Hot pressing device, battery production system, battery monomer, battery device and power utilization device

Abstract

The embodiment of the invention provides a hot-pressing device, a battery production system, a battery monomer, a battery device and a power utilization device, the hot-pressing device is used for hot-pressing an electrode assembly, the electrode assembly comprises a tab, the tab is convexly arranged along a first direction, the hot-pressing device comprises a driving part, a lower hot-pressing part and an upper hot-pressing part, and the upper hot-pressing part and the lower hot-pressing part are oppositely arranged; at least one of the upper hot-pressing piece and the lower hot-pressing piece is connected with a driving piece and is configured to be close to or far away from each other under the driving of the driving piece; wherein at least one of the upper hot-pressing piece and the lower hot-pressing piece comprises a plate body and a compaction structure, the compaction structure is located on the side, facing the electrode assembly, of the plate body, the compaction structure is provided with at least one pair of openings arranged oppositely in the first direction, and the two paired openings extend towards the center area, in the first direction, of the compaction structure respectively; the plate body covers at least part of the opening and is used for pressing the electrode assembly through the opening. According to the invention, the capacity retention ratio of the battery monomer can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to a hot pressing device, a battery production system, a battery cell, a battery device, and an electrical device. Background Art

[0002] Battery monomers are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] In the development of battery technology, how to improve the capacity retention rate of battery cells is a research direction in battery technology. Summary of the invention

[0004] The present application provides a hot pressing device, a battery production system, a battery cell, a battery device and an electrical device, which can improve the capacity retention rate of the battery cell.

[0005] An embodiment of the present application provides a hot pressing device for hot pressing an electrode assembly, the electrode assembly including a pole ear, the pole ear being protruding along a first direction, the hot pressing device including a driving member, a lower hot pressing member and an upper hot pressing member, the upper hot pressing member being arranged opposite to the lower hot pressing member, at least one of the upper hot pressing member and the lower hot pressing member being connected to the driving member, and being configured to approach or move away from each other under the drive of the driving member; wherein, at least one of the upper hot pressing member and the lower hot pressing member includes a plate body and a compacting structure, the compacting structure being located on a side of the plate body facing the electrode assembly, the plate body being used to generate heat, the compacting structure being used to press the electrode assembly, the compacting structure being provided with at least a pair of openings arranged opposite to each other along the first direction, the two paired openings respectively extending toward a central area of ​​the compacting structure in the first direction, the plate body covering at least part of the opening and being used to press the electrode assembly through the opening.

[0006] In the above technical scheme, the hot pressing device of this embodiment arranges a compaction structure on the upper hot pressing part and / or the lower hot pressing part, and the compaction structure has a pair of openings arranged back to back along the first direction, and the two pairs of openings extend respectively to the central area of ​​the compaction structure in the first direction. In this way, the two parts of the electrode assembly corresponding to the two openings are not compacted to form two upper and lower exhaust channels, and the gas generated in the central area of ​​the electrode assembly in the first direction is discharged through the two exhaust channels, thereby reducing the influence of bubbles on the negative electrode plate of the battery cell, reducing problems such as purple spots and lithium plating, improving the interface of the battery cell, and improving the capacity retention rate of the battery cell.

[0007] In some embodiments, the compaction structure is provided with a plurality of pairs of openings, the plurality of pairs of openings are spaced apart along the second direction, and the first direction and the second direction intersect.

[0008] In the above technical solution, a plurality of pairs of openings are provided to increase the number of exhaust channels distributed in the second direction and improve the uniformity of exhaust of the electrode assembly.

[0009] In some embodiments, at least one pair of openings among all the openings is located in a central area of ​​the compacted structure in the second direction, and the first direction and the second direction intersect.

[0010] In the above technical solution, at least one pair of openings is arranged in the central area of ​​the compacted structure in the second direction, so as to improve the exhaust effect of the central area where the electrode assembly intersects in the second direction and the first direction.

[0011] In some embodiments, the compaction structure includes at least two first compaction parts and one second compaction part. The two first compaction parts are arranged at intervals along the second direction and connected by a second compaction part. The two first compaction parts and the second compaction parts are arranged to form a pair of openings, and the first direction and the second direction intersect.

[0012] In the above technical solution, this embodiment forms a pair of openings by two first compaction parts and one second compaction part. In this way, by setting the size of the second compaction part along the first direction, the central area of ​​the electrode assembly in the first direction can be well vented under the premise of compaction.

[0013] In some embodiments, the number of first compaction parts is greater than two, the number of second compaction parts is at least two, the multiple first compaction parts and the multiple second compaction parts are respectively arranged in sequence along the second direction, any two adjacent first compaction parts are connected by the second compaction parts, and the multiple first compaction parts and the multiple second compaction parts are arranged to form multiple pairs of openings arranged at intervals along the second direction.

[0014] In the above technical solution, multiple first compaction parts and multiple second compaction parts are arranged to form multiple pairs of openings, and the multiple pairs of openings are arranged at intervals along the second direction. In this way, the electrode assembly can form more exhaust channels to increase the number of exhaust channels distributed in the second direction and improve the uniformity of exhaust of the electrode assembly.

[0015] In some embodiments, the number of the first compaction parts is two, the number of the second compaction parts is one, the size of the first compaction part along the second direction is W1, the size of the second compaction part along the second direction is W2, and W1 and W2 satisfy: W1≤W2.

[0016] In the above technical solution, the size of the second compacted portion is set to be greater than or equal to the size of the first compacted portion to form a wider exhaust channel and improve the exhaust effect of the central area of ​​the electrode assembly.

[0017] In some embodiments, W1, W2, and W3 satisfy: 1 / 4W3≤W1≤W2≤1 / 2 W3.

[0018] In the above technical solution, the values ​​of W1 and W2 are limited to be greater than or equal to 1 / 4W3 to improve the exhaust effect on the electrode assembly; the values ​​of W1 and W2 are limited to be less than or equal to 1 / 2 W3 to make the sizes of the first compaction part 322 and the second compaction part 323 along the second direction Y more balanced, thereby forming a better compaction effect.

[0019] In some embodiments, the two openings constituting a pair are arranged in a mirror image, and / or the two first compacting portions are arranged in a mirror image.

[0020] In the above technical solution, the two openings arranged in pairs are arranged in mirror images to improve the uniformity of exhausting the upper and lower parts of the electrode assembly. The two first compacting parts are arranged in mirror images to improve the uniformity of compaction degree of the left and right areas of the electrode assembly.

[0021] In some embodiments, a size of the opening along the first direction is h1, a size of the compacted structure along the first direction is h2, and h1 and h2 satisfy: 35%≤h1 / h2≤45%.

[0022] In the above technical scheme, the value of h1 / h2 is limited to greater than or equal to 35% to form an exhaust channel with a larger size in the first direction, thereby improving the exhaust effect on the central area of ​​the electrode assembly; the value of h1 / h2 is limited to less than or equal to 45% to improve the compaction effect on the central area of ​​the electrode assembly in the first direction.

[0023] In some embodiments, h1 and h2 satisfy: 38%≤h1 / h2≤42%.

[0024] In the above technical scheme, the value of h1 / h2 is further limited to greater than or equal to 38% to form an exhaust channel with a larger size in the first direction, thereby further improving the exhaust effect on the central area of ​​the electrode assembly; the value of h1 / h2 is further limited to less than or equal to 42% to further improve the compaction effect on the central area of ​​the electrode assembly in the first direction.

[0025] In some embodiments, the plate body and the compacted structure are integrally formed.

[0026] In the above technical solution, the plate body and the compaction structure are formed in one piece, so the relative position relationship between the plate body and the compaction structure is more accurate, and the connection is more firm.

[0027] In some embodiments, the compaction structure is adhered to the board body.

[0028] In the above technical solution, the compaction structure is pasted to the plate body. In this way, the compaction structure of the required size can be pasted according to actual needs. For example, the overall size or opening size of the compaction structure can be adjusted, thereby improving the applicability of the hot pressing device.

[0029] In some embodiments, a projection of the compaction structure on the plate body along a third direction is located within the plate body, and the third direction is parallel to an arrangement direction from the plate body to the compaction structure.

[0030] In the above technical solution, the projection of the compaction structure on the plate body along the third direction is located inside the plate body, so that the heat generated by the plate body can spread throughout the compaction structure, while also facilitating the arrangement of the compaction structure.

[0031] In some embodiments, the hot pressing device also includes a pressure sensor, a first temperature sensor and a second temperature sensor. The upper hot pressing piece is provided with a pressure sensor and a first temperature sensor, and the lower hot pressing piece is provided with a second temperature sensor. The pressure sensor is used to measure the pressure between the upper hot pressing piece and the electrode assembly, the first temperature sensor is used to measure the temperature of the upper hot pressing piece, and the second temperature sensor is used to measure the temperature of the lower hot pressing piece.

[0032] In the above technical solution, a pressure sensor, a first temperature sensor and a second temperature sensor are provided to monitor the pressure and temperature parameters during the hot pressing process, thereby realizing accurate monitoring of the pressure and temperature during the hot pressing process.

[0033] In a second aspect, an embodiment of the present application further provides a battery production system, comprising the above-mentioned hot pressing device and a molding device, wherein the molding device is used to wind or stack positive electrode sheets, negative electrode sheets and isolation films to form an electrode assembly.

[0034] In a third aspect, an embodiment of the present application further provides a battery cell, comprising a housing and an electrode assembly, wherein the electrode assembly is located within the housing, and the electrode assembly is configured to be hot pressed by a hot pressing device as described above, wherein a surface of the electrode assembly is provided with indentations corresponding to at least a portion of the compacted structure, and the indentations are arranged to form areas corresponding to the paired openings.

[0035] In a fourth aspect, an embodiment of the present application further provides a battery device, comprising the battery cell as described above.

[0036] In a fifth aspect, an embodiment of the present application further provides an electrical device, comprising a battery device as described above, and the battery device is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the structure of a battery production system provided in some embodiments of the present application;

[0039] Figure 2 A schematic diagram of the structure of a hot pressing device and an electrode assembly provided in some embodiments of the present application;

[0040] Figure 3 A schematic diagram of the structure of an upper hot pressing part in a hot pressing device provided in some embodiments of the present application;

[0041] Figure 4 Another structural schematic diagram of an upper hot pressing part in a hot pressing device provided in some embodiments of the present application;

[0042] Figure 5 A partial structural schematic diagram of a hot pressing device provided in some embodiments of the present application;

[0043] Figure 6 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0044] Figure 7 A schematic diagram of the structure of a battery device provided in some embodiments of the present application;

[0045] Figure 8 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0046] The reference numerals of the specific embodiments are as follows:

[0047] 100, battery production system; 200, hot pressing device; 300, forming device; 400, preheating device; 500, prepressing device; 600, electrode assembly; 610, pole ear; 620, dent; 700, battery cell; 710, housing; 800, battery device; 810, battery cell assembly; 820, box; 900, vehicle; 910, controller; 920, motor;

[0048] 1. Driving parts;

[0049] 2. Lower hot pressing parts;

[0050] 3. Upper hot pressing part; 31. Plate body; 32. Compacting structure; 321. Opening; 322. First compacting part; 323. Second compacting part;

[0051] 4. Pressure sensor;

[0052] 5. The first temperature sensor;

[0053] 6. Controller;

[0054] X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] The term "plurality" used in the present application refers to two or more (including two).

[0062] In the present application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, etc., and the embodiments of the present application do not limit this. The battery cell may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this.

[0063] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. A 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 current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive coating area and a positive electrode ear connected to the positive coating area. The positive coating area is coated with a positive active material layer, and the positive electrode ear is not coated with a positive active material layer. Taking a lithium-ion battery cell as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area, and the negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode tab is not coated with a negative electrode active material layer. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.

[0064] A battery cell generally includes an electrode assembly and a shell. The electrode assembly needs to undergo a hot pressing process before entering the shell, that is, the electrode assembly is hot pressed into a compact whole using an upper hot pressing plate and a lower hot pressing plate to improve the performance of the battery cell.

[0065] After research, it was found that during the formation stage, the gas production in the central area of ​​the electrode assembly in the height direction is relatively large, and the electrode assembly as a whole is in a compacted state. As a result, the gas generated in the central area cannot be discharged from the electrode assembly in time, resulting in bubble-like purple spots and lithium deposition on the negative electrode sheet, affecting the interface of the battery cell and causing the capacity retention rate of the battery cell to decrease.

[0066] In view of this, the present application provides a hot pressing device, which arranges a compaction structure on the upper hot pressing part and / or the lower hot pressing part, and the compaction structure is provided with at least two openings opposite to each other along a first direction, and the openings extend toward the central area of ​​the compaction structure in the height direction. In this way, the electrode assembly corresponding to the opening is not completely compacted, and the gas is discharged through the loose part that is not completely compacted, thereby reducing the influence of bubbles on the negative electrode plate of the battery cell, improving the interface of the battery cell, and improving the capacity retention rate of the battery cell.

[0067] Figure 1 A schematic diagram of the structure of a battery production system 100 provided in some embodiments of the present application.

[0068] like Figure 1 As shown, the battery production system 100 includes a molding device 300 and a hot pressing device 200 . The molding device 300 is used to wind or stack the positive electrode sheet, the negative electrode sheet and the separator to form an electrode assembly 600 .

[0069] Exemplarily, the battery production system 100 further includes a pole piece coating device, which is used to coat the active material on at least one side of the current collector.

[0070] Exemplarily, the battery production system 100 further includes a drying device, which is located downstream of the electrode coating device and is used to dry the current collector coated with the active material to form a dried electrode.

[0071] Exemplarily, the battery production system 100 further includes a preheating device 400, which includes a heating furnace for heating the electrode assembly 600. The preheating device 400 is located upstream of the hot pressing device 200. Optionally, the electrode assembly 600 is placed in the heating furnace for heating for 300s-600s to maintain the temperature of the electrode assembly 600 at a preset temperature.

[0072] Exemplarily, the battery production system 100 further includes a pre-pressing device 500, which includes an upper pressing plate, a lower pressing plate and a driving mechanism, wherein the upper pressing plate and the lower pressing plate are arranged opposite to each other, the lower pressing plate is used to carry the electrode assembly 600, and the driving mechanism is connected to the upper pressing plate and drives the upper pressing plate to press the electrode assembly 600. The pre-pressing device 500 is located upstream of the preheating device 400.

[0073] Figure 2 A schematic diagram of the structure of a hot pressing device and an electrode assembly provided in some embodiments of the present application, Figure 3 A schematic structural diagram of an upper hot pressing part in a hot pressing device provided in some embodiments of the present application.

[0074] like Figure 2 and Figure 3 As shown, the present application also provides a hot pressing device 200 for hot pressing an electrode assembly 600, wherein the electrode assembly 600 includes a tab 610, and the tab 610 is protrudingly arranged along a first direction X. The hot pressing device 200 includes a driving member 1, a lower hot pressing member 2, and an upper hot pressing member 3. The upper hot pressing member 3 is arranged opposite to the lower hot pressing member 2, and at least one of the upper hot pressing member 3 and the lower hot pressing member 2 is connected to the driving member 1, and is configured to approach or move away from each other under the drive of the driving member 1. Among them, at least one of the upper hot-pressed part 3 and the lower hot-pressed part 2 includes a plate body 31 and a compaction structure 32, the compaction structure 32 is located on the side of the plate body 31 facing the electrode assembly 600, the plate body 31 is used to generate heat, and the compaction structure 32 is used to press the electrode assembly 600, the compaction structure 32 is provided with at least one pair of openings 321 arranged back to back along the first direction X, the two pairs of openings 321 extend respectively to the central area of ​​the compaction structure 32 in the first direction X, the plate body 31 covers at least part of the openings 321 and is used to press the electrode assembly 600 through the openings 321.

[0075] The tab 610 of this embodiment is protruding along the first direction X, which means that the tab 610 and the non-tab portion of the electrode assembly 600 are arranged along the first direction X. Specifically, the positive tab and the negative tab may extend from the same side of the electrode assembly 600 or from opposite sides.

[0076] Exemplarily, a resistance wire or a resistance rod is provided in the board body 31 to generate heat.

[0077] The pressing of this embodiment may be direct contact or may not be in direct contact but generate a force. For example, the compacting structure 32 presses the electrode assembly, and the two may be in direct contact or not.

[0078] The compaction structure 32 of the present embodiment is provided with at least one pair of openings 321 arranged back to back along the first direction X, and the two pairs of openings 321 extend respectively to the central area of ​​the compaction structure 32 in the first direction X, wherein the central area of ​​the compaction structure 32 in the first direction X refers to the area where the midline L1 of the dimension of the compaction structure 32 in the first direction X is located, which also corresponds to the area where the midline of the dimension of the electrode assembly 600 excluding the tab 610 in the first direction X is approximately located.

[0079] In this embodiment, the areas of the two openings 321 in a pair may be the same or different; the shapes may be the same or different.

[0080] The pair of openings 321 of this embodiment can be located in the central area of ​​the compaction structure 32 in the second direction Y, or in other areas of the compaction structure 32 in the second direction Y. The second direction Y intersects with the first direction X. Further, the second direction Y is perpendicular to the first direction X.

[0081] In this embodiment, the upper hot pressing member 3 may be provided with a compaction structure 32, the lower hot pressing member 2 may be provided with a compaction structure 32, and both the upper hot pressing member 3 and the lower hot pressing member 2 may be provided with a compaction structure 32. Exemplarily, the pressure applied by the upper hot pressing member 3 and the lower hot pressing member 2 to the electrode assembly 600 ranges from 8 MPa to 10 MPa.

[0082] The plate body 31 of this embodiment covers at least part of the opening 321 and is used to press the electrode assembly 600 through the opening 321, that is, the projection of the plate body 31 on the compaction structure 32 along the arrangement direction from the plate body 31 to the compaction structure 32 covers at least part of the opening 321, and the part of the plate body 31 covering the opening 321 has a pressing effect on the electrode assembly 600.

[0083] Optionally, the plate body 31 covers the entirety of each opening 321 .

[0084] The hot pressing device 200 of this embodiment is provided with a compaction structure 32 on the upper hot pressing part 3 and / or the lower hot pressing part 2. The compaction structure 32 has openings 321 arranged opposite to each other along the first direction X, and the two pairs of openings 321 extend respectively to the central area of ​​the compaction structure 32 in the first direction X. In this way, the two parts of the electrode assembly 600 corresponding to the two openings 321 are not compacted to form two upper and lower exhaust channels. The gas generated in the central area of ​​the electrode assembly 600 in the first direction X is discharged through the two exhaust channels, thereby reducing the influence of bubbles on the negative electrode plate of the battery cell, reducing problems such as purple spots and lithium precipitation, improving the interface of the battery cell, and improving the capacity retention rate of the battery cell.

[0085] Figure 4 Another schematic structural diagram of the upper hot pressing part in the hot pressing device provided in some embodiments of the present application.

[0086] See also Figure 4 In some embodiments, the compaction structure 32 is provided with a plurality of pairs of openings 321 , and the plurality of pairs of openings 321 are arranged at intervals along the second direction Y, and the first direction X and the second direction Y intersect.

[0087] In this embodiment, the number of the multiple pairs of openings 321 can be two pairs, three pairs, four pairs, five pairs, etc.

[0088] Optionally, the first direction X and the second direction Y are perpendicular.

[0089] A plurality of pairs of openings 321 are provided to increase the number of exhaust channels distributed in the second direction Y and improve the uniformity of exhaust of the electrode assembly 600 .

[0090] In some embodiments, at least one pair of openings 321 among all the openings 321 is located in a central area of ​​the compaction structure 32 in the second direction Y, and the first direction X and the second direction Y intersect.

[0091] The central area of ​​the compaction structure 32 in the second direction Y of this embodiment refers to the area where the midline L2 of the dimension of the compaction structure 32 in the second direction Y is located, which roughly corresponds to the area where the midline of the dimension of the electrode assembly 600 in the second direction Y is located.

[0092] Optionally, the first direction X and the second direction Y are perpendicular.

[0093] At least one pair of openings 321 is disposed in the central region of the compaction structure 32 in the second direction Y, so as to improve the exhaust effect of the central region of the electrode assembly 600 that intersects the second direction Y and the first direction X.

[0094] In some embodiments, the compaction structure 32 includes at least two first compaction parts 322 and one second compaction part 323. The two first compaction parts 322 are arranged at intervals along the second direction Y and are connected by a second compaction part 323. The two first compaction parts 322 and the second compaction parts 323 are arranged to form a pair of openings 321, and the first direction X and the second direction Y intersect.

[0095] The second compacting portion 323 of this embodiment is located in the center area of ​​the compacting structure 32 in the first direction X. Optionally, one second compacting portion 323 is located in the center area of ​​the compacting structure 32 in the second direction Y.

[0096] Optionally, the first direction X and the second direction Y are perpendicular.

[0097] The shapes of the two first compacting parts 322 in this embodiment may be the same or different.

[0098] In this embodiment, the size of the first compacting portion 322 in the second direction Y may be greater than, less than, or equal to the size of the second compacting portion 323 in the second direction Y.

[0099] Optionally, the shape of the first compacting portion 322 facing the electrode assembly 600 is a rectangle with rounded corners, and the shape of the second compacting portion 323 facing the electrode assembly 600 is a long strip.

[0100] In this embodiment, a pair of openings 321 are formed by two first compacting parts 322 and one second compacting part 323. In this way, by setting the size of the second compacting part 323 along the first direction X, the central area of ​​the electrode assembly 600 in the first direction X can be well vented under the premise of compaction.

[0101] In other embodiments, the two first compacting parts 322 are connected by two second compacting parts 323 .

[0102] Please continue reading Figure 4 In some embodiments, the number of first compaction parts 322 is greater than two, the number of second compaction parts 323 is at least two, and the multiple first compaction parts 322 and the multiple second compaction parts 323 are respectively arranged in sequence along the second direction Y, and any two adjacent first compaction parts 322 are connected by the second compaction parts 323. The multiple first compaction parts 322 and the multiple second compaction parts 323 are surrounded to form multiple pairs of openings 321 arranged at intervals along the second direction Y.

[0103] In this embodiment, the number of the first compacting parts 322 is one more than the number of the second compacting parts 323. For example, the number of the first compacting parts 322 is three, and the number of the second compacting parts 323 is two; the number of the first compacting parts 322 is four, and the number of the second compacting parts 323 is three.

[0104] In this embodiment, any two adjacent first compacting parts 322 are connected by a second compacting part 323 .

[0105] Optionally, a plurality of first compacting parts 322 are arranged at equal intervals.

[0106] A plurality of first compaction parts 322 and a plurality of second compaction parts 323 are provided to form a plurality of pairs of openings 321, and the plurality of pairs of openings 321 are spaced apart along the second direction Y. In this way, the electrode assembly 600 can form more exhaust channels to increase the number of exhaust channels distributed in the second direction Y and improve the uniformity of exhaust of the electrode assembly 600.

[0107] In some embodiments, the number of first compacting parts 322 is two, the number of second compacting parts 323 is one, the size of the first compacting part 322 along the second direction Y is W1, the size of the second compacting part 323 along the second direction Y is W2, and W1 and W2 satisfy: W1≤W2.

[0108] In this embodiment, two first compacting parts 322 and one second compacting part 323 are arranged to form two openings 321 .

[0109] In this embodiment, the sizes of the two first compacting parts 322 along the second direction Y may be the same or different.

[0110] The size of the second compacting portion 323 is set to be greater than or equal to the size of the first compacting portion 322 to form a wider exhaust channel and improve the exhaust effect of the central area of ​​the electrode assembly 600 .

[0111] In some embodiments, W1, W2, and W3 satisfy: 1 / 4W3≤W1≤W2≤1 / 2W3.

[0112] Optionally, the value of W1 may be 1 / 4W3, 3 / 8W3 or 1 / 2 W3.

[0113] Optionally, the value of W2 may be 1 / 4W3, 3 / 8W3 or 1 / 2 W3.

[0114] The values ​​of W1 and W2 are limited to be greater than or equal to 1 / 4W3 to improve the exhaust effect on the electrode assembly 600; the values ​​of W1 and W2 are limited to be less than or equal to 1 / 2 W3 to make the sizes of the first compaction part 322 and the second compaction part 323 along the second direction Y more balanced, thereby forming a better compaction effect.

[0115] In some embodiments, the two openings 321 constituting a pair are arranged in a mirror image, and / or the two first compacting portions 322 are arranged in a mirror image.

[0116] In this embodiment, mirror image setting means that the shape and size are consistent.

[0117] The two openings 321 arranged in pairs are arranged in mirror image to improve the uniformity of exhausting the upper and lower parts of the electrode assembly 600. The two first compacting parts 322 are arranged in mirror image to improve the uniformity of compaction degree of the left and right areas of the electrode assembly 600.

[0118] In some embodiments, the size of the opening 321 along the first direction X is h1, the size of the compacted structure 32 along the first direction X is h2, and h1 and h2 satisfy: 35%≤h1 / h2≤45%.

[0119] Optionally, the value of h1 / h2 may be 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44% or 45%.

[0120] The value of h1 / h2 is limited to greater than or equal to 35% to form an exhaust channel with a larger size in the first direction X, thereby improving the exhaust effect of the central area of ​​the electrode assembly 600; the value of h1 / h2 is limited to less than or equal to 45% to improve the compaction effect of the central area of ​​the electrode assembly 600 in the first direction X.

[0121] In some embodiments, h1 and h2 satisfy: 38%≤h1 / h2≤42%.

[0122] The value of h1 / h2 is further limited to greater than or equal to 38% to form an exhaust channel with a larger size in the first direction X, thereby further improving the exhaust effect on the central area of ​​the electrode assembly 600; the value of h1 / h2 is further limited to less than or equal to 42% to further improve the compaction effect on the central area of ​​the electrode assembly 600 in the first direction X.

[0123] In some embodiments, the plate body 31 and the compacting structure 32 are integrally formed.

[0124] The plate body 31 and the compacting structure 32 of the present embodiment can be integrally formed by injection molding, die casting or pouring, or integrally formed by 3D printing.

[0125] The plate body 31 and the compacting structure 32 are integrally formed, so that the relative positional relationship between the plate body 31 and the compacting structure 32 is more accurate, and the connection is more firm and will hardly fall off.

[0126] In some embodiments, the compaction structure 32 is adhered to the plate body 31 .

[0127] The compacting structure 32 of this embodiment may be a business card paper structure, and the business card paper structure is pasted on the plate body 31 .

[0128] The compaction structure 32 is pasted to the plate body 31 . In this way, the compaction structure 32 of a required size can be pasted according to actual needs. For example, the overall size of the compaction structure 32 or the size of the opening 321 can be adjusted, thereby improving the applicability of the hot pressing device 200 .

[0129] In some embodiments, a projection of the compacting structure 32 on the plate body 31 along the third direction Z is located inside the plate body 31 , and the third direction Z is parallel to an arrangement direction from the plate body 31 to the compacting structure 32 .

[0130] In this embodiment, the projection of the compaction structure 32 along the third direction Z on the plate body 31 is located inside the plate body 31, that is, the projection of the plate body 31 along the third direction Z on the compaction structure 32 covers the compaction structure 32, and the area of ​​the plate body 31 facing the electrode assembly 600 is larger than the area of ​​the compaction structure 32 facing the electrode assembly 600.

[0131] Optionally, the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0132] The projection of the compaction structure 32 on the plate body 31 along the third direction Z is located inside the plate body 31 , so that the heat generated by the plate body 31 can be distributed throughout the compaction structure 32 , while also facilitating the arrangement of the compaction structure 32 .

[0133] Optionally, the plate body 31 is arranged in a circle protruding from the compacting structure 32 in its own extension direction. That is, the plate body 31 is arranged in a circle around the projection of the compacting structure 32 along the third direction Z on the plate body 31 .

[0134] Optionally, the electrode assembly 600 is a wound electrode assembly, and the compaction structure 32 is used to avoid a bending area of ​​the wound electrode assembly.

[0135] The bending area of ​​the wound electrode assembly of the present embodiment refers to the area where the pole piece in the wound electrode assembly is bent due to winding, which is located at the two edges of the wound electrode assembly.

[0136] With such arrangement, the compaction structure 32 does not press down on the bending area of ​​the wound electrode assembly, thereby reducing the possibility of fracture of the electrode sheet.

[0137] In some embodiments, the upper hot press member 3 is connected to the driving member 1 and is configured to move closer to or farther away from the lower hot press member 2 under the driving of the driving member 1 , and only the upper hot press member 3 is provided with a compacting structure 32 .

[0138] Figure 5 A partial structural schematic diagram of a hot pressing device provided in some embodiments of the present application.

[0139] See also Figure 5 In some embodiments, the hot pressing device 200 further includes a pressure sensor 4, a first temperature sensor 5 and a second temperature sensor. The upper hot pressing part 3 is provided with a pressure sensor 4 and a first temperature sensor 5, and the lower hot pressing part 2 is provided with a second temperature sensor. The pressure sensor 4 is used to measure the pressure between the upper hot pressing part 3 and the electrode assembly 600, the first temperature sensor 5 is used to measure the temperature of the upper hot pressing part 3, and the second temperature sensor is used to measure the temperature of the lower hot pressing part 2.

[0140] Exemplarily, the pressure sensor 4 and the first temperature sensor 5 are both disposed inside the upper hot pressing member 3 .

[0141] Exemplarily, the second temperature sensor is disposed inside the lower hot pressing member 2 .

[0142] The pressure sensor 4, the first temperature sensor 5 and the second temperature sensor are provided to monitor the pressure and temperature parameters during the hot pressing process, thereby realizing accurate monitoring of the pressure and temperature during the hot pressing process.

[0143] Optionally, the hot pressing device 200 further includes a controller 6, and the driving member 1, the pressure sensor 4, the first temperature sensor 5 and the second temperature sensor are respectively connected to the controller 6, and the controller 6 controls the pressure of the hot pressing process and monitors the temperature.

[0144] Optionally, the controller 6 is also connected to a heating mechanism in the plate body to control the temperature of the hot pressing process. Exemplarily, the heating structure is the above-mentioned resistance wire or resistance rod.

[0145] In a second aspect, an embodiment of the present application further provides a battery production system 100, including a molding device 300 and the above-mentioned hot pressing device 200, wherein the molding device 300 is used to wind or stack positive electrode sheets, negative electrode sheets and isolation films to form an electrode assembly 600.

[0146] Figure 6 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application.

[0147] See also Figure 6 In the third aspect, the embodiment of the present application further provides a battery cell 700, the battery cell 700 includes a shell 710 and an electrode assembly 600, the electrode assembly 600 is located in the shell 710, the electrode assembly 600 is configured to be hot pressed by the above-mentioned hot pressing device, and the surface of the electrode assembly 600 is provided with a dent 620 corresponding to at least a portion of the compaction structure 32, and the dent 620 is surrounded to form an area corresponding to the paired openings 321.

[0148] The housing 710 of this embodiment may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing 710 ), or the like.

[0149] The electrode assembly 600 of the present embodiment may be a winding structure, a stacked structure, or a mixed structure of winding and stacked structures.

[0150] Optionally, the electrode assembly 600 is a wound electrode assembly 600, and the indentation 620 does not interfere with the edge bending area of ​​the wound electrode assembly 600. In this way, the impact of the compaction structure on the electrode sheet in the bending area is reduced.

[0151] The indentation 620 on the surface of the electrode assembly 600 of the embodiment of the present application may correspond to the entire compaction structure 32 , or may correspond to only a portion of the compaction structure 32 .

[0152] Figure 7 A schematic diagram of the structure of a battery device provided in some embodiments of the present application.

[0153] See also Figure 7 The embodiment of the present application further provides a battery device 800 , including the above-mentioned battery cell 700 .

[0154] The battery device 800 mentioned in the embodiment of the present application may include one or more battery cell assemblies 810 for providing voltage and capacity. The battery cell assembly 810 includes a plurality of battery cells 700, and the plurality of battery cells 700 are connected in series, in parallel or in mixed connection through a busbar.

[0155] In some embodiments, the battery cell assembly 810 is generally formed by arranging a plurality of battery cells 700; as an example, the battery cell assembly 810 may be a battery module, which is formed by arranging and fixing a plurality of battery cells 700 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 700 by a cable tie.

[0156] In some embodiments, the battery device 800 may be a battery pack, which includes a case 820 and one or more battery cell assemblies 810 , wherein the battery cell assemblies 810 are accommodated in the case 820 .

[0157] As an example, the battery cell assembly 810 may be a battery module, and the battery cell assembly 810 may be accommodated in the box body 820 by fixing the battery module in the box body 820 .

[0158] As an example, the battery cell assembly 810 may also be accommodated in the box body 820 by directly fixing the plurality of battery cells 700 to the box body 820 .

[0159] As an example, the box 820 may include a first box and a second box. The first box and the second box are buckled together to form a closed space inside the box to accommodate the battery cell assembly 810. The closed here means covered or closed, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0160] As an example, the box body 820 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body 820 to accommodate the battery cell assembly 810.

[0161] As an example, the box 820 can be a part of the chassis structure of the vehicle 900. For example, the roof of the box 820 can become at least a part of the floor of the vehicle 900, or the frame of the box 820 can become at least a part of the cross beam and longitudinal beam of the vehicle 900.

[0162] In some embodiments, the battery device 800 refers to an energy storage device, which includes a box 820, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0163] Figure 8 A schematic diagram of the structure of a vehicle 900 provided for some embodiments of the present application.

[0164] See also Figure 8 The embodiment of the present application also provides an electrical device, including the above-mentioned battery device 800, and the battery device 800 is used to provide electrical energy.

[0165] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery cells 700 and battery devices 800, such as mobile phones, portable devices, laptop computers, battery cars, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc. For the convenience of description, the following embodiments are described by taking the electrical device as a vehicle as an example.

[0166] The vehicle 900 is provided with a battery device 800 inside, and the battery device 800 may be provided at the bottom, head, or tail of the vehicle 900. The battery device 800 may be used for powering the vehicle 900, for example, the battery device 800 may be used as an operating power source of the vehicle 900.

[0167] The vehicle 900 may further include a controller 910 and a motor 920 , wherein the controller 910 is used to control the battery device 800 to supply power to the motor 920 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 900 .

[0168] In some embodiments of the present application, the battery device 800 can not only serve as an operating power source for the vehicle 900, but also serve as a driving power source for the vehicle 900, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 900.

[0169] See also Figure 2-Figure 4The embodiment of the present application provides a hot pressing device 200 for hot pressing an electrode assembly 600, wherein the electrode assembly 600 includes a tab 610, and the tab 610 is protrudingly arranged along a first direction X. The hot pressing device 200 includes a driving member 1, a lower hot pressing member 2, and an upper hot pressing member 3. The upper hot pressing member 3 is arranged opposite to the lower hot pressing member 2, the upper hot pressing member 3 is connected to the driving member 1, and is configured to move closer to or away from the lower hot pressing member 2 under the drive of the driving member 1. Among them, at least one of the upper hot pressing part 3 and the lower hot pressing part 2 includes a plate body 31 and a compacting structure 32, the compacting structure 32 is located on the side of the plate body 31 facing the electrode assembly 600, the plate body 31 is used to generate heat, the compacting structure 32 is used to press the electrode assembly 600, the compacting structure 32 is provided with at least one pair of openings 321 arranged opposite to each other along the first direction X, the two paired openings 321 extend respectively to the central area of ​​the compacting structure 32 in the first direction X, the plate body 31 covers the openings 321 and is used to press the electrode assembly 600 through the openings 321. At least one pair of openings 321 among all the openings 321 is located in the central area of ​​the compacting structure 32 in the second direction Y, and the first direction X and the second direction Y intersect. The compaction structure 32 includes at least two first compaction parts 322 and one second compaction part 323. The two first compaction parts 322 are arranged at intervals along the second direction Y and connected by a second compaction part 323. The two first compaction parts 322 and the second compaction parts 323 are arranged to form a pair of openings 321. The projection of the compaction structure 32 on the plate body 31 along the third direction Z is located inside the plate body 31. The third direction Z is parallel to the arrangement direction from the plate body 31 to the compaction structure 32.

[0170] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0171] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hot pressing device for hot pressing an electrode assembly, wherein the electrode assembly comprises a tab, wherein the tab is protruding along a first direction, wherein: include: Driving parts; Lower hot pressing part; An upper hot pressing member is arranged opposite to the lower hot pressing member, at least one of the upper hot pressing member and the lower hot pressing member is connected to the driving member and is configured to move closer to or away from the other member under the driving of the driving member; Among them, at least one of the upper hot-pressing part and the lower hot-pressing part includes a plate body and a compaction structure, the compaction structure is located on the side of the plate body facing the electrode assembly, the plate body is used to generate heat, and the compaction structure is used to press the electrode assembly, the compaction structure is provided with at least one pair of openings arranged opposite to each other along the first direction, the two paired openings respectively extend toward the center area of ​​the compaction structure in the first direction, the plate body covers at least part of the openings and is used to press the electrode assembly through the openings.

2. The hot pressing device according to claim 1, characterized in that: The compacting structure is provided with a plurality of pairs of the openings, and the plurality of pairs of the openings are arranged at intervals along a second direction, and the first direction and the second direction intersect.

3. The hot pressing device according to claim 1, characterized in that: At least one pair of the openings among all the openings is located in a central area of ​​the compacted structure in a second direction, and the first direction and the second direction intersect.

4. The hot pressing device according to claim 1, characterized in that: The compaction structure includes at least two first compaction parts and one second compaction part, the two first compaction parts are arranged at intervals along the second direction and connected by one second compaction part, the two first compaction parts and the second compaction part are arranged to form a pair of openings, and the first direction and the second direction intersect.

5. The hot pressing device according to claim 4, characterized in that: The number of the first compaction parts is greater than two, the number of the second compaction parts is at least two, a plurality of the first compaction parts and a plurality of the second compaction parts are respectively arranged in sequence along the second direction, any two adjacent first compaction parts are connected by the second compaction parts, and a plurality of the first compaction parts and a plurality of the second compaction parts are arranged to form a plurality of pairs of the openings arranged in sequence along the second direction.

6. The hot pressing device according to claim 4, characterized in that: The number of the first compacting parts is two, the number of the second compacting parts is one, a size of the first compacting part along the second direction is W1, a size of the second compacting part along the second direction is W2, and W1 and W2 satisfy: W1≤W2.

7. The hot pressing device according to claim 6, characterized in that: The W1, the W2 and the W3 satisfy: 1 / 4W3≤W1≤W2≤1 / 2W3.

8. The hot pressing device according to claim 4, characterized in that: The two openings constituting a pair are arranged in mirror images, and / or the two first compacting parts are arranged in mirror images.

9. The hot pressing device according to claim 1, characterized in that: The size of the opening along the first direction is h1, the size of the compacted structure along the first direction is h2, and h1 and h2 satisfy: 35%≤h1 / h2≤45%.

10. The hot pressing device according to claim 9, characterized in that: The h1 and the h2 satisfy: 38%≤h1 / h2≤42%.

11. The hot pressing device according to claim 1, characterized in that: The plate body and the compacting structure are integrally formed.

12. The hot pressing device according to claim 1, characterized in that: The compacting structure is adhered to the plate body.

13. The hot pressing device according to claim 1, characterized in that: The projection of the compacting structure on the plate body along a third direction is located inside the plate body, and the third direction is parallel to an arrangement direction from the plate body to the compacting structure.

14. The hot pressing device according to claim 1, characterized in that: The hot pressing device also includes a pressure sensor, a first temperature sensor and a second temperature sensor. The upper hot pressing member is provided with the pressure sensor and the first temperature sensor, and the lower hot pressing member is provided with the second temperature sensor. The pressure sensor is used to measure the pressure between the upper hot pressing member and the electrode assembly, the first temperature sensor is used to measure the temperature of the upper hot pressing member, and the second temperature sensor is used to measure the temperature of the lower hot pressing member.

15. A battery production system, characterized in that: include: A forming device, the forming device is used to wind or stack the positive electrode sheet, the negative electrode sheet and the separator to form an electrode assembly; A hot pressing device as claimed in any one of claims 1 to 14.

16. A battery cell, characterized in that: include: shell; An electrode assembly is located in the shell, and the electrode assembly is configured to be hot pressed by a hot pressing device as described in any one of claims 1 to 14, and the surface of the electrode assembly is provided with indentations corresponding to at least part of the compacted structure, and the indentations are arranged to form areas corresponding to the paired openings.

17. A battery device, characterized in that: Comprising the battery cell as claimed in claim 16.

18. An electrical device, characterized in that: Comprising the battery device as claimed in claim 17, the battery device is used to provide electrical energy.

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