Battery cell and manufacturing method therefor, electrode assembly, battery device and electric device

Abstract

A battery cell and a manufacturing method therefor, an electrode assembly, a battery device and an electric device, relating to the field of batteries. The battery cell 20 comprises a casing 21 and a solid-state electrode assembly 22, the solid-state electrode assembly 22 being accommodated in the casing 21. The outer surface of the solid-state electrode assembly 22 is provided with electrolyte residues 23, which include electrolyte salts. The electrolyte salts can improve ionic conductivity and reduce the internal resistance of the battery cell 20.

Description

Battery cells and their manufacturing methods, electrode assemblies, battery devices and electrical devices Cross-references to related applications

[0001] This application claims priority to Chinese patent application filed on December 31, 2024, entitled “Battery cell and method of manufacturing thereof, electrode assembly, battery device and power device” (application number: 202411997456X), the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of batteries, and more specifically, to a battery cell and its manufacturing method, electrode assembly, battery device and power-consuming device. Background Technology

[0003] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology requires consideration of multiple design factors, such as energy density, cycle life, discharge capacity, and charge / discharge rate, as well as the battery's internal resistance. However, the internal resistance of batteries still needs further reduction. Summary of the Invention

[0004] This application provides a battery cell and its manufacturing method, electrode assembly, battery device, and power device, which can reduce the internal resistance of the battery.

[0005] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a housing and a solid electrode assembly, the solid electrode assembly being housed within the housing; wherein, the outer surface of the solid electrode assembly has electrolyte residue, the electrolyte residue including electrolyte salt.

[0006] The outer surface of the solid electrode assembly of the battery cell has electrolyte residue, which includes electrolyte salts. The electrolyte salts can improve ionic conductivity and reduce the internal resistance of the battery cell.

[0007] As an optional technical solution in this application embodiment, the electrolyte residue further includes at least one of sulfides, alcohols, and esters.

[0008] As an optional technical solution in this application embodiment, the electrolyte residue is uniformly distributed on the outer surface of the solid electrode assembly.

[0009] In the above technical solution, by making the electrolyte residue evenly distributed on the outer surface of the solid electrode assembly, it is beneficial to further improve the ionic conductivity and further reduce the internal resistance of the battery cell.

[0010] As an optional technical solution in this application embodiment, the solid electrode assembly includes a solid electrolyte layer and a plurality of electrodes. The solid electrolyte layer is disposed between two adjacent electrodes. Each electrode includes an active material layer. In the two adjacent electrodes, the active material layer facing the solid electrolyte layer located between the two adjacent electrodes has opposite polarities.

[0011] In the above technical solution, in two adjacent electrodes, the polarity of the active material layer facing the solid electrolyte layer between the two adjacent electrodes is opposite, and the polarity of the two active material layers adjacent to the solid electrolyte layer and located on both sides of the solid electrolyte layer is opposite. The solid electrolyte layer simultaneously plays the role of transporting ions and isolating the positive electrode active material layer and the negative electrode active material layer.

[0012] As an optional technical solution in this application embodiment, the plurality of electrode sheets include positive electrode sheets and negative electrode sheets, the positive electrode sheets, the solid electrolyte layer and the negative electrode sheets are stacked, and the solid electrolyte layer is disposed between the positive electrode sheets and the negative electrode sheets.

[0013] In the above technical solution, the solid electrode assembly includes a positive electrode sheet, a solid electrolyte layer and a negative electrode sheet stacked together. In this way, the solid electrode assembly is simple and convenient to manufacture and has a low cost.

[0014] As an optional technical solution in this application embodiment, the electrode includes a current collector, a positive active material layer, and a negative active material layer, wherein the positive active material layer and the negative active material layer are respectively disposed on both sides of the current collector.

[0015] In the above technical solution, by making the electrode sheet include a current collector, a positive electrode active material layer and a negative electrode active material layer, it is beneficial to make the battery cell have a higher energy density.

[0016] As an optional technical solution in this application embodiment, the active material layer includes a positive electrode active material layer, the positive electrode active material layer includes a lithium-containing compound, and the electrolyte salt includes a lithium salt.

[0017] In the above technical solution, both the positive electrode active material layer and the electrolyte salt contain lithium ions, which is beneficial to further reduce the internal resistance of the battery cell.

[0018] Secondly, embodiments of this application provide a method for manufacturing a battery cell, the method comprising: isostatically packing a first packaging bag containing a solid electrode assembly and an electrolyte; draining at least a portion of the electrolyte from the first packaging bag; and repackaging the solid electrode assembly to form a battery cell.

[0019] In the above technical solution, in this battery cell manufacturing method, the first packaging bag containing the solid electrode assembly and electrolyte is isostatically pressed. Because the electrolyte fills the cavity inside the first packaging bag, the pressure difference between the inside and outside of the first packaging bag remains consistent during isostatic pressing. This allows the first packaging bag, solid electrode assembly, and electrolyte to be compacted as a whole, which helps reduce the risk of breakage of the negative electrode sheet during isostatic pressing, facilitates the densification of the solid electrode assembly, and improves the reliability and energy density of the battery cell. Furthermore, the battery cell manufactured using this method has electrolyte residue on the outer surface of its solid electrode assembly. This electrolyte residue includes electrolyte salts, which can improve ionic conductivity and reduce the internal resistance of the battery cell.

[0020] As an optional technical solution in this application embodiment, the electrolyte includes at least one of electrolyte salts, sulfides, alcohols, and esters.

[0021] As an optional technical solution in this application embodiment, after the step of draining at least a portion of the electrolyte in the first packaging bag and before the step of repackaging the solid electrode assembly to form a battery cell, the battery cell manufacturing method further includes: drying the solid electrode assembly.

[0022] In the above technical solution, after at least part of the electrolyte in the first packaging bag is discharged, the solid electrode assembly is dried before repackaging the solid electrode assembly to reduce the residual liquid on the solid electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0023] As an optional technical solution in this application embodiment, the solid electrode assembly includes a positive electrode sheet, a solid electrolyte layer and a negative electrode sheet stacked together; after the step of drying the solid electrode assembly and before repackaging the solid electrode assembly to form a battery cell, the battery cell manufacturing method further includes: welding a positive electrode tab on the positive electrode sheet; and welding a negative electrode tab on the negative electrode sheet.

[0024] In the above technical solution, after drying the solid electrode assembly, welding a positive electrode tab onto the positive electrode sheet of the solid electrode assembly and welding a negative electrode tab onto the negative electrode sheet of the solid electrode assembly is beneficial to reducing the interference of the electrolyte on the welding and improving the welding quality.

[0025] As an optional technical solution in this application embodiment, the repackaging of the solid-state electrode assembly to form a battery cell includes: placing the solid-state electrode assembly into a second packaging bag and sealing the second packaging bag to form the battery cell.

[0026] In the above technical solution, by placing the solid electrode assembly into the second packaging bag, the battery cell has better sealing performance, which helps to improve the reliability of the battery cell.

[0027] As an optional technical solution in the embodiments of this application, in the step of isostatically pressing the first packaging bag containing the solid electrode assembly and electrolyte, the isostatic pressing time is controlled to be between 1 and 100 minutes.

[0028] In the above technical solutions, when the isostatic pressing time is greater than or equal to 1 minute, the longer isostatic pressing time is beneficial for improving the densification of the solid-state electrode assembly and increasing the energy density of the battery cell. When the isostatic pressing time is less than or equal to 100 minutes, the isostatic pressing time is not too long, which helps to shorten the manufacturing time of the battery cell and improve the manufacturing efficiency of the battery cell. Therefore, when the isostatic pressing time is controlled between 1 and 100 minutes, both the energy density and manufacturing efficiency of the battery cell can be balanced.

[0029] As an optional technical solution in this application embodiment, in the step of isostatically pressing the first packaging bag containing the solid electrode assembly and electrolyte, the isostatic pressing time is controlled to be 5 to 15 minutes.

[0030] In the above technical solutions, when the isostatic pressing time is greater than or equal to 5 minutes, the longer the isostatic pressing time, the more beneficial it is to improving the densification of the solid-state electrode assembly and increasing the energy density of the battery cell. When the isostatic pressing time is less than or equal to 15 minutes, the isostatic pressing time is not too long, which helps to shorten the manufacturing time of the battery cell and improve the manufacturing efficiency of the battery cell. Therefore, when the isostatic pressing time is controlled between 5 and 15 minutes, it is possible to better balance the energy density and manufacturing efficiency of the battery cell.

[0031] As an optional technical solution in this application embodiment, in the step of isostatically pressing a first packaging bag containing solid electrode components and electrolyte, the temperature of the isostatic pressing is controlled at 90-300°C.

[0032] In the above technical solution, when the isostatic pressing temperature is greater than or equal to 90℃, the higher temperature is beneficial for improving the binding properties of sulfides in the solid electrolyte layer and thus improving its ionic conductivity. When the isostatic pressing temperature is less than or equal to 300℃, the temperature is not too high, which helps reduce the risk of spontaneous combustion of the solid electrode assembly. Therefore, when the isostatic pressing temperature is controlled between 90 and 300℃, both the ionic conductivity of the solid electrolyte layer and the risk of spontaneous combustion of the solid electrode assembly can be improved.

[0033] As an optional technical solution in this application embodiment, in the step of isostatically pressing a first packaging bag containing solid electrode components and electrolyte, the temperature of the isostatic pressing is controlled at 90-150°C.

[0034] In the above technical solution, when the isostatic pressing temperature is greater than or equal to 90℃, the relatively high temperature is beneficial for improving the binding properties of sulfides in the solid electrolyte layer and thus for increasing the ionic conductivity of the solid electrolyte layer. When the isostatic pressing temperature is less than or equal to 150℃, the temperature is not too high, which helps to further reduce the risk of spontaneous combustion of the solid electrode assembly. Therefore, when the isostatic pressing temperature is controlled between 90 and 150℃, it is possible to both improve the ionic conductivity of the solid electrolyte layer and further reduce the risk of spontaneous combustion of the solid electrode assembly.

[0035] As an optional technical solution in the embodiments of this application, in the step of the first packaging bag containing the solid electrode assembly and electrolyte under isostatic pressure, the pressure of the isostatic pressure is controlled at 100-1000 MPa.

[0036] In the above technical solutions, when the isostatic pressure is greater than or equal to 100 MPa, the higher pressure is beneficial for improving the densification of solid-state electrode components and increasing the energy density of individual battery cells. When the isostatic pressure is less than or equal to 1000 MPa, the pressure is not too high, the requirements for production equipment are not too demanding, and production costs are easier to control. Therefore, when the isostatic pressure is controlled between 100 and 1000 MPa, both the energy density of individual battery cells and production costs can be balanced.

[0037] As an optional technical solution in the embodiments of this application, in the step of the first packaging bag containing the solid electrode assembly and electrolyte under isostatic pressure, the pressure of the isostatic pressure is controlled at 300-700 MPa.

[0038] In the above technical solutions, when the isostatic pressure is greater than or equal to 300 MPa, the higher pressure is more conducive to improving the densification of solid-state electrode components and increasing the energy density of individual battery cells. When the isostatic pressure is less than or equal to 700 MPa, the pressure is not too high, the requirements for production equipment are not too demanding, and production costs are easier to control. Therefore, when the isostatic pressure is controlled between 300 and 700 MPa, it is possible to better balance the energy density of individual battery cells and production costs.

[0039] As an optional technical solution in this application embodiment, before the step of isostatically packing the solid electrode assembly and electrolyte in the first packaging bag, the battery cell manufacturing method further includes: providing a solid electrode assembly; packing the solid electrode assembly into the first packaging bag; injecting electrolyte into the first packaging bag; and sealing the first packaging bag.

[0040] In the above technical solution, in the battery cell manufacturing method, by loading the solid-state electrode assembly into a first packaging bag and injecting electrolyte into the first packaging bag, the electrolyte can fill the cavity inside the first packaging bag, ensuring that the pressure difference between the inside and outside of the first packaging bag remains consistent during isostatic pressing of the solid-state electrode assembly. In this way, the first packaging bag, the solid-state electrode assembly, and the electrolyte are compacted as a whole, which helps reduce the risk of breakage of the negative electrode sheet during isostatic pressing, facilitates the densification of the solid-state electrode assembly, and improves the reliability and energy density of the battery cell.

[0041] As an optional technical solution in this application embodiment, the provision of the solid electrode assembly includes: providing a plurality of electrode sheets and providing a solid electrolyte layer; stacking the plurality of electrode sheets and the solid electrolyte layer, wherein the solid electrolyte layer is disposed between two adjacent electrode sheets.

[0042] In the above technical solution, by stacking multiple electrode sheets and solid electrolyte layers, the manufacturing process is simple and convenient, and the production cost is low. Furthermore, isostatic pressing of the solid electrode assembly helps to improve the density of the solid electrode assembly.

[0043] As an optional technical solution in this application embodiment, the plurality of electrode sheets include positive electrode sheets and negative electrode sheets, the positive electrode sheets, the solid electrolyte layer and the negative electrode sheets are stacked, and the solid electrolyte layer is disposed between the positive electrode sheets and the negative electrode sheets; in the step of stacking the plurality of electrode sheets and the solid electrolyte layer, the negative electrode sheet is controlled to exceed the positive electrode sheet by 0.1 to 10 mm in both its length and width directions.

[0044] In the above technical solutions, when the negative electrode sheet extends beyond the positive electrode sheet by 0.1 mm or more in both length and width, it helps reduce assembly difficulty and enables an overhang design. When the negative electrode sheet extends beyond the positive electrode sheet by less than or equal to 10 mm in both length and width, it helps reduce the volume of the solid-state electrode assembly, improves the internal space utilization of the battery cell, and increases the energy density of the battery cell. Therefore, when the negative electrode sheet extends beyond the positive electrode sheet by 0.1–10 mm in both length and width, it can both reduce assembly difficulty and enable an overhang design, while also increasing the energy density of the battery cell.

[0045] As an optional technical solution in this application embodiment, in the step of stacking multiple electrodes and the solid electrolyte layer, the negative electrode extends beyond the positive electrode by 0.3 to 3 mm in both the length and width directions.

[0046] In the above technical solutions, when the negative electrode sheet exceeds the positive electrode sheet by 0.3 mm or more in both length and width, it is more conducive to reducing assembly difficulty and realizing overhang design. When the negative electrode sheet exceeds the positive electrode sheet by less than or equal to 3 mm in both length and width, it is more conducive to reducing the volume of solid-state electrode assembly, improving the internal space utilization of the battery cell, and increasing the energy density of the battery cell. Therefore, when the negative electrode sheet exceeds the positive electrode sheet by 0.3 to 3 mm in both length and width, it can further reduce assembly difficulty, realize overhang design, and further improve the energy density of the battery cell.

[0047] As an optional technical solution in this application embodiment, after the step of stacking multiple electrode sheets and the solid electrolyte layer, the provision of the solid electrode assembly includes: hot pressing multiple electrode sheets and the solid electrolyte layer.

[0048] In the above technical solution, by hot-pressing multiple electrodes and solid electrolyte layers, a relatively stable solid electrode assembly structure is formed, which is beneficial for the solid electrode assembly to maintain its shape during subsequent operations.

[0049] Thirdly, embodiments of this application also provide an electrode assembly, which is a solid electrode assembly. The outer surface of the solid electrode assembly has electrolyte residue, which includes electrolyte salts.

[0050] As an optional technical solution in this application embodiment, the electrolyte residue further includes at least one of sulfides, alcohols, and esters.

[0051] As an optional technical solution in this application embodiment, the electrolyte residue is uniformly distributed on the outer surface of the solid electrode assembly.

[0052] In the above technical solution, by making the electrolyte residue evenly distributed on the outer surface of the solid electrode assembly, it is beneficial to further improve the ionic conductivity and further reduce the internal resistance of the battery cell.

[0053] As an optional technical solution in this application embodiment, the solid electrode assembly includes a solid electrolyte layer and a plurality of electrodes. The solid electrolyte layer is disposed between two adjacent electrodes. Each electrode includes an active material layer. In the two adjacent electrodes, the active material layer facing the solid electrolyte layer located between the two adjacent electrodes has opposite polarities.

[0054] In the above technical solution, in two adjacent electrodes, the polarity of the active material layer facing the solid electrolyte layer between the two adjacent electrodes is opposite, and the polarity of the two active material layers adjacent to the solid electrolyte layer and located on both sides of the solid electrolyte layer is opposite. The solid electrolyte layer simultaneously plays the role of transporting ions and isolating the positive electrode active material layer and the negative electrode active material layer.

[0055] As an optional technical solution in this application embodiment, the plurality of electrode sheets include positive electrode sheets and negative electrode sheets, the positive electrode sheets, the solid electrolyte layer and the negative electrode sheets are stacked, and the solid electrolyte layer is disposed between the positive electrode sheets and the negative electrode sheets.

[0056] In the above technical solution, the solid electrode assembly includes a positive electrode sheet, a solid electrolyte layer and a negative electrode sheet stacked together. In this way, the solid electrode assembly is simple and convenient to manufacture and has a low cost.

[0057] As an optional technical solution in this application embodiment, the electrode includes a current collector, a positive active material layer, and a negative active material layer, wherein the positive active material layer and the negative active material layer are respectively disposed on both sides of the current collector.

[0058] In the above technical solution, by making the electrode sheet include a current collector, a positive electrode active material layer and a negative electrode active material layer, it is beneficial to make the battery cell have a higher energy density.

[0059] As an optional technical solution in this application embodiment, the active material layer includes a positive electrode active material layer, the positive electrode active material layer includes a lithium-containing compound, and the electrolyte salt includes a lithium salt.

[0060] In the above technical solution, both the positive electrode active material layer and the electrolyte salt contain lithium ions, which is beneficial to further reduce the internal resistance of the battery cell.

[0061] Fourthly, embodiments of this application also provide a battery device, the battery device comprising the aforementioned battery cell.

[0062] Fifthly, embodiments of this application also provide an electrical device, the electrical device including the aforementioned battery cell, the battery cell being used to provide electrical energy to the electrical device. Attached Figure Description

[0063] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0064] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0065] Figure 2 is an exploded view of a battery device provided in some embodiments of this application;

[0066] Figure 3 is an exploded view of a single battery cell provided in some embodiments of this application;

[0067] Figure 4 is a cross-sectional view of a solid-state electrode assembly provided in some embodiments of this application;

[0068] Figure 5 is a cross-sectional view of a solid-state electrode assembly provided in some other embodiments of this application;

[0069] Figure 6 is a schematic block diagram of a battery cell manufacturing method provided in some embodiments of this application;

[0070] Figure 7 is a schematic block diagram of a battery cell manufacturing method provided in some other embodiments of this application;

[0071] Figure 8 is a schematic block diagram of a battery cell manufacturing method provided in some embodiments of this application;

[0072] Figure 9 is a schematic block diagram of a battery cell manufacturing method provided in some embodiments of this application;

[0073] Figure 10 is a schematic block diagram of a battery cell manufacturing method provided in some other embodiments of this application;

[0074] Figure 11 is a schematic block diagram of a battery cell manufacturing method provided in some other embodiments of this application;

[0075] Figure 12 is a schematic block diagram of a battery cell manufacturing method provided in some other embodiments of this application.

[0076] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Casing; 211-Shell; 212-End cap; 22-Solid electrode assembly; 221-Electrode; 2211-Negative electrode; 2212-Positive electrode; 2213-Current collector; 2214-Negative active material layer; 2215-Positive active material layer; 222-Solid electrolyte layer; 23-Electrolyte residue; 30-Battery cell manufacturing method; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0078] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0079] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0080] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0081] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0082] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0083] In this application, "multiple" means two or more (including two).

[0084] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0085] A single battery cell typically includes a solid-state electrode assembly. This assembly comprises a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a battery cell, active ions repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0086] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0087] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0088] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0089] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0090] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0091] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0092] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0093] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0094] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0095] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0096] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0097] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0098] As an example, inorganic solid electrolytes may include 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 phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0099] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0100] In some implementations, the solid-state electrode assembly is a stacked structure.

[0101] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0102] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0103] In some implementations, the solid-state electrode assembly has tabs that allow current to be drawn from the solid-state electrode assembly. The tabs include a positive tab and a negative tab.

[0104] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as solid-state electrode assemblies. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0105] 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 a busbar.

[0106] 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 multiple battery cells and fixing them together to form an independent module.

[0107] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0108] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0109] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0110] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0111] As an example, the enclosure may include a first part and a second part. The first and second parts are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or shutting off; it can be sealed or not sealed. The first part may be a top cover or a bottom plate.

[0112] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0113] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0114] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0115] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0116] The development of battery technology requires consideration of multiple design factors, such as energy density, cycle life, discharge capacity, and charge / discharge rate. Additionally, the battery's internal resistance also needs to be taken into account. However, the internal resistance of current batteries still needs further reduction.

[0117] Solid-state batteries are characterized by high energy density, and their application in new energy vehicles will significantly improve their range. Solid-state batteries consist of solid-state electrode components, which in turn include a solid-state electrolyte layer. Currently, the ionic conductivity of the solid-state electrolyte layer is relatively low, which means the battery's internal resistance needs further reduction.

[0118] Therefore, this application provides a battery cell, which includes a casing and a solid-state electrode assembly housed within the casing. The outer surface of the solid-state electrode assembly has electrolyte residue, which includes electrolyte salts.

[0119] The outer surface of the solid electrode assembly of the battery cell has electrolyte residue, which includes electrolyte salts. The electrolyte salts can improve ionic conductivity and reduce the internal resistance of the battery cell.

[0120] The technical solutions described in this application are applicable to the manufacture of battery cells. The battery cells are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0121] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0122] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0123] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0124] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0125] Please refer to Figure 2, which is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and battery cells 20, with the housing 10 used to house the battery cells 20.

[0126] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first part 11 and a second part 12, which are interlocked. The first part 11 and the second part 12 can have various shapes, such as cuboids or cylinders. The first part 11 can be a hollow structure open on one side, and the second part 12 can also be a hollow structure open on one side. The open side of the second part 12 interlocks with the open side of the first part 11, thus forming a housing 10 with an enclosed space. Alternatively, the first part 11 can be a hollow structure open on one side, and the second part 12 can be a plate-like structure, with the second part 12 interlocking with the open side of the first part 11, thus forming a housing 10 with an accommodating space.

[0127] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first 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, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0128] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0129] Please refer to Figures 3 and 4. Figure 3 is an exploded view of a battery cell 20 provided in some embodiments of this application. Figure 4 is a cross-sectional view of a solid-state electrode assembly 22 provided in some embodiments of this application. This application provides a battery cell 20, which includes a housing 21 and a solid-state electrode assembly 22, the solid-state electrode assembly 22 being housed within the housing 21. The outer surface of the solid-state electrode assembly 22 has electrolyte residue 23, which includes electrolyte salts.

[0130] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0131] In some embodiments, the housing 21 may include a housing 211 and an end cap 212, the housing 211 having an opening and the end cap 212 closing the opening of the housing 211. Here, "closing" refers to covering or shutting down, and can be either sealed or unsealed.

[0132] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 212 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved reliability. The material of end cap 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0133] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the solid-state electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the solid-state electrode assembly 22. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0134] In an embodiment where the housing 211 has an opening at one end, one end cap 212 may be provided. In an embodiment where the housing 211 has openings at both opposite ends, two end caps 212 may be provided. The two end caps 212 respectively close the two openings of the housing 211, and the two end caps 212 and the housing 211 together define a receiving space for accommodating the solid electrode assembly 22.

[0135] The solid electrode assembly 22 includes a solid electrolyte layer, which may include a polymer solid electrolyte layer, an inorganic solid electrolyte layer, or a composite solid electrolyte layer.

[0136] As an example, the polymer solid electrolyte layer can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymer, polyionic liquid-lithium salt, cellulose, etc.

[0137] As an example, the inorganic solid electrolyte layer may include 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 sulfide, silver germanium sulfide), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0138] As an example, a composite solid electrolyte layer is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0139] The outer surface of the solid electrode assembly 22 has electrolyte residue 23, which is the residue remaining after the electrolyte has dried. The electrolyte residue 23 includes electrolyte salts, which may include lithium hexafluorophosphate, lithium tetrafluoroborate, etc.

[0140] Electrolyte residue 23 can be detected by EDS (Energy Dispersive Spectrometer) or XPS (X-ray Photoelectron Spectroscopy).

[0141] The outer surface of the solid electrode assembly 22 of the battery cell 20 has electrolyte residue 23, which includes electrolyte salt. The electrolyte salt can improve ionic conductivity and reduce the internal resistance of the battery cell 20.

[0142] In some embodiments, electrolyte residue 23 further includes at least one of sulfides, alcohols, and esters.

[0143] Sulfides can include nickel sulfide, lithium phosphine oxysulfide, lithium sulfide, etc. Alcohols can include methanol, ethanol, benzyl alcohol, etc. Lipids can include monoglycerides, diglycerides, triglycerides, etc.

[0144] In some embodiments, electrolyte residue 23 is uniformly distributed on the outer surface of the solid electrode assembly 22.

[0145] Electrolyte residue 23 is uniformly distributed on the outer surface of the solid electrode assembly 22. Here, uniform distribution means relatively uniform, not completely uniform.

[0146] By uniformly distributing the electrolyte residue 23 on the outer surface of the solid electrode assembly 22, it is beneficial to further improve the ionic conductivity and further reduce the internal resistance of the battery cell 20.

[0147] Referring to Figures 3 and 4, in some embodiments, the solid-state electrode assembly 22 includes a solid electrolyte layer 222 and a plurality of electrodes 221, wherein the solid electrolyte layer 222 is disposed between two adjacent electrodes 221. Each electrode 221 includes an active material layer, and in two adjacent electrodes 221, the active material layers facing the solid electrolyte layer 222 located between the two adjacent electrodes have opposite polarities.

[0148] "In two adjacent electrodes 221, the polarity of the active material layer facing the solid electrolyte layer 222 between the two adjacent electrodes 221 is opposite." That is, in two adjacent electrodes 221, the polarity of the active material layer facing the solid electrolyte layer 222 between the two adjacent electrodes 221 of one electrode 221 is opposite to that of the active material layer facing the solid electrolyte layer 222 between the two adjacent electrodes 221 of the other electrode 221. In other words, in two adjacent electrodes 221, the active material layer facing the solid electrolyte layer 222 between the two adjacent electrodes of one electrode 221 is the positive electrode active material layer 2215, and the active material layer facing the solid electrolyte layer 222 between the two adjacent electrodes of the other electrode 221 is the negative electrode active material layer 2214.

[0149] In two adjacent electrodes 221, the polarity of the active material layer facing the solid electrolyte layer 222 located between the two adjacent electrodes 221 is opposite. The polarity of the two active material layers adjacent to the solid electrolyte layer 222 and located on both sides of the solid electrolyte layer 222 is opposite. The solid electrolyte layer 222 simultaneously plays the role of transporting ions and isolating the positive electrode active material layer 2215 and the negative electrode active material layer 2214.

[0150] Referring to Figures 3 and 4, in some embodiments, the plurality of electrodes 221 include a positive electrode 2212 and a negative electrode 2211, and the positive electrode 2212, the solid electrolyte layer 222, and the negative electrode 2211 are stacked. The solid electrolyte layer 222 is disposed between the positive electrode 2212 and the negative electrode 2211.

[0151] The positive electrode 2212 includes a positive current collector and a positive active material, the positive active material being coated on the surface of the positive current collector. In some embodiments, the positive current collector also has a portion uncoated with positive active material, the uncoated portion protruding from the coated portion, serving as a positive electrode tab. In other embodiments, the positive electrode tab may be separately disposed from the positive current collector and then electrically connected.

[0152] The negative electrode sheet 2211 includes a negative electrode current collector and a negative electrode active material, the negative electrode active material being coated on the surface of the negative electrode current collector. In some embodiments, the negative electrode current collector also has a portion uncoated with negative electrode active material, the uncoated portion protruding from the coated portion, and serving as a negative electrode tab. In other embodiments, the negative electrode tab may be separately disposed from the negative electrode current collector and then electrically connected.

[0153] Electrolyte residue 23 is present on the outer surface of the positive electrode 2212, the outer surface of the solid electrolyte layer 222, and the outer surface of the negative electrode 2211.

[0154] The solid electrolyte layer 222 is disposed between the positive electrode 2212 and the negative electrode 2211, and serves to both transport ions and isolate the positive electrode 2212 and the negative electrode 2211.

[0155] The solid electrode assembly includes a positive electrode 2212, a solid electrolyte layer 222, and a negative electrode 2211 stacked together. This makes the solid electrode assembly simple and convenient to manufacture, and at a low cost.

[0156] Please refer to Figure 5, which is a cross-sectional view of a solid-state electrode assembly provided in some other embodiments of this application. In some other embodiments, the electrode 221 includes a current collector 2213, a positive electrode active material layer 2215, and a negative electrode active material layer 2214, with the positive electrode active material layer 2215 and the negative electrode active material layer 2214 respectively disposed on both sides of the current collector 2213.

[0157] Electrode 221 is a bipolar electrode. A positive electrode active material layer 2215 is provided on one side of electrode 221, and a negative electrode active material layer 2214 is provided on the other side of electrode 221.

[0158] Electrolyte residue 23 is present on the outer surface of the current collector 2213, the outer surface of the positive electrode active material layer 2215, and the outer surface of the negative electrode active material layer 2214.

[0159] By including a current collector 2213, a positive electrode active material layer 2215, and a negative electrode active material layer 2214 in the electrode 221, it is beneficial to enable the battery cell 20 to have a higher energy density.

[0160] In some embodiments, the active material layer includes a positive electrode active material layer 2215, which includes a lithium-containing compound, and the electrolyte salt includes a lithium salt.

[0161] The positive electrode active material layer 2215 may include ternary lithium, lithium iron phosphate, etc. The electrolyte salt may include lithium hexafluorophosphate, lithium tetrafluoroborate, etc.

[0162] Both the positive electrode active material layer 2215 and the electrolyte salt contain lithium ions, which helps to further reduce the internal resistance of the battery cell 20.

[0163] Please refer to Figure 6, which is a schematic block diagram of a battery cell manufacturing method 30 provided in some embodiments of this application. This application provides a battery cell manufacturing method 30, which includes:

[0164] Step S100: The first packaging bag containing the solid electrode assembly 22 and electrolyte is isostatically pressed.

[0165] Step S200: Drain at least a portion of the electrolyte from the first packaging bag;

[0166] Step S300: Repackage the solid electrode assembly 22 to form a battery cell 20.

[0167] In step S100, the first encapsulation bag containing the solid electrode assembly 22 and the electrolyte can be placed into the hydraulic oil, and then the hydraulic oil can be pressurized to achieve isostatic pressure treatment.

[0168] The working principle of isostatic pressing is based on Pascal's law: "Pressure in a medium (liquid or gas) within a closed container is transmitted equally in all directions." Isostatic pressing facilitates the densification of the solid-state electrode assembly 22, thereby improving the reliability and energy density of the battery cell 20.

[0169] In step S200, the first packaging bag is opened and at least a portion of the electrolyte in the first packaging bag is discharged.

[0170] In step S300, the solid electrode assembly 22 is repackaged. The first packaging bag described above can be used for packaging, or other packaging structures can be used.

[0171] In this battery cell manufacturing method 30, the first encapsulation bag containing the solid electrode assembly 22 and electrolyte is isostatically pressed. Because the electrolyte fills the cavity within the first encapsulation bag, the pressure difference between the inside and outside of the first encapsulation bag remains consistent during isostatic pressing. This compacts the first encapsulation bag, the solid electrode assembly 22, and the electrolyte as a whole, reducing the risk of breakage of the negative electrode sheet 2211 during isostatic pressing, promoting the densification of the solid electrode assembly, and improving the reliability and energy density of the battery cell 20. Furthermore, the battery cell 20 manufactured using this method 30 has electrolyte residue 23 on the outer surface of its solid electrode assembly 22. The electrolyte residue 23 includes electrolyte salts, which can improve ionic conductivity and reduce the internal resistance of the battery cell 20. In some embodiments, the electrolyte includes at least one of electrolyte salts, sulfides, alcohols, and esters.

[0172] Electrolyte salts may include lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate, etc.

[0173] Sulfides can include nickel sulfide, lithium phosphine oxysulfide, lithium sulfide, etc.

[0174] Alcohols can include methanol, ethanol, benzyl alcohol, etc.

[0175] Lipids can include monoglycerides, diglycerides, triglycerides, ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone, etc.

[0176] Please refer to Figure 7, which is a schematic block diagram of a battery cell manufacturing method 30 provided in other embodiments of this application. In other embodiments, after the step of draining at least a portion of the electrolyte from the first packaging bag and before the step of repackaging the solid electrode assembly 22 to form the battery cell 20, the battery cell manufacturing method 30 further includes:

[0177] Step S250: Dry the solid electrode assembly 22.

[0178] Step S250 is located after step S200 and before step S300. That is, after opening the first packaging bag and draining at least part of the electrolyte, the solid electrode assembly 22 is dried and then repackaged.

[0179] After at least a portion of the electrolyte is drained from the first encapsulation bag, the solid electrode assembly 22 is dried before resealing it to reduce the residual liquid on the solid electrode assembly 22, which helps to improve the energy density of the battery cell 20.

[0180] Please refer to Figure 8, which is a schematic block diagram of a battery cell manufacturing method 30 provided in some embodiments of this application. In some embodiments, the solid electrode assembly 22 includes a positive electrode 2212, a solid electrolyte layer 222, and a negative electrode 2211 stacked together. After the step of drying the solid electrode assembly 22, and before repackaging the solid electrode assembly 22 to form the battery cell 20, the battery cell manufacturing method 30 further includes: step S260: welding a positive electrode tab on the positive electrode 2212 and welding a negative electrode tab on the negative electrode 2211.

[0181] Step S260 is located after step S250 and before step S300. That is, after opening the first packaging bag and draining at least part of the electrolyte, the solid electrode assembly 22 must be dried first, then the positive electrode tab is welded on the positive electrode plate 2212, and the negative electrode tab is welded on the negative electrode plate 2211, and then the solid electrode assembly 22 is repackaged.

[0182] In step S260, a positive electrode tab is welded onto the positive current collector 2213 of the positive electrode plate 2212, and a negative electrode tab is welded onto the negative current collector 2213 of the negative electrode plate 2211.

[0183] After drying the solid electrode assembly 22, welding a positive electrode tab onto the positive electrode plate 2212 and a negative electrode tab onto the negative electrode plate 2211 of the solid electrode assembly 22 helps to reduce the interference of the electrolyte on the welding and improves the welding quality.

[0184] Please refer to Figure 9, which is a schematic block diagram of a battery cell manufacturing method 30 provided in some embodiments of this application. In some embodiments, repackaging the solid-state electrode assembly 22 to form the battery cell 20 includes:

[0185] Step S310: The solid electrode assembly 22 is placed into the second packaging bag and the second packaging bag is sealed to form the battery cell 20.

[0186] In step S310, the second packaging bag and the first packaging bag are different packaging bags. The second packaging bag has a receiving cavity with one end open, allowing the solid electrode assembly 22 to be inserted into the second packaging bag through the open end. The second packaging bag can be a soft outer shell, such as aluminum-plastic film, heat-shrink film, etc.

[0187] The encapsulation process creates a sealed space within the receiving cavity, enclosing the solid-state electrode assembly 22 inside. The encapsulation process for the second encapsulation bag includes, but is not limited to, melting, welding, and setting seals. Optionally, encapsulating the second encapsulation bag includes vacuum encapsulation.

[0188] By placing the solid electrode assembly 22 into the second packaging bag, the battery cell 20 can have better sealing performance, which in turn helps to improve the reliability of the battery cell 20.

[0189] In some embodiments, in the step of isostatically pressing a first encapsulation bag containing the solid electrode assembly 22 and the electrolyte, the isostatic pressing time is controlled between 1 and 100 minutes.

[0190] In step S400, the isostatic pressing time is greater than or equal to 1 min and less than or equal to 100 min.

[0191] The isostatic pressing time can be: 1 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, etc.

[0192] When the isostatic pressing time is greater than or equal to 1 minute, the longer isostatic pressing time is beneficial for improving the densification of the solid-state electrode assembly 22 and increasing the energy density of the battery cell 20. When the isostatic pressing time is less than or equal to 100 minutes, the isostatic pressing time is not too long, which helps to shorten the manufacturing time of the battery cell 20 and improve the manufacturing efficiency of the battery cell 20. Therefore, when the isostatic pressing time is controlled between 1 and 100 minutes, both the energy density and manufacturing efficiency of the battery cell 20 can be balanced.

[0193] Optionally, in the step of isostatically pressing the first packaging bag containing the solid electrode assembly 22 and the electrolyte, the isostatic pressing time is controlled to be 5 to 15 minutes.

[0194] In step S100, the isostatic pressing time is greater than or equal to 5 min and less than or equal to 15 min.

[0195] The isostatic pressing time can be: 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, etc.

[0196] When the isostatic pressing time is greater than or equal to 5 minutes, a longer isostatic pressing time is more conducive to improving the densification of the solid-state electrode assembly 22 and increasing the energy density of the battery cell 20. When the isostatic pressing time is less than or equal to 15 minutes, the isostatic pressing time is not too long, which helps to shorten the manufacturing time of the battery cell 20 and improve the manufacturing efficiency of the battery cell 20. Therefore, when the isostatic pressing time is controlled between 5 and 15 minutes, it is possible to better balance the energy density and manufacturing efficiency of the battery cell 20.

[0197] In some embodiments, in the step of isostatically packing the first encapsulation bag containing the solid electrode assembly 22 and the electrolyte, the temperature of the isostatic packing is controlled at 90–300°C.

[0198] In step S100, the isostatic temperature is greater than or equal to 90°C and less than or equal to 300°C.

[0199] The isostatic pressure temperature can be: 90℃, 110℃, 130℃, 150℃, 180℃, 200℃, 220℃, 250℃, 280℃, 300℃, etc.

[0200] When the isostatic pressing temperature is greater than or equal to 90℃, the higher temperature is beneficial for improving the binding of sulfides in the solid electrolyte layer 222 and thus its ionic conductivity. When the isostatic pressing temperature is less than or equal to 300℃, the temperature is not too high, which helps reduce the risk of spontaneous combustion of the solid electrode assembly 22. Therefore, when the isostatic pressing temperature is controlled between 90 and 300℃, both the ionic conductivity of the solid electrolyte layer 222 and the risk of spontaneous combustion of the solid electrode assembly 22 can be improved.

[0201] Optionally, in the step of isostatically pressing the first encapsulation bag containing the solid electrode assembly 22 and the electrolyte, the temperature of the isostatic pressing is controlled at 90–150°C.

[0202] In step S100, the isostatic temperature is greater than or equal to 90°C and less than or equal to 150°C.

[0203] The isostatic pressure temperature can be: 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, etc.

[0204] When the isostatic pressing temperature is greater than or equal to 90℃, the higher temperature is beneficial for improving the binding of sulfides in the solid electrolyte layer 222 and thus its ionic conductivity. When the isostatic pressing temperature is less than or equal to 150℃, the temperature is not too high, which helps to further reduce the risk of spontaneous combustion of the solid electrode assembly 22. Therefore, when the isostatic pressing temperature is controlled between 90 and 150℃, both the ionic conductivity of the solid electrolyte layer 222 and the risk of spontaneous combustion of the solid electrode assembly 22 can be improved.

[0205] In some embodiments, in the first encapsulation bag step of isostatically packing the solid electrode assembly 22 and electrolyte, the isostatic pressure is controlled at 100-1000 MPa.

[0206] In step S100, the isostatic pressure is greater than or equal to 100 MPa and less than or equal to 1000 MPa.

[0207] The isostatic pressure can be: 100Mpa, 200Mpa, 300Mpa, 400Mpa, 500Mpa, 600Mpa, 700Mpa, 800Mpa, 900Mpa, 1000Mpa, etc.

[0208] When the isostatic pressure is greater than or equal to 100 MPa, the higher pressure is beneficial for increasing the density of the solid-state electrode assembly 22 and improving the energy density of the battery cell 20. When the isostatic pressure is less than or equal to 1000 MPa, the pressure is not too high, the requirements for production equipment are not too demanding, and production costs are easier to control. Therefore, when the isostatic pressure is controlled between 100 and 1000 MPa, both the energy density of the battery cell 20 and the production cost can be balanced.

[0209] Optionally, in the step of isostatically packing the solid electrode assembly 22 and electrolyte in the first packaging bag, the isostatic pressure is controlled at 300-700 MPa.

[0210] In step S100, the isostatic pressure is greater than or equal to 300 MPa and less than or equal to 700 MPa.

[0211] The isostatic pressure can be: 300Mpa, 350Mpa, 400Mpa, 450Mpa, 500Mpa, 550Mpa, 600Mpa, 650Mpa, 700Mpa, etc.

[0212] When the isostatic pressure is greater than or equal to 300 MPa, the higher pressure is more conducive to improving the densification of the solid-state electrode assembly 22 and increasing the energy density of the battery cell 20. When the isostatic pressure is less than or equal to 700 MPa, the pressure is not too high, the requirements for production equipment are not too demanding, and production costs are easier to control. Therefore, when the isostatic pressure is controlled between 300 and 700 MPa, it is possible to better balance the energy density of the battery cell 20 and the production cost.

[0213] Please refer to Figure 10, which is a schematic block diagram of a battery cell manufacturing method 30 provided in some other embodiments of this application. In some embodiments, before the step of isostatically packing a first encapsulation bag containing the solid electrode assembly 22 and the electrolyte, the battery cell manufacturing method 30 further includes:

[0214] Step S10: Provide solid-state electrode assembly 22;

[0215] Step S20: Pack the solid-state electrode assembly 22 into the first packaging bag;

[0216] Step S30: Inject electrolyte into the first packaging bag and seal the first packaging bag.

[0217] In step S20, the first packaging bag has a receiving cavity with an opening at one end, allowing the solid electrode assembly 22 to be inserted into the first packaging bag through the opening. The first packaging bag can be a soft outer shell, such as aluminum-plastic film or heat-shrink film.

[0218] In step S30, electrolyte is injected into the first encapsulation bag through the opening. The electrolyte does not react with the solid electrolyte layer 222 of the solid electrode assembly 22. The encapsulation process forms a sealed space within the cavity, enclosing the solid electrode assembly 22 inside. The encapsulation process of the first encapsulation bag includes, but is not limited to, melting, welding, and setting seals.

[0219] Optionally, the encapsulation of the first encapsulation bag includes: vacuum sealing the first encapsulation bag.

[0220] In this battery cell manufacturing method 30, by loading the solid-state electrode assembly 22 into a first packaging bag and injecting electrolyte into the first packaging bag, the electrolyte can fill the cavity inside the first packaging bag, ensuring that the pressure difference between the inside and outside of the first packaging bag remains consistent during isostatic pressing of the solid-state electrode assembly 22. In this way, the first packaging bag, the solid-state electrode assembly 22, and the electrolyte are compacted as a whole, which helps reduce the risk of breakage of the negative electrode sheet 2211 during isostatic pressing, facilitates the densification of the solid-state electrode assembly 22, and improves the reliability and energy density of the battery cell 20.

[0221] Please refer to Figure 11, which is a schematic block diagram of a battery cell manufacturing method 30 provided in some other embodiments of this application. In some embodiments, providing a solid-state electrode assembly 22 includes:

[0222] Step S11: Provide multiple electrode sheets 221 and provide a solid electrolyte layer 222;

[0223] Step S12: Multiple electrode sheets 221 and solid electrolyte layer 222 are stacked together, with the solid electrolyte layer 222 disposed between two adjacent electrode sheets 221.

[0224] By stacking multiple electrode sheets 221 and a solid electrolyte layer 222, the manufacturing process is simple and convenient, and the production cost is low. In addition, isostatic pressing of the solid electrode assembly 22 helps to improve the densification of the solid electrode assembly 22.

[0225] In some embodiments, the plurality of electrodes 221 include a positive electrode 2212 and a negative electrode 2211. The positive electrode 2212, the solid electrolyte layer 222, and the negative electrode 2211 are stacked, with the solid electrolyte layer 222 disposed between the positive electrode 2212 and the negative electrode 2211. In the step of stacking the plurality of electrodes 221 and the solid electrolyte layer 222, the dimension of the negative electrode 2211 extending beyond the positive electrode 2212 in both its length and width directions is controlled to be between 0.1 and 10 mm.

[0226] The negative electrode 2211 extends beyond the positive electrode 2212 by a length greater than or equal to 0.1 mm and less than or equal to 10 mm. The negative electrode 2211 extends beyond the positive electrode 2212 by a width greater than or equal to 0.1 mm and less than or equal to 100 mm.

[0227] The dimension by which the negative electrode 2211 extends beyond the positive electrode 2212 in its length direction can be the same as or different from the dimension by which the negative electrode 2211 extends beyond the positive electrode 2212 in its width direction.

[0228] The negative electrode 2211 can extend beyond the positive electrode 2212 by the following dimensions in its length direction: 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.

[0229] The negative electrode 2211 can exceed the positive electrode 2212 in width by the following dimensions: 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc.

[0230] When the negative electrode 2211 extends beyond the positive electrode 2212 by 0.1 mm or more in both length and width, it helps reduce assembly difficulty and enables an overhang design. When the negative electrode 2211 extends beyond the positive electrode 2212 by 10 mm or less in both length and width, it helps reduce the volume of the solid-state electrode assembly 22, improves the internal space utilization of the battery cell 20, and increases the energy density of the battery cell 20. Therefore, when the extension of the negative electrode 2211 beyond the positive electrode 2212 in both length and width is controlled within the range of 0.1–10 mm, it can both reduce assembly difficulty and enable an overhang design, while also increasing the energy density of the battery cell 20.

[0231] Optionally, in the step of stacking multiple electrode sheets 221 and solid electrolyte layer 222, the negative electrode sheet 2211 is made to extend beyond the positive electrode sheet 2212 by 0.3 to 3 mm in both length and width directions.

[0232] The negative electrode 2211 extends beyond the positive electrode 2212 by a length greater than or equal to 0.3 mm and less than or equal to 3 mm. The negative electrode 2211 extends beyond the positive electrode 2212 by a width greater than or equal to 0.3 mm and less than or equal to 3 mm.

[0233] The negative electrode 2211 can extend beyond the positive electrode 2212 by the following dimensions in its length direction: 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc.

[0234] The negative electrode 2211 can extend beyond the positive electrode 2212 in width by the following dimensions: 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc.

[0235] When the negative electrode 2211 extends beyond the positive electrode 2212 by 0.3 mm or more in both length and width, it is more conducive to reducing assembly difficulty and achieving an overhang design. When the negative electrode 2211 extends beyond the positive electrode 2212 by 3 mm or less in both length and width, it is more conducive to reducing the volume of the solid-state electrode assembly 22, improving the internal space utilization of the battery cell 20, and increasing the energy density of the battery cell 20. Therefore, when the extension of the negative electrode 2211 beyond the positive electrode 2212 in both length and width is controlled within the range of 0.3 to 3 mm, it can further reduce assembly difficulty, achieve an overhang design, and further improve the energy density of the battery cell 20.

[0236] Please refer to Figure 12, which is a schematic block diagram of a battery cell manufacturing method 30 provided in some other embodiments of this application. After the step of stacking and configuring multiple electrode sheets 221 and a solid electrolyte layer 222, the solid electrode assembly 22 is provided, including:

[0237] Step S13: Hot-press multiple electrode sheets 221 and solid electrolyte layer 222.

[0238] By hot-pressing multiple electrode sheets 221 and solid electrolyte layer 222, a relatively stable solid electrode assembly structure is formed, which is beneficial for the solid electrode assembly to maintain its shape during subsequent operations.

[0239] Referring to Figures 4 and 5, this embodiment of the application also provides an electrode assembly, which is a solid electrode assembly 22. The outer surface of the solid electrode assembly 22 has electrolyte residue 23, which includes electrolyte salts.

[0240] In some embodiments, electrolyte residue 23 further includes at least one of sulfides, alcohols, and esters.

[0241] In some embodiments, electrolyte residue 23 is uniformly distributed on the outer surface of the solid-state electrode assembly 22. By uniformly distributing electrolyte residue 23 on the outer surface of the solid-state electrode assembly 22, it is beneficial to further improve ionic conductivity and further reduce the internal resistance of the battery cell 20.

[0242] In some embodiments, the solid-state electrode assembly 22 includes a solid electrolyte layer 222 and a plurality of electrodes 221. The solid electrolyte layer 222 is disposed between two adjacent electrodes 221. Each electrode 221 includes an active material layer. In two adjacent electrodes 221, the active material layers facing the solid electrolyte layer 222 between the two adjacent electrodes 221 have opposite polarities. Similarly, the two active material layers adjacent to and located on either side of the solid electrolyte layer 222 have opposite polarities. The solid electrolyte layer 222 simultaneously serves to transport ions and isolate the positive electrode active material layer 2215 and the negative electrode active material layer 2214.

[0243] In some embodiments, the plurality of electrodes 221 include a positive electrode 2212 and a negative electrode 2211, and the positive electrode 2212, a solid electrolyte layer 222, and the negative electrode 2211 are stacked together, with the solid electrolyte layer 222 disposed between the positive electrode 2212 and the negative electrode 2211. The solid electrode assembly includes the stacked positive electrode 2212, solid electrolyte layer 222, and negative electrode 2211, thus making the solid electrode assembly simple and convenient to manufacture, and at a low cost.

[0244] In other embodiments, the electrode 221 includes a current collector 2213, a positive electrode active material layer 2215, and a negative electrode active material layer 2214, with the positive electrode active material layer 2215 and the negative electrode active material layer 2214 respectively disposed on both sides of the current collector 2213. By including the current collector 2213, the positive electrode active material layer 2215, and the negative electrode active material layer 2214 in the electrode 221, it is beneficial to enable the battery cell 20 to have a higher energy density.

[0245] In some embodiments, the active material layer includes a positive electrode active material layer 2215, which includes a lithium-containing compound, and the electrolyte salt includes a lithium salt. Both the positive electrode active material layer 2215 and the electrolyte salt include lithium ions, which is beneficial for further reducing the internal resistance of the battery cell 20.

[0246] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0247] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0248] Please refer to Figures 3 to 12 for some embodiments of this application.

[0249] This application provides a battery cell 20, which includes a housing 21 and a solid-state electrode assembly 22 housed within the housing 21. The outer surface of the solid-state electrode assembly 22 has an electrolyte residue 23, which includes an electrolyte salt. The electrolyte residue 23, comprising an electrolyte salt, can improve ionic conductivity and reduce the internal resistance of the battery cell 20.

[0250] This application also provides a battery cell manufacturing method 30, which includes: isostatically pressing a first packaging bag containing a solid electrode assembly 22 and an electrolyte; draining at least a portion of the electrolyte from the first packaging bag; and repackaging the solid electrode assembly 22 to form a battery cell 20. In this battery cell manufacturing method 30, the first packaging bag containing the solid electrode assembly 22 and electrolyte isostatically pressed ensures that the electrolyte fills the cavity within the first packaging bag, maintaining a consistent pressure difference between the inside and outside of the first packaging bag during isostatic pressing. This compacts the first packaging bag, the solid electrode assembly 22, and the electrolyte as a whole, reducing the risk of breakage of the negative electrode sheet 2211 during isostatic pressing, promoting the densification of the solid electrode assembly, and improving the reliability and energy density of the battery cell 20. In addition, the battery cell 20 manufactured using the battery cell manufacturing method 30 has electrolyte residue 23 on the outer surface of its solid electrode assembly 22. The electrolyte residue 23 includes electrolyte salt, which can improve ionic conductivity and reduce the internal resistance of the battery cell 20.

[0251] After draining at least a portion of the electrolyte from the first packaging bag and before repackaging the solid electrode assembly 22 to form the battery cell 20, the battery cell manufacturing method 30 further includes drying the solid electrode assembly 22. Drying the solid electrode assembly 22 after draining at least a portion of the electrolyte from the first packaging bag and before repackaging it reduces residual liquid on the solid electrode assembly 22, which is beneficial for improving the energy density of the battery cell 20.

[0252] The solid-state electrode assembly 22 includes a positive electrode 2212, a solid electrolyte layer 222, and a negative electrode 2211 stacked together. After drying the solid-state electrode assembly 22 and before repackaging the solid-state electrode assembly 22 to form a battery cell 20, the battery cell manufacturing method 30 further includes: welding a positive electrode tab onto the positive electrode 2212; and welding a negative electrode tab onto the negative electrode 2211. Welding the positive electrode tab onto the positive electrode 2212 and the negative electrode tab onto the negative electrode 2211 of the solid-state electrode assembly 22 after drying the solid-state electrode assembly 22 helps reduce the interference of the electrolyte on the welding and improves the welding quality.

[0253] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, wherein, The battery cell manufacturing method comprises the following steps: a housing; a solid-state electrode assembly accommodated in the housing; an outer surface of the solid-state electrode assembly has electrolyte residue, the electrolyte residue comprising electrolyte salt.

2. The battery cell of claim 1, wherein, The electrolyte residue further comprises at least one of sulfide, alcohol, and lipid.

3. The battery cell of claim 1 or 2, wherein, The electrolyte residue is uniformly distributed on the outer surface of the solid-state electrode assembly.

4. The battery cell of any one of claims 1-3, wherein, The solid-state electrode assembly comprises a solid-state electrolyte layer and a plurality of electrode sheets, the solid-state electrolyte layer being arranged between two adjacent electrode sheets, the electrode sheet comprising an active material layer, the polarity of the active material layer facing the solid-state electrolyte layer between the two adjacent electrode sheets being opposite.

5. The battery cell of claim 4, wherein, The plurality of electrode sheets comprises positive electrode sheets and negative electrode sheets, the positive electrode sheets, the solid-state electrolyte layer, and the negative electrode sheets being arranged in a stack, the solid-state electrolyte layer being arranged between the positive electrode sheets and the negative electrode sheets.

6. The battery cell of claim 4, wherein, The electrode sheet comprises a current collector, a positive active material layer, and a negative active material layer, the positive active material layer and the negative active material layer being arranged on two sides of the current collector, respectively.

7. The battery cell of any one of claims 4-6, wherein, The active material layer comprises a positive active material layer, the positive active material layer comprising a lithium-containing compound, and the electrolyte salt comprising a lithium salt.

8. A method of manufacturing a battery cell, wherein, The battery cell manufacturing method comprises the following steps: a first packaging bag containing a solid-state electrode assembly and electrolyte under isostatic pressing; discharging at least part of the electrolyte in the first packaging bag; repackaging the solid-state electrode assembly to form a battery cell.

9. The battery cell manufacturing method of claim 8, wherein, The electrolyte comprises at least one of electrolyte salt, sulfide, alcohol, and lipid.

10. The battery cell manufacturing method according to claim 8 or 9, wherein, After the step of discharging at least part of the electrolyte in the first packaging bag, and before the step of repackaging the solid-state electrode assembly to form a battery cell, the battery cell manufacturing method further comprises: drying the solid-state electrode assembly.

11. The battery cell manufacturing method of claim 10, wherein, The solid-state electrode assembly comprises positive electrode sheets, a solid-state electrolyte layer, and negative electrode sheets arranged in a stack; After the step of drying the solid-state electrode assembly, and before the step of repackaging the solid-state electrode assembly to form a battery cell, welding positive electrode tabs on the positive electrode sheets; welding negative electrode tabs on the negative electrode sheets.

12. The battery cell manufacturing method according to any one of claims 8-11, wherein, The repackaging the solid-state electrode assembly to form a battery cell comprises: packaging the solid-state electrode assembly into a second packaging bag, and sealing the second packaging bag to form the battery cell.

13. The battery cell manufacturing method according to any one of claims 8-12, wherein, In the step of packaging a first packaging bag containing a solid-state electrode assembly and electrolyte under isostatic pressing, the time of isostatic pressing is controlled to be 1-100 min.

14. The battery cell manufacturing method of claim 13, wherein, In the step of packaging a first packaging bag containing a solid-state electrode assembly and electrolyte, the time of isostatic pressing is controlled to be 5-15 min.

15. The battery cell manufacturing method according to any one of claims 8-14, wherein, In the step of packaging a first packaging bag containing a solid-state electrode assembly and electrolytes under isostatic pressing, the temperature of isostatic pressing is controlled to be 90-300℃.

16. The battery cell manufacturing method of claim 15, wherein, In the step of packaging a first packaging bag containing a solid-state electrode assembly and electrolytes, the temperature of isostatic pressing is controlled to be 90-150℃.

17. The battery cell manufacturing method according to any one of claims 8-16, wherein, In the step of packaging a first packaging bag containing a solid-state electrode assembly and electrolyte solution under isostatic pressing, the pressure of isostatic pressing is controlled to be 100-1000 Mpa.

18. The battery cell manufacturing method of claim 17, wherein, In the step of loading the first packaging bag of the isostatic press with the solid electrode assembly and the electrolyte, the pressure of the isostatic press is controlled at 300-700 MPa.

19. The battery cell manufacturing method according to any one of claims 8-18, wherein, Before the step of loading the first packaging bag of the isostatic press with the solid electrode assembly, the battery cell manufacturing method further comprises: providing a solid electrode assembly; loading the solid electrode assembly into the first packaging bag; injecting electrolyte into the first packaging bag, and packaging the first packaging bag.

20. The battery cell manufacturing method of claim 19, wherein, The step of providing a solid electrode assembly comprises: providing a plurality of electrode sheets and providing a solid electrolyte layer; stacking the plurality of electrode sheets and the solid electrolyte layer, the solid electrolyte layer being disposed between two adjacent electrode sheets.

21. The battery cell manufacturing method of claim 20, wherein, The plurality of electrode sheets comprises a positive electrode sheet and a negative electrode sheet, the positive electrode sheet, the solid electrolyte layer, and the negative electrode sheet being stacked, the solid electrolyte layer being disposed between the positive electrode sheet and the negative electrode sheet. In the step of stacking the plurality of electrode sheets and the solid electrolyte layer, the size of the negative electrode sheet exceeding that of the positive electrode sheet in the length direction and the width direction is controlled at 0.1-10 mm.

22. The battery cell manufacturing method of claim 21, wherein, In the step of stacking the plurality of electrode sheets and the solid electrolyte layer, the negative electrode sheet exceeding the positive electrode sheet in the length direction and the width direction is controlled at 0.3-3 mm.

23. The battery cell manufacturing method according to any one of claims 20-22, wherein, After the step of stacking the plurality of electrode sheets and the solid electrolyte layer, the step of providing a solid electrode assembly comprises: hot-pressing the plurality of electrode sheets and the solid electrolyte layer.

24. An electrode assembly, wherein, The electrode assembly is a solid electrode assembly, the outer surface of the solid electrode assembly has electrolyte residues, and the electrolyte residues comprise electrolyte salts.

25. The electrode assembly of claim 24, wherein, The electrolyte residues further comprise at least one of sulfides, alcohols, and lipids.

26. The electrode assembly of claim 24 or 25, wherein, The electrolyte residues are uniformly distributed on the outer surface of the solid electrode assembly.

27. The electrode assembly of any one of claims 24-26, wherein, The solid electrode assembly comprises a solid electrolyte layer and a plurality of electrode sheets, the solid electrolyte layer being disposed between two adjacent electrode sheets, the electrode sheets comprising active material layers, and the polarities of the active material layers facing the solid electrolyte layer between two adjacent electrode sheets are opposite.

28. The electrode assembly of claim 27, wherein, The plurality of electrode sheets comprises a positive electrode sheet and a negative electrode sheet, the positive, the solid electrolyte layer, and the negative electrode sheet being stacked, the solid electrolyte being disposed between the positive electrode sheet and the negative electrode sheet.

29. The electrode assembly of claim 27, wherein, The electrode sheet comprises a current collector, a positive active material layer, and a negative active material layer, the positive active material layer and the negative active material layer being disposed on two sides of the current collector, respectively.

30. The electrode assembly of any of claims 27-29, wherein, The active material layer comprises a positive active material layer, the positive active material layer comprising a lithium-containing compound, and the electrolyte salts comprise lithium salts.

31. A battery device, wherein, The battery cell according to any one of claims 1-7.

32. An electrical device, comprising: The battery cell according to any one of claims 1-7 is used to provide electric energy for the electric device.

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