Solid-state battery cell, manufacturing method therefor, battery apparatus, and electric apparatus

Abstract

A solid-state battery cell (7), a manufacturing method therefor, a battery apparatus (2), and an electric apparatus. The solid-state battery cell (7) comprises a casing (30) and a battery cell provided within the casing (30), the battery cell comprising an electrode assembly (10) and a coating layer (20), the electrode assembly (10) comprising a plurality of first electrode sheets and a plurality of second electrode sheets, each first electrode sheet comprising at least one first stacked section, each second electrode sheet comprising at least one second stacked section, the first stacked section and the second stacked section being stacked in a first direction; the electrode assembly (10) further comprises a first surface (101) and a tab lead-out surface (103) adjacent to and connected to the first surface (101), and a second surface (102), wherein the first surface (101) is perpendicular to the first direction, the coating layer (20) covers a periphery of the electrode assembly (10), the coating layer (20) is coated onto the first surface (101) by means of a first bonding region (21) and coated onto the second surface (102) by means of a second bonding region (22), a first peel strength a is provided between the first bonding region (21) and the first surface (101), a second peel strength b is provided between the second bonding region (22) and the second surface (102), and the first peel strength a is less than the second peel strength b.

Description

Solid-state battery cells and their manufacturing methods, battery devices and electrical devices

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411854056.3, filed on December 16, 2024, entitled “Solid-state battery cell and method of manufacturing thereof, battery device and power supply device”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a solid-state battery cell and its manufacturing method, battery device and power-consuming device. Background Technology

[0004] With the widespread application and promotion of solid-state battery cells, their overall performance has received increasing attention.

[0005] In related technologies, the poor adhesion between the electrolyte and the current collector of the electrode in solid-state battery cells presents a series of challenges during mass production, especially during the decoupling process after isostatic pressing, which can lead to the peeling or misalignment of various components within the cell. This situation can easily affect the yield and reliability of solid-state battery cells. Therefore, there is an urgent need to provide a solid-state battery cell with excellent overall performance. Summary of the Invention

[0006] This application provides a solid-state battery cell. The solid-state battery cell exhibits minimal delamination or sliding displacement between electrodes, resulting in low or no electrolyte failure, thus improving the reliability and operational stability of the solid-state battery cell. The manufacturing method of this application can produce the aforementioned solid-state battery cell, where the components within the cell are fixedly joined together during the manufacturing process, improving the yield rate of the solid-state battery cell. The battery device and power-consuming device of this application, incorporating this solid-state battery cell, possess at least the aforementioned beneficial effects.

[0007] In a first aspect, embodiments of this application propose a solid-state battery cell, including a housing and a cell disposed within the housing. The cell includes: an electrode assembly comprising a plurality of first electrodes and a plurality of second electrodes, the first electrodes comprising at least one first stacked segment, the second electrodes comprising at least one second stacked segment, the first stacked segment and the second stacked segment being stacked along a first direction; the electrode assembly further comprising a first surface and a tab lead-out surface and a second surface adjacent to and interconnected with the first surface, the first surface being perpendicular to the first direction; and a covering layer disposed around the outer periphery of the electrode assembly, the covering layer comprising a first adhesive region and a second adhesive region, the covering layer covering the first surface through the first adhesive region and covering the second surface through the second adhesive region, wherein the first peel strength 'a' between the first adhesive region and the first surface, the second peel strength 'b' between the second adhesive region and the second surface, and the first peel strength 'a' being less than the second peel strength 'b'.

[0008] According to the embodiments of this application, in a solid-state battery cell, a first stacked segment and a second stacked segment are stacked along a first direction. A solid electrolyte is contained between the stacked electrodes. This solid electrolyte is highly susceptible to failure during the manufacturing process of the solid-state battery cell. During manufacturing, the first and second stacked segments are prone to relative sliding and misalignment, or the negative electrode may separate from the solid electrolyte, leading to delamination. By providing a coating layer covering the outer periphery of the electrode assembly, a first adhesive area covers the first surface, and a second adhesive area covers the second surface. The first peel strength 'a' between the first adhesive area and the first surface, and the second peel strength 'b' between the second adhesive area and the second surface, with the first peel strength 'a' being less than the second peel strength 'b', the bonding force between the multiple first and second electrodes in the cell is improved. This ensures that all components in the cell are fixed together, reducing the risk of solid electrolyte failure caused by misalignment / sliding / separation or delamination between electrodes, thus reducing the amount of electrolyte failure in the cell and improving the yield of the solid-state battery cell. Therefore, the stability of the cell during manufacturing is improved, as is the operational stability of the solid-state battery cell.

[0009] In some optional embodiments, the first peel strength α between the first adhesive area and the first surface is 5 N / m to 20 N / m, and optionally 6 N / m to 15 N / m.

[0010] In some optional embodiments, the second peel strength b between the second adhesive area and the second surface is 80 N / m to 350 N / m, and optionally 100 N / m to 280 N / m.

[0011] In some optional embodiments, the first electrode is a negative electrode, which includes a negative current collector and a base coating disposed on the surface of the negative current collector, and at least one side of any negative electrode is provided with a solid electrolyte.

[0012] In some alternative embodiments, the area of ​​the first bonding region is greater than or equal to the area of ​​the first surface.

[0013] In some alternative embodiments, the area of ​​the second surface is smaller than the area of ​​the second adhesive region.

[0014] In some alternative embodiments, the second bonding region includes a first sub-region and a second sub-region that are in contact with the second surface, the bonding surfaces of the second sub-regions being mutually abutted.

[0015] In some alternative embodiments, the adhesive surfaces of the second sub-regions are bonded together to form a second adhesive region, which is close to the second surface.

[0016] In some alternative embodiments, the width of the second sub-region is 2 to 10 mm.

[0017] In some alternative embodiments, the width of the first adhesive area is the width of the first surface.

[0018] In some alternative embodiments, the length of the first adhesive region is the length of the first surface.

[0019] In some alternative embodiments, the thickness of the coating layer is 30 to 150 micrometers.

[0020] In some alternative embodiments, the material of the covering layer includes one or more of polyethylene, polypropylene, polytetrafluoroethylene, polyimide, polyethylene terephthalate, acrylic acid, natural rubber, acrylate, nonwoven fabric, washi paper, and paraffin wax.

[0021] Secondly, embodiments of this application provide a method for manufacturing a solid-state battery cell, comprising:

[0022] An electrode assembly and a covering sheet including a first adhesive region and a second adhesive region are provided, and the first adhesive region is adhered to the electrode assembly to be applied to an electrode sheet; wherein, the electrode assembly includes a plurality of first electrode sheets and a plurality of second electrode sheets stacked along a first direction, the electrode assembly also includes a first surface and a tab lead-out surface and a second surface adjacent to and connected to the first surface, the first surface is located on the electrode sheet to be applied, the second adhesive region is distributed along the periphery of the first adhesive region, and the adhesive strength a' of the first adhesive region is less than the adhesive strength b' of the second adhesive region;

[0023] At least a portion of the second adhesive region of the covering sheet is adhered to the second surface of the electrode assembly to form a battery cell;

[0024] By placing the battery cell in the casing, a solid-state battery cell is obtained.

[0025] According to the solid-state battery cell manufacturing method of this application embodiment, by adhering the first bonding area of ​​the coating sheet to the electrode to be bonded, the components in the cell are fixed together, reducing the risk of misalignment / slippage / separation between the electrodes. Therefore, during isostatic pressing and decoating processes, the amount of electrolyte failure caused by cell decopping is reduced, improving the yield of solid-state battery cells. Thus, the stability of the cell during the manufacturing process is improved, as is the operational stability of the solid-state battery cell.

[0026] In some optional embodiments, an electrode assembly and a covering sheet including a first adhesive region and a second adhesive region are provided, and the first adhesive region is adhered to the electrode assembly to be fitted with an electrode sheet, including:

[0027] Two covering sheets are provided, and the first adhesive areas of the two covering sheets are respectively adhered to two electrodes to be applied, forming two electrodes with covering sheets, wherein the two electrodes to be applied include at least one of a first electrode and a second electrode.

[0028] Two coated electrodes are spaced apart in a first direction, such that the two surfaces of the uncoated sheet of the coated electrodes are placed opposite each other to form a gap space;

[0029] Multiple first electrodes and multiple second electrodes are stacked in a spaced-out direction along a first direction.

[0030] According to the solid-state battery cell manufacturing method of this application embodiment, by adhering the first bonding area of ​​the coating sheet to two electrode sheets to be bonded, and stacking multiple first electrode sheets and multiple second electrode sheets in a spaced-out direction along a first direction, the components in the cell are fixedly combined, reducing misalignment / separation between the electrode sheets. Therefore, during isostatic pressing and decoupling processes, the failure of solid electrolyte caused by cell decoupling is reduced, the amount of electrolyte failure in the cell is reduced, and the yield of solid-state battery cells is improved. Thus, the stability of the cell during the manufacturing process is improved, as is the operational stability of the solid-state battery cell.

[0031] In some alternative embodiments, the bond strength of the first bonding region is 0.1 to 10 N / m.

[0032] In some optional embodiments, the bonding strength of the second bonding region is 20 to 200 N / m.

[0033] In some optional embodiments, adhering at least a portion of the second adhesive region of the covering sheet to the second surface of the electrode assembly to form a battery cell includes: adhering at least a portion of the second adhesive region of the covering sheet to the second surface of the electrode assembly; and performing a flat pressing treatment on the battery cell surface to form the battery cell. The flat pressing treatment on the battery cell surface further improves the adhesion between the covering sheet and the electrode surface, fixing the components in the battery cell together and reducing misalignment / separation between the electrodes.

[0034] In some optional embodiments, the pressure for the flattening process is 10–2000 MPa.

[0035] In some optional embodiments, the flattening treatment temperature is 25–200°C.

[0036] In some optional embodiments, the flattening treatment time is 3 to 20 minutes.

[0037] In some optional embodiments, before placing the cell in the casing to obtain a solid-state battery cell, the method further includes: performing isostatic pressing on the cell. Due to the presence of the coating sheet, misalignment / separation between the electrodes is reduced during isostatic pressing and decoating processes; solid electrolyte failure caused by cell decoating is reduced, the amount of electrolyte failure in the cell is decreased, and the yield of solid-state battery cells is improved.

[0038] In some optional embodiments, the step of performing isostatic pressing on the battery cell specifically includes:

[0039] The static pressure film is attached to the surface of the battery cell to obtain the battery cell to be shaped;

[0040] Place the battery cell to be shaped into the storage space;

[0041] A pressure medium is introduced to bring the storage space to the isostatic pressure condition required for the cell to be shaped, and the isostatic pressure condition is maintained for a preset time to obtain the cell after static pressure.

[0042] After static pressing, the cell is delaminated to obtain the cell.

[0043] In some optional embodiments, the thickness of the hydrostatic membrane is 50 μm to 300 μm.

[0044] In some alternative embodiments, the hydrostatic membrane is made of one or more of aluminum-plastic film, polypropylene, polyethylene, and polyethylene terephthalate.

[0045] In some alternative embodiments, the initial vacuum level in the storage space is -101 to -80 kPa.

[0046] In some optional embodiments, the vacuum holding time under isostatic pressure conditions is 1 to 10 minutes.

[0047] In some alternative embodiments, the temperature under isostatic pressure conditions is 25–1000°C.

[0048] In some alternative embodiments, the pressure under isostatic conditions is 100–2000 MPa.

[0049] In some optional embodiments, the preset time for isostatic pressing is 5 to 60 minutes.

[0050] In some alternative embodiments, the pressure medium in the isostatic pressure condition is one or more of an inert gas and oil.

[0051] Thirdly, embodiments of this application provide a battery device, including a solid-state battery cell of the first aspect or a solid-state battery cell manufactured by the manufacturing method of the second aspect.

[0052] Fourthly, embodiments of this application provide an electrical device, including the battery device of the third aspect. Attached Figure Description

[0053] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0054] Figure 1 shows a schematic diagram of the structure of a vehicle provided in some embodiments of this application;

[0055] Figure 2 shows an exploded structural diagram of a battery device provided in some embodiments of this application;

[0056] Figure 3 shows a schematic diagram of the structure of a solid-state battery cell provided in some embodiments of this application;

[0057] Figure 4 shows a schematic diagram of the structure of an electrode assembly provided in some other embodiments of this application;

[0058] Figure 5 shows a schematic diagram of the location of a second sub-region of a covered sheet provided in some embodiments of this application;

[0059] Figure 6 shows another schematic diagram of the location of the second sub-region of the covered sheet provided in some embodiments of this application;

[0060] Figure 7 shows a schematic flowchart of a method for manufacturing a solid-state battery cell according to some embodiments of this application;

[0061] Figure 8 shows a schematic diagram of the planar structure of a covered sheet provided in some embodiments of this application;

[0062] Figure 9 shows a schematic diagram of the planar structure of another covered sheet provided in some embodiments of this application;

[0063] Figure 10 shows a schematic diagram of the process of coating electrode assemblies with coated sheet material according to some embodiments of this application;

[0064] Figure 11 shows another schematic diagram of the process of coating electrode assemblies with coated sheet material according to some embodiments of this application;

[0065] Figure 12 shows a schematic diagram of the defilming of a solid-state battery cell after isostatic pressing according to some embodiments of this application.

[0066] Figure 13 shows a schematic diagram of a qualified solid-state battery cell after isostatic pressing according to some embodiments of this application.

[0067] Explanation of reference numerals in the attached drawings: 1. Vehicle; 2. Battery assembly; 3. Controller; 4. Motor; 5. Housing; 51. First housing section; 52. Second housing section; 53. Receiving space; X, First direction; 7. Solid-state battery cell; 10. Electrode assembly; 101. First surface; 102. Second surface; 103. Tab lead-out surface; 20. Covering layer; 21. First bonding area; 22. Second bonding area; 221. First sub-region; 222. Second sub-region; 30. Housing.

[0068] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0069] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the solid-state battery cell, its manufacturing method, battery device, and power-consuming device of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0070] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0071] Unless otherwise specified, all embodiments and optional embodiments of this application may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of this application.

[0072] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0073] In this application, "multiple" refers to two or more (including two). Similarly, "several items" or "multiple items" in this application refers to two or more (including two).

[0074] Furthermore, the terms “first,” “second,” “third,” etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0075] 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.

[0076] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0077] The battery device of this application will now be described in detail.

[0078] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via busbars.

[0079] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0080] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0081] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0082] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0083] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0084] Battery cells may include, but are not limited to, solid-state battery cells, lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-metal hydride battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0085] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0086] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0087] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0088] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0089] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0090] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0091] As shown in Figure 1, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0092] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0093] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0094] Figure 2 is an exploded view of the battery device provided in some embodiments of this application.

[0095] The housing 5 is used to house individual battery cells, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 51 and a second housing portion 52, which overlap each other, and together define a housing space 53 for housing the individual battery cells. The second housing portion 52 may be a hollow structure with one end open, and the first housing portion 51 may be a plate-like structure, with the first housing portion 51 covering the open side of the second housing portion 52 to form a housing 5 with the housing space 53; alternatively, both the first housing portion 51 and the second housing portion 52 may be hollow structures with one side open, with the open side of the first housing portion 51 covering the open side of the second housing portion 52 to form a housing 5 with the housing space 53. Of course, the first housing portion 51 and the second housing portion 52 can have various shapes, such as cylinders, cuboids, etc.

[0096] To improve the sealing performance after the first housing part 51 and the second housing part 52 are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 51 and the second housing part 52.

[0097] Assuming that the first box part 51 covers the top of the second box part 52, the first box part 51 can also be called the upper box cover, and the second box part 52 can also be called the lower box.

[0098] In battery device 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel. Multiple battery cells can be directly connected in series, parallel, or in a mixed configuration and then housed in housing 5. Alternatively, multiple battery cells can first be connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole and housed in housing 5.

[0099] In some alternative embodiments, individual battery cells can also be directly housed within the housing 5 to reduce the number of connecting or supporting components required to assemble the battery module and improve the energy density of the battery device 2.

[0100] For example, a single battery cell may be the smallest unit that makes up the battery device 2.

[0101] The battery cell is a solid-state battery cell, which typically includes a casing 30 and a battery cell. The casing 30 has an inner cavity, in which the battery cell is housed. The casing 30 can be made of materials such as aluminum, aluminum alloy, or plastic.

[0102] The battery cell includes an electrode assembly, which comprises a positive electrode and a negative electrode. The positive and negative electrode plates are coated with an electrolyte, which can be a solid electrolyte or a gel electrolyte, etc.

[0103] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid—lithium salt.

[0104] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0105] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0106] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor, lithium germanium phosphorus sulfur, silver sulfide), amorphous sulfides, halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0107] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0108] In solid-state battery cells, the electrolyte is typically attached to the current collector or a coated current collector. The current collector can be made of materials such as aluminum, iron, or copper. However, due to the incompatibility of the electrolyte materials, especially solid electrolytes, with the current collector in terms of chemical and physical properties, the adhesion between the two is insufficient. This insufficient adhesion can lead to interfacial separation of components within the cell during solid-state battery cell manufacturing. For example, in the isostatic pressing process of solid-state battery cells, the electrodes separate from the electrolyte, and this problem can be further exacerbated by high pressure.

[0109] Hot isostatic pressing (HIP) or cold isostatic pressing (CIP) is a processing method that applies high pressure uniformly in all directions to improve the density, mechanical strength, and conductivity of materials in solid-state battery cells. This process is crucial for the fabrication of solid-state battery cells because the densification and homogenization of the solid electrolyte are key steps in achieving high-performance solid-state battery cells. Isostatic pressing is mainly divided into two forms: cold isostatic pressing (CIP) and hot isostatic pressing (HIP). Cold isostatic pressing is typically performed at room temperature or low temperature, using a liquid (such as water or oil) to transfer pressure, and is suitable for preliminary molding and pre-compaction. Hot isostatic pressing (HIP) is typically performed at high temperature, using a high-temperature gas (such as argon) to transfer pressure; this process provides both high pressure and high temperature. Therefore, the isostatic pressing process can lead to the separation of electrodes from each other or from the electrolyte in related technologies, affecting the yield of the cells and solid-state battery cells.

[0110] One method in related technologies to address the issue of delamination between the negative electrode and the solid electrolyte or related components in a battery cell is an integrated sealing process. This involves retaining the membrane material intact within the cell during encapsulation without removing it. However, a single sealing process can lead to wavy deformation at the cell edges. This wavy edge affects the cell's electrical characteristics, such as stability and lifespan.

[0111] Based on this, this application provides a solid-state battery cell and its manufacturing method, which can improve electrolyte failure and relative sliding displacement of electrodes, thereby increasing the yield of solid-state battery cells.

[0112] Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of the structure of a solid-state battery cell 7 provided in some embodiments of this application. Figure 4 is a schematic diagram of the structure of an electrode assembly 10 provided in some embodiments of this application.

[0113] This application provides a solid-state battery cell 7, including a housing 30 and a battery cell disposed within the housing 30. The battery cell includes an electrode assembly 10, comprising a plurality of first electrodes and a plurality of second electrodes. The first electrodes include at least one first stacked segment, and the second electrodes include at least one second stacked segment. The first and second stacked segments are stacked along a first direction X.

[0114] The first direction X can be the direction set by the first and second stacked segments. Multiple first electrodes and multiple second electrodes can be positive or negative electrodes.

[0115] Referring to Figure 3, the electrode assembly 10 of this embodiment includes a positive electrode, a negative electrode, and an insulator, wherein the insulator is an insulator located between the positive and negative electrode. The electrode assembly 10 has a main body and tabs. The main body of this embodiment can be a flat structure with a predetermined thickness, height, and width. The active material of the positive electrode is coated on the coated area of ​​the positive electrode, and the active material of the negative electrode is coated on the coated area of ​​the negative electrode. The uncoated area extending from the coated area of ​​the main body serves as the tab. The electrode assembly 10 includes two tabs, namely a positive tab and a negative tab. The positive tab extends from the coated area of ​​the positive electrode, and the negative tab extends from the coated area of ​​the negative electrode. The positive tab and the negative tab can extend from the same side or different sides of the electrode assembly 10.

[0116] In some alternative embodiments, the electrode assembly 10 may include two sides as tab lead-out surfaces 103, or one side as a tab lead-out surface 103. The electrode assembly 10 also includes a first surface 101 and a second surface 102 adjacent to and connected to the first surface 101, wherein the first surface 101 is perpendicular to a first direction. The number of first surfaces 101 may be two; the number of second surfaces 102 may be two or three.

[0117] Referring to Figure 4, the battery cell includes: a coating layer 20, which is disposed around the outer periphery of the electrode assembly 10. The coating layer 20 includes a first bonding area 21 and a second bonding area 22. The coating layer 20 covers the first surface 101 through the first bonding area 21 and covers the second surface 102 through the second bonding area 22. The first peel strength a between the first bonding area 21 and the first surface 101 and the second peel strength b between the second bonding area 22 and the second surface 102 are respectively, and the first peel strength a is less than the second peel strength b.

[0118] It is understood that the coating layer 20 is disposed on the first surface 101 and the second surface 102 of the electrode assembly 10. When the electrode assembly 10 has only one tab lead-out surface 103, the coating layer 20 can be disposed on the side of the electrode assembly 10 parallel to the tab lead-out surface 103.

[0119] According to an embodiment of this application, the solid-state battery cell 7 has a first stacked segment and a second stacked segment stacked along a first direction X. A solid electrolyte is contained between the stacked electrodes. This solid electrolyte is highly susceptible to failure during the manufacturing process of the solid-state battery cell 7. During manufacturing, the first and second stacked segments are prone to relative sliding misalignment or separation of the negative electrode from the solid electrolyte, leading to delamination. A coating layer 20 is provided to cover the outer periphery of the electrode assembly 10. A first adhesive region 21 covers the first surface 101, and a second adhesive region 22 covers the second surface 102. The first adhesive region 21 and the second adhesive region 22 are connected to the first surface 101 and the second surface 102 respectively. The first peel strength 'a' between the first surfaces 101 and the second peel strength 'b' between the second bonding area 22 and the second surface 102, and the first peel strength 'a' being less than the second peel strength 'b', reduces the displacement and misalignment of the cell sidewalls, as well as the gas infiltration into the cell caused by cracks or micropores in the sidewall coating layer 20. This improves the bonding force between multiple first and second electrodes in the cell, firmly fixing the components together, reducing the risk of misalignment / slippage / separation between electrodes and electrolyte failure, thus reducing the amount of electrolyte failure in the cell and improving the yield of the solid-state battery cell 7. Therefore, it improves the stability of the cell during the manufacturing process and also improves the operational stability of the solid-state battery cell 7.

[0120] The first peel strength 'a' between the first adhesive region 21 and the first surface 101, or the second peel strength 'b' between the second adhesive region 22 and the second surface 102, can be tested using methods commonly used in the art. For example, it can be tested according to the method in GB / T2792-2014.

[0121] As an example, the testing method can be as follows: Take a sample of double-sided adhesive tape (e.g., model 3M9448A, 20mm wide and 90mm to 150mm long) and attach it to the non-adhesive side of the covering sheet corresponding to the first adhesive area 21. Use a 2kg pressure roller to press the tape, ensuring the negative electrode film layer is fully bonded to the double-sided adhesive tape. Adjust the tensile testing machine's limit block to a suitable position and perform a 180° bending peel test to obtain the first peel strength 'a' between the first adhesive area 21 and the first surface 101. During the test, the peel distance can be 40mm and the peel rate can be 50mm / min. An Instron 33652 testing machine can be used as the testing instrument.

[0122] In some optional embodiments, the first peel strength α between the first adhesive region 21 and the first surface 101 is 5 N / m to 20 N / m, and can be selected as 6 N / m to 15 N / m.

[0123] Optionally, the first peel strength α can be any value or a range of combinations thereof from 5 N / m, 6 N / m, 7 N / m, 8 N / m, 9 N / m, 10 N / m, 11 N / m, 12 N / m, 13 N / m, 14 N / m, 15 N / m, 16 N / m, 17 N / m, 18 N / m, 19 N / m, and 20 N / m.

[0124] The first peel strength a is within the above range, which is beneficial to fixing the relative positions of the two first surfaces 101 in the electrode assembly 10, improving the stability of the cell during the manufacturing process, and also improving the operational stability of the solid-state battery cell 7.

[0125] In some optional embodiments, the second peel strength b between the second adhesive region 22 and the second surface 102 is 80 N / m to 350 N / m, and can be selected as 100 N / m to 280 N / m.

[0126] Optionally, the second peel strength b can be any value or a range of combinations thereof from 80 N / m, 90 N / m, 100 N / m, 110 N / m, 120 N / m, 130 N / m, 140 N / m, 150 N / m, 160 N / m, 170 N / m, 180 N / m, 190 N / m, 200 N / m, 210 N / m, 220 N / m, 230 N / m, 240 N / m, 250 N / m, 260 N / m, 270 N / m, 280 N / m, 290 N / m, 300 N / m, 310 N / m, 320 N / m, 330 N / m, 340 N / m, and 350 N / m. The second peel strength b is within the above range, which helps to fix the relative positions of the two first surfaces 101 in the electrode assembly 10, improves the stability of the cell during the manufacturing process, and also improves the operational stability of the solid-state battery cell 7.

[0127] In some optional embodiments, the first electrode is a negative electrode, which includes a negative current collector and a base coating disposed on the surface of the negative current collector. At least one surface of any negative electrode is provided with a solid electrolyte. The base coating of this negative electrode has poor adhesion to the positive electrode. During the fabrication of the solid-state battery cell 7, the positive and negative electrodes are prone to relative sliding and displacement, causing the solid electrolyte on the surface of the negative electrode to be exposed or come into contact with air, leading to solid electrolyte failure. Therefore, a coating layer 20 is provided to improve the relative bonding between the electrodes, reduce displacement caused by sliding, reduce solid electrolyte failure, and improve the yield of the solid-state battery cell 7.

[0128] In some alternative implementations, the area of ​​the first bonding region 21 is greater than or equal to the area of ​​the first surface 101.

[0129] It is understandable that when the area of ​​the first bonding area 21 is larger than the area of ​​the first surface 101 of the electrode assembly 10, the first bonding area 21 is partially adhered to the second surface 102 or a surface parallel to the tab lead-out surface 103. This arrangement allows for a certain degree of coating offset at the corners of the electrode assembly 10, facilitating subsequent shaping and correction processes. It also reduces sliding displacement, decreases the degree of solid electrolyte failure, and improves the yield of solid-state battery cells 7.

[0130] It is understandable that when the area of ​​the first bonding area 21 is equal to the area of ​​the first surface 101 of the electrode assembly 10, the first bonding area 21 is completely adhered to the first surface 101. The second bonding area 22 is disposed on the second surface 102 or a surface parallel to the tab lead-out surface 103. This arrangement can improve the adhesion force in the first direction X, reduce the displacement caused by the sliding of the first and second electrodes, reduce solid electrolyte failure, and improve the yield of solid-state battery cells 7.

[0131] In some optional embodiments, the width of the first bonding area 21 is the same as the width of the first surface 101. In some optional embodiments, the length of the first bonding area 21 is the same as the length of the first surface 101. The above-described configurations can respectively improve the bonding force in the first direction X, reduce the displacement caused by the sliding of the first and second electrodes, reduce solid electrolyte failure, and improve the yield of solid-state battery cells 7.

[0132] In some alternative implementations, the area of ​​the second surface 102 is smaller than the area of ​​the second adhesive region 22.

[0133] When the area of ​​the second surface 102 is equal to the area of ​​the second bonding region 22, the second bonding region 22 has no overlapping portion. During the fabrication process, the electrode assembly 10 in the first direction X may come into contact with the outside through the coating layer 20, causing electrolyte failure. Since the second bonding region 22 has no overlapping portion, it may have less resistance, limiting the relative sliding of the first and second electrodes. Therefore, by setting the area of ​​the second surface 102 to be smaller than the area of ​​the second bonding region 22, and having an overlapping portion in the second bonding region 22, mechanical stress that may occur during the coating process can be effectively reduced, thereby reducing the relative sliding of the electrodes caused by wrinkles in the coating layer 20. The overlapping portion can be adjusted later to remove wrinkles on the coating layer 20, or it can be "absorbed" by the second bonding region without compromising the overall sealing of the coating layer 20 and its adhesion to the surface of the electrode assembly 10.

[0134] In some alternative embodiments, the second bonding area 22 includes a first sub-area 221 and a second sub-area 222 that are in contact with the second surface 102, and the bonding surfaces of the second sub-area 222 are in contact with each other.

[0135] It is understood that the second bonding area 22 comprises two parts: a first sub-area 221 that is in contact with the second surface 102, and a second sub-area 222 whose bonding surfaces are in contact with each other, as shown in Figure 5. The bonding surfaces of the second sub-area 222 are in contact with each other, forming a folded portion, which is attached to the surface of the first sub-area 221. In Figure 5, there are no pores between the electrode assembly 10 and the coating layer 20; in actual operation, they are tightly fitted together. The gap in Figure 5 is to distinguish different parts of the structure. This arrangement effectively resists mechanical stresses that may occur during the coating process, such as bending and stretching, thereby reducing the relative slippage of the electrode sheets caused by wrinkles in the coating layer 20, reducing the probability of electrolyte failure, and improving the yield of the solid-state battery cell 7. This arrangement also reduces the formation of unevenness such as wrinkles or warping.

[0136] In some optional embodiments, the adhesive surfaces of the second sub-region 222 are bonded together to form a second adhesive area, which is close to the second surface 102. The second adhesive area close to the second surface 102 forms a raised structure, which can further resist mechanical stresses that may be generated during the coating process, such as bending and stretching, and can further reduce the relative sliding of the electrode caused by wrinkles in the coating layer 20, and can further reduce the probability of electrolyte failure; it can also further form uneven phenomena such as wrinkles or warping.

[0137] In some alternative embodiments, the width of the second sub-region 222 is 2–10 mm. This can further reduce the relative slippage of the electrode caused by wrinkles in the coating layer 20, and further reduce the probability of electrolyte failure; it can also further prevent unevenness such as wrinkles or warping.

[0138] In some optional embodiments, as shown in FIG6, the second bonding area 22 includes a first sub-area 221 and a second sub-area 222 that are in contact with the second surface 102, and at least two second sub-areas 222 are arranged overlapping each other. One second sub-area 222 is bonded to the second surface 102, and the bonding surface of the other second sub-area 222 is disposed on the surface of one of the second sub-areas 222. The second sub-area 222 is circumferentially disposed on the surface of the electrode assembly 10, and is in close contact with the surface of the electrode assembly 10, providing uniformity and tightness of the covering layer 20, improving the sealing effect, and reducing the gap between the covering layer 20 and the electrode assembly 10.

[0139] In some optional embodiments, the thickness of the coating layer 20 is 30 to 150 μm. Optionally, the thickness of the coating layer 20 can be any value or a combination thereof from 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, and 150 μm. A thickness of the coating layer 20 within the above range is advantageous in providing good strength and can form a good connection while improving the local strength of the coating layer 20 under high temperature and / or high pressure, which is beneficial for fixing the electrode assembly 10, reducing electrode displacement, and reducing gas infiltration into the electrode assembly 10.

[0140] In some optional embodiments, the material of the coating layer 20 includes one or more of polyethylene, polypropylene, polytetrafluoroethylene, polyimide, polyethylene terephthalate, acrylic acid, natural rubber, acrylate, nonwoven fabric, washi paper, and paraffin wax. The material of the coating layer 20 has high strength and can form a good connection while improving the local strength of the coating layer 20 at high temperature and / or high pressure, which is beneficial for fixing the electrode assembly 10, reducing electrode displacement, and reducing gas infiltration into the electrode assembly 10.

[0141] In some optional embodiments, the coating layer 20 includes holes perpendicular to the surface direction of the electrode assembly 10. That is, the channels of the holes can be perpendicular to the surface direction of the electrode assembly 10. The holes can be through holes, blind holes, countersunk holes, etc. In some optional embodiments, the coating layer 20 includes holes parallel to the surface of the electrode assembly 10. That is, the channels of the holes can be parallel to the surface direction of the electrode assembly 10. This arrangement is beneficial for determining whether the position of the coating layer 20 has shifted during the production of the solid-state battery cell 7 or for observing the state of the internal electrode assembly 10.

[0142] In some alternative embodiments, the cladding layer 20 includes reinforcing structures located at the edges or corners of the electrode assembly 10. These reinforcing structures can be stiffeners or thickened cladding sheets at these locations. The inclusion of reinforcing structures reduces the risk of wrinkles in the cladding layer 20 at the edges or corners of the electrode assembly, ensuring coherence and stability of the cladding connection, improving the smoothness of the cladding layer 20 surface, and enhancing structural integrity.

[0143] Based on the same concept, this application also provides a method for manufacturing a solid-state battery cell. This will be explained in detail with reference to Figure 7.

[0144] Figure 7 shows a schematic diagram of the manufacturing process of some solid-state battery cells in this application.

[0145] As shown in Figure 7, the manufacturing method of this solid-state battery cell may specifically include steps 100 to 300. Details are as follows:

[0146] Step 100: Provide an electrode assembly 10 and a covering sheet including a first bonding area 21 and a second bonding area 22, and adhere the first bonding area 21 to the electrode sheet to be applied in the electrode assembly 10; wherein, the electrode assembly 10 includes a plurality of first electrodes and a plurality of second electrodes stacked along a first direction X, the electrode assembly 10 also includes a first surface 101 and a tab lead-out surface 103 and a second surface 102 adjacent to and connected to the first surface 101, the first surface 101 is located on the electrode sheet to be applied, the second bonding area 22 is distributed around the first bonding area 21, and the bonding strength a' of the first bonding area 21 is less than the bonding strength b' of the second bonding area 22.

[0147] In this step, the covering sheet can be one, two, or three pieces. For example, one covering sheet can be placed on the surface of the electrode to be attached for subsequent coating of the electrode assembly 10. Alternatively, two covering sheets can be placed on the surfaces of two electrode pieces to be attached, respectively, to coat the electrode assembly 10 from both top and bottom. The electrode pieces at both ends of the electrode assembly 10 can be referred to as the electrode pieces to be attached. The covering sheet can be adhesive tape, adhesive paper, etc.

[0148] In some optional embodiments, the bonding strength of the first bonding area 21 is 0.1 to 10 N / m. Optionally, the bonding strength of the first bonding area 21 can be any value or a range thereof from 0.1 N / m, 0.2 N / m, 0.3 N / m, 0.4 N / m, 0.5 N / m, 0.6 N / m, 0.7 N / m, 0.8 N / m, 0.9 N / m, 1.0 N / m, 2 N / m, 3 N / m, 4 N / m, 5 N / m, 6 N / m, 7 N / m, 8 N / m, 9 N / m, and 10 N / m. When the bonding strength of the first bonding area 21 is within the above range, it provides a certain degree of adhesion to the first surface 101, which is beneficial for fixing one end of the covering sheet and realizing the covering sheet covering the electrode assembly 10.

[0149] In some optional embodiments, the bonding strength of the second bonding region 22 is 20–200 N / m. Optionally, the bonding strength of the second bonding region 22 can be any value or a range thereof from 20 N / m, 30 N / m, 40 N / m, 50 N / m, 60 N / m, 70 N / m, 80 N / m, 90 N / m, 100 N / m, 110 N / m, 120 N / m, 130 N / m, 140 N / m, 150 N / m, 160 N / m, 170 N / m, 180 N / m, 190 N / m, and 200 N / m. A bonding strength of the second bonding region 22 within the above range facilitates fixing the relative position of the electrodes during cell movement and isostatic pressing processes, reduces sliding displacement, and also reduces failures caused by electrolyte exposure, thereby improving the stability of the cell.

[0150] Step 200: At least a portion of the second adhesive area 22 of the covering sheet is adhered to the second surface 102 of the electrode assembly 10 to form a battery cell.

[0151] In this step, the coating sheet is further wrapped around the surface of the electrode assembly 10 to further fix the electrode assembly 10 and reduce the positional movement of each electrode in the electrode assembly 10 and electrolyte failure.

[0152] Step 300: Place the battery cell in the housing 30 to obtain a solid-state battery cell 7.

[0153] According to the manufacturing method of the solid-state battery cell 7 in this application embodiment, by adhering the first bonding area 21 of the coating sheet to the electrode sheet to be bonded, the components in the cell are fixedly combined together, reducing the distance / risk of slippage / separation between the electrodes, and also reducing the amount of electrolyte failure caused by cell delamination, thereby improving the yield of the solid-state battery cell 7. Therefore, the stability of the cell during the manufacturing process is improved, as is the operational stability of the solid-state battery cell 7.

[0154] The method for manufacturing solid-state battery cells provided in this application can prepare any solid-state battery cell described in the above embodiments. The materials used and the resulting structure can be the same, and will not be elaborated further here.

[0155] In some optional embodiments, step 100, providing an electrode assembly 10 and a covering sheet including a first adhesive region 21 and a second adhesive region 22, and adhering the first adhesive region 21 to the electrode assembly 10 to be fitted with an electrode sheet, includes:

[0156] Step 110: Provide two covering sheets, and attach the first bonding area 21 of the two covering sheets to two electrodes to be applied, respectively, to form two electrodes to be applied with covering sheets, wherein the two electrodes to be applied include at least one of the first electrode and the second electrode.

[0157] Step 120: Place two coated electrodes spaced apart in the first direction X such that the two surfaces of the uncoated sheet of the coated electrodes face each other to form a gap space;

[0158] Step 130: Stack multiple first electrodes and multiple second electrodes in the spacer along the first direction X.

[0159] This step can be understood as stacking multiple electrodes on the inner side of the electrodes to be applied at both ends. During the stacking process of this electrode assembly 10, the electrodes may have a first stacked section and a second stacked section, or there may be areas that are not stacked, such as the tab portion.

[0160] According to the manufacturing method of the solid-state battery cell 7 in this application embodiment, by adhering the first bonding area 21 of the coating sheet to two electrode sheets to be bonded, and stacking multiple first electrode sheets and multiple second electrode sheets in a spaced manner along the first direction X, the components in the cell are fixedly combined, reducing the distance / separation of sliding misalignment between the electrode sheets; therefore, during isostatic pressing and decoupling processes, the failure of solid electrolyte caused by cell decoupling is reduced, the amount of electrolyte failure in the cell is reduced, and the yield of the solid-state battery cell 7 is improved. Thus, the stability of the cell during the manufacturing process is improved, as is the operational stability of the solid-state battery cell 7.

[0161] Figure 8 shows a schematic planar structure of a covered sheet provided in some embodiments of this application. Figure 9 shows a schematic planar structure of another covered sheet provided in some embodiments of this application.

[0162] Referring to Figures 8 and 9, when the tabs of the prepared electrode assembly 10 are led out from one side, the first covering sheet and the second covering sheet respectively have a first bonding area 21 and a second bonding area 22. The first bonding area 21 is disposed inside the second bonding area 22, and the second bonding area 22 is located at the edges of the first covering sheet and the second covering sheet respectively. The second bonding area 22 is disposed on the edges of the first covering sheet and the second covering sheet on three sides respectively. When the tabs of the prepared electrode assembly 10 are led out from both sides, the first covering sheet and the second covering sheet respectively have a first bonding area 21 and a second bonding area 22; the first bonding area 21 is disposed inside the second bonding area 22, and the second bonding area 22 is located at the edges of the first covering sheet and the second covering sheet respectively. The second bonding area 22 is disposed on the edges of the first covering sheet and the second covering sheet on both sides respectively.

[0163] Figure 10 shows a schematic diagram of the process of coating electrode assemblies with coated sheet provided in some embodiments of this application.

[0164] Referring to Figure 10, the first adhesive area 21 of the first covering sheet adheres to the first surface 101 of an electrode to be attached, and the first adhesive area 21 of the second covering sheet adheres to the other surface of another electrode to be attached. Therefore, the electrode assembly 10 can be covered from both the top and bottom ends to form a covering layer 20.

[0165] In some alternative embodiments, after step 200, which involves adhering at least a portion of the second adhesive region 22 of the covering sheet to the second surface 102 of the electrode assembly 10, the method further includes:

[0166] Step 210 involves bonding the second adhesive areas 22 that are not attached to the second surface 102 together to obtain a battery cell covered by a covering sheet. Bonding the second adhesive areas 22 together increases the tightness of the covering material and improves the fixation effect on the electrode assembly 10.

[0167] It is understood that the covering sheet includes a first covering sheet and a second covering sheet, and the second adhesive area 22 is respectively disposed on the edge of the first covering sheet and the second covering sheet. The second adhesive area 22 is adhered to the second surface 102 along the first direction XX, so that the second adhesive areas 22 that are not attached to the second surface 102 are attached to each other.

[0168] Figure 11 shows another schematic diagram of the process of coating electrode assembly with a coated sheet provided in some embodiments of this application.

[0169] In step 210, the second adhesive areas 22 that are not adhered to the second surface 102 are brought together. The second adhesive areas 22 can be divided into a first sub-area 221 that adheres to the second surface 102 and a second sub-area 222 that does not adhere to the second surface 102. There are various ways to adhere the second sub-areas 222. For example, the adhesive surfaces of the second sub-areas 222 are brought together to form a folded portion, as shown in Figure 11. When the electrode assembly 10 surface is flattened in a subsequent process, the folded portion, as shown in Figure 5, is attached to the surface of the first sub-area 221.

[0170] In some alternative embodiments, after step 200, which involves adhering at least a portion of the second adhesive region 22 of the covering sheet to the second surface 102 of the electrode assembly 10, the method further includes:

[0171] Step 220: The surface of the battery cell is flattened to form the battery cell. Flattening the battery cell surface further improves the adhesion between the coating sheet and the electrode surface, fixing the components in the battery cell together and reducing the distance of sliding misalignment between the electrodes.

[0172] In this step, the flat pressing process allows the coating sheet to adhere well to the surface of the electrode assembly 10, reducing wrinkles and other defects. After the flat pressing process, the electrode assembly 10 covered by the coating sheet can be subjected to isostatic pressing. The isostatic pressing process generally involves coating the surface of the electrode assembly 10 with a static pressure film, followed by a film removal process.

[0173] Therefore, by attaching the coating sheet to the surface of the electrode assembly 10 and applying a flat pressing treatment to the surface of the electrode assembly 10, wrinkles on the surface of the coating sheet can be reduced. The coating sheet can also limit and fix the electrode to a certain extent, thereby improving the stability of the battery cell.

[0174] In some optional embodiments, in step 220, the pressure of the flattening treatment is 10–2000 MPa. Optionally, the pressure of the flattening treatment can be any value or a range of combinations thereof from 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, 1100 MPa, 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600 MPa, 1700 MPa, 1800 MPa, 1900 MPa, and 2000 MPa. Therefore, the covering sheet can be attached to and firmly bonded to the surface of the electrode assembly 10, which is beneficial for limiting the electrode in the electrode assembly 10 and improving the stability of the battery cell.

[0175] In some optional embodiments, in step 220, the flattening treatment temperature is 25–200°C. Optionally, the flattening treatment temperature can be any value or a range thereof from 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, and 200°C. This facilitates the adhesion of the adhesive surface of the coating sheet, better bonding it to the electrode assembly 10, improving the adhesion between the coating sheet and the surface of the electrode assembly 10, and enhancing the stability of the battery cell.

[0176] In some optional embodiments, step 220, the flattening treatment time is 3 to 20 minutes. Optionally, the flattening treatment time can be any value or a range of combinations thereof from 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, and 20 minutes. Therefore, the adhesion between the coating sheet and the surface of the electrode assembly 10 can be improved, thereby enhancing the stability of the battery cell.

[0177] In some optional embodiments, before step 300, placing the cell in the housing 30 to obtain the solid-state battery cell 7, the method further includes step 230, performing isostatic pressing on the cell. Due to the presence of the covering sheet, the distance / separation of the sliding misalignment between the electrodes is reduced during isostatic pressing, especially during the decoupling process; this reduces solid electrolyte failure caused by cell decoupling, reduces the amount of electrolyte failure in the cell, and improves the yield of the solid-state battery cell 7.

[0178] In some optional embodiments, step 230, the step of performing isostatic pressing on the battery cell, specifically includes:

[0179] The static pressure film is attached to the surface of the battery cell to obtain the battery cell to be shaped;

[0180] Place the battery cell to be shaped into the storage space;

[0181] A pressure medium is introduced to bring the storage space to the isostatic pressure condition required for the cell to be shaped, and the isostatic pressure condition is maintained for a preset time to obtain the cell after static pressure.

[0182] After static pressing, the cell is delaminated to obtain the cell.

[0183] In step 230 of this embodiment, the electrode assembly 10 is an electrode assembly 10 that is covered and fixed by a covering sheet. Following isostatic pressing and the decoupling process, the failure of the solid electrolyte caused by cell decoupling is reduced, the amount of electrolyte failure in the cell is decreased, and the yield of the solid-state battery cell 7 is improved. Therefore, the stability of the cell during the manufacturing process is improved, as is the operational stability of the solid-state battery cell 7.

[0184] As an example, the steps for isostatic pressing of a battery cell specifically include: fixing the battery cell, which has been sealed with a hydrostatic membrane, using a clamp; after the medium temperature and other parameters meet the standards, placing the clamp into the isostatic pressing chamber; sealing the plug; and pressurizing the medium to densify the battery cell. Densification then begins with depressurization, opening the plug, removing the clamp from the chamber, and finally disassembling the clamp to obtain the densified battery cell.

[0185] In some alternative embodiments, the thickness of the hydrostatic membrane is from 50 μm to 300 μm, and optionally from 60 μm to 110 μm.

[0186] In some alternative embodiments, the isostatic pressing membrane is made of one or more of the following materials: aluminum-plastic film, polypropylene, polyethylene, and polyethylene terephthalate. The above-mentioned types of isostatic pressing membranes can effectively encapsulate battery materials, ensuring that pressure is evenly distributed throughout the battery material during isostatic pressing, reducing defects (such as pores and cracks) generated during the process, and preventing the ingress of oxygen and moisture. This reduces the impact of material oxidation and moisture on battery performance, thereby ensuring that solid-state battery cells maintain ideal environmental conditions during isostatic pressing.

[0187] In some alternative implementations, the vacuum level in the storage space is -101 to -80 kPa. For example, the vacuum level can be -95 kPa, -90 kPa, -88 kPa, -85 kPa, etc.

[0188] In some optional embodiments, the vacuum holding time under isostatic pressure conditions is 1 to 10 minutes. For example, the vacuum holding time can be 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc.

[0189] In some optional embodiments, the temperature under isostatic pressure conditions is 25–1000°C. Optionally, the temperature can be 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, etc.

[0190] In some optional embodiments, the pressure in the isostatic pressure condition is 100–2000 MPa. Optionally, the pressure in the isostatic pressure condition can be any value or a range of combinations thereof from 100 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, 1100 MPa, 1200 MPa, 1300 MPa, 1400 MPa, 1500 MPa, 1600 MPa, 1700 MPa, 1800 MPa, 1900 MPa, and 2000 MPa.

[0191] In some optional embodiments, the preset time length for isostatic pressing is 5 to 60 minutes. Optionally, the preset time length can be any value or a range of combinations thereof from 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 30 min, 40 min, 50 min, and 60 min.

[0192] In some alternative embodiments, the pressure medium under isostatic conditions is one or more of an inert gas and oil. The oil can be mineral oil, water-based liquid oil, or synthetic ester oil, such as polyol esters or diesters.

[0193] Embodiments of this application also provide a solid-state battery cell 7, which is manufactured using the manufacturing method of the solid-state battery cell 7 described in the above embodiments. In this solid-state battery cell 7, the connection efficiency and connection strength of the coating layer 20 are improved by connecting two coating sheets. Optionally, reinforcing structures or through holes can be provided in the coating layer 20 to improve local strength, or the position of the coating layer 20 can be visualized to improve the limiting and fixing performance of the coating layer 20, thereby improving the operational stability of the solid-state battery cell 7.

[0194] Example

[0195] The following examples describe the contents of this disclosure in more detail. These examples are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on mass, and all reagents used in the examples are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0196] Example 1

[0197] This application provides a method for manufacturing a solid-state battery cell, including:

[0198] Two covering sheets are provided, namely M6U adhesive tape, which is made of polyethylene and includes a first bonding area and a second bonding area; the first bonding area is located on the inner side, as shown in Figure 8; the bonding strengths of the first bonding area and the second bonding area are 5 N / m and 40 N / m, respectively;

[0199] An electrode assembly is provided, wherein the electrode assembly includes a negative electrode sheet, a solid electrolyte and a positive electrode sheet, the negative electrode sheet includes a negative current collector and a base coating disposed on the surface of the negative current collector, and at least one surface of any negative electrode sheet is in contact with the solid electrolyte;

[0200] The first adhesive areas of the two covering sheets are respectively adhered to the first surfaces of the electrode sheets to be applied in the two electrode assemblies, forming two electrode sheets with covering sheets, and the first adhesive areas are attached to the first surfaces.

[0201] At least a portion of the second bonding area of ​​the covering sheet is adhered to the second surface of the electrode assembly to form a battery cell; the battery cell is pressed together by flat pressing at a pressure of 20 MPa, a temperature of 90°C, and a time of 5 min.

[0202] Shape the adhesive tape of the integrated battery cell; after shaping, laminate it to achieve full coverage of the surface of the battery cell's de-electrode side; the excess second bonding areas are bonded together, as shown in Figure 11;

[0203] The battery cell is subjected to isostatic pressing. The isostatic pressing film is made of aluminum-plastic film. Solid-state battery cells are obtained by isostatic pressing. The isostatic pressing medium is helium gas, pressure is 300 MPa, temperature is 500℃, and time is 10 min.

[0204] The cell is placed in the casing to obtain a solid-state battery cell, wherein the first bonding area and the first surface have a first peel strength a, the second bonding area and the second surface have a second peel strength b, and the first peel strength a is less than the second peel strength b.

[0205] Examples 2-5

[0206] Except for the following differences, the preparation of the battery cells is the same as in Example 1.

[0207] The bonding strength of the first bonding area and the second bonding area are different, as shown in Table 1.

[0208] Example 6

[0209] Except for the following differences, the preparation of the battery cells is the same as in Example 1.

[0210] Two covering sheets are provided, namely M6U adhesive tape, which is made of polyethylene and includes a first bonding area and a second bonding area; the first bonding area is located on the inner side, as shown in Figure 9; the bonding strengths of the first bonding area and the second bonding area are 5 N / m and 40 N / m, respectively;

[0211] An electrode assembly is provided, wherein the tabs of the electrode assembly are led out on both sides.

[0212] Example 7

[0213] Except for the following differences, the preparation of the battery cells is the same as in Example 1.

[0214] The difference between the preparation of the battery cell in this embodiment and that in Embodiment 1 is that the bonding strength between the first bonding area and the second bonding area is 5 N / m.

[0215] Example 8

[0216] Except for the following differences, the preparation of the battery cells is the same as in Example 1.

[0217] The difference between the preparation of the battery cell in this embodiment and that in Embodiment 1 is that the bonding strength of the first bonding area and the second bonding area is 40 N / m.

[0218] Comparative Example 1

[0219] The preparation of the battery cell in this comparative example differs from that in Example 1 in that it does not use two coating sheets to coat the electrode assembly, but directly obtains the battery cell. The battery cell is directly subjected to isostatic pressing, with the isostatic pressing film material being an aluminum-plastic film. The isostatic pressing is performed to obtain a solid-state battery cell, with helium gas as the isostatic pressing medium, a pressure of 300 MPa, a temperature of 500°C, and a time of 10 min.

[0220] By placing the battery cell in the casing, a solid-state battery cell is obtained.

[0221] Performance testing

[0222] 1) Testing the failure rate of solid electrolyte in solid-state battery cells: The solid-state battery cells prepared in the above embodiments or comparative examples were subjected to internal resistance testing. The test environment temperature was 60℃, and the cells were charged to 50% SOC using a 0.1C method. A current pulse of 10A was used to test the AC internal resistance during charge and discharge. If the internal resistance was ≤10000mΩ, the solid electrolyte in the solid-state battery cell was considered to be without failure; otherwise, the solid electrolyte was considered to have failed. The solid electrolyte failure rate of 1000 sets of solid-state battery cells was tested.

[0223] Solid electrolyte failure rate = number of solid electrolytes that did not fail / 1000 × 100%.

[0224] 2) Solid-state battery cell yield: The yield rate of solid-state battery cells is tested for the appearance of the cells, the positional misalignment of the positive and negative electrode plates stacked within the cells, and the failure of the solid electrolyte. A cell is considered good if all three conditions are within acceptable limits. The yield rate of 1000 sets of solid-state battery cells is tested.

[0225] Yield rate = (Number of good products / 1000) × 100%

[0226] 3) Cell decoupling rate: The cells with the static pressure membrane removed after the isostatic pressing process are tested. If the negative electrode plate in the cell is separated from the solid electrolyte, it is decoupling, as shown in Figure 12; if the negative electrode plate in the cell is separated from the solid electrolyte, it is a qualified product, as shown in Figure 13.

[0227] Cell stripping ratio = number of cells stripped / 1000 × 100%.

[0228] In Table 1, the electrode assembly of the embodiment is covered with a coating sheet to form a coating layer, which fixes the relative positions of the electrodes in the cell. The bonding strength of the coating sheet at different positions is appropriate, effectively reducing cell delamination and solid electrolyte failure, as well as reducing electrode slippage and improving the yield of solid-state battery cells. In contrast, the comparative example does not use a coating sheet to fix the electrodes in the cell, resulting in a lower yield, severe cell delamination, and some solid electrolyte failure.

[0229] In Example 7, the bonding strength of the second bonding area is insufficient, resulting in insufficient binding force on the battery cell and making it easy for some battery cells to fail due to delamination. In Example 8, the adhesiveness of the first bonding area is too high, and the adhesive tape is prone to wrinkling during the manufacturing process, causing large-area wrinkling of the adhesive tape and resulting in some battery cells having unqualified appearance. However, compared with Comparative Example 1, which did not have a covering sheet, the performance in all aspects has been improved to a certain extent.

[0230] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. 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 solid-state battery cell, wherein, Includes a housing and a battery cell disposed within the housing, the battery cell comprising: An electrode assembly includes a plurality of first electrode plates and a plurality of second electrode plates. The first electrode plates include at least one first stacked segment, and the second electrode plates include at least one second stacked segment. The first stacked segment and the second stacked segment are stacked along a first direction. The electrode assembly also includes a first surface and a tab lead-out surface and a second surface that are adjacent to and connected to the first surface. The first surface is perpendicular to the first direction. A coating layer is disposed around the outer periphery of the electrode assembly. The coating layer includes a first adhesive area and a second adhesive area. The coating layer covers the first surface through the first adhesive area and covers the second surface through the second adhesive area. Wherein, the first peel strength 'a' between the first adhesive area and the first surface, the second peel strength 'b' between the second adhesive area and the second surface, and the first peel strength 'a' is less than the second peel strength 'b'.

2. The solid-state battery cell according to claim 1, wherein, The coating layer satisfies one or more of the following conditions: 1) The first peel strength α between the first adhesive area and the first surface is 5 N / m to 20 N / m; 2) The second peel strength b between the second adhesive area and the second surface is 80 N / m to 350 N / m.

3. The solid-state battery cell according to claim 1 or 2, wherein, The coating layer satisfies one or more of the following conditions: 1) The first peel strength α between the first adhesive area and the first surface is 6 N / m to 15 N / m; 2) The second peel strength b between the second adhesive area and the second surface is 100 N / m to 280 N / m.

4. The solid-state battery cell according to any one of claims 1 to 3, wherein, The first electrode is a negative electrode, which includes a negative current collector and a base coating disposed on the surface of the negative current collector. At least one side of any one of the negative electrode electrodes is provided with a solid electrolyte.

5. The solid-state battery cell according to any one of claims 1 to 4, wherein, The area of ​​the first bonding region is greater than or equal to the area of ​​the first surface; and / or, The area of ​​the second surface is smaller than the area of ​​the second bonding area.

6. The solid-state battery cell according to claim 5, wherein, The second bonding area includes a first sub-area and a second sub-area that are in contact with the second surface, and the bonding surfaces of the second sub-area are in contact with each other.

7. The solid-state battery cell according to claim 6, wherein, The adhesive surfaces of the second sub-region are bonded together to form the second adhesive area, which is close to the second surface.

8. The solid-state battery cell according to claim 6 or 7, wherein, The width of the second sub-region is 2 to 10 mm.

9. The solid-state battery cell according to any one of claims 1 to 8, wherein, The first bonding area satisfies one or more of the following conditions: 1) The width of the first bonding area is the width of the first surface; 2) The length of the first bonding area is the length of the first surface.

10. The solid-state battery cell according to any one of claims 1 to 9, wherein, The battery cell meets one or more of the following conditions: 1) The thickness of the coating layer is 30 micrometers to 150 micrometers; 2) The material of the coating layer includes one or more of polyethylene, polypropylene, polytetrafluoroethylene, polyimide, polyethylene terephthalate, acrylic acid, natural rubber, acrylate, non-woven fabric, paper and paraffin wax.

11. A method for manufacturing a solid-state battery cell, wherein, include: An electrode assembly and a covering sheet including a first adhesive region and a second adhesive region are provided, and the first adhesive region is adhered to the electrode assembly to be applied to an electrode sheet; wherein, the electrode assembly includes a plurality of first electrode sheets and a plurality of second electrode sheets stacked along a first direction, the electrode assembly further includes a first surface and a tab lead-out surface and a second surface adjacent to and connected to the first surface, the first surface is located on the electrode sheet to be applied, the second adhesive region is distributed along the periphery of the first adhesive region, and the adhesive strength a' of the first adhesive region is less than the adhesive strength b' of the second adhesive region; At least a portion of the second adhesive area of ​​the covering sheet is adhered to the second surface of the electrode assembly to form a battery cell; The battery cell is placed in a housing to obtain the solid-state battery cell.

12. The manufacturing method according to claim 11, wherein, The provision of an electrode assembly and a covering sheet including a first adhesive region and a second adhesive region, and the adhesion of the first adhesive region to the electrode assembly for application of an electrode sheet, includes: Two covering sheets are provided, and the first adhesive areas of the two covering sheets are respectively adhered to two electrodes to be applied, forming two electrodes with covering sheets, wherein the two electrodes to be applied include at least one of the first electrode and the second electrode. The two adhesive electrodes are spaced apart in the first direction, such that the two surfaces of the adhesive electrodes that are not covered with the covering sheet are placed opposite each other to form a gap space; Multiple first electrodes and multiple second electrodes are stacked in the spaced space along the first direction.

13. The manufacturing method according to claim 11, wherein, The step of adhering at least a portion of the second adhesive region of the covering sheet to the second surface of the electrode assembly to form a battery cell includes: At least a portion of the second adhesive area of ​​the covering sheet is adhered to the second surface of the electrode assembly; The surface of the battery cell is flattened to form the battery cell.

14. The manufacturing method according to claim 13, wherein, The manufacturing method satisfies one or more of the following conditions: 1) The pressure of the pressure treatment is 10-2000 MPa; 2) The temperature for the flattening treatment is 25–200℃; 3) The flattening treatment time is 3 to 20 minutes; 4) The bonding strength of the first bonding area is 0.1 to 10 N / m; 5) The bonding strength of the second bonding area is 20 to 200 N / m.

15. The manufacturing method according to any one of claims 11 to 14, wherein, Before placing the battery cell into the casing to obtain the solid-state battery cell, the method further includes: The battery cell is subjected to isostatic pressing.

16. The manufacturing method according to claim 15, wherein, The isostatic pressing treatment of the battery cell includes: The static pressure film is attached to the battery cell to obtain the battery cell to be shaped; Place the battery cell to be shaped into the storage space; A pressure medium is introduced to bring the storage space to the isostatic pressure condition required by the battery cell and the isostatic pressure condition is maintained for a preset time to obtain the battery cell after static pressure. The electrode assembly after static pressing is delaminated to form the battery cell.

17. The manufacturing method according to claim 16, wherein, In the step of performing isostatic pressing on the battery cell, the isostatic pressing process satisfies one or more of the following conditions: 1) The thickness of the hydrostatic membrane is 50 μm to 300 μm; 2) The material of the static pressure membrane includes one or more of aluminum-plastic film, polypropylene, polyethylene, and polyethylene terephthalate; 3) The initial vacuum level in the storage space is -101 to -80 kPa; 4) The vacuum holding time under the isostatic pressure conditions is 1 to 10 minutes; 5) The temperature under the isostatic pressure conditions is 25–1000℃; 6) The pressure under the isostatic pressure condition is 100–2000 MPa; 7) The preset time for the isostatic pressing treatment is 5 to 60 minutes; 8) The pressure medium in the isostatic pressure condition is one or more of inert gas and oil.

18. A battery device, wherein, Includes solid-state battery cells according to any one of claims 1 to 10 or solid-state battery cells obtained by the manufacturing method according to any one of claims 11 to 17.

19. An electrical appliance, wherein, Includes the battery device as described in claim 18.

Images