Solid-state battery cell and manufacturing method therefor

Abstract

The present application discloses a solid-state battery cell and a manufacturing method therefor. The solid-state battery cell comprises an electrode assembly and a packaging casing. The packaging casing comprises two packaging films; the electrode assembly is arranged between the two packaging films; the two packaging films are connected to form a packaging portion arranged along a circumferential direction of the electrode assembly; the packaging portion comprises an packaging region and a reinforcement region; and the thickness of the reinforcement region is greater than that of the packaging region, and / or the hardness of the reinforcement region is greater than that of the packaging region. In the solid-state battery cell and the manufacturing method therefor in the present application, the packaging portion is arranged along the circumferential direction of the electrode assembly and matches the shape of the electrode assembly, thereby improving the sealing stability. In addition, the packaging portion is provided with a reinforcement region, and the reinforcement region has a larger thickness or higher strength, thereby reducing the risk of wrinkling of the packaging portion. The structure improves packaging efficiency, and also reduces the risk of wrinkling during packaging, thereby improving the sealing performance of the solid-state battery cell.

Description

Solid-state battery cell and manufacturing method thereof

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Chinese Patent Application No. 202411370196.3, filed on September 29, 2024, entitled “Solid-state battery cell and manufacturing method thereof”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of batteries, in particular to a solid-state battery cell and a manufacturing method thereof. BACKGROUND

[0004] A solid-state battery is a battery that uses a solid substance as an electrolyte. The solid-state battery has high charging efficiency, high energy density, and low risk of combustion and explosion, and has high research value.

[0005] In the production process of the solid-state battery, the plastic sealing film is subjected to heat pressing to seal the electrode assembly inside the plastic sealing shell. During the heat pressing process, the sealing edge of the plastic sealing film is prone to wrinkling. How to improve the flatness of the plastic sealing film during the heat pressing process is one of the problems in the field. SUMMARY

[0006] In view of the above problems, the present application provides a solid-state battery cell and a manufacturing method thereof, which can reduce the risk of wrinkling of the sealing edge of the plastic sealing film, improve the sealing performance of the plastic sealing shell, and thus improve the operation stability of the solid-state battery cell.

[0007] In a first aspect, the present application provides a solid-state battery cell, comprising an electrode assembly and a packaging shell. The packaging shell comprises two packaging films, the electrode assembly is arranged between the two packaging films, the two packaging films are connected and form a packaging portion arranged circumferentially around the electrode assembly, the packaging portion comprises a packaging area and a reinforcing area, the thickness of the reinforcing area is greater than the thickness of the packaging area, and / or the hardness of the reinforcing area is greater than the hardness of the packaging area. Wherein, the packaging film comprises a metal layer, a connecting layer and an insulating layer, the connecting layer is arranged on one side surface of the metal layer, the insulating layer is arranged on the other side surface of the metal layer away from the connecting layer, the connecting layers of the two packaging films are oppositely arranged, and at least one packaging film further comprises a reinforcing sheet, the reinforcing sheet is connected between the two connecting layers, or the reinforcing sheet is connected to the insulating layer.

[0008] In the technical scheme of the embodiment of the present application, the electrode assembly is sealed by the packaging shell to provide a stable reaction environment for the electrode assembly and improve the operation stability of the solid-state battery monomer. The packaging part is arranged along the circumference of the electrode assembly and matches the shape of the electrode assembly, thereby improving the sealing stability. Moreover, the packaging area on the packaging part is directly connected with the two packaging films of the packaging area, thereby improving the connection efficiency. The reinforcing area is arranged on the packaging part, the thickness or strength of the reinforcing area is relatively large, and the risk of wrinkle generation is reduced. The above structure improves the packaging efficiency and reduces the risk of wrinkle generation during the packaging process, thereby improving the sealing performance of the solid-state battery monomer. The metal layer is arranged to provide structural support for the whole packaging film, thereby improving the structural stability of the packaging film. The insulating layer is arranged to improve the insulation performance of the packaging film and reduce the risk of short circuit during the operation of the solid-state battery monomer. The connecting layer is arranged to facilitate the hot-pressing connection of the two packaging films, thereby improving the connection efficiency. The reinforcing sheet is arranged on the packaging film to improve the strength or thickness of the local packaging film and reduce the risk of wrinkle generation during the packaging process of the area. The reinforcing sheet is arranged between the two packaging films to improve the flatness and structural integrity of the outer surface of the packaging shell.

[0009] In some embodiments, the solid-state battery monomer further comprises an electrode lead-out piece connected to the electrode assembly, the electrode lead-out piece passes through between the two packaging films, and the reinforcing area is arranged on the side of the electrode assembly away from the electrode lead-out piece. In the above structure, the electrode lead-out piece is arranged to transmit the electrical energy of the electrode assembly, the electrode lead-out piece passes through between the two packaging films, which facilitates the hot-pressing packaging of the packaging film and improves the packaging efficiency and the connection stability of the electrode lead-out piece. In particular, the reinforcing area is arranged on the side away from the electrode lead-out piece, which reduces the interference between the negative pressure equipment and the electrode lead-out piece during the hot-pressing process and improves the manufacturing efficiency of the solid-state battery monomer and the structural stability of the electrode lead-out piece.

[0010] In some embodiments, the reinforcing sheet is connected with the packaging film by adhesion or fusion. The above structure improves the structural strength and installation efficiency between the reinforcing sheet and the packaging film. In some embodiments, the reinforcing sheet comprises at least one of a polypropylene sheet, a polyethylene sheet, a polystyrene sheet, and a polyvinyl chloride sheet. The above materials have high strength and can be melted at high temperature, thereby improving the local strength of the packaging area and forming a good connection with the packaging film.

[0011] In some embodiments, the packaging area includes a first packaging strip extending along a first direction, and a second packaging strip, a third packaging strip extending along a second direction, and a fourth packaging strip. The first direction is perpendicular to the second direction. The first packaging strip, the second packaging strip, the third packaging strip, and the fourth packaging strip are sequentially connected head to tail and arranged along the circumference of the electrode assembly. The reinforcing sheet is arranged in at least one of the first packaging strip, the second packaging strip, the third packaging strip, and the fourth packaging strip. In the above structure, by arranging the first packaging strip, the second packaging strip, the third packaging strip, and the fourth packaging strip along the four sides of the electrode assembly, the shape of the electrode assembly can be matched, the redundant space of the plastic packaging can be reduced, and the sealing effect can be improved.

[0012] In a second aspect, the application provides a manufacturing method of a solid-state battery cell, for manufacturing the solid-state battery cell in the above embodiments, the manufacturing method comprising: providing a first packaging film and a second packaging film, the first packaging film having a first packaging area and a second packaging area arranged along the circumference thereof, and the second packaging film having a third packaging area and a fourth packaging area arranged along the circumference thereof. A reinforcing structure is arranged in the second packaging area. An electrode assembly is arranged between the first packaging film and the second packaging film. The two packaging films are heat-pressed to fuse the first packaging area and the third packaging area to form a packaging area. The two packaging films are heat-pressed to fuse the second packaging area and the fourth packaging area to form a reinforcing area. The packaging area and the reinforcing area are enclosed to form a sealed inner cavity between the first packaging film and the second packaging film, and the inner cavity is used to accommodate the electrode assembly.

[0013] In the above technical solution, the two packaging films are connected by heat pressing, which improves the connection efficiency and strength of the packaging film. The reinforcing structure is arranged in the second packaging area, which improves the local strength of the second packaging area, reduces the risk of wrinkles in the second packaging area during packaging, and improves the sealing performance of the packaging shell, thereby improving the operation stability of the solid-state battery cell.

[0014] In some embodiments, the step of arranging the reinforcing structure in the second packaging area comprises: heating the second packaging area for a time T1. The second packaging area is cooled to form a reinforcing structure on the surface of the second packaging area. The above method improves the local structural strength of the second packaging area by preheating, which is convenient to operate without increasing the cost of materials.

[0015] In some embodiments, the step of arranging the reinforcing structure in the second packaging area comprises: providing a reinforcing sheet, the hardness of the reinforcing sheet being greater than the hardness of the first packaging film. The reinforcing sheet is arranged in the second packaging area. The above method improves the local structural strength of the second packaging area by adding a reinforcing sheet, which effectively reduces the risk of wrinkles in the second packaging area during packaging and improves the sealing performance of the solid-state battery cell.

[0016] In some embodiments, the reinforcing sheet is arranged on one side of the first encapsulation film facing the second encapsulation film. In the above structure, arranging the reinforcing sheet between the first encapsulation film and the second encapsulation film can improve the connection stability between the reinforcing sheet and the encapsulation film, and improve the flatness and structural integrity of the outer surface of the encapsulation shell.

[0017] In some embodiments, the reinforcing sheet comprises at least one of a polypropylene sheet, a polyethylene sheet, a polystyrene sheet, and a polyvinyl chloride sheet. The above materials have high strength and can be melted at high temperature, thereby forming a good connection with the encapsulation film while improving the local strength of the encapsulation area.

[0018] In some embodiments, the reinforcing sheet is connected to the first encapsulation film by adhesion or fusion. The above structure improves the structural strength and mounting efficiency between the reinforcing sheet and the encapsulation film.

[0019] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, and to be implemented according to the content of the description, and in order to enable the above and other purposes, features and advantages of the present application to be more apparent and easy to understand, the specific embodiments of the present application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0020] The features, advantages, and technical effects of the exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0021] FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application;

[0022] FIG. 2 is an exploded structural schematic diagram of a battery device according to some embodiments of the present application;

[0023] FIG. 3 is a structural schematic diagram of a solid-state battery according to some embodiments of the present application;

[0024] FIG. 4 is a structural schematic diagram of a solid-state battery according to some other embodiments of the present application;

[0025] FIG. 5 is a structural schematic diagram of a reinforcing area of an encapsulation film according to some other embodiments of the present application;

[0026] FIG. 6 is a flowchart of a manufacturing method of a solid-state battery cell according to some embodiments of the present application;

[0027] FIG. 7 is a flowchart of a manufacturing method of a solid-state battery cell according to some other embodiments of the present application;

[0028] FIG. 8 is a flowchart of a manufacturing method of a reinforcing structure of a solid-state battery cell according to some embodiments of the present application;

[0029] FIG. 9 is a flowchart of a manufacturing method of a reinforcing structure of a solid-state battery cell according to some other embodiments of the present application;

[0030] Detailed description of reference signs 1, vehicle; 2, battery device; 3, controller; 4, motor; 5, case; 51, first case portion; 52, second case portion; 53, accommodation space; X, first direction; Y, second direction; 7, solid-state battery cell; 701, first packaging strip; 702, second packaging strip; 703, third packaging strip; 704, fourth packaging strip; 10, electrode assembly; 20, packaging shell; 30, packaging region; 40, reinforcing region; 60, packaging portion; 70, electrode lead-out; 80, reinforcing sheet; 706, metal layer; 707, connection layer; 708, insulating layer. DETAILED DESCRIPTION

[0031] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0032] 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 belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0034] In this paper, "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment that is not mutually exclusive with other embodiments. The skilled person in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.

[0036] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0037] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0038] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0039] In the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0040] In the embodiments of the present application, the same reference signs represent the same parts, and for the sake of brevity, detailed description of the same parts is 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 and should not constitute any limitation on the present application.

[0041] A solid-state battery refers to a battery using a solid-state substance as an electrolyte. The solid-state battery generally includes a packaging case and an electrode assembly disposed in the packaging case. The packaging process of the packaging case is generally to stack two packaging films and then place them in a vacuum environment for packaging. The outer periphery of the electrode assembly on the packaging film is heated and pressurized, and the two packaging films are heat-welded to form an internal cavity that is internally sealed to package the electrode assembly. Since there is no liquid substance in the solid-state battery, during the heat-welding process of the packaging film, the packaging connection part is prone to uneven wrinkles. The existence of wrinkles reduces the sealing performance of the packaging and reduces the stability of the operation of the solid-state battery.

[0042] Based on the above problems, the embodiments of the present application provide a manufacturing method of a solid-state battery monomer. Two packaging films are connected by heat pressing, which improves the connection efficiency and connection strength of the packaging film. A reinforcing structure is provided in the second packaging area to improve the local strength of the second packaging area, reduce the risk of wrinkles in the second packaging area during the packaging process, improve the sealing performance of the packaging case, and thus improve the operation stability of the solid-state battery monomer.

[0043] The battery apparatus of the present application will be described in detail below.

[0044] The battery apparatus (Battery Apparatus) mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly (Battery Cell Assembly) can include a plurality of battery cells connected in series, parallel, or mixed connection through a busbar component.

[0045] In some embodiments, the battery cell assembly (Battery Cell Assembly) is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module (Battery Module) formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0046] In some embodiments, the battery apparatus can be a battery pack (battery Pack), which includes a box body and one or more battery cell assemblies accommodated in the box body.

[0047] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box body by fixing the battery module in the box body.

[0048] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing a plurality of battery cells in the box body.

[0049] In the embodiments of the present application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be activated by charging after discharging to continue to be used.

[0050] The battery cell can include, but is not limited to, a solid-state battery, a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, and the like.

[0051] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, or a battery cell of other shapes, including a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, and the like, without specific limitation in the present application.

[0052] In some embodiments, the box can be part of the chassis structure of the vehicle. For example, part of the box can become at least part of the floor of the vehicle, or part of the box can become at least part of the cross beams and longitudinal beams of the vehicle.

[0053] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0054] The battery device disclosed in the embodiments of the present application can be used in various energy storage systems using the battery device as an energy storage element or in various electrical equipment using the battery device as a power supply. The electrical equipment can include, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric aircraft toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0055] The following embodiments are described for convenience with the electrical equipment being a vehicle as an example.

[0056] FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application.

[0057] As shown in FIG. 1, the vehicle 1 is internally provided with a battery device 2, which can be arranged at the bottom, head, or tail of the vehicle 1. The battery device 2 can be used for power supply of the vehicle 1, for example, the battery device 2 can be used as an operating power supply of the vehicle 1.

[0058] The vehicle 1 can further include a controller 3 and a motor 4, and the controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power demand of the vehicle 1 during starting, navigation, and driving.

[0059] In some embodiments of the present application, the battery device 2 can not only serve as the power source for operating the vehicle 1, but also serve as the driving power source for the vehicle 1, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle 1.

[0060] FIG. 2 is an exploded structural schematic view of the battery device according to some embodiments of the present application.

[0061] The box 5 is used to accommodate the battery cells, and the box 5 can have various structures. In some embodiments, the box 5 can include a first box part 51 and a second box part 52, the first box part 51 and the second box part 52 are mutually covered, and the first box part 51 and the second box part 52 jointly define an accommodation space 53 for accommodating the battery cells. The second box part 52 can be a hollow structure with one end open, and the first box part 51 is a plate-like structure, which is covered on the open side of the second box part 52 to form the box 5 with the accommodation space 53; the first box part 51 and the second box part 52 can also be hollow structures with one side open, and the open side of the first box part 51 is covered on the open side of the second box part 52 to form the box 5 with the accommodation space 53. Of course, the first box part 51 and the second box part 52 can have various shapes, such as a cylinder, a cuboid, etc.

[0062] In order to improve the sealing performance of the first box part 51 and the second box part 52 after being connected, a sealing member such as sealing glue, a sealing ring, etc. can be arranged between the first box part 51 and the second box part 52.

[0063] Suppose the first box part 51 is covered on the top of the second box part 52, the first box part 51 can also be called an upper box cover, and the second box part 52 can also be called a lower box.

[0064] In the battery device 2, the battery cells can be one or multiple. If the battery cells are multiple, the multiple battery cells can be connected in series, in parallel or in a mixed manner, and the mixed manner means that the multiple battery cells are connected in series and in parallel. The multiple battery cells can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery cells is accommodated in the box 5; of course, the multiple battery cells can be first connected in series, in parallel or in a mixed manner to form a battery module, and then the multiple battery modules are connected in series, in parallel or in a mixed manner to form a whole, which is accommodated in the box 5.

[0065] In some optional embodiments, the battery cells can also be directly accommodated in the box 5, so as to reduce the connection components or support components required for forming the battery module and improve the energy density of the battery device 2.

[0066] Exemplarily, the battery cell can be the smallest unit constituting the battery device 2.

[0067] The battery cell is a solid-state battery cell, which generally comprises an encapsulation shell 20 and an electrode assembly 10. The encapsulation shell has an inner cavity, and the electrode assembly is arranged in the inner cavity. The electrode assembly comprises a positive electrode tab and a negative electrode tab arranged in a stack. The electrode tab is provided with a solid-state electrolyte.

[0068] In some optional embodiments, the solid-state electrolyte comprises one or more of a sulfide solid-state electrolyte, an oxide solid-state electrolyte, a halide solid-state electrolyte, and a polymer solid-state electrolyte.

[0069] The sulfide solid-state electrolyte comprises a sulfide crystalline solid-state electrolyte, a sulfide glass, and a glass-ceramic solid-state electrolyte.

[0070] Please refer to FIGS. 3-5 for further details. FIG. 3 is a structural schematic diagram of a solid-state battery according to some embodiments of the present application. FIG. 4 is a structural schematic diagram of a solid-state battery according to some other embodiments of the present application. FIG. 5 is a structural schematic diagram of a reinforcing region of an encapsulation film according to some other embodiments of the present application.

[0071] As shown in the figures, the embodiments of the present application provide a solid-state battery cell 7 comprising an electrode assembly 10 and an encapsulation shell 20. The encapsulation shell 20 comprises two encapsulation films, and the electrode assembly 10 is arranged between the two encapsulation films. The two encapsulation films are connected and form an encapsulation portion 60 arranged circumferentially around the electrode assembly 10. The encapsulation portion 60 comprises an encapsulation region 30 and a reinforcing region 40. The thickness of the reinforcing region 40 is greater than that of the encapsulation region 30, and / or the hardness of the reinforcing region 40 is greater than that of the encapsulation region 30.

[0072] Optionally, the encapsulation film can be an aluminum-plastic film or a steel-plastic film. The encapsulation region 30 and the reinforcing region 40 comprise two encapsulation films arranged in a stack and closely attached.

[0073] The encapsulation process of the encapsulation film of the solid-state battery cell 7 is generally carried out in a vacuum environment. The inside of the sealed shell loses the support of the flowing electrode liquid, and encapsulation in a vacuum environment is prone to form unevenness such as wrinkles or buckling in the encapsulation region 30. Through research on the above process, the reinforcing portion is arranged on the final edge region, which can reduce the problem of encapsulation wrinkles in a vacuum condition.

[0074] In the technical solutions of the embodiments of the present application, the existence of the packaging shell 20 provides a sealed space for the electrode assembly 10 to isolate the external environment, which is particularly important for solid-state batteries because solid-state electrolytes are sensitive to environmental factors such as humidity and oxygen. A stable reaction environment helps to prolong the service life of the battery and improve the performance stability. The packaging part 60 is designed to be circumferentially arranged along the electrode assembly 10, which not only closely matches the shape of the electrode assembly 10, but also reduces the gap between the packaging material and the electrode assembly 10, and increases the uniformity and reliability of the sealing. This design can reduce the intrusion of external impurities and improve the safety of the battery. The packaging area 30 is directly connected by two packaging films, which simplifies the packaging process and improves the packaging efficiency. At the same time, direct connection also reduces potential connection failure points, further enhancing the reliability of the packaging. The reinforcement area 40 can effectively resist the mechanical stress that may occur during the packaging process, such as bending and stretching, thereby reducing the risk of packaging film wrinkles. Wrinkles not only affect the aesthetics of the battery, but also can damage the integrity of the packaging, leading to problems such as electrolyte leakage. Therefore, the setting of the reinforcement area 40 improves the overall performance and reliability of the solid-state battery monomer 7.

[0075] In the above structure, the electrode assembly 10 is sealed by the packaging shell 20 to provide a stable reaction environment for the electrode assembly 10 and improve the operating stability of the solid-state battery monomer 7. The packaging part 60 is arranged along the circumference of the electrode assembly 10 and closely matches the shape of the electrode assembly 10, providing uniformity and tightness of the packaging, which not only improves the sealing effect, but also reduces the gap between the packaging material and the electrode assembly 10.

[0076] In some embodiments of the present application, the solid-state battery monomer 7 further comprises an electrode lead-out piece 70 connected to the electrode assembly 10, and the electrode lead-out piece 70 passes between the two packaging films. The reinforcement area 40 is arranged on the side of the electrode assembly 10 away from the electrode lead-out piece 70.

[0077] In the above structure, the electrode lead-out piece 70 serves as a bridge for the solid-state battery monomer 7 to connect with external circuits, and is responsible for transmitting the electrical energy generated by the electrode assembly 10. The electrode lead-out piece 70 passes between the two packaging films, which not only facilitates the heat sealing of the packaging film, but also ensures the stable connection between the electrode lead-out piece 70 and the electrode assembly 10. During the heat sealing process, the packaging film can tightly wrap around the electrode lead-out piece 70, forming a reliable sealing structure to prevent external impurities from entering the interior of the packaging shell 20. Moreover, since the electrode lead-out piece 70 has already passed through the packaging film, it does not need to be additionally treated or fixed during the heat sealing process. This greatly simplifies the packaging process and improves the packaging efficiency.

[0078] In the hot-pressing packaging process, a negative pressure device is often used to apply pressure to the packaging film to achieve a tight package. If the reinforced area 40 is close to the electrode lead-out piece 70, it will increase the risk of interference between the negative pressure device and the electrode lead-out piece 70, resulting in poor packaging effect or damage to the electrode lead-out piece 70. By setting the reinforced area 40 on the side away from the electrode lead-out piece 70, the risk of such interference can be effectively reduced, improving the manufacturing efficiency of the solid-state battery cell 7 and the structural stability of the electrode lead-out piece 70.

[0079] As shown in FIG. 6, in some embodiments of the present application, the packaging film includes a metal layer 706, a connecting layer 707, and an insulating layer 708. The connecting layer 707 is arranged on one side surface of the metal layer 706, and the insulating layer 708 is arranged on the other side surface of the metal layer 706 away from the connecting layer 707. Among them, the connecting layers 707 of the two packaging films are oppositely arranged; at least one packaging film further includes a reinforcing sheet 80 connected between the two connecting layers 707, or the reinforcing sheet 80 is connected to the insulating layer 708.

[0080] The metal layer 706 serves as the main structural support of the packaging film, providing sufficient strength and rigidity to enable the packaging film to withstand various mechanical stresses and pressures during the packaging process. This structural stability is crucial for ensuring the normal operation of the solid-state battery cell 7 in complex working environments. The design of the connecting layer 707 allows for easy connection between the two packaging films, not only improving the efficiency of the connection, but also ensuring the tightness and reliability of the connection. For example, during the hot-pressing process, the connecting layer 707 can quickly soften and tightly bond with other layers, forming a stable packaging structure. Alternatively, the two opposing connecting layers 707 are adhesive layers that can be directly bonded. The insulating layer 708 isolates the metal layer 706 from electrical contact with the external environment, reducing the risk of short circuits that may occur inside the solid-state battery cell 7, and improving the safety and reliability of the battery device 2.

[0081] The reinforcing sheet 80 can be arranged between the two connecting layers 707 or on the insulating layer 708 as needed to increase the strength or thickness of the packaging film in that area. This design can significantly reduce the risk of wrinkles in that area during the packaging process, thereby maintaining the flatness and structural integrity of the outer surface of the packaging shell 20. The reinforcing sheet 80 also enhances the compression resistance and durability of the packaging shell 20, extending the service life of the battery cell.

[0082] In some embodiments of the present application, the reinforcing sheet 80 is connected to the packaging film by adhesion or fusion.

[0083] The adhesive connection refers to tightly adhering the reinforcing sheet 80 and the packaging film together by using an adhesive. The adhesive generally has excellent adhesion and chemical stability, and can maintain the firmness of the connection under various environmental conditions. The advantage of the adhesive connection is that it is easy to operate and has high flexibility, and the amount and position of the adhesive can be adjusted as needed to achieve the best connection effect. In addition, the adhesive connection can also adapt to the connection between different materials, including metals, plastics, etc. In the packaging process of the solid-state battery cell 7, the reinforcing sheet 80 and the packaging film are connected by the adhesive connection, which can ensure the reliability and sealing of the connection, while reducing the manufacturing cost and process complexity.

[0084] The fusion connection refers to using high temperature to melt and fuse part of the material of the packaging film, forming an integrated connection structure. This method is generally suitable for thermoplastic materials such as polypropylene, polyethylene, etc. The advantage of fusion is that it has high connection strength and good sealing performance, which can ensure that there is no gap and no leakage point between the reinforcing sheet 80 and the packaging film. In addition, the fusion method can also improve the overall strength and rigidity of the packaging film, and enhance the compression resistance and durability of the battery cell.

[0085] By connecting the reinforcing sheet 80 and the packaging film together by adhesive or fusion, the structural strength and installation efficiency of the solid-state battery cell 7 can be improved.

[0086] In some embodiments of the present application, the reinforcing sheet 80 includes at least one of a polypropylene sheet, a polyethylene sheet, a polystyrene sheet, and a polyvinyl chloride sheet. The above-mentioned materials have high strength and can be melted at high temperature, thereby improving the local strength of the packaging area 30 and forming a good connection with the packaging film.

[0087] As shown in FIG. 4, in some embodiments of the present application, the packaging area 30 includes a first packaging strip 701 extending along a first direction X and a second packaging strip 702, a third packaging strip 703 extending along a second direction Y and a fourth packaging strip 704. The first direction X is perpendicular to the second direction Y. The first packaging strip 701, the second packaging strip 702, the third packaging strip 703, and the fourth packaging strip 704 are connected end to end in sequence and are arranged along the circumference of the electrode assembly 10. The reinforcing sheet 80 is arranged on at least one of the first packaging strip 701, the second packaging strip 702, the third packaging strip 703, and the fourth packaging strip 704.

[0088] The electrode assembly 10 of the solid-state battery cell 7 is generally a cuboid-like structure. In the above structure, the four encapsulation strips respectively extend along the four sides of the electrode assembly 10, which can closely fit the shape of the electrode assembly 10 and reduce the gap caused by the shape mismatch. This not only helps to improve the sealing of the encapsulation, but also prevents external impurities or moisture from entering the battery, which can adversely affect the performance of the battery. With the design of four encapsulation strips, the encapsulation area 30 can be accurately controlled, and unnecessary redundant space can be reduced, making the encapsulation more compact and efficient. Since the four encapsulation strips are connected in sequence, a complete encapsulation closed loop is formed, and each joint can be well sealed during the encapsulation process. At the same time, the arrangement of the reinforcing sheet 80 on at least one of the encapsulation strips can further enhance the strength and sealing of this area, and improve the reliability and durability of the entire encapsulation area 30.

[0089] Optionally, a plurality of reinforcing sheets 80 can be provided, one on each of the first encapsulation strip 701, the second encapsulation strip 702, the third encapsulation strip 703, and the fourth encapsulation strip 704. Alternatively, the size and shape of the encapsulation strips can be adjusted to accommodate electrode assemblies 10 of different specifications. This design makes the encapsulation process more flexible and variable, and can meet the needs of different application scenarios.

[0090] As shown in FIG. 6, the embodiments of the present application provide a manufacturing method of a solid-state battery cell 7 for manufacturing the solid-state battery cell in the above embodiments, the manufacturing method comprising:

[0091] S1, providing a first encapsulation film and a second encapsulation film, the first encapsulation film having a first encapsulation area and a second encapsulation area arranged along the circumferential direction thereof, and the second encapsulation film having a third encapsulation area and a fourth encapsulation area arranged along the circumferential direction thereof;

[0092] S2, providing a reinforcing structure in the second encapsulation area;

[0093] S3, placing the electrode assembly 10 between the first encapsulation film and the second encapsulation film;

[0094] S4, hot pressing the two encapsulation films to fuse the first encapsulation area and the third encapsulation area to form an encapsulation area 30;

[0095] S5, hot pressing the two encapsulation films to fuse the second encapsulation area and the fourth encapsulation area to form a reinforcing area 40; wherein the encapsulation area 30 and the reinforcing area 40 are enclosed to form a sealed inner cavity between the first encapsulation film and the second encapsulation film, and the inner cavity is used to accommodate the electrode assembly 10.

[0096] In step S1, the first packaging film and the second packaging film can be an aluminum plastic film or a steel plastic film. The first packaging area and the second packaging area are areas that can be melted after being heated and bonded with other packaging films. In step S3, the electrode assembly 10 refers to the electrode assembly 10 of the solid-state battery cell 7.

[0097] In the above technical solution, the two packaging films are connected by heat pressing, which improves the connection efficiency and strength of the packaging film. The reinforcing structure is provided in the second packaging area, which improves the local strength of the second packaging area, reduces the risk of wrinkles in the second packaging area during packaging, improves the sealing performance of the packaging shell 20, and thus improves the operation stability of the solid-state battery cell 7.

[0098] As shown in FIG. 7, in some optional embodiments, between step S4 and step S5, the following steps are further included:

[0099] S4.5, placing the first packaging film, the second packaging film, and the electrode assembly 10 in a sealing cavity, and vacuumizing the sealing cavity.

[0100] The above steps can reduce impurities in the packaging shell 20 and improve the sealing performance of the packaging. Optionally, steps S4.5 and S5 are performed in a vacuum environment of the sealing cavity.

[0101] During the sealing process of the packaging shell 20, the last step of sealing in the sealing cavity can reserve a vent hole for exhaust, improving the sealing performance of the packaging shell 20. However, the vent hole is prone to wrinkles during the final heat pressing packaging, and therefore the reinforcing area 40 in the present application strengthens the vent hole, resists deformation force, and improves the packaging flatness of the reinforcing area 40.

[0102] Optionally, the number of reinforcing areas 40 can be multiple, and the multiple reinforcing areas 40 are arranged along the circumference of the electrode assembly 10. The number of vent holes can be set as needed to improve the efficiency and convenience of assembly.

[0103] As shown in FIG. 8, in some embodiments of the present application, step S2 includes:

[0104] S21, heating the second packaging area, and the heating time is T1;

[0105] S22, cooling the second packaging area to form a reinforcing structure on the surface of the second packaging area. The above method improves the local structural strength of the second packaging area by preheating, which is convenient to operate and does not increase the material cost.

[0106] As shown in FIG. 9, in some embodiments of the present application, step S2 includes:

[0107] S2A, a reinforcing sheet 80 is provided, the hardness of the reinforcing sheet 80 is greater than the hardness of the first encapsulation film;

[0108] S2B, the reinforcing sheet 80 is arranged at the second encapsulation area.

[0109] The method described above improves the local structural strength of the second encapsulation area by additionally arranging the reinforcing sheet 80, effectively reduces the risk of wrinkles in the second encapsulation area during encapsulation, and improves the sealing performance of the solid-state battery cell 7.

[0110] In some embodiments of the present application, the reinforcing sheet 80 is arranged on the side of the first encapsulation film facing the second encapsulation film. In the structure described above, arranging the reinforcing sheet 80 between the first encapsulation film and the second encapsulation film can improve the connection stability between the reinforcing sheet 80 and the encapsulation film, and improve the flatness and structural integrity of the outer side of the encapsulation shell 20.

[0111] In some embodiments of the present application, the reinforcing sheet 80 includes at least one of a polypropylene sheet, a polyethylene sheet, a polystyrene sheet, and a polyvinyl chloride sheet. The materials described above have high strength and can be melted at high temperatures, thereby improving the local strength of the encapsulation area 30 and forming a good connection with the encapsulation film.

[0112] In some embodiments of the present application, the reinforcing sheet 80 is connected to the first encapsulation film by adhesion or fusion. The structure described above improves the structural strength and installation efficiency between the reinforcing sheet 80 and the encapsulation film.

[0113] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A solid-state battery cell, comprising: an electrode assembly; an encapsulation shell comprising two encapsulation films, the electrode assembly being disposed between the two encapsulation films, the two encapsulation films being connected and forming an encapsulation portion disposed circumferentially around the electrode assembly, the encapsulation portion comprising an encapsulation region and a reinforcing region, the reinforcing region having a thickness greater than that of the encapsulation region, and / or the reinforcing region having a hardness greater than that of the encapsulation region, wherein the encapsulation film comprises a metal layer, a connecting layer disposed on one side surface of the metal layer, and an insulating layer disposed on the other side surface of the metal layer opposite to the connecting layer, the connecting layers of the two encapsulation films being oppositely disposed, and at least one of the encapsulation films further comprises a reinforcing sheet connected between the two connecting layers or connected to the insulating layer.

2. The solid-state battery cell of claim 1, wherein, The solid-state battery cell further comprises an electrode lead connected to the electrode assembly, and the electrode lead passes through between the two encapsulation films, and the reinforcing region is disposed on a side of the electrode assembly away from the electrode lead.

3. The solid-state battery cell of claim 1, wherein, The reinforcing sheet is connected to the encapsulation film by adhesion or fusion.

4. The solid-state battery cell of claim 1, wherein, The reinforcing sheet comprises at least one of a polypropylene sheet, a polyethylene sheet, a polystyrene sheet, and a polyvinyl chloride sheet.

5. The solid-state battery cell of claim 1, wherein, The encapsulation region comprises a first encapsulation strip and a second encapsulation strip extending in a first direction, and a third encapsulation strip and a fourth encapsulation strip extending in a second direction, wherein the first direction is perpendicular to the second direction, the first encapsulation strip, the second encapsulation strip, the third encapsulation strip, and the fourth encapsulation strip are sequentially connected end to end and disposed circumferentially around the electrode assembly, and the reinforcing sheet is disposed on at least one of the first encapsulation strip, the second encapsulation strip, the third encapsulation strip, and the fourth encapsulation strip. 6.A manufacturing method of a solid-state battery cell, for manufacturing the solid-state battery cell according to any one of claims 1-5, the manufacturing method comprising: providing a first encapsulation film and a second encapsulation film, the first encapsulation film having a first encapsulation region and a second encapsulation region disposed circumferentially around the first encapsulation film, and the second encapsulation film having a third encapsulation region and a fourth encapsulation region disposed circumferentially around the second encapsulation film; providing a reinforcing structure in the second encapsulation region; placing an electrode assembly between the first encapsulation film and the second encapsulation film; heat pressing the two encapsulation films to fuse the first encapsulation region and the third encapsulation region to form an encapsulation region; heat pressing the two encapsulation films to fuse the second encapsulation region and the fourth encapsulation region to form a reinforcing region; wherein the encapsulation region and the reinforcing region are enclosed to form a sealed inner cavity between the first encapsulation film and the second encapsulation film, and the inner cavity is used to accommodate the electrode assembly.

7. The method for manufacturing a solid-state battery cell according to claim 6, wherein The step of providing a reinforcing structure in the second encapsulation region comprises: heating the second encapsulation region, and the heating time is T1; cooling the second encapsulation region to form the reinforcing structure on the surface of the second encapsulation region.

8. The method for manufacturing a solid-state battery cell according to claim 6, wherein The step of providing a reinforcing structure in the second encapsulation region comprises: providing a reinforcing sheet, and the reinforcing sheet has a hardness greater than that of the first encapsulation film. The reinforcing sheet is disposed in the second encapsulation region.

9. The method for manufacturing a solid-state battery cell according to claim 8, wherein, The reinforcing sheet is disposed on a side of the first encapsulation film facing the second encapsulation film. 10.The method of manufacturing a solid-state battery cell according to claim 8 or 9, wherein, The reinforcing sheet includes at least one of a polypropylene sheet, a polyethylene sheet, a polystyrene sheet, and a polyvinyl chloride sheet.

11. The method for manufacturing a solid-state battery cell according to claim 8 or 9, wherein, The reinforcing sheet is connected to the first encapsulation film by adhesion or fusion.

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