is conducive to the electrolyte reaching the area near the center of the electrode assembly 30, which can not only shorten the wetting time of the electrode assembly 30, but also improve the wetting effect of the electrode assembly 30 and extend the life of the electrode assembly 30.

[0121] The pressing device includes a pressing plate 20, and a pressing part 10 is connected to the pressing plate 20. The pressing plate 20 is a hot pressing plate or a cold pressing plate. When the pressing device is a hot pressing device, the pressing plate 20 is a hot pressing plate. At this time, compared with the prior art, the present application may not change the shape of the hot pressing plate, but additionally set the pressing part 10 on the basis of the hot pressing plate, and the hot pressing plate can transfer heat to the pressing part 10 to achieve hot pressing of the electrode assembly 30. When the pressing device is a cold pressing device, the pressing plate 20 is a cold pressing plate. At this time, compared with the prior art, the present application may not change the shape of the cold pressing plate, but additionally set the pressing part 10 on the basis of the cold pressing plate to achieve hot pressing of the electrode assembly 30.

[0122] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pressing device, characterized in that: The pressing part comprises a pressing piece, wherein the pressing piece has a gap-avoiding portion and a pressing surface, wherein the pressing surface is used to contact and press the electrode assembly, the gap-avoiding portion is used to avoid the electrode assembly, and the pressing surface is arranged around the gap-avoiding portion.

2. The pressing device according to claim 1, characterized in that: The avoidance portion is a groove arranged on the pressing piece, and a groove side surface of the groove is connected to the pressing surface.

3. The pressing device according to claim 1, characterized in that: The air avoidance portion is a through hole provided in the pressing piece, and a hole wall surface of the through hole is connected to the pressing surface.

4. The pressing device according to any one of claims 1 to 3, characterized in that: The outer edge of the pressed surface is a rectangle, and the outer edge includes a first long side, a second long side, a first short side, and a second short side, and the first long side, the first short side, the second long side, and the second short side are connected end to end in sequence; The minimum distance between the gap avoidance portion and the first long side is A1, and the minimum distance between the gap avoidance portion and the second long side is A2, satisfying: 0.8≤A1 / A2≤1.2; and / or The minimum distance between the gap avoidance portion and the first short side is B1, and the minimum distance between the gap avoidance portion and the second short side is B2, satisfying: 0.8≤B1 / B2≤1.

2.

5. The pressing device according to any one of claims 1 to 4, characterized in that: The avoidance portion intersects with the pressing surface to form a contour line, and the distance between the geometric center of the contour line and the geometric center of the outer edge of the pressing surface is D, satisfying 0≤D≤5mm.

6. The pressing device according to claim 5, characterized in that: The geometric center of the contour line coincides with the geometric center of the outer edge.

7. The pressing device according to any one of claims 1 to 6, characterized in that: The pressing piece is a pressing plate used for hot pressing or cold pressing the electrode assembly.

8. The pressing device according to any one of claims 1 to 6, characterized in that: The pressing device comprises a pressing plate, the pressing member is connected to the pressing plate, and the pressing plate is a hot pressing plate or a cold pressing plate.

9. The pressing device according to claim 8, characterized in that: The pressing piece is made of insulating material.

10. The pressing device according to claim 8 or 9, characterized in that: The pressing piece is made of anti-sticking material.

11. The pressing device according to any one of claims 8 to 10, characterized in that: The material of the pressing part includes at least one of Teflon material and ceramic.

12. The pressing device according to claim 8, characterized in that: The laminating component comprises a connecting layer and an anti-adhesive layer, the connecting layer connects the pressing plate and the anti-adhesive layer, the laminating surface is located on a side of the anti-adhesive layer away from the connecting layer, and the air-avoiding portion is at least partially disposed on the anti-adhesive layer.

13. The pressing device according to claim 12, characterized in that: The connecting layer is made of cardboard or an adhesive layer, and the anti-sticking layer is made of at least one of Teflon and ceramic.

14. The pressing device according to any one of claims 7 to 13, characterized in that: The pressing piece is bonded to the pressing plate.

15. The pressing device according to any one of claims 7 to 13, characterized in that: The pressing piece is detachably connected to the pressing plate.

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