Clamp, battery production equipment, electrode assembly, shaping method of electrode assembly and battery

Abstract

The invention provides a clamp, battery production equipment, an electrode assembly, a shaping method of the electrode assembly and a battery, and belongs to the field of batteries. The clamp comprises a first clamping plate, a second clamping plate and a packaging film, and the second clamping plate and the first clamping plate are stacked. A placing groove is formed in the plate surface of one side, facing the second clamping plate, of the first clamping plate, a mounting groove is formed in the plate surface of one side, facing the first clamping plate, of the second clamping plate, the placing groove is configured to be used for placing an electrode assembly, and at least part of the first clamping plate is located in the mounting groove. The packaging film wraps the first clamping plate and the second clamping plate. In the isostatic pressing process, the first clamping plate is limited by the mounting groove, mutual movement between the first clamping plate and the second clamping plate is reduced, the electrode assembly is limited by the placing groove, mutual movement between the electrode assembly and the first clamping plate is reduced, the stability of the clamp and the electrode assembly in the isostatic pressing process is improved, and the clamping efficiency is improved. Therefore, the densification effect of the electrode assembly is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a clamp, a battery production device, an electrode assembly, a shaping method thereof and a battery. BACKGROUND

[0002] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy saving and environmental protection advantages. For electric vehicles, battery technology is an important factor for their development.

[0003] A solid-state battery is a battery that uses solid electrodes and solid electrolytes. The isostatic pressing technology of the solid-state battery is one of the key technologies for preparing the solid-state battery. The isostatic pressing technology refers to improving the performance and stability of the solid-state battery by applying static pressure. Usually, the electrode assembly is compacted under high pressure with uniform force to achieve densification treatment of the electrode assembly. However, during the isostatic pressing process, the electrode assembly may move, affecting the densification effect of the electrode assembly and the performance of the solid-state battery. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the background art. To this end, one object of the present application is to provide a clamp, a battery production device, an electrode assembly, a shaping method thereof and a battery to improve the problem of movement of the electrode assembly during isostatic pressing.

[0005] Embodiments of the first aspect of the present application provide a clamp for clamping an electrode assembly, the clamp comprising: a first clamping plate; a second clamping plate stacked with the first clamping plate; wherein a side surface of the first clamping plate facing the second clamping plate has a placement groove, a side surface of the second clamping plate facing the first clamping plate has a mounting groove, the placement groove is configured to place the electrode assembly, and at least part of the first clamping plate is located in the mounting groove; an encapsulation film covering the first clamping plate and the second clamping plate.

[0006] In the technical solution of the embodiments of the present application, the electrode assembly is first placed in the placement groove, then the electrode assembly and the first clamping plate as a whole are placed in the mounting groove, and then the first clamping plate and the second clamping plate encapsulated by the encapsulation film are placed in the isostatic pressing cavity for isostatic pressing. During isostatic pressing, the mounting groove limits the first clamping plate, reducing the mutual movement between the first clamping plate and the second clamping plate, and the placement groove limits the electrode assembly, reducing the mutual movement between the electrode assembly and the first clamping plate, thereby improving the stability of the clamp and the electrode assembly during isostatic pressing, and thus improving the densification effect of the electrode assembly.

[0007] In some embodiments, the depth D1 of the mounting groove is less than or equal to the thickness D2 of the first clamping plate. The first clamping plate is not completely located within the mounting groove, which facilitates the transfer medium to push the first clamping plate and the second clamping plate closer together, thereby applying pressure to the electrode assembly.

[0008] In some embodiments, the depth D1 of the mounting groove and the thickness D2 of the first clamping plate satisfy: 0.5 × D2 ≤ D1 ≤ D2. The mounting groove is used to limit the first clamping plate. By setting it within the above range, a sufficient portion of the first clamping plate is located within the mounting groove, thereby improving the limiting effect of the mounting groove on the first clamping plate. At the same time, the first clamping plate is not completely located within the mounting groove, which facilitates the transmission medium to push the first clamping plate and the second clamping plate closer together, thereby applying pressure to the electrode assembly.

[0009] In some embodiments, the fixture further includes a pre-compression component configured to pre-compress the laminated assembly to obtain an electrode assembly. Pre-compressing the laminated assembly with the pre-compression component to obtain the electrode assembly is essentially pre-processing the laminated assembly to obtain the electrode assembly, ensuring that the morphology of the electrode assembly meets expectations and that the state of the electrode assembly is more stable. This results in better stability of the electrode assembly when subsequently clamped by the first and second clamping plates.

[0010] In some embodiments, the pre-compression assembly includes at least two stacked pre-compression plates, with the stacked assembly located between any two adjacent pre-compression plates. Setting the pre-compression assembly in the form of pre-compression plates simplifies its structure and makes its fabrication easier.

[0011] In some embodiments, the encapsulation film includes a perforated area and an encapsulation area, with a first clamping plate and a second clamping plate located in the perforated area, and the encapsulation area surrounding the perforated area. The perforated area and encapsulation area on the encapsulation film facilitate the encapsulation film wrapping around the first and second clamping plates. The encapsulation area surrounding the perforated area allows the first and second clamping plates to be sealed within the encapsulation area, preventing external impurities from contaminating the first and second clamping plates and the electrode assembly during isostatic pressing.

[0012] In some embodiments, the encapsulation film includes at least one of aluminum-plastic film, polyethylene film, and polypropylene film. Aluminum-plastic film, polyethylene film, and polypropylene film are common encapsulation films that are easy to purchase, inexpensive, and provide good encapsulation results.

[0013] In some embodiments, the thickness of the encapsulation film is greater than or equal to 50 μm and less than or equal to 500 μm. Setting the thickness of the encapsulation film within this range ensures that it is not too thin, allowing it to withstand high pressure without rupture when the first clamping plate, the second clamping plate, and the electrode assembly are under isostatic pressure. Conversely, within this range, the thickness of the encapsulation film is also not too thick, allowing it to easily shrink under pressure when the first clamping plate, the second clamping plate, and the electrode assembly are under isostatic pressure, thereby compacting the electrode assembly and achieving better densification performance.

[0014] An embodiment of the second aspect of this application provides a battery production apparatus, which includes the fixture of any of the above embodiments.

[0015] An embodiment of the third aspect of this application provides a method for shaping an electrode assembly. The method includes: acquiring an electrode assembly; clamping the electrode assembly using a first clamping plate and a second clamping plate; encapsulating the first clamping plate and the second clamping plate holding the electrode assembly using an encapsulation film; and performing isostatic pressing on the electrode assembly encapsulated in the first clamping plate and the second clamping plate to achieve shaping of the electrode assembly. During the isostatic pressing process, the mounting groove limits the first clamping plate, reducing the mutual movement between the first clamping plate and the second clamping plate. The placement of the groove limits the electrode assembly, reducing the mutual movement between the electrode assembly and the first clamping plate, improving the stability of the clamp and the electrode assembly during the isostatic pressing process, thereby improving the densification effect of the electrode assembly.

[0016] In some embodiments, obtaining the electrode assembly includes: pre-compressing the laminated assembly using a pre-compressing component to obtain the electrode assembly. Pre-processing the laminated assembly to obtain the electrode assembly ensures that the morphology of the electrode assembly meets expectations and that the state of the electrode assembly is more stable, resulting in better stability of the electrode assembly when subsequently clamped by the first clamping plate and the second clamping plate.

[0017] In some embodiments, isostatic pressing is applied to the electrode assembly encapsulated in the first and second clamping plates to achieve electrode assembly shaping. This includes: placing the encapsulated first and second clamping plates in an isostatic pressing chamber; pressurizing and heating the transfer medium within the isostatic pressing chamber to achieve preset temperature and pressure conditions; and removing the first and second clamping plates after they have been placed in the isostatic pressing chamber under preset conditions for a preset time. By placing both the electrode assembly and the clamping fixture in the isostatic pressing chamber, and pressurizing and heating the electrode assembly through the transfer medium, densification of the electrode assembly is achieved.

[0018] In some embodiments, the preset conditions include: the temperature of the isostatic pressing chamber is greater than 0°C and less than or equal to 300°C; the pressure of the isostatic pressing chamber is greater than or equal to 100 MPa and less than or equal to 2000 MPa; and the preset time is greater than or equal to 10 min and less than or equal to 50 min. Under these conditions, the electrode assembly can be shaped to achieve excellent densification performance while avoiding deformation of the encapsulation film under prolonged isostatic pressing, thus resulting in a better shaping effect for the electrode assembly.

[0019] An embodiment of the fourth aspect of this application provides an electrode assembly, which is held by a clamp according to any of the above embodiments. The electrode assembly includes multiple electrodes and a solid electrolyte, wherein the multiple electrodes are stacked along a first direction, and the solid electrolyte is located between any two adjacent electrodes. Setting the electrode assembly of the solid-state battery in a stacked form facilitates subsequent isostatic pressing of the electrode assembly by clamping it with a clamp, thereby giving the electrode assembly excellent densification performance.

[0020] In some embodiments, the plurality of electrodes includes a plurality of first electrodes and two second electrodes. Each first electrode includes a current collector and active material coated on opposite surfaces of the current collector. Each second electrode includes a current collector and active material coated on one side of the current collector. The solid electrolyte and the plurality of first electrodes are located between the two second electrodes, and the active material of the second electrodes is located between the current collector and the solid electrolyte. By providing current collectors on both opposite sides of the electrode assembly, the current collectors are less likely to adhere to the pre-pressing assembly and the first or second clamping plate during subsequent pre-pressing or densification treatment of the electrode assembly.

[0021] An embodiment of the fifth aspect of this application provides a battery that includes the electrode assembly described in the above embodiments.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0023] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0024] Figure 1 This is an exploded structural diagram of a solid-state battery provided in some embodiments of this application;

[0025] Figure 2 This is an exploded view of the fixture in the embodiments of this application;

[0026] Figure 3 This is an exploded view of the first clamping plate and the second clamping plate in the embodiments of this application;

[0027] Figure 4 This is an exploded view of the first and second clamping plates from another perspective in an embodiment of this application.

[0028] Figure 5 This is an exploded view of the pre-compression component in an embodiment of this application;

[0029] Figure 6 This is a schematic flowchart of a battery assembly shaping method according to some embodiments of this application;

[0030] Figure 7 This is a cross-sectional view of an electrode assembly provided in an embodiment of this application.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100. Solid-state battery; 101. Housing; 1011. First part; 1012. Second part; 102. Battery cell; 11. First clamping plate; 111. Placement groove; 12. Second clamping plate; 121. Mounting groove; 20. Encapsulation film; 21. Punching area; 22. Encapsulation area; 30. Pre-pressing assembly; 31. Pre-pressing plate; 40. Electrode assembly; 41. Electrode; 411. First electrode; 412. Second electrode; 413. Current collector; 414. Active material; 415. Positive electrode; 416. Negative electrode; 42. Solid electrolyte; 50. Stacked assembly. Detailed Implementation

[0033] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0035] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0038] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0039] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0040] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0041] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0042] Solid-state batteries typically use solid electrolytes composed of various solid particles, and the contact performance between these particles has a significant impact on the battery's performance. For example, weak contact between solid particles can lead to low transport kinetics of charged ions between them, thus affecting the battery's performance.

[0043] In related technologies, isostatic pressing is applied to solid-state batteries to improve their densification performance. For example, after fabricating the electrode assembly of the solid-state battery, the electrode assembly can be subjected to isostatic pressing, placing it in an isostatic pressing environment to apply pressure and achieve densification. In these technologies, the electrode assembly is placed between two clamping plates, which are brought close together in the isostatic pressing environment to apply pressure. However, during the isostatic pressing process, the clamping plates may move, causing the electrode assembly to shift and affecting the densification effect.

[0044] Based on the above considerations, to improve the problem of electrode assembly movement during isostatic pressing, this application provides a clamp for holding the electrode assembly. The clamp includes a first clamping plate, a second clamping plate, and an encapsulating film, with the second clamping plate stacked on top of the first clamping plate. The side of the first clamping plate facing the second clamping plate has a placement groove, and the side of the second clamping plate facing the first clamping plate has a mounting groove. The placement groove is configured to place the electrode assembly, and at least a portion of the first clamping plate is located in the mounting groove. The encapsulating film covers the first and second clamping plates. During isostatic pressing, the mounting groove limits the first clamping plate, reducing mutual movement between the first and second clamping plates, and the placement groove limits the electrode assembly, reducing mutual movement between the electrode assembly and the first clamping plate. This improves the stability of the clamp and the electrode assembly during isostatic pressing, thereby enhancing the densification effect on the electrode assembly.

[0045] The batteries and electrode assemblies disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using battery cells and batteries disclosed in this application.

[0046] Please refer to Figure 1 , Figure 1This is an exploded structural diagram of a solid-state battery provided in some embodiments of this application. The solid-state battery 100 includes a housing 101 and a battery cell 102, with the battery cell 102 housed within the housing 101. The housing 101 provides a space for housing the battery cell 102, and the housing 101 can adopt various structures. In some embodiments, the housing 101 may include a first portion 1011 and a second portion 1012, which overlap each other, and together define a space for housing the battery cell 102.

[0047] In the solid-state battery 100, there can be multiple battery cells 102. These multiple battery cells 102 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 102 are connected in both series and parallel. Multiple battery cells 102 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 102 is housed within a housing 101. Alternatively, the solid-state battery 100 can also be composed of multiple battery cells 102 first connected in series, parallel, or in a mixed configuration to form a battery module, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is also housed within the housing 101. The solid-state battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 102.

[0048] A battery cell is the smallest unit that makes up a battery. A battery cell includes an end cap, casing, electrode assembly, and other functional components. The electrode assembly is the part of the battery cell where electrochemical reactions occur. A battery cell may contain one or more electrode assemblies.

[0049] This application provides a clamp for holding an electrode assembly. Figure 2 This is an exploded view of the clamp in an embodiment of this application. See also... Figure 2 The fixture includes a first clamping plate 11, a second clamping plate 12 and an encapsulation film 20, with the second clamping plate 12 stacked on top of the first clamping plate 11. Figure 3 This is an exploded view of the first clamping plate and the second clamping plate in the embodiments of this application. Figure 4 This is an exploded view of the first and second clamping plates from another perspective in an embodiment of this application. See also... Figure 3 and Figure 4 The first clamping plate 11 has a placement groove 111 on the side facing the second clamping plate 12, and the second clamping plate 12 has a mounting groove 121 on the side facing the first clamping plate 11. The placement groove 111 is configured to place the electrode assembly 40, and at least a portion of the first clamping plate 11 is located in the mounting groove 121. An encapsulation film 20 covers the first clamping plate 11 and the second clamping plate 12.

[0050] In the embodiments of this application, the electrode assembly 40 is clamped in the first clamping plate 11 and the second clamping plate 12. The first clamping plate 11 and the second clamping plate 12 are close to each other and can apply pressure to the electrode assembly 40.

[0051] In the embodiments of this application, the encapsulation film 20 covers the first clamping plate 11 and the second clamping plate 12. During the isostatic pressing process, the encapsulation film 20 can isolate the first clamping plate 11 and the second clamping plate 12 from the external environment, reducing the possibility of external impurities entering between the first clamping plate 11 and the second clamping plate 12 and affecting the electrode assembly 40.

[0052] In some embodiments of this application, the first clamping plate 11 and the second clamping plate 12 are corresponding, that is, one first clamping plate 11 corresponds to one second clamping plate 12, and the electrode assembly 40 is clamped between the first clamping plate 11 and the second clamping plate 12. Figure 2 In the fixture, there is a first clamping plate 11 and a second clamping plate 12. In other implementations, the fixture may include multiple first clamping plates 11 and multiple second clamping plates 12 corresponding to the multiple first clamping plates 11. Each set of corresponding first clamping plates 11 and second clamping plates 12 can be used to clamp the electrode assembly 40.

[0053] In embodiments of this application, the shape of the placement groove 111 matches the shape of the electrode assembly 40. The shape of the mounting groove 121 matches the shape of the first clamping plate 11.

[0054] In the embodiments of this application, the electrode assembly 40 is first placed in the placement groove 111, and then the electrode assembly 40 and the first clamping plate 11 are placed together in the mounting groove 121. Next, the first clamping plate 11 and the second clamping plate 12 are covered with an encapsulation film 20, and then the first clamping plate 11 and the second clamping plate 12 covered with the encapsulation film 20 are placed in an isostatic pressing chamber for isostatic pressing. During the isostatic pressing process, the mounting groove 121 limits the first clamping plate 11, reducing the mutual movement between the first clamping plate 11 and the second clamping plate 12. The placement groove 111 limits the electrode assembly 40, reducing the mutual movement between the electrode assembly 40 and the first clamping plate 11, thus improving the stability of the clamp and the electrode assembly 40 during the isostatic pressing process, thereby improving the densification effect of the electrode assembly 40.

[0055] In some related technologies, the encapsulation film is directly wrapped around the electrode assembly. However, due to the difference in material between the encapsulation film and the electrode assembly, the encapsulation film can deform during isostatic pressing, resulting in problems such as wavy edges. This causes the entire encapsulation film to deform, which in turn causes the electrode assembly to deform, leading to tearing between the electrode tabs and the main body, affecting the performance of the electrode assembly. In the embodiments of this application, the encapsulation film 20 covers the first clamping plate 11 and the second clamping plate 12. The encapsulation film 20 does not directly contact the electrode assembly 40. Even if the encapsulation film 20 deforms, the deformation of the encapsulation film 20 will not affect the electrode assembly 40 and will not cause deformation of the electrode assembly 40.

[0056] In the embodiments of this application, during the isostatic pressing process, the transmission medium applies pressure to the first clamping plate 11 and the second clamping plate 12, and the first clamping plate 11 and the second clamping plate 12 transmit the pressure to the electrode assembly 40 to achieve pressurization of the electrode assembly 40.

[0057] In related technologies, the encapsulation film 20 covers the electrode assembly 40. To prevent the corners of the electrode assembly 40 from puncturing the encapsulation film 20 during isostatic pressing, chamfers are provided at the corners of the electrode assembly 40, which reduces the energy density of the electrode assembly 40. The fixture provided in this application embodiment, with the encapsulation film 20 covering the first clamping plate 11 and the second clamping plate 12, can have chamfers provided on the first clamping plate 11 and the second clamping plate 12, eliminating the need for chamfers on the electrode assembly 40, thus improving the energy density of the electrode assembly 40.

[0058] According to some embodiments of this application, the depth D1 of the mounting groove 121 is less than or equal to the thickness D2 of the first clamping plate 11.

[0059] In some embodiments of this application, the placement groove 111 is used to place the electrode assembly 40, and the depth of the placement groove 111 is less than the thickness of the electrode assembly 40.

[0060] In the embodiments of this application, the depth D1 of the mounting groove 121 is less than or equal to the thickness D2 of the first clamping plate 11, and the first clamping plate 11 is not completely located in the mounting groove 121, which facilitates the transmission medium to push the first clamping plate 11 and the second clamping plate 12 to meet and approach each other, thereby applying pressure to the electrode assembly 40.

[0061] According to some embodiments of this application, the depth D1 of the mounting groove 121 and the thickness D2 of the first clamping plate 11 satisfy: 0.5×D2≤D1≤D2.

[0062] For example, D1 = 0.75 × D2.

[0063] In some embodiments of this application, the depth of the placement groove 111 is greater than or equal to 0.5 times the thickness of the electrode assembly 40, and the depth of the placement groove 111 is less than the thickness of the electrode assembly 40.

[0064] For example, the thickness of the electrode assembly 40 is between 10mm and 15mm, and the depth of the placement groove 111 is greater than or equal to 5mm and less than 10mm.

[0065] For example, the thickness D2 of the first clamping plate 11 is greater than or equal to 10 mm and less than 50 mm; the depth D1 of the mounting groove 121 is greater than or equal to 5 mm and less than 20 mm.

[0066] In the embodiments of this application, the mounting groove 121 is used to limit the first clamping plate 11. The depth D1 of the mounting groove 121 and the thickness D2 of the first clamping plate 11 are set to 0.5×D2≤D1≤D2, so that a sufficient portion of the first clamping plate 11 is located in the mounting groove 121, thereby improving the limiting effect of the mounting groove 121 on the first clamping plate 11. At the same time, the first clamping plate 11 is not completely located in the mounting groove 121, which facilitates the transmission medium to push the first clamping plate 11 and the second clamping plate 12 closer together, thereby applying pressure to the electrode assembly 40.

[0067] According to some embodiments of this application, the fixture also includes a preload assembly. Figure 5 This is an exploded view of the pre-compression assembly in an embodiment of this application. The pre-compression assembly 30 is configured to pre-compress the stacked assembly 50 to obtain the electrode assembly 40.

[0068] The battery electrodes and the solid electrolyte sandwiched between the battery electrodes are wound or stacked to form a stacked assembly 50.

[0069] In the embodiments of this application, the pre-compression component 30 is used to pre-compress the stacked component 50 to obtain the electrode component 40, that is, the stacked component 50 is pre-processed to obtain the electrode component 40, so that the morphology of the electrode component 40 meets the expectations and the state of the electrode component 40 is more stable. When the electrode component 40 is subsequently clamped by the first clamping plate 11 and the second clamping plate 12, the stability of the electrode component 40 is better.

[0070] For example, after the battery electrode and solid electrolyte are wound or stacked to form a stacked assembly 50, the stacked assembly 50 is first pre-pressed by the pre-pressing assembly 30 to obtain the electrode assembly 40. Then, the electrode assembly 40 is clamped by the first clamping plate 11 and the second clamping plate 12. Then, the first clamping plate 11 and the second clamping plate 12 are covered by the encapsulation film 20. Then, the first clamping plate 11 and the second clamping plate 12 covered by the encapsulation film 20 are placed in the isostatic pressing chamber for isostatic pressing.

[0071] According to some embodiments of this application, see Figure 5 The pre-compression assembly 30 includes at least two stacked pre-compression plates 31, and the stacked assembly 50 is located between any two adjacent pre-compression plates 31.

[0072] In some embodiments of this application, see Figure 5 The pre-compression assembly 30 includes two stacked pre-compression plates 31, and the stacked assembly 50 is located between the two pre-compression plates 31.

[0073] In other implementations, the pre-compression assembly 30 may include a greater number of pre-compression plates 31, and the stacked assembly 50 is located between any two adjacent pre-compression plates 31, that is, one pre-compression assembly 30 can pre-compress multiple stacked assemblies 50.

[0074] In the embodiments of this application, the pre-compression component 30 is set in the form of a pre-compression plate 31, which makes the structure of the pre-compression component 30 simpler and the manufacturing of the pre-compression component 30 easier.

[0075] According to some embodiments of this application, see Figure 2 The encapsulation film 20 includes a perforated area 21 and an encapsulation area 22. The first clamping plate 11 and the second clamping plate 12 are located in the perforated area 21, and the encapsulation area 22 surrounds the perforated area 21.

[0076] The perforated area 21 is recessed relative to the encapsulation area 22 to form a groove for accommodating the first clamping plate 11 and the second clamping plate 12. The encapsulation area 22 is disposed around the outer periphery of the perforated area 21. After the first clamping plate 11 and the second clamping plate 12 are placed in the perforated area 21, the encapsulation area 22 encapsulates the encapsulation film 20 and seals the first clamping plate 11 and the second clamping plate 12 within the encapsulation area 22. It is understood that the perforated area 21 of the encapsulation film 20 may cover the entire outer surface of the first clamping plate 11 and the second clamping plate 12, and the encapsulation area 22 of the encapsulation film 20 is a sealing edge extending from the outer periphery of the perforated area 21 for sealing the perforated area 21, and is not used to cover the outer surface of the first clamping plate 11 and the second clamping plate 12.

[0077] In the embodiments of this application, a perforated area 21 and an encapsulation area 22 are provided on the encapsulation film 20 to facilitate the encapsulation film 20 to wrap the first clamping plate 11 and the second clamping plate 12. The encapsulation area 22 surrounds the perforated area 21, so that the first clamping plate 11 and the second clamping plate 12 can be sealed in the encapsulation area 22, avoiding external impurities from contaminating the first clamping plate 11, the second clamping plate 12 and the electrode assembly 40 during the isostatic pressing process.

[0078] According to some embodiments of this application, the encapsulation film 20 includes at least one of aluminum-plastic film, polyethylene film, and polypropylene film.

[0079] Aluminum-plastic film, polyethylene film, and polypropylene film are common encapsulation films that are easy to purchase, inexpensive, and provide good encapsulation results.

[0080] According to some embodiments of this application, the thickness of the encapsulation film 20 is greater than or equal to 50 μm (micrometers) and less than or equal to 500 μm.

[0081] For example, the thickness of the encapsulation film 20 can be 300 μm.

[0082] The thickness of the encapsulation film 20 is set within the aforementioned range. The thickness of the encapsulation film 20 is not too thin, so that it can withstand high pressure without rupturing when the first clamping plate 11, the second clamping plate 12, and the electrode assembly 40 are under isostatic pressure. On the other hand, within the aforementioned range, the thickness of the encapsulation film 20 is not too thick, so that when the first clamping plate 11, the second clamping plate 12, and the electrode assembly 40 are under isostatic pressure, the encapsulation film 20 can easily shrink under pressure, thereby compacting the electrode assembly 40 and enabling the electrode assembly 40 to achieve better densification performance.

[0083] Embodiments of this application also provide a battery production apparatus, which includes the fixture of any of the above embodiments.

[0084] Battery production equipment can be used to produce solid-state batteries.

[0085] Because the use of fixtures can improve the problem of electrode assembly movement and deformation during isostatic pressing, the electrode assembly has excellent densification performance, thereby improving the yield of batteries produced by battery production equipment.

[0086] Embodiments of this application also provide an electrode assembly shaping method. Figure 6 This is a schematic flowchart illustrating the battery assembly shaping method of some embodiments of this application. See also... Figure 6 The methods include:

[0087] Step S601: Obtain the electrode assembly.

[0088] Step S602: The electrode assembly is clamped using the first clamping plate and the second clamping plate.

[0089] Step S603: The first clamping plate and the second clamping plate holding the electrode assembly are encapsulated with an encapsulation film.

[0090] Step S604: Perform isostatic pressing on the electrode assembly encapsulated in the first clamping plate and the second clamping plate to shape the electrode assembly.

[0091] The structure of the encapsulation film, the first clamping plate, and the second clamping plate can be referred to the above description.

[0092] In some embodiments of this application, the electrode assembly 40 can be placed in the placement groove 111 of the first clamping plate 11 first, and then the entire first clamping plate 11 and the electrode assembly 40 can be placed in the mounting groove 121 of the second clamping plate 12 to achieve step S602.

[0093] In some embodiments of this application, when the encapsulation film 20 includes a perforated area 21 and an encapsulation area 22, the first clamping plate 11, the second clamping plate 12 and the electrode assembly 40 are placed in the perforated area 21 and then encapsulated in the encapsulation area 22 to achieve step S603.

[0094] When using the encapsulation film to encapsulate the first and second clamping plates of the electrode assembly, any three sides can be encapsulated first. Before encapsulating the fourth side, a conventional vacuum encapsulation machine can be used to evacuate the inside of the encapsulation film 20 through its self-evacuation opening to create a negative pressure and give the encapsulation film 20 a certain degree of vacuum.

[0095] In some embodiments, the vacuum level can be less than or equal to -100 kPa and greater than or equal to -10 kPa. For example, the vacuum level can be -98 kPa. Within the above range, on the one hand, the vacuum level of the encapsulation film 20 is not too high, so that the shrinkage of the encapsulation film 20 during the vacuuming process is not too large. On the other hand, within the above range, the problem of excessive residual gas in the encapsulation film 20, which would affect the densification of the electrode assembly, can be avoided to a certain extent.

[0096] After the electrode assembly 40 is shaped using the method provided in the embodiments of this application, the density of the electrode assembly 40 is ≥90%, and the flatness of the electrode assembly 40 is ≤0.1mm.

[0097] The density of electrode assembly 40 can be calculated using the following formula:

[0098]

[0099] Where τ is the packing density; m is the mass of the electrode assembly 40; V is the apparent volume of the electrode assembly 40; and ρ is the true density of the electrode assembly 40, which can be measured using a conventional true density meter.

[0100] The flatness of electrode assembly 40 refers to the distance deviation between the surface of electrode assembly 40 and the reference plane. The flatness of electrode assembly 40 can be measured using methods such as flat interferometry, dial indicator measurement, liquid level method, beam plane method, or laser flatness measuring instrument.

[0101] In the embodiments of this application, during isostatic pressing, the mounting groove limits the first clamping plate, reducing the mutual movement between the first and second clamping plates. The placement of the groove also limits the electrode assembly, reducing the mutual movement between the electrode assembly and the first clamping plate, thus improving the stability of the fixture and the electrode assembly during isostatic pressing, thereby enhancing the densification effect on the electrode assembly. Simultaneously, the encapsulation film does not directly contact the electrode assembly; even if the encapsulation film deforms, the deformation will not affect the electrode assembly and will not cause deformation.

[0102] According to some embodiments of this application, step S601 includes:

[0103] Step S611: Pre-compress the stacked assembly using a pre-compressing component to obtain the electrode assembly.

[0104] Battery electrodes and solid electrolyte sandwiched between the battery electrodes are wound or stacked to form a laminated assembly. A pre-compression assembly can pre-compress one laminated assembly, or a pre-compression assembly can pre-compress multiple laminated assemblies simultaneously.

[0105] For example, the temperature during pre-compression of the laminated assembly is greater than or equal to 25°C and less than or equal to 150°C, and the pre-compression pressure is greater than or equal to 30KN and less than or equal to 200KN. This translates to a surface pressure of the electrode assembly that is greater than or equal to 3MPa and less than or equal to 10MPa. The conversion formula satisfies the following equation:

[0106]

[0107] Where P is the surface pressure of the electrode assembly; F is the pre-pressure; and S is the surface pressure of the electrode assembly.

[0108] In the embodiments of this application, the stacked components are pre-processed to obtain the electrode components, so that the morphology of the electrode components meets the expectations and the state of the electrode components is more stable. When the electrode components are subsequently clamped by the first clamping plate and the second clamping plate, the stability of the electrode components is better.

[0109] For example, after the battery electrode and solid electrolyte are wound or stacked to form a stacked assembly, the stacked assembly is first pre-pressed using a pre-pressing assembly to obtain an electrode assembly. Then, the electrode assembly is clamped using a first clamping plate and a second clamping plate. Then, the first clamping plate and the second clamping plate are covered with an encapsulation film. Finally, the first clamping plate and the second clamping plate covered with the encapsulation film are placed in an isostatic pressing chamber for isostatic pressing.

[0110] According to some embodiments of this application, step S604 includes:

[0111] Step S641: Place the encapsulated first clamping plate and second clamping plate into the isostatic pressure chamber.

[0112] Step S642: Pressurize and heat the transfer medium in the isostatic chamber so that the temperature and pressure in the isostatic chamber reach the preset conditions.

[0113] Step S643: The first clamping plate and the second clamping plate are placed in the isostatic pressure chamber under preset conditions for a preset time and then removed.

[0114] The isostatic pressure chamber can be a chamber in an isostatic pressure apparatus used for isostatic pressure treatment, such as the inner cavity of an insulated pressure vessel in an isostatic pressure apparatus. An isostatic pressure environment can be formed within the isostatic pressure chamber, thereby transmitting pressure to the first clamping plate, the second clamping plate, and the electrode assembly.

[0115] In some embodiments, isostatic pressing (OSP) can be categorized into cold OSP, warm OSP, and hot OSP, depending on the temperature within the OSP environment. During cold OSP, the temperature within the OSP chamber can be room temperature. During warm OSP, the temperature within the OSP chamber can be between 80°C and 450°C. In this embodiment, any of the methods—cold OSP, warm OSP, or hot OSP—can be used to perform OSP on the electrode assembly. During OSP, a certain pressure is maintained within the OSP chamber to compact the electrode assembly under pressure, thereby achieving excellent densification properties.

[0116] In step 642, a transfer medium can be introduced into the isostatic chamber through a pipe connected to the isostatic chamber. The transfer medium covers the entire fixture and electrode assembly, thereby transferring pressure to the electrode assembly.

[0117] In some embodiments, the transfer medium can be at least one of a gas, a liquid, or a solid. After the transfer medium flows through the isostatic chamber, the isostatic chamber has a certain pressure. Then, by heating the transfer medium in the isostatic chamber to raise it to a target temperature, pressure and heat can be transferred to the electrode assembly through the transfer medium. In some embodiments, the transfer medium can be heated by placing a thermocouple in the isostatic chamber.

[0118] For example, the transfer medium can be a liquid, which has good flowability and can efficiently transfer pressure and heat to the electrode assembly. In some embodiments, the transfer medium can be oil or water.

[0119] In step 643, when the transfer medium causes the pressure in the isostatic chamber to reach the target pressure and target temperature, the preset conditions can be considered met. Then, under the target pressure and target temperature, the fixture and electrode assembly are left to stand for a preset time before being removed.

[0120] After removing the clamp, first remove the encapsulation film from the first clamping plate and the second clamping plate, then remove the electrode assembly from the first clamping plate and the second clamping plate, and clean the first clamping plate and the second clamping plate.

[0121] In some embodiments, the transfer medium on the outer surface of the encapsulation film can be removed by wiping the outer surface of the encapsulation film with anhydrous ethanol, ultrasonically cleaning the first and second clamping plates covered with the encapsulation film, or by high-speed centrifugation.

[0122] In the above technical solution, the electrode assembly and the fixture are both placed in an isostatic chamber. The electrode assembly can be pressurized and heated through the transfer medium to achieve densification of the electrode assembly.

[0123] According to some embodiments of this application, the preset conditions include: the temperature of the isostatic chamber is greater than 0°C and less than or equal to 300°C, the pressure of the isostatic chamber is greater than or equal to 100 MPa and less than or equal to 2000 MPa, and the preset time is greater than or equal to 10 min and less than or equal to 50 min.

[0124] For example, the temperature of the isostatic chamber can be 200°C, the pressure of the isostatic chamber can be 800 MPa, and the preset time can be 30 min.

[0125] Under the above conditions, it is possible to shape the electrode assembly to give it excellent densification performance, while avoiding the deformation of the encapsulation film under long-term isostatic pressing, thus enabling the electrode assembly to achieve a better shaping effect.

[0126] Embodiments of this application also provide an electrode assembly, which is held by a clamp according to any of the above embodiments. Figure 7 This is a cross-sectional view of an electrode assembly provided in an embodiment of this application. See also... Figure 7 The electrode assembly 40 includes a plurality of electrodes 41 and a solid electrolyte 42. The plurality of electrodes 41 are stacked along a first direction X, and the solid electrolyte 42 is located between any two adjacent electrodes 41.

[0127] For example, the plurality of electrodes 41 include a plurality of positive electrodes and a plurality of negative electrodes. Along the first direction X, the plurality of positive electrodes and the plurality of negative electrodes are stacked alternately in sequence, and the solid electrolyte 42 is located between any adjacent positive electrodes and the plurality of negative electrodes.

[0128] The electrode assembly 40 of the solid-state battery is set in a stacked form, which makes it easier to clamp the electrode assembly 40 with a fixture to perform isostatic pressing on the electrode assembly 40, so that the electrode assembly 40 has excellent densification performance.

[0129] In the embodiments of this application, when the first clamping plate 11 and the second clamping plate 12 clamp the electrode assembly 40, the stacking direction of the first clamping plate 11 and the second clamping plate 12 is the same as the first direction X.

[0130] According to some embodiments of this application, see Figure 7 The plurality of electrodes 41 include a plurality of first electrodes 411 and two second electrodes 412. The first electrodes 411 include a current collector 413 and active material 414 coated on opposite surfaces of the current collector 413. The second electrodes 412 include a current collector 413 and active material 414 coated on one side of the current collector 413. The solid electrolyte 42 and the plurality of first electrodes 411 are located between the two second electrodes 412, and the active material 414 of the second electrodes 412 is located between the current collector 413 of the second electrodes 412 and the solid electrolyte 42.

[0131] In embodiments of this application, the plurality of first electrodes 411 include the aforementioned plurality of positive electrode electrodes 415 and plurality of negative electrode electrodes 416. The current collector 413 of the positive electrode electrode 415 comprises aluminum, and the active material 414 on the opposite surfaces of the current collector 413 of the positive electrode electrode 415 is a positive electrode active material. The current collector 413 of the negative electrode electrode 416 comprises at least one of copper, stainless steel, and nickel, and the active material 414 on the opposite surfaces of the current collector 413 of the negative electrode electrode 416 is a negative electrode active material.

[0132] The current collector 413 of the second electrode 412 can be the same as the current collector 413 of the positive electrode; or the current collector 413 of the second electrode 412 can be the same as the current collector 413 of the negative electrode; or the current collector 413 of the second electrode 412 can be different from both the current collector 413 of the positive electrode and the current collector 413 of the negative electrode. For example, the current collector 413 of the second electrode 412 includes one of aluminum, copper, stainless steel, and nickel, and the active material 414 of the second electrode 412 can be either a positive or negative active material.

[0133] It is understandable that, along the first direction X, both sides of the electrode assembly 40 are current collectors 413.

[0134] In the embodiments of this application, current collectors 413 are provided on both opposite sides of the electrode assembly 40. During the subsequent pre-pressing or densification process of the electrode assembly 40, the current collectors 413 are not easily adhered to the pre-pressing assembly 30 and the first clamping plate 11 or the second clamping plate 12.

[0135] Embodiments of this application also provide a battery, which includes the electrode assembly described in the above embodiments.

[0136] For example, the battery can be a solid-state battery.

[0137] The battery provided in this application embodiment, during the preceding isostatic pressing process, uses mounting grooves to limit the first clamping plate, reducing the mutual movement between the first and second clamping plates. The placement of the grooves also limits the electrode assembly, reducing the mutual movement between the electrode assembly and the first clamping plate, thus improving the stability of the clamp and electrode assembly during isostatic pressing, thereby enhancing the densification effect on the electrode assembly. The encapsulation film does not directly contact the battery's electrode assembly; even if the encapsulation film deforms, the deformation will not affect the electrode assembly, preventing electrode assembly deformation and resulting in higher battery stability.

[0138] Embodiments of this application provide a clamp for holding an electrode assembly 40. The clamp includes a first clamping plate 11, a second clamping plate 12, an encapsulation film 20, and a pre-compression assembly 30. The second clamping plate 12 is stacked on top of the first clamping plate 11. The side of the first clamping plate 11 facing the second clamping plate 12 has a placement groove 111, and the side of the second clamping plate 12 facing the first clamping plate 11 has a mounting groove 121. The placement groove 111 is configured to place the electrode assembly 40, and at least a portion of the first clamping plate 11 is located in the mounting groove 121. The encapsulation film 20 covers the first clamping plate 11 and the second clamping plate 12. The pre-compression assembly 30 is configured to pre-compress the stacked assembly 50 to obtain the electrode assembly 40.

[0139] The depth D1 of the mounting groove 121 and the thickness D2 of the first clamping plate 11 satisfy: 0.5×D2≤D1≤D2.

[0140] The encapsulation film 20 includes a perforated area 21 and an encapsulation area 22. A first clamping plate 11 and a second clamping plate 12 are located in the perforated area 21, and the encapsulation area 22 surrounds the perforated area 21. The encapsulation film 20 includes at least one of aluminum-plastic film, polyethylene film, and polypropylene film. The thickness of the encapsulation film 20 is greater than or equal to 50 μm and less than or equal to 500 μm.

[0141] The pre-compression assembly 30 includes at least two stacked pre-compression plates 31, and the stacked assembly 50 is located between any two adjacent pre-compression plates 31.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A clamp for clamping an electrode assembly, characterized by, The clamp comprises: a first clamping plate (11); a second clamping plate (12) stacked with the first clamping plate (11); wherein a side surface of the first clamping plate (11) facing the second clamping plate (12) has a placement groove (111) configured for placing the electrode assembly (40), and a side surface of the second clamping plate (12) facing the first clamping plate (11) has a mounting groove (121) in which at least part of the first clamping plate (11) is located; a packaging film (20) covering the first clamping plate (11) and the second clamping plate (12).

2. The clamp of claim 1, wherein The depth D1 of the mounting groove (121) is less than or equal to the thickness D2 of the first clamping plate (11).

3. The clamp of claim 2, wherein The depth D1 of the mounting groove (121) and the thickness D2 of the first clamping plate (11) satisfy: 0.5×D2≤D1≤D2.

4. The clamp of any one of claims 1 to 3, wherein, The clamp further comprises: a pre-pressing assembly (30) configured for pre-pressing the stacked assembly (50) to obtain the electrode assembly (40).

5. The clamp of claim 4, wherein The pre-pressing assembly (30) comprises at least two stacked pre-pressing plates (31), and the stacked assembly (50) is located between any two adjacent pre-pressing plates (31).

6. The clamp of any one of claims 1 to 5, wherein, The packaging film (20) comprises a punched region (21) and a packaging region (22), the first clamping plate (11) and the second clamping plate (12) are located in the punched region (21), and the packaging region (22) surrounds the punched region (21).

7. The clamp of any one of claims 1 to 6, wherein, The packaging film (20) comprises at least one of an aluminum plastic film, a polyethylene film, and a polypropylene film.

8. The clamp of any one of claims 1 to 7, wherein, The thickness of the packaging film (20) is greater than or equal to 50 μm and less than or equal to 500 μm.

9. A battery production apparatus characterized by comprising: The battery production equipment comprises the clamp according to any one of claims 1 to 8.

10. A method of shaping an electrode assembly, characterized by, The method comprises: obtaining an electrode assembly; clamping the electrode assembly by using a first clamping plate and a second clamping plate; packaging the first clamping plate and the second clamping plate clamping the electrode assembly by using a packaging film; performing isostatic pressing treatment on the electrode assembly packaged in the first clamping plate and the second clamping plate to realize shaping of the electrode assembly.

11. The method of claim 10, wherein, Obtaining an electrode assembly comprises: pre-pressing a stacked assembly by using a pre-pressing assembly to obtain the electrode assembly.

12. The method according to claim 10 or 11, characterized in that, Performing isostatic pressing treatment on the electrode assembly packaged in the first clamping plate and the second clamping plate to realize shaping of the electrode assembly comprises: placing the packaged first clamping plate and second clamping plate in an isostatic pressing chamber; performing pressure and heating treatment on a transmission medium in the isostatic pressing chamber, so that the temperature and pressure in the isostatic pressing chamber reach a preset condition; removing the first clamping plate and the second clamping plate after they are placed in the isostatic pressing chamber under the preset condition for a preset time.

13. The method of claim 12, wherein, The preset condition includes that the temperature of the isostatic pressing chamber is greater than 0 DEG C and less than or equal to 300 DEG C, the pressure of the isostatic pressing chamber is greater than or equal to 100 Mpa and less than or equal to 2000 Mpa, and the preset time is greater than or equal to 10 min and less than or equal to 50 min.

14. An electrode assembly held by the clamp as claimed in any one of claims 1 to 8, characterized by The electrode assembly (40) comprises a plurality of pole pieces (41) and a solid-state electrolyte (42), the plurality of pole pieces (41) are stacked along a first direction, and the solid-state electrolyte (42) is located between any two adjacent pole pieces (41).

15. The electrode assembly of claim 14, wherein, The plurality of pole pieces (41) comprises a plurality of first pole pieces (411) and two second pole pieces (412), the first pole piece (411) comprises a current collector (413) and an active material (414) coated on opposite surfaces of the current collector (413), and the second pole piece (412) comprises the current collector (413) and the active material (414) coated on one side surface of the current collector (413). The solid-state electrolyte (42) and the plurality of first pole pieces (411) are located between the two second pole pieces (412), and the active material (414) of the second pole piece (412) is located between the current collector (413) of the second pole piece (412) and the solid-state electrolyte (42).

16. A battery, characterized by The battery comprises the electrode assembly according to claim 14 or 15.

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