Solid-state battery cell, binder polymer, battery device, and electric device

Abstract

Provided are a solid-state battery cell, a binder polymer, a battery device, and an electric device. The solid-state battery cell comprises a positive electrode sheet; the positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer arranged on at least one side of the positive electrode current collector; the positive electrode active material layer comprises a sulfide solid-state electrolyte, a binder polymer, and a positive electrode active material; the binder polymer comprises a first structural unit and a second structural unit; the first structural unit includes any one or more of -OCH2CH2-, -CH2-O-CH2-, and -CH2CH2- in which at least two hydrogen atoms bonded to the same carbon atom are substituted with fluorine atoms; the second structural unit includes -CH2CH2- optionally substituted with halogen atoms, wherein the halogen atoms include any one or more of Cl, Br, and I. The binder polymer in the solid-state battery cell can reduce heat generation, improve active-ion transport capability, and improve the reliability and cycle performance of the solid-state battery cell.

Description

Solid-state battery cells, binder polymers, battery devices, and electrical devices

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 202510364059.7, filed on March 26, 2025, entitled "Solid-state battery cell, binder polymer, battery device and power supply device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a solid-state battery cell, a binder polymer, a battery device, and an electrical device. Background Technology

[0004] Solid-state battery cells use solid electrolyte sheets instead of non-aqueous organic electrolytes. Since solid electrolyte sheets cannot spontaneously penetrate into the electrodes, solid electrolytes are usually used in combination with electrode active materials to improve the ion transport characteristics of the electrodes.

[0005] Sulfide solid electrolytes are one of the ideal solid electrolytes currently available. However, sulfide solid electrolytes are prone to react with the positive electrode active material in the positive electrode sheet, which reduces the overall performance of solid battery cells. Therefore, improvements are urgently needed. Summary of the Invention

[0006] This disclosure provides a solid-state battery cell, a binder polymer battery device, and an electrical device. The binder polymer in the solid-state battery cell can reduce the heat generated by the positive electrode, improve the active ion transport capability, and improve the reliability and cycle performance of the solid-state battery cell.

[0007] In a first aspect, this disclosure provides a solid-state battery cell, including a positive electrode sheet. The positive electrode sheet includes a positive current collector and a positive active material layer disposed on at least one side of the positive current collector. The positive active material layer includes a sulfide solid electrolyte, a binder polymer, and a positive active material. The binder polymer includes a first structural unit and a second structural unit. The first structural unit includes any one or more of -OCH2CH2-, -CH2-O-CH2-, and -CH2CH2- in which at least two hydrogen atoms are replaced by F atoms in the same carbon atom. The second structural unit includes -CH2CH2- in which halogen atoms are arbitrarily replaced, wherein the halogen atoms include any one or more of Cl, Br, and I.

[0008] According to embodiments of this application, the ether group in the first structural unit of the binder polymer in the solid-state battery cell can reduce or decrease the reaction between the positive electrode active material and the sulfide solid electrolyte; it can also conduct active ions, such as lithium ions, and improve the cycle performance of the solid-state battery cell; the second structural unit contains halogen atoms, which can anchor the oxygen released by the positive electrode active material during electrochemical cycling, reduce the probability of thermal failure reaction between the positive electrode active material and the sulfide solid electrolyte at high temperature in the solid-state battery, reduce heat generation; suppress the interdiffusion of elements between the positive electrode active material and the sulfide solid electrolyte, reduce the side reactions of the solid-state battery cell, and improve the reliability of the solid-state battery cell.

[0009] In summary, the synergistic combination of the first and second structural units in the binder polymer can improve the cycle performance and reliability of solid-state battery cells containing sulfide solid electrolyte, binder polymer and positive electrode active material while maintaining good kinetic performance.

[0010] In some optional embodiments, the weight-average molecular weight of the binder polymer is from 10,000 to 1,000,000; optionally, it is from 400,000 to 800,000. Thus, the binder polymer has a longer molecular chain and a more complex structure, providing more active sites and a larger specific surface area, thereby potentially forming more interactions with oxygen molecules, such as physical adsorption or chemisorption, thereby enhancing the oxygen fixation capacity and improving the bonding strength between substances in the positive electrode active material layer. The binder polymer has a more regular arrangement and a more complex pore structure, providing more ordered and unobstructed transport channels for active ions, which is beneficial for the conduction of active ions within it.

[0011] In some optional embodiments, the glass transition temperature (Tg) of the binder polymer is -100°C to 200°C; optionally, it is -50°C to 60°C. The glass transition temperature (Tg) of the binder polymer is within a specific temperature range 1 to ensure suitable flexibility and adhesion properties are maintained within the operating temperature range of the solid-state battery cell.

[0012] In some optional embodiments, the binder polymer is a block polymer. Different segments of the block polymer can perform different functions. The first structural unit can reduce or decrease the reaction between the positive electrode active material and the sulfide solid electrolyte, thereby reducing heat generation. The second structural unit can anchor the oxygen released by the positive electrode active material during electrochemical cycling, thereby reducing side reactions in the solid-state battery cell and further improving the reliability and cycle performance of the solid-state battery cell.

[0013] In some optional embodiments, the molar ratio of the first structural unit to the second structural unit is 1:(0.01 to 100); alternatively, it is 1:(0.1 to 0.8). This is beneficial for the block polymer to balance adhesion, ion conduction, and anchoring of oxygen released from the positive electrode active material during electrochemical cycling, thereby improving the reliability and cycle performance of solid-state battery cells.

[0014] In some alternative embodiments, the adhesive polymer comprises the structure of any one of formulas (1) to (22):

[0015] Where x and y are positive integers, ranging from 10 to 10000. This allows for improvements in both reliability and cycle performance of solid-state battery cells.

[0016] In some optional embodiments, the binder polymer has a mass content of 0.1 wt% to 10 wt% in the positive electrode active material layer. This allows for improved conduction of active ions, reduced heat generation, and reduced side reactions in solid-state battery cells, while maintaining the performance of the positive electrode active material layer.

[0017] In some optional embodiments, the sulfide solid electrolyte includes one or more of Li6PS5Y, LGPS-type sulfide solid electrolytes, and multi-element sulfide solid electrolytes, where Y includes one or more elements selected from F, Cl, Br, and I. Therefore, the above-mentioned types of sulfide solid electrolytes can provide a more stable and reliable operating environment for solid-state battery cells; the high ionic conductivity, good mechanical properties, and chemical stability of sulfide solid electrolytes improve the overall performance of solid-state battery cells.

[0018] In some optional embodiments, the sulfide solid electrolyte has a mass content of 0.1 wt% to 20 wt% in the positive electrode active material layer. This can improve the overall performance of the solid-state battery cell.

[0019] In some optional embodiments, the positive electrode active material has the general formula Li. a Ni b Co c M d O e A fThe positive electrode active material comprises one or more of lithium transition metal oxides and their modified materials, wherein 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A may include one or more of N, F, S and Cl. The above-mentioned positive electrode active materials give the positive electrode sheet high voltage and oxidizing properties. Under this high voltage, the oxidizing properties of the positive electrode active material will cause the positive electrode active material to react with the sulfide solid electrolyte. The ether group in the first structural unit of the binder polymer can reduce or decrease the reaction between the positive electrode active material and the sulfide solid electrolyte, reducing side reactions and heat generation; the second structural unit contains halogen atoms, which can anchor the oxygen released by the positive electrode active material during electrochemical cycling, reducing heat generation and lowering the probability of thermal failure reaction between the positive electrode active material and the sulfide solid electrolyte at high temperatures in the solid-state battery.

[0020] In some optional embodiments, the mass content of the positive electrode active material in the positive electrode active material layer is 50 wt% to 90 wt%. This can further improve the energy density of the solid-state battery cell.

[0021] In some optional embodiments, the positive electrode active material layer further includes a conductive agent, which may be one or more selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers. This can reduce the internal resistance of the positive electrode and improve the kinetic performance of the solid-state battery cell.

[0022] Secondly, embodiments of this application provide a binder polymer for solid-state battery cells. The binder polymer includes a first structural unit and a second structural unit. The first structural unit includes any one or more of -OCH2CH2-, -CH2-O-CH2-, and -CH2CH2- in which at least two hydrogen atoms are replaced by F atoms in the same carbon atom. The second structural unit includes -CH2CH2- in which halogen atoms are arbitrarily replaced, wherein the halogen atoms include any one or more of Cl, Br, and I.

[0023] According to embodiments of this application, the ether group in the first structural unit of the binder polymer can form hydrogen bonds or other chemical bonds with the polar groups on the surface of the positive electrode active material of the battery, thereby enhancing the adhesion; the ether group can reduce or decrease the reaction between the positive electrode active material and the sulfide solid electrolyte; it can also conduct active ions, such as lithium ions, and improve the cycle performance of the solid battery cell; the second structural unit contains halogen atoms, which can anchor the oxygen released by the positive electrode active material during electrochemical cycling, reduce the probability of thermal failure reaction between the positive electrode active material and the sulfide solid electrolyte at high temperature in the solid battery, and reduce heat generation; it inhibits the interdiffusion of elements between the positive electrode active material and the sulfide solid electrolyte, reduces the side reactions of the solid battery cell, and improves the reliability of the solid battery cell.

[0024] Thirdly, embodiments of this application provide a battery device including a plurality of solid-state battery cells as described in the first aspect. The battery device of this application at least possesses the beneficial effects of solid-state battery cells.

[0025] Fourthly, embodiments of this application provide an electrical device, including a solid-state battery cell (as described in the first aspect) or a battery device (as described in the third aspect). The electrical device of this application at least possesses the beneficial effects of a solid-state battery cell or a battery device. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are merely some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the drawings without any creative effort.

[0027] Figure 1 shows a schematic diagram of a solid-state battery cell provided in some embodiments of this disclosure.

[0028] Figure 2 shows a schematic diagram of an electrical device provided in some embodiments of this disclosure.

[0029] Figure 3 shows a curve of differential scanning calorimetry analysis of the positive electrode active material layer powder of Example 1.

[0030] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0031] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the solid-state battery cell, binder polymer, battery device, and power supply device of this disclosure. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter of the claims.

[0032] The "range" disclosed in this disclosure is defined by a lower limit and an upper limit, whereby a given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this disclosure, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0033] Unless otherwise specified, all embodiments and optional embodiments of this disclosure may be combined with each other to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0034] Unless otherwise specified, all technical features and optional technical features of this disclosure can be combined to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0035] Unless otherwise specified, all steps of this disclosure may be performed sequentially or randomly, preferably sequentially. For example, if a method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if it is mentioned that the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0036] Unless otherwise specified, in this disclosure, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0037] In this disclosure, the terms "multiple" or "a variety" refer to two or more kinds.

[0038] Unless otherwise stated, the test temperature for all parameters mentioned in this disclosure is 25°C.

[0039] The solid-state battery cell mentioned in the embodiments of this disclosure can independently perform charge and discharge functions. After discharge, it can be reactivated by charging to allow the active materials to continue to be used. The solid-state battery cell can be cylindrical, cuboid, or other shapes, etc., and the embodiments of this disclosure are not limited to this. Figure 1 shows a cuboid solid-state battery cell 5 as an example.

[0040] The battery apparatus mentioned in the embodiments of this disclosure may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple solid-state battery cells, which are connected in series, parallel, or mixed connections via busbars.

[0041] In some alternative embodiments, the battery cell assembly is typically formed by arranging multiple solid-state battery cells.

[0042] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple solid-state battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple solid-state battery cells together with cable ties.

[0043] In some alternative embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0044] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0045] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple solid-state battery cells to the housing.

[0046] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0047] 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.

[0048] In some alternative embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0049] The technical solutions described in this disclosure are applicable to various electrical devices that use solid-state battery cells or battery devices, such as, but not limited to, mobile devices (e.g., mobile phones, tablets, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc. Solid-state battery cells and battery devices are used to store or provide electrical energy.

[0050] Figure 2 is a schematic diagram of an example electrical device. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0051] The use of liquid electrolytes in battery cells may pose safety risks such as fire and explosion. Replacing flammable organic liquid electrolytes with safer solid electrolytes can solve these problems. However, in a fully charged state, the positive electrode active material of a solid-state battery cell undergoes a phase transition at high temperatures, releasing oxygen, especially in ternary cathode materials. The oxygen released by these materials reacts with the sulfide solid electrolyte to produce sulfur dioxide, releasing a large amount of heat and affecting the reliability of the solid-state battery cell.

[0052] In related technologies, the surface of the positive electrode active material is coated to prevent direct contact between it and the sulfide solid electrolyte, thereby mitigating the reaction between the positive electrode and the sulfide electrolyte at high temperatures. The coating layer generally has low lithium-ion conductivity and electronic conductivity, affecting electron and ion transport on the positive electrode during charging and discharging, resulting in problems such as low capacity utilization and rapid capacity decay in solid-state battery cells.

[0053] Based on this, the present disclosure provides a solid-state battery cell in which the binder polymer of the positive electrode can reduce heat generation and improve the transport capacity of active ions, thereby improving the cycle performance and reliability of the solid-state battery cell while maintaining good kinetic performance.

[0054] This disclosure provides a solid-state battery cell, including a positive electrode sheet, the positive electrode sheet including a positive current collector and a positive active material layer disposed on at least one side of the positive current collector.

[0055] The positive electrode current collector has two surfaces opposite each other in its thickness direction, and the positive electrode active material layer is disposed on one or both of the two opposite surfaces of the positive electrode current collector.

[0056] In some alternative embodiments, the positive current collector may be a metal foil or a composite current collector. Examples of metal foils include aluminum foil, carbon-coated aluminum foil, and stainless steel foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. Examples of metal materials include, but are not limited to, one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Examples of polymer substrates include, but are not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene.

[0057] In some optional embodiments, the positive electrode active material layer includes a sulfide solid electrolyte, a binder polymer, and a positive electrode active material. The binder polymer includes a first structural unit and a second structural unit. The first structural unit includes any one or more of -OCH2CH2-, -CH2-O-CH2-, and -CH2CH2- in which at least two hydrogen atoms are replaced by F atoms in the same carbon atom. The second structural unit includes -CH2CH2- in which halogen atoms are arbitrarily replaced, wherein the halogen atoms include any one or more of Cl, Br, and I.

[0058] Any one or more of -CH2CH2- whose F atom replaces at least two hydrogen atoms in the same carbon atom can be understood as any one of -CF2CH2-, -CF2CHF-, and -CF2CF2-.

[0059] According to embodiments of this application, the ether group in the first structural unit of the binder polymer in the solid-state battery cell can form hydrogen bonds or other chemical bonds with the polar groups on the surface of the positive electrode active material, thereby enhancing the adhesion; the ether group can reduce or decrease the reaction between the positive electrode active material and the sulfide solid electrolyte; it can also conduct active ions, such as lithium ions, improving the cycle performance of the solid-state battery cell; the second structural unit contains halogen atoms, which can anchor the oxygen released by the positive electrode active material during electrochemical cycling, reducing the probability of thermal failure reaction between the positive electrode active material and the sulfide solid electrolyte at high temperatures in the solid-state battery, reducing heat generation; it also inhibits the interdiffusion of elements between the positive electrode active material and the sulfide solid electrolyte, reducing side reactions in the solid-state battery cell and improving the reliability of the solid-state battery cell.

[0060] In summary, the synergistic combination of the first and second structural units in the binder polymer can improve the cycle performance and reliability of solid-state battery cells containing sulfide solid electrolyte, binder polymer and positive electrode active material while maintaining good kinetic performance.

[0061] The reason why ether groups can reduce or decrease the reaction between positive electrode active materials and sulfide solid electrolytes is that ether groups have good chemical stability and a certain steric volume, and have a steric hindrance effect. In the oxidizing environment of positive electrode active materials and the relatively active chemical environment that sulfide solid electrolytes may exist, the ether groups of binder polymers containing ether groups can prevent direct contact between positive electrode active materials and sulfide solid electrolytes, and also play a certain role in isolation and stabilization.

[0062] Functional groups in adhesive polymers can be detected using methods commonly used in the art, such as Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance spectroscopy (NMR). As an example, in X-ray photoelectron spectroscopy (XPS), the positive electrode sample is placed in the vacuum chamber of the XPS instrument, irradiated with an X-ray source, and the emitted photoelectron signals are collected and analyzed. By analyzing the position and intensity of the peaks in the spectrum, the functional groups on the sample surface and their relative amounts can be determined.

[0063] In some optional embodiments, the binder polymer is a block polymer. Different segments of the block polymer can perform different functions. The first structural unit can reduce or decrease the reaction probability between the positive electrode active material and the sulfide solid electrolyte, thereby reducing heat generation. The second structural unit can anchor the oxygen released by the positive electrode active material during electrochemical cycling, thereby reducing side reactions in the solid-state battery cell and further improving the reliability and cycle performance of the solid-state battery cell.

[0064] In some optional embodiments, the weight-average molecular weight of the adhesive polymer is from 100,000 to 1,000,000; optionally, it is from 400,000 to 800,000. For example, the weight-average molecular weight of the adhesive polymer can be any range of 400,000, 500,000, 600,000, 700,000, and 800,000.

[0065] Therefore, the longer molecular chains and more complex structures of the binder polymer provide more active sites and a larger specific surface area, which may lead to more interactions with oxygen molecules, such as physical adsorption or chemical adsorption, thereby enhancing the ability to fix oxygen and improving the bonding strength between substances in the positive electrode active material layer. The binder polymer has a more regular arrangement and a more complex pore structure, which can provide more ordered and unobstructed transport channels for active ions, which is beneficial to the conduction of active ions.

[0066] The weight-average molecular weight of the binder polymer has a meaning known in the art and can be determined using instruments and methods known in the art, such as high-temperature gel permeation chromatography. The test can be performed using a gel permeation chromatography (GPC) instrument, such as the PolymerChar GPC-IR high-temperature gel permeation chromatograph. The test can be referenced to the international standard ISO 16014-1-2019.

[0067] In some optional embodiments, the glass transition temperature (Tg) of the binder polymer is -100°C to 200°C; optionally, it is -50°C to 60°C. The glass transition temperature (Tg) of the binder polymer is within the above temperature range to ensure suitable flexibility and adhesion properties are maintained within the operating temperature range of the solid-state battery cell.

[0068] In some optional embodiments, the molar ratio of the first structural unit to the second structural unit is 1:(0.01 to 100); optionally, it is 1:(0.1 to 0.8). The molar ratio of the first structural unit to the second structural unit can also be 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.06, 1:0.7, etc. This is beneficial for the block polymer to balance adhesion, ion conduction, and anchoring of oxygen released from the positive electrode active material during electrochemical cycling, thereby improving the reliability and cycle performance of the solid-state battery cell.

[0069] In some alternative embodiments, the adhesive polymer comprises the structure of any one of formulas (1) to (22):

[0070] Where x and y are positive integers, ranging from 10 to 10000. This allows for improvements in both reliability and cycle performance of solid-state battery cells.

[0071] In some optional embodiments, the mass content of the binder polymer in the positive electrode active material layer is 0.1 wt% to 10 wt%.

[0072] The mass content of the binder polymer in the positive electrode active material layer can be a range formed by any value from 0.1%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5% and 10.0%. Accordingly, on the basis of balancing the performance of the positive electrode active material layer, the ability to conduct active ions can be improved, heat generation can be reduced, and side reactions occurring in the solid-state battery cell can be decreased.

[0073] In some optional embodiments, the sulfide solid electrolyte comprises one or more of Li₆PS₅Y, LGPS-type sulfide solid electrolyte, and multi-component sulfide solid electrolyte, and Y comprises one or more elements selected from F, Cl, Br and I. Accordingly, the sulfide solid electrolyte of the above type can provide a more stable and reliable working environment for the solid-state battery cell; characteristics of the sulfide solid electrolyte such as high ionic conductivity, good mechanical properties and chemical stability improve the overall performance of the solid-state battery cell.

[0074] Optionally, the LGPS-type sulfide solid electrolyte may comprise Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w , wherein 0≤δ₅<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G comprises one or two elements selected from Si and Sn, Q comprises Sb, and W comprises one or more elements selected from O, Se, Te, Cl, Br, I and F.

[0075] Optionally, the multi-component sulfide solid electrolyte may comprise one or more of Li₂S-P₂S₅, Li₂S-SiS₂, Li₂S-GeS₂, (100-u-v)Li₂S·uP₂S₅·vM m N n , wherein 0<u<100, 0<v<100, 0<u+v<100, 0≤m<4, 0≤n<6, M comprises one or more elements selected from Li, B, Ge, Si, Sn and Sb, and N comprises one or more elements selected from S, Se, Te, O, Cl, Br, I and F.

[0076] In some optional embodiments, by way of example, the sulfide solid electrolyte may comprise Li₆PS₅Cl, Li₆PS₅Br, Li10 GeP2S 12 Li3PS4, Li7P3S 11 Li6P2S8, Li 10 GeP2S 12 Li 10 SnP2S 12 Li 10 SiP2S 12 Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Li 9.6 P3S 12 One or more of Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0077] In some optional embodiments, the sulfide solid electrolyte in the positive electrode active material layer comprises 0.1 wt% to 20 wt% by mass. The mass content of the sulfide solid electrolyte in the positive electrode active material layer can be any range consisting of 50.0%, 55.0%, 60.0%, 65.0%, 70.0%, 75.0%, 80.0%, 85.0%, and 90.0%. This improves the overall performance of the solid-state battery cell.

[0078] In some optional embodiments, the average particle size of the sulfide solid electrolyte can be 50 nm to 5 μm.

[0079] In some alternative embodiments, the positive electrode may also include other solid electrolytes, which may include one or more of halide solid electrolytes and oxide solid electrolytes.

[0080] In some alternative embodiments, the halide solid electrolyte may include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6.

[0081] In some optional embodiments, the oxide solid electrolyte may include one or more of the following: perovskite structure oxide solid electrolyte, garnet structure oxide solid electrolyte, NASICON structure oxide solid electrolyte, and LISICON structure oxide solid electrolyte.

[0082] In some optional embodiments, to further improve the energy density of solid-state battery cells, the positive electrode active material includes materials with the general formula Li. a Ni b Co c M d O eA f One or more of lithium transition metal oxides and their modified materials, wherein 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A may include one or more of N, F, S and Cl.

[0083] As an example, the positive electrode active material may include, but is not limited to, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (abbreviated as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (abbreviated as NCM811), LiNi 0.96 Co 0.02 Mn 0.02 O2 (abbreviated as Ni96), LiNi 0.80 Co 0.15 Al 0.05 One or more of O2, LiFePO4, LiMnPO4 and their respective modified materials.

[0084] In some optional embodiments, the positive electrode active material also includes one or more of lithium phosphate and its modified materials, and lithium titanate. The above-mentioned types of positive electrode active materials have high specific capacity, which is beneficial for solid-state battery cells to achieve their energy density.

[0085] Optionally, examples of lithium phosphates may include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0086] During the charging and discharging process, solid-state battery cells undergo Li insertion / extraction and consumption, resulting in varying Li molar content at different discharge states. In this disclosure, the Li molar content listed for positive electrode active materials represents the initial state of the material, i.e., the state before material addition. As the positive electrode active material is applied to a solid-state battery cell, the Li molar content changes after charge-discharge cycles. Similarly, the O molar content listed for positive electrode active materials in this disclosure is only a theoretical value; lattice oxygen release causes changes in the O molar content, leading to fluctuations in the actual O molar content.

[0087] The modified materials for the above-mentioned positive electrode active materials can be doped and / or surface coated.

[0088] In some optional embodiments, the mass content of the positive electrode active material in the positive electrode active material layer is from 50 wt% to 90 wt%. The mass content of the positive electrode active material in the positive electrode active material layer can be any range consisting of 50.0%, 55.0%, 60.0%, 65.0%, 70.0%, 75.0%, 80.0%, 85.0%, and 90.0%. This can further improve the energy density of the solid-state battery cell.

[0089] In some optional embodiments, the positive electrode active material layer further includes a conductive agent, which may be one or more selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers. This can reduce the internal resistance of the positive electrode and improve the kinetic performance of the solid-state battery cell.

[0090] In some alternative embodiments, the thickness of the positive electrode can be 10 μm-50 μm.

[0091] In some alternative embodiments, the ionic conductivity of the positive electrode is from 0.01 mS / cm to 0.1 mS / cm, and optionally from 0.051 mS / cm to 0.08 mS / cm.

[0092] Method for detecting the ionic conductivity of the positive electrode: The positive electrode is installed in a sleeve, and lithium-plated copper sheets are then installed on both sides of the sleeve to assemble a symmetrical battery. A pressure of 4000 kg is applied to the symmetrical battery and held for 5 min. The AC impedance value R of the positive electrode is obtained by AC impedance spectroscopy (EIS) on an electrochemical workstation. The test temperature is 25℃, and the test frequency range is 10. 5 -10 -2 Hz, bias voltage is 10mV.

[0093] The ionic conductivity of the positive electrode is calculated using the following formula: σ = L / (R*S). L is the thickness of the positive electrode film, R is the AC impedance value in the AC impedance spectrum, and S is the area of ​​the positive electrode film.

[0094] [Preparation Method]

[0095] This disclosure also provides a method for preparing a positive electrode sheet, which can prepare the positive electrode sheet provided in this disclosure.

[0096] This disclosure also provides a positive electrode slurry. In some optional embodiments, the positive electrode slurry may include a positive electrode active material, a conductive agent, a binder polymer, and a sulfide solid electrolyte.

[0097] In some optional embodiments, the preparation method of the positive electrode slurry includes the following steps: stirring the positive electrode active material, binder polymer and sulfide solid electrolyte in a solvent until homogeneous to obtain the positive electrode slurry.

[0098] The solvent can be a nonpolar solvent, a weakly polar solvent, or a mixture of both, such as N-methylpyrrolidone.

[0099] In some optional embodiments, the preparation method of the positive electrode slurry includes the following steps: stirring the positive electrode active material and the binder polymer in a solvent until homogeneous; adding the positive electrode active material and the binder polymer to a solid electrolyte slurry and stirring until homogeneous to obtain the positive electrode slurry.

[0100] This disclosure also provides a positive electrode sheet, which is obtained by drying the positive electrode slurry provided in this disclosure.

[0101] In some alternative embodiments, the solid-state battery cell includes a positive electrode, a solid electrolyte sheet, and a negative electrode, with the solid electrolyte sheet located between the positive and negative electrode sheets.

[0102] The types of substances in the positive electrode active material layer can be referred to above, and will not be repeated here; or, the positive electrode active material layer is obtained by drying the positive electrode slurry provided in this disclosure.

[0103] [Negative electrode plate]

[0104] In some alternative embodiments, the negative electrode may include a negative current collector and a lithium-based metal layer located on at least one surface of the negative current collector. The negative current collector has two surfaces opposite each other in its thickness direction, and the lithium-based metal layer is disposed on either or both of the two opposite surfaces of the negative current collector.

[0105] In some alternative embodiments, the lithium-based metal layer may include lithium or a lithium alloy, wherein the lithium alloy contains more than 90% lithium by mass.

[0106] Alternatively, other elements in the lithium alloy may include one or more of In, Mg, Al, Zn, Sn, Ag, Au, Ga, Pt, and Fe.

[0107] Alternatively, lithium alloys may include Li-In alloys, Li-Mg alloys, Li-Al alloys, Li-Zn alloys, Li-Fe alloys, etc.

[0108] In other embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer located on at least one surface of the negative electrode current collector, the negative electrode active material layer including a negative electrode active material and a negative electrode binder. The negative electrode current collector has two surfaces opposite each other in its thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0109] In some optional embodiments, the negative electrode active material may include, but is not limited to, one or more of natural graphite, artificial graphite, mesophase microcarbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides. Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Optionally, the tin-based material may include, but is not limited to, one or more of elemental tin, tin oxides, and tin alloys. Optionally, the metal oxide includes one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, and Bi2O5.

[0110] Optionally, the negative electrode binder may include one or more of the following: methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), styrene-butadiene rubber (SBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0111] Optionally, the negative electrode active material layer may also include a negative electrode conductive agent. The negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0112] In some other embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer located on at least one surface of the negative electrode current collector. The negative electrode active material layer includes a negative electrode active material, a sulfide solid electrolyte, a polyacrylate binder, and a non-polar polyolefin binder. The types of the negative electrode active material, the sulfide solid electrolyte, the polyacrylate binder, and the non-polar polyolefin binder can be referred to above and will not be repeated here. Alternatively, the negative electrode active material layer may be obtained by drying the negative electrode slurry provided in this disclosure.

[0113] Optionally, based on the total mass of the negative electrode active material layer as 100%, the mass content of the sulfide solid electrolyte in the negative electrode active material layer can be 1wt%-20wt%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any combination of the above values.

[0114] Optionally, based on the total mass of the negative electrode active material layer as 100%, the total mass content of polyacrylate binders and non-polar polyolefin binders in the negative electrode active material layer can be 0.1wt%-10wt%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any combination of the above values.

[0115] Optionally, the negative electrode active material layer may also include a negative electrode conductive agent. The negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0116] In some optional embodiments, the negative electrode current collector may be a metal foil or a composite current collector. Examples of metal foils include copper foil, nickel foil, copper alloy foil, and nickel alloy foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. Examples of metal materials include, but are not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Examples of polymer substrates include, but are not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene.

[0117] [Solid Electrolyte Sheets]

[0118] In some optional embodiments, the solid electrolyte sheet includes a solid electrolyte. Optionally, the solid electrolyte may include one or more of sulfide solid electrolytes, halide solid electrolytes, and oxide solid electrolytes. The types of sulfide solid electrolytes, halide solid electrolytes, and oxide solid electrolytes can be found above and will not be repeated here.

[0119] Optionally, the solid electrolyte sheet may also include a binder. The binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0120] In other embodiments, the solid electrolyte sheet may include a sulfide solid electrolyte and a binder. The types of sulfide solid electrolytes and binders can be referred to above and will not be repeated here; alternatively, the solid electrolyte sheet may be obtained by drying the solid electrolyte slurry provided in this disclosure.

[0121] In some alternative embodiments, the thickness of the solid electrolyte sheet can be 10 μm-50 μm.

[0122] In some alternative embodiments, the solid-state battery cell may further include an outer packaging for housing the positive electrode, solid electrolyte sheet, and negative electrode. The outer packaging may be a rigid shell, such as a hard plastic shell, aluminum shell, or steel shell. The outer packaging may also be a flexible package, such as a pouch. The material of the flexible package may be plastic, such as aluminum-plastic film, polypropylene, polybutylene terephthalate (PBT), and polybutylene succinate (PBS) or one or more of these materials.

[0123] The methods for preparing solid-state battery cells are well known. In some optional embodiments, a positive electrode, a solid electrolyte sheet, and a negative electrode can be assembled to obtain an electrode assembly, which is then placed in an outer package to obtain a solid-state battery cell.

[0124] Example

[0125] The following examples describe the contents of this disclosure in more detail. These examples are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on mass, and all reagents used in the examples are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0126] Example 1

[0127] Preparation of the positive electrode: The positive electrode active material LiNi... 0.83 Co 0.11 Mn0.06 O2, sulfide solid electrolyte Li6PS5Cl, binder polymer, and conductive agent are dispersed in solvent N-methylpyrrolidone at a mass ratio of 8:1:0.5:0.5. The conductive agent is vapor-grown carbon fiber (VGCF), and the binder polymer has the structure shown in formula (1). The weight average molecular weight of the binder polymer is 600,000, and the molar ratio of the first structural unit to the second structural unit is 1:0.3. The positive electrode slurry is prepared by magnetic stirring for 12 hours. Then, the positive electrode slurry is coated onto the surface of aluminum foil with a thickness of 15 μm. After vacuum drying for 12 hours and cutting, the positive electrode sheet D1# is obtained.

[0128] Preparation of negative electrode sheet: The negative electrode active material silicon-carbon composite material, sulfide solid electrolyte Li6PS5Cl: and negative electrode binder styrene-butadiene rubber are weighed and mixed in a solid mass ratio of 90:15:5 and added to the solvent N-methylpyrrolidone to make a negative electrode slurry. Then the negative electrode slurry is coated on both sides of a copper foil with a thickness of 15μm and dried to obtain a negative electrode sheet.

[0129] Preparation of electrolyte sheet: The sulfide solid electrolyte Li6PS5Cl and styrene-butadiene rubber are weighed and mixed at a solid mass ratio of 90:10 and added to the weakly polar solvent xylene to prepare a solid electrolyte slurry. The solid electrolyte slurry is then coated onto the surface of the negative electrode active material layer prepared above. After drying and cutting, a negative electrode sheet with a solid electrolyte sheet is obtained.

[0130] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain a solid-state battery cell.

[0131] Examples 2 to 7

[0132] The difference between this embodiment and embodiment 1 is that the type of adhesive polymer is different. The adhesive polymers in embodiments 2 to 7 are, in order, the structure shown in formula (2), the structure shown in formula (3), the structure shown in formula (5), the structure shown in formula (6), the structure shown in formula (13), and the structure shown in formula (20).

[0133] Examples 8 to 9

[0134] The difference between this embodiment and embodiment 1 is that the type of binder polymer is the same, and the structure is shown in formula (1). The mass content of the binder polymer in the positive electrode active material layer in embodiments 8 to 9 is different. The mass content of the binder polymer in embodiments 8 to 9 is 0.1 wt% and 10 wt%, respectively.

[0135] Examples 10 to 12

[0136] The difference between this embodiment and Example 1 is that the weight-average molecular weight of the binder polymer is different. The weight-average molecular weights in Examples 10 to 12 are 400,000, 700,000 and 800,000, respectively.

[0137] Examples 13 to 14

[0138] The difference between this embodiment and Embodiment 1 is that the molar ratio of the first structural unit and the second structural unit of the adhesive polymer is different. The molar ratios of the first structural unit and the second structural unit in Embodiments 13 and 14 are 1:0.1 and 1:0.8, respectively.

[0139] Comparative Example 1

[0140] The difference between this comparative example and Example 1 is that the binder polymer in the positive electrode is polyvinylidene fluoride with a weight-average molecular weight of 600,000.

[0141] Comparative Example 2

[0142] The difference between this comparative example and Example 1 is that the binder polymer in the positive electrode is polytetrafluoroethylene with a weight-average molecular weight of 600,000.

[0143] Comparative Example 3

[0144] The difference between this comparative example and Example 1 is that the binder polymer in the positive electrode is as shown in formula (23), and its weight-average molecular weight is 600,000. The molar ratio of the first structural unit (-OCH2CH2-) and the second structural unit (-CH2CH2-) is 1:0.3, and the second structural unit does not contain halogen atoms.

[0145] Performance testing

[0146] (1) Ionic conductivity test of positive electrode

[0147] A sample of the positive electrode active material layer on the surface of the prepared positive electrode sheet was taken, and 100 mg of positive electrode powder was placed in a sleeve. A pressure of 4000 kg was applied to press it into a positive electrode film, and its thickness was measured and recorded as L. 60 mg of sulfide solid electrolyte Li6PS5Cl was placed on each side of the sleeve, and a pressure of 2000 kg was applied to each side to press it into a sheet. Then, 60 mg of indium powder was placed on each side of the sleeve, and a pressure of 2000 kg was applied to each side to press it into a sheet. Finally, lithium-plated copper sheets were placed on each side of the sleeve to assemble a symmetrical battery. A pressure of 4000 kg was applied to the symmetrical battery and held for 5 min. The AC impedance value R of the positive electrode sheet was obtained using electrochemical impedance spectroscopy (EIS) on an electrochemical workstation. The test temperature was 25℃, and the test frequency range was 10 Hz. 5 -10 -2 Hz, bias voltage is 10mV.

[0148] The ionic conductivity of the positive electrode is calculated using the following formula: σ = L / (R*S). L is the thickness of the positive electrode film, R is the AC impedance value in the AC impedance spectrum, and S is the area of ​​the positive electrode film.

[0149] (2) Thermal testing of the positive electrode

[0150] The solid-state battery cells in the fully charged state of the above embodiments or comparative examples were disassembled, the tabs in the cell were removed, and the positive electrode sheet was obtained after disassembling the cell. The positive active material layer on the surface of the positive electrode sheet was sampled using a scraper, and the powder of the positive active material layer was scraped off to obtain 10mg of fully charged composite positive electrode powder. Under an argon atmosphere, the temperature was increased from 35°C to 460°C at a rate of 10°C / min. The differential scanning calorimetry curve of the composite positive electrode powder was obtained using a Netzsch DSC3500 differential scanning calorimeter. The total heat generation of the composite positive electrode powder at high temperature was obtained by analyzing the peak area in the curve.

[0151] Figure 3 shows a differential scanning calorimetry (DSC) curve of the composite cathode powder of Example 1. The heat released by the fully charged composite cathode sheet can be obtained by the area in the curve.

[0152] (2) First-cycle charge specific capacity and cycle performance test of solid-state battery cells

[0153] The test temperature was 25℃, and the solid-state battery cells were tested under a pressure of 15MPa.

[0154] The solid-state battery cells were charged at a constant current rate of 0.1C to a voltage of 4.3V (vs. Li). + / Li), the specific capacity at this point is recorded as the first charge capacity; then let it stand for 5 minutes, and then discharge at a constant current rate of 0.1C until the voltage is 2V (vs. Li). + / Li), record the discharge capacity of the first cycle. After repeating the above steps for 100 cycles, record the discharge capacity of the 100th cycle. This discharge capacity is recorded as the discharge capacity of the first cycle.

[0155] Solid-state battery cell capacity retention (%) = 100 discharge cycle capacity / first charge cycle capacity × 100%.

[0156] Table 1

[0157] As can be seen from the above test results, compared with comparative examples 1-3, the positive electrode active material layer powder of the positive electrode sheet of this application embodiment has high ionic conductivity and low heat generation. The reason for this is that: the ether group in the first structural unit can reduce or decrease the reaction between the positive electrode active material and the sulfide solid electrolyte; the ether group or F atom can conduct active ions, such as lithium ions, and improve the cycle performance of the solid battery cell; the fluorine atom in the first structural unit and the halogen atom in the second structural unit can anchor the oxygen released by the positive electrode active material during electrochemical cycling, reduce the probability of thermal failure reaction between the positive electrode active material and the sulfide solid electrolyte at high temperature in the solid battery, and reduce heat generation.

[0158] Compared to Comparative Examples 1-3, the solid-state battery cells of this application embodiment have added the binder polymer of this application embodiment to the positive electrode sheet. Compared to cases without the first structural unit or the second structural unit, the first and second structural units of this application anchor the oxygen released by the positive electrode active material during electrochemical cycling, reduce the probability of thermal failure reaction between the positive electrode active material and the sulfide solid electrolyte at high temperature in the solid-state battery, reduce heat generation, improve the initial charge specific capacity of the battery cell, and also improve cycle performance.

[0159] It should be noted that this disclosure is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this disclosure are included within the technical scope of this disclosure. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, are also included within the scope of this disclosure without departing from the spirit of this disclosure.

Claims

1. A solid-state battery cell, comprising a positive electrode sheet, wherein the positive electrode sheet comprises a positive current collector and a positive active material layer disposed on at least one side of the positive current collector, the positive active material layer comprising a sulfide solid electrolyte, a binder polymer, and a positive active material, the binder polymer comprising a first structural unit and a second structural unit, the first structural unit comprising any one or more of -OCH2CH2-, -CH2-O-CH2-, and -CH2CH2- in which at least two hydrogen atoms are replaced by F atoms in the same carbon atom, the second structural unit comprising -CH2CH2- in which halogen atoms are arbitrarily substituted, wherein... The halogen atom includes any one or more of Cl, Br and I.

2. The solid-state battery cell according to claim 1, wherein, The adhesive polymer is a block polymer.

3. The solid-state battery cell according to claim 1 or 2, wherein, The adhesive polymer satisfies one or more of the following conditions: (1) The weight-average molecular weight of the adhesive polymer is 10,000 to 1,000,000; (2) The glass transition temperature Tg of the adhesive polymer is -100℃ to 200℃.

4. The solid-state battery cell according to any one of claims 1 to 3, wherein, The adhesive polymer satisfies one or more of the following conditions: (1) The weight-average molecular weight of the adhesive polymer is 400,000 to 800,000; (2) The glass transition temperature Tg of the adhesive polymer is -50℃ to 60℃.

5. The solid-state battery cell according to any one of claims 1 to 4, wherein, The molar ratio of the first structural unit to the second structural unit is 1:(0.1 to 0.8).

6. The solid-state battery cell of any one of claims 1 to 5, wherein, The binder polymer comprises a structure according to any one of formulae (1) to (22): Where x and y are positive integers, and x and y are between 10 and 10000.

7. The solid-state battery cell of any one of claims 1 to 6, wherein, The binder polymer has a mass content of 0.1% to 10% in the positive electrode active material layer.

8. The solid-state battery cell of any one of claims 1 to 7, wherein, The sulfide solid electrolyte includes one or more of Li6PS5Y, LGPS-type sulfide solid electrolytes, and multi-element sulfide solid electrolytes, where Y includes one or more elements selected from F, Cl, Br, and I; and / or, The sulfide solid electrolyte has a mass content of 0.1% to 20% in the positive electrode active material layer.

9. The solid-state battery cell of any one of claims 1 to 8, wherein, The positive electrode active material includes materials with the general formula Li. a Ni b Co c M d O e A f One or more of lithium transition metal oxides and their modified materials, wherein 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A may include one or more of N, F, S and Cl; and / or, The positive electrode active material has a mass content of 50% to 90% in the positive electrode active material layer.

10. The solid-state battery cell of any one of claims 1 to 9, wherein, The positive electrode active material layer further includes a conductive agent, which includes one or more of the following: superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers.

11. A binder polymer for solid state battery cells, wherein, The adhesive polymer includes a first structural unit and a second structural unit. The first structural unit includes any one or more of -OCH2CH2-, -CH2-O-CH2-, and -CH2CH2- in which at least two hydrogen atoms are replaced by an F atom in the same carbon atom. The second structural unit includes -CH2CH2- in which a halogen atom is arbitrarily replaced. The halogen atom includes any one or more of Cl, Br, and I.

12. A battery device, wherein, It includes any one of the solid-state battery cells according to claims 1-10.

13. An electrical device, comprising: Includes the solid-state battery cell according to any one of claims 1-10 or the battery device according to claim 12.

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