All-solid-state battery cell and preparation method and application thereof

Abstract

The application discloses a kind of full solid-state battery and its preparation method and application, it is related to solid-state battery technical field.The edge of positive active layer is attached with solidified insulating glue, so as to use the solidified insulating glue to fill the size difference between the positive active layer and the negative active layer, and the end of the positive active layer and the negative active layer is flush, the insulating glue plays a supporting role under extrusion, avoids the problems such as collapse and short circuit caused by the size difference between the positive active layer and the negative active layer;The insulating glue at the edge can be bonded with the negative electrode under high pressure, and when the positive electrode is charged and discharged, the cycle performance difference caused by the volume change of the positive electrode during charging and discharging can be effectively alleviated, and the cycle of the battery is improved;It can also effectively avoid the occurrence of problems such as the edge of the positive electrode dropping material.By setting electrolyte film between the positive active layer and the negative active layer, the impedance between the electrolyte film and the electrode sheet is reduced by using the ionic liquid treatment layer on the electrolyte film, and the battery performance is improved.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, and more specifically, to an all-solid-state battery cell, its preparation method, and its application. Background Technology

[0002] Solid-state batteries are characterized by high energy density and high safety, representing a major trend in lithium-ion battery development. The biggest difference between solid-state batteries and traditional batteries is the use of a solid electrolyte, which also leads to significant differences in their manufacturing processes. With continuous research into solid-state battery technology, the manufacturing processes for the positive and negative electrodes and electrolyte membranes have gradually matured, with most processes employing cutting and stacking methods.

[0003] Currently, existing solid-state battery manufacturing methods mainly have the following defects: (1) In all-solid-state electrodes, the size of the positive electrode is designed to be smaller than that of the negative electrode. The negative electrode covers the edge of the positive electrode, which is prone to collapse after hot pressing or isostatic pressing, causing a short circuit in the cell. (2) Existing electrodes do not address the de-contact and performance degradation problems (such as decreased cycle performance) caused by changes in the volume of the positive electrode. Existing materials have poor adhesion to the electrode and cannot form an effective bond with the electrode to address the de-contact caused by changes in volume.

[0004] Furthermore, the electrolyte membrane is thin and lacks flexibility, making it difficult to quickly, stably, and accurately grasp and transport using conventional stacking or shoving methods. This also poses a significant risk of breakage, leading to cell quality issues or even cell scrapping. Traditional stacking methods have bottlenecks in single-cell grasping and stacking efficiency during solid-state battery manufacturing, are prone to damage, and are difficult to detect and control.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an all-solid-state battery cell, its preparation method and application, which aims to avoid problems such as collapse and short circuit caused by the size difference between the positive and negative electrode sheets, and to alleviate the problem of poor cycle performance caused by the volume change of the positive electrode sheet during charging and discharging.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides an all-solid-state battery cell, comprising a positive active layer, a negative active layer and an electrolyte membrane, wherein the positive active layer is bonded to the negative active layer through the electrolyte membrane; and an ionic liquid treatment layer is provided between the electrolyte membrane and the positive active layer and / or the negative active layer.

[0009] Cured insulating adhesive is attached to the edge of the positive electrode active layer to fill the size difference between the positive electrode active layer and the negative electrode active layer.

[0010] In an optional embodiment, it also includes a positive current collector and a negative current collector. The positive active layer is attached to both sides of the positive current collector to form a positive electrode sheet, and the negative active layer is attached to both sides of the negative current collector to form a negative electrode sheet. An electrolyte membrane is attached to both sides of the negative electrode sheet to form a composite negative electrode sheet. There are multiple positive electrode sheets and multiple composite negative electrode sheets.

[0011] Positive electrode plates and composite negative electrode plates are alternately stacked;

[0012] Two adjacent negative electrode plates are connected by a negative electrode current collector;

[0013] Preferably, the width of the cured insulating adhesive attached to the positive electrode sheet is 0.5μm-1.5μm;

[0014] Preferably, both sides of the negative current collector connecting two adjacent negative electrode sheets are coated with cured insulating adhesive.

[0015] In an optional embodiment, the raw materials for the insulating adhesive include a first adhesive and a viscoelastic material, wherein the viscoelastic material is selected from at least one of thermoplastic adhesives and thermosetting adhesives.

[0016] Preferably, the first adhesive is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, and polyacrylonitrile;

[0017] Preferably, the mass ratio of the first adhesive to the viscoelastic material is 1:(0.5-1.5);

[0018] Preferably, the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, polyester, epoxy resin, polyurethane, polybutadiene acid, silicone resin, styrene-butadiene copolymer, polyesterimide and polyimide.

[0019] In an optional embodiment, the positive electrode active layer includes a positive electrode active material, a second binder, and a conductive agent; the second binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, and polyacrylonitrile.

[0020] Preferably, the first adhesive and the second adhesive are of the same type;

[0021] Preferably, the positive electrode active layer further includes an electrolyte, which is selected from at least one of sulfide electrolytes, oxide electrolytes, and halide electrolytes.

[0022] In an optional embodiment, an ionic liquid treatment layer is prepared by depositing an ionic liquid on the surface of an electrolyte membrane; preferably, the ionic liquid treatment layer is prepared by vapor deposition.

[0023] Preferably, the ionic liquid used in preparing the ionic liquid treatment layer is selected from at least one of 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium diazonium, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate.

[0024] Preferably, the thickness of the ionic liquid treatment layer is 5nm-1000nm, and the thickness of the electrolyte membrane is 10μm-100μm;

[0025] Preferably, the electrolyte membrane comprises a sulfide electrolyte and a third binder, wherein the sulfide electrolyte accounts for 80%-99% by mass; wherein the sulfide electrolyte is selected from Li3PS4 and Li7P3S. 11 Li 10 GeP2S 12 Li6PS5Cl, Li6PS5I, Li6PS5Br and Li 3.875 Sn 0.875 As 0.125 At least one of S4 and Li4SnS4; the third binder in the electrolyte membrane is selected from at least one of polyvinylidene fluoride binders, silicone rubber, styrene-butadiene rubber, polyvinyl alcohol, acrylates and nitrile rubber.

[0026] In a second aspect, the present invention provides a method for preparing an all-solid-state battery cell in any of the foregoing embodiments, comprising: providing a positive electrode strip, the positive electrode strip comprising a positive electrode current collector and a positive electrode active layer attached to the positive electrode current collector;

[0027] Based on the dimensions of the positive electrode product, a positive electrode groove is formed by marking on the positive electrode active layer. Insulating adhesive is injected into the positive electrode groove and cured. After curing, the positive electrode is die-cut at the location of the insulating adhesive to obtain a positive electrode with the required dimensions.

[0028] The positive electrode, electrolyte membrane, and negative electrode are bonded together, with the electrolyte membrane located between the positive and negative electrode.

[0029] In an optional embodiment, the method includes: providing a negative electrode tape and a solid electrolyte tape, wherein the negative electrode tape includes a negative electrode current collector and a negative electrode active layer attached to the negative electrode current collector, and the solid electrolyte tape includes a base film and an electrolyte film attached to the base film.

[0030] Solid electrolyte strips are transferred onto the negative electrode active layer of negative electrode strips, and the base film is separated so that electrolyte films are attached to both sides of the negative electrode strips, resulting in composite negative electrode strips.

[0031] A negative electrode groove is formed by marking on the composite negative electrode strip to penetrate the negative electrode active layer and the electrolyte membrane. Insulating glue is injected into the negative electrode groove and cured to form multiple composite negative electrode sheets spaced apart.

[0032] Multiple positive electrode sheets obtained after die-cutting are combined with multiple composite negative electrode sheets, then stacked alternately and hot-pressed to obtain an all-solid-state battery cell.

[0033] Preferably, the thickness of the insulating adhesive injected into the negative electrode marking groove is less than or equal to the thickness of the negative electrode active layer.

[0034] In an optional embodiment, the preparation method satisfies at least one of the following conditions:

[0035] Condition 1: Before transferring the solid electrolyte strip onto the negative electrode active layer of the negative electrode strip, an ionic liquid treatment layer is set on the surface of the electrolyte membrane away from the base membrane.

[0036] Condition 2: After separating the base membrane, an ionic liquid treatment layer is set on the surface of the electrolyte membrane on the side away from the negative electrode active layer;

[0037] Preferably, the electrolyte membrane formation process includes: mixing a sulfide electrolyte, a third binder, and an electrolyte solvent according to the composition of the electrolyte membrane to obtain an electrolyte slurry; coating the electrolyte slurry onto one side of a base membrane; and drying to form an electrolyte membrane.

[0038] More preferably, the electrolyte solvent is selected from at least one of butyl butyrate, isobutyl isobutyrate, n-hexane, n-heptane, toluene, xylene, anisole, cyclohexanone, and 1,3,5-trimethylbenzene;

[0039] More preferably, the material of the base film is selected from at least one of polyethylene terephthalate, polyamide, polyimide, polypropylene, aluminum foil, and stainless steel foil.

[0040] Thirdly, the present invention provides a lithium-ion battery, comprising any of the all-solid-state cells in the foregoing embodiments or all-solid-state cells prepared by any of the preparation methods in the foregoing embodiments.

[0041] Fourthly, the present invention provides an electrical device including the lithium-ion battery of the aforementioned embodiments.

[0042] The present invention has the following beneficial effects: by attaching cured insulating adhesive to the edge of the positive electrode active layer, the cured insulating adhesive can fill the size difference between the positive electrode active layer and the negative electrode active layer, making the ends of the positive electrode active layer and the negative electrode active layer flush. Under compression, the insulating adhesive plays a supporting role, avoiding problems such as collapse and short circuit caused by the size difference between the positive and negative active layers; the edge insulating adhesive can bond with the negative electrode under high pressure, and when the positive electrode is charged and discharged, it can effectively alleviate the problem of poor cycle performance caused by the volume change of the positive electrode sheet during charging and discharging, and improve the cycle performance of the battery; it can also effectively avoid the occurrence of problems such as material falling off the edge of the positive electrode sheet.

[0043] By placing an electrolyte membrane between the positive and negative electrode active layers and utilizing an ionic liquid treatment layer on the electrolyte membrane, the solid-solid contact between the electrolyte membrane and the electrode sheet is improved, the impedance between the electrolyte membrane and the electrode sheet is reduced, and battery performance is enhanced. The ionic liquid can effectively improve the membrane strength and ionic conductivity by filling micropores, self-leveling, and forming ionic bonds with the electrolyte, and significantly improve subsequent transfer efficiency. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, 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 the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the marking and coating process for the positive electrode strip;

[0046] Figure 2 This is a schematic diagram of the transfer and composite process of solid electrolyte strip and negative electrode strip;

[0047] Figure 3 A schematic diagram of the marking and coating process for composite negative electrode strips;

[0048] Figure 4 This is a schematic diagram of a composite stack of positive and negative electrodes;

[0049] Figure 5 This diagram illustrates the process of alternating stacking of positive and composite negative electrodes. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0051] An embodiment of the present invention provides a method for preparing an all-solid-state battery cell, comprising the following steps:

[0052] S1. Prepare a positive electrode tape, a negative electrode tape, and a solid electrolyte tape

[0053] Prepare a positive electrode tape, a negative electrode tape, and a solid electrolyte tape respectively for standby. The preparation processes of the three tapes will be described separately below:

[0054] (1) Prepare the positive electrode tape

[0055] The positive electrode tape includes a positive electrode current collector and a positive electrode active layer adhered to the positive electrode current collector. Forming the positive electrode active layer on the positive electrode current collector obtains the positive electrode tape, and it can be prepared by a dry process or a wet process, and the specific preparation process is not limited.

[0056] In some embodiments, the positive electrode current collector can be aluminum foil, but is not limited thereto.

[0057] In some embodiments, by mass fraction, the positive electrode active layer includes 60%-85% of positive electrode active material, 1%-30% of conductive agent, 1%-30% of sulfide electrolyte, and 0.1%-10% of second binder. It is appropriate to control the dosage of each component within the above range to further improve the electrochemical performance of the battery.

[0058] Among them, the positive electrode active material is selected from at least one of lithium manganate (LiMn2O4), lithium cobaltate (LiCoO2), lithium iron phosphate (LiFePO4), lithium nickel cobalt manganese oxide (LiNi x Co y Mn z O2), high-nickel positive electrode material (LiNi x Co y Al z O2), and lithium-rich manganese positive electrode material, and can be at least one or several of the above common positive electrode active materials. The parameter values in the chemical formula of LiNi x Co y Mn z O2 and LiNi x Co y Al z O2 satisfy: x + y + z = 1, 0 < x < 1, 0 < y < 1, 0 < z < 1. Specifically, the specific type of the positive electrode active material is not limited. For example, it can be commercially available NCM811, but is not limited thereto.

[0059] The conductive agent is selected from at least one of carbon black, acetylene black, vapor-grown carbon fiber (VGCF), and carbon nanotubes (CNTs), and can be any one or more of the above. The electrolyte is selected from at least one of sulfide electrolytes, oxide electrolytes, and halide electrolytes, and can be any one or more of the above. The sulfide electrolyte is selected from Li3PS4 and Li7P3S. 11 Li 10 GeP2S 12 Li6PS5Cl, Li6PS5I, Li6PS5Br and Li 3.875 Sn 0.875 As 0.125S4 It can be any one or more of Li4SnS4, such as sulfide electrolyte LPSC, but is not limited thereto.

[0060] The second binder in the positive electrode active coating is selected from at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), carboxymethyl cellulose (CMC), polyacrylic acid (PAA), and polyacrylonitrile (PAN). The second binder in the positive electrode active coating can be any one or more of the above.

[0061] When using a dry process to prepare the positive electrode strip, the preparation process includes: sequentially mixing the raw materials at low speed, shearing at high speed, and hot rolling according to the composition of the positive electrode active layer to obtain the positive electrode active layer; and then attaching the positive electrode active layer to the positive electrode current collector to obtain the positive electrode strip. Specifically, the rotation speed can be controlled at 50-200 r / min during low-speed mixing; the rotation speed can be controlled at 800-1500 r / min during high-speed shearing; and the rolling temperature can be controlled at 60℃-220℃ during hot rolling.

[0062] When a wet process is used to prepare the positive electrode strip, the preparation process includes: mixing the raw materials according to the composition of the positive electrode active layer, coating them onto the positive electrode current collector, and drying them to obtain the positive electrode strip.

[0063] In some embodiments, the thickness of the positive electrode active layer can be controlled to be 50μm-400μm, whether using a dry process or a wet process, to ensure the electrochemical performance of the battery.

[0064] It should be noted that "positive electrode strip" refers to the material before rolling, and the positive electrode strip becomes the positive electrode sheet in the final product.

[0065] (2) Preparation of negative electrode strip

[0066] The negative electrode material strip includes a negative electrode current collector and a negative electrode active layer. The negative electrode material strip is obtained by forming a negative electrode active layer on the negative electrode current collector. It can be prepared by dry process or wet process, and the specific preparation process is not limited.

[0067] In some embodiments, the negative current collector may be copper foil, but is not limited thereto.

[0068] In some embodiments, the negative electrode active layer comprises, by mass fraction, 60%-85% negative electrode active material, 1%-30% conductive agent, 1%-30% sulfide electrolyte and 0.1%-10% binder. The amount of each component should preferably be controlled within the above range to further improve the electrochemical performance of the battery.

[0069] Furthermore, the negative electrode active material is selected from at least one of graphite, lithium titanate, silicon oxide, silicon-carbon, and silicon-based alloys, and can be any one or more of the above. The conductive agent is selected from at least one of conductive carbon, acetylene black, vapor-grown carbon fiber (VGCF), and carbon nanotubes (CNTs), and can be any one or more of the above. The sulfide electrolyte is selected from Li3PS4 and Li7P3S. 11 Li 10 GeP2S 12 Li6PS5Cl, Li6PS5I, Li6PS5Br and Li 3.875 Sn 0.875 As 0.125 At least one of S4 and Li4SnS4, or any one or more of the above.

[0070] Furthermore, the type of binder in the negative electrode active layer varies slightly depending on the preparation process. When preparing the negative electrode tape using a dry process, the binder is selected from at least one of polytetrafluoroethylene (PTFE), polyvinylidene fluoride binders (which may be modified copolymers of PVDF), acrylic resin (PAA), polytetrafluoroethylene (PTFE), and styrene-butadiene rubber (SBR), and can be at least one or more of the above. When preparing the negative electrode tape using a wet process, the binder is selected from at least one of polyvinylidene fluoride binders (which may be modified copolymers of PVDF), silicone rubber (SR), styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), acrylates (CMA), and nitrile rubber (NBR), and can be any one or more of the above.

[0071] When using a dry process to prepare the negative electrode strip, the preparation process includes: sequentially mixing the raw materials at low speed, shearing at high speed, and hot rolling according to the composition of the negative electrode active layer to obtain the negative electrode active layer; then attaching the negative electrode active layer to the negative electrode current collector to obtain the negative electrode strip. Specifically, the rotation speed can be controlled at 50-200 r / min during low-speed mixing; the rotation speed can be controlled at 800-1500 r / min during high-speed shearing; and the rolling temperature can be controlled at 60℃-220℃ during hot rolling.

[0072] When a wet process is used to prepare the negative electrode strip, the preparation process includes: mixing the raw materials according to the composition of the negative electrode active layer, coating them onto the negative electrode current collector, and drying them to obtain the negative electrode strip.

[0073] In some embodiments, the thickness of the negative electrode active layer can be controlled to be 40μm-400μm, whether using a dry process or a wet process, to ensure the electrochemical performance of the battery.

[0074] (3) Preparation of solid electrolyte tape

[0075] Solid electrolyte tape includes a base film and an electrolyte membrane bonded to the base film. In actual operation, the preparation process of the electrolyte membrane includes: mixing the components according to the composition of the electrolyte membrane to obtain an electrolyte slurry, coating the electrolyte slurry onto one side of the base film, and drying to form an electrolyte membrane.

[0076] In some embodiments, the raw materials for preparing the electrolyte membrane include a sulfide electrolyte, a third binder, and an electrolyte solvent. The electrolyte solvent evaporates after drying, so the electrolyte membrane in the product contains both the sulfide electrolyte and the third binder. In the electrolyte membrane, the mass percentage of the sulfide electrolyte is 80%-99% (e.g., 80%, 85%, 90%, 95%, 99%, etc.), with the remainder being the third binder. A solid electrolyte strip can be prepared using the following process: the sulfide electrolyte, the third binder, and the electrolyte solvent are mixed according to the composition of the electrolyte membrane to obtain an electrolyte slurry; the electrolyte slurry is coated onto one side of the electrolyte base membrane; and after drying, an electrolytic membrane roll is obtained.

[0077] The sulfide electrolytes are selected from Li3PS4 and Li7P3S. 11 Li 10 GeP2S 12 Li6PS5Cl, Li6PS5I, Li6PS5Br and Li 3.875 Sn 0.875 As 0.125 The third binder in the electrolyte membrane is selected from at least one of S4 and Li4SnS4, and can be any one or more of the above, but is not limited to the above. The third binder in the electrolyte membrane is selected from at least one of polyvinylidene fluoride binders (which can be PVDF-modified polymers), SR, styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), CMA, and nitrile rubber (NBR), and can be any one or more of the above, but is not limited to the above. The electrolyte solvent is selected from at least one of butyl butyrate, isobutyl isobutyrate, n-hexane, n-heptane, toluene, xylene, anisole, cyclohexanone, and 1,3,5-trimethylbenzene, and can be any one or more of the above, but is not limited to the above.

[0078] The electrolyte base membrane is the substrate, and its material is selected from at least one of polyethylene terephthalate (PET), polyamide (PA), polyimide (PI), polypropylene (PP), aluminum foil, and stainless steel foil. It can be any one or more of the above, but is not limited to these. The substrate can be a general Mylar film.

[0079] In some embodiments, the solid electrolyte strip preparation process involves sequentially forming an electrolyte membrane and an ionic liquid treatment layer on an electrolyte base membrane. Introducing the ionic liquid treatment layer enhances the surface adhesion and density of the electrolyte membrane, resulting in a treated electrolyte membrane roll for later use. In other words, before transferring the electrolyte membrane onto the negative electrode active layer of the negative electrode strip, an ionic liquid treatment layer is applied to the surface of the electrolyte membrane away from the base membrane.

[0080] The ionic liquid treatment layer can be prepared using vapor deposition, but is not limited to this method. By combining vapor deposition with the process, the ionic liquid can effectively bond with the sulfur bonds in the sulfide electrolyte membrane. The ionic bond chemical interaction enhances the interaction between the ionic liquid and the sulfide electrolyte, thereby improving the surface density and mechanical strength of the electrolyte membrane. Furthermore, the inherent viscosity of the ionic liquid improves the success rate of subsequent transfer and bonding of the electrolyte membrane to the negative electrode.

[0081] It's worth noting that, combined with vapor deposition, the fluidity of ionic liquids can fill the micropores in the electrolyte membrane, increasing its density and improving ionic conductivity. The self-leveling properties of ionic liquids can improve the surface smoothness of the electrolyte membrane, thereby enhancing the solid-solid contact between the electrolyte membrane and the electrode, reducing the impedance between them, and improving battery performance. In summary, ionic liquids, through filling micropores, self-leveling, and ionic bonding with the electrolyte, can effectively improve membrane strength and ionic conductivity, and significantly enhance subsequent transfer efficiency.

[0082] Furthermore, the ionic liquid contained in the ionic liquid treatment layer is selected from at least one of 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium diazonium, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate. It can be any one or more of the above, but is not limited to the above.

[0083] In some embodiments, the thickness of the electrolyte base film is 10 μm-100 μm (e.g., 10 μm, 30 μm, 50 μm, 80 μm, 100 μm, etc.), the thickness of the electrolyte membrane is 15 μm-120 μm, and the deposition thickness of the ionic liquid treatment layer is 5 nm-1000 nm (e.g., 5 μm, 10 μm, 50 μm, 100 μm, 300 μm, 500 μm, 800 μm, 1000 μm, etc.). By optimizing the thickness of each layer, especially the deposition thickness of the ionic liquid treatment layer, the high ionic conductivity of the electrolyte surface can be effectively preserved, which plays a certain role in improving battery performance.

[0084] In other embodiments, the ionic liquid treatment layer may not be introduced during the preparation of the electrolyte membrane. Instead, the ionic liquid treatment layer is introduced later, as detailed in step S3.

[0085] In some embodiments, the positive electrode tape, negative electrode tape, and solid electrolyte tape can be in continuous roll form, and can be bonded together by pressing.

[0086] S2, positive electrode strip markings

[0087] like Figure 1 As shown, based on the dimensions of the positive electrode product, a positive electrode marking groove is formed on the positive electrode active layer. Insulating adhesive is then injected into the marking groove and cured. Specifically, the depth of the marking groove can be the same as the thickness of the positive electrode active layer, just enough to peel off a certain width of the positive electrode active layer. After the injected insulating adhesive cures, it forms a support frame. After die-cutting at the insulating adhesive, a positive electrode sheet of the preset size can be obtained.

[0088] Specifically, the texturing equipment can remove the active coating on the surface of the current collector, forming regular grooves. The specific model is not limited; the texturing equipment can be an existing laser cleaning device (such as Hymex's laser cleaning machine), a current collector drilling and peeling texturing device, or a mechanical tool cleaning device. It can achieve texturing with micron-level precision without damaging the current collector, affecting its strength and electrode winding, or producing burrs. When both sides of the current collector are coated with an active coating, a double-sided texturing method is used; when only one side of the current collector is coated with an active coating, a single-sided texturing method is used. During double-sided texturing, the positive electrode texturing grooves on the active coatings on both sides correspond in position, allowing texturing to be performed at the same location. The texturing width can be the same or different, preferably the same width.

[0089] like Figure 1 and Figure 2As shown, the positive electrode marking groove has a length direction and a width direction. In the length direction, the marking groove extends from one end of the active coating to the opposite end. The width of the positive electrode marking groove is preferably 1mm-3mm, such as 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, etc.

[0090] Furthermore, the depth of the positive electrode tracer trench is 80μm-120μm, and the depth of the positive electrode tracer trench is less than or equal to the thickness of the active coating. That is to say, the depth of the positive electrode tracer trench can be approximately the same as the thickness of the active coating, or it can be slightly less than the thickness of the active coating.

[0091] In some embodiments, the raw materials for the injected insulating adhesive include a first binder and a viscoelastic material. The viscoelastic material is selected from at least one of thermoplastic and thermosetting adhesives, and can be any one or more of them. By mixing the viscoelastic material with the binder material in the electrode, the prepared composite material can bond well with the electrode and has excellent viscoelasticity. This effectively alleviates the problem of cycle performance degradation caused by volume changes in the electrode during charge and discharge, and has very strong operability, providing a very feasible method for the large-scale manufacturing of all-solid-state materials.

[0092] In some embodiments, the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, polyester, epoxy resin, polyurethane, polybutadiene acid, silicone resin, styrene-butadiene copolymer, polyesterimide, and polyimide. The viscoelastic material can be any one or more of these, all of which enable the cured colloid to possess good viscoelasticity. The first binder in the insulating adhesive is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, and polyacrylonitrile. The first binder in the insulating adhesive can be any one or more of these. Preferably, the first binder in the insulating adhesive is the same type as the binder in the positive electrode active coating.

[0093] Furthermore, the mass ratio of the first binder to the viscoelastic material is 1:(0.5-1.5). This ratio is preferable as it helps mitigate the degradation of cycle performance caused by volume changes in the electrode during charging and discharging. Specifically, the mass ratio of the first binder to the viscoelastic material can be 1:0.5, 1:0.8, 1:1.0, 1:1.2, 1:1.5, etc. The insulating adhesive can be prepared by co-extrusion, but is not limited to this method. During injection molding, the prepared insulating adhesive can be injected, with the injection thickness matching or slightly less than the electrode thickness. The injection location can be at the marking point or around the active coating.

[0094] S3, negative electrode tape and solid electrolyte tape are bonded together

[0095] Please refer to Figure 2 The negative electrode tape and solid electrolyte tape provided in this embodiment of the invention are bonded together. The negative electrode tape includes a negative electrode current collector and a negative electrode active layer bonded to the negative electrode current collector (i.e., Figure 2 The anode material (solid electrolyte tape) includes a base film and an electrolyte membrane bonded to the base film. In actual operation, the solid electrolyte tape is transferred onto the anode active layer of the anode tape, and the base film is separated, so that electrolyte membranes are bonded to both sides of the anode tape, resulting in a composite anode tape.

[0096] like Figure 2 As shown, the negative electrode current collector can be copper foil, but is not limited to it. First, the solid electrolyte is transferred and bonded to the negative electrode material on one side of the copper foil. During the transfer process, the base film (i.e., ...) is peeled off. Figure 2 (Mera membrane); After one side of the transfer is completed, the negative electrode material on the other side of the copper foil is transferred and bonded to the solid electrolyte. During the transfer process, the base film is peeled off at the same time, realizing electrolyte stripping and electrolyte bonding simultaneously.

[0097] Specifically, the electrolyte membrane can be transferred and bonded to both sides of the negative electrode strip using multiple rollers. During the multi-roller bonding process, the multi-roller composite line pressure is controlled at 10MPa-500MPa and the roller temperature is controlled at 25℃-200℃. After the transfer is completed, the strip is wound up to obtain the composite negative electrode strip.

[0098] In some embodiments, both the negative electrode strip and the solid electrolyte strip are in continuous roll form. After unwinding the negative electrode strip and the solid electrolyte strip, the solid electrolyte strip is transferred onto the negative electrode active layer by pressing. The pressing method is not limited and can be at least one of roll pressing, isostatic pressing, and flat pressing, preferably flat pressing. Pressing can also include hot pressing and cold pressing. Multiple pressing can be performed, or multiple pressing methods can be mixed. For example, cold roll pressing can be performed first, followed by hot flat pressing, or hot flat pressing can be performed first, followed by cold flat pressing.

[0099] In some embodiments, the preparation method satisfies at least one of the following conditions: Condition 1: Before transferring the solid electrolyte strip onto the negative electrode active layer, an ionic liquid treatment layer is provided on the surface of the electrolyte membrane away from the base film, i.e., the scheme described in step S1; Condition 2: After separating the base film, an ionic liquid treatment layer is provided on the surface of the electrolyte membrane away from the negative electrode active layer, i.e., the ionic liquid treatment layer is prepared after the negative electrode strip and the solid electrolyte strip are bonded together.

[0100] S4, Markings on composite negative electrode strip

[0101] like Figure 3As shown, a negative electrode groove is formed by marking on the composite negative electrode strip, which penetrates the negative electrode active layer and the electrolyte membrane. Insulating glue is injected into the negative electrode groove and cured to form multiple composite negative electrode sheets with insulating glue as the separation point.

[0102] Specifically, the depth of the negative electrode texturing groove is approximately equal to the total thickness of the negative electrode active layer and the electrolyte membrane. The texturing method can be the commonly used laser texturing. After texturing, adhesive is applied. The type of insulating adhesive used can be referred to the instructions in S2.

[0103] In some embodiments, the thickness of the insulating adhesive injected into the negative electrode marking groove is less than or equal to the thickness of the negative electrode active layer, and the thickness should not be too thick. Figure 4 As shown, this copper foil coated with insulating adhesive is bent in the battery cell product to connect to the adjacent negative electrode.

[0104] S5, positive electrode die-cutting, positive and negative electrode superposition

[0105] like Figure 4 As shown, the positive electrode cutting, electrode heating, electrode compositing, cell stacking, and cell hot pressing are carried out in sequence.

[0106] After curing in step S2, the positive electrode strip is die-cut at the location of the insulating adhesive to obtain a positive electrode sheet with the required dimensions. The positive electrode sheet is fed into the drying oven via a feeding roller, and the composite negative electrode strip also enters the drying oven. The electrode sheets are heated in the drying oven and then pressed by the composite roller to bond them together. After bonding, the electrolyte membrane on the composite negative electrode strip is located between the positive and negative electrode sheets.

[0107] Furthermore, after die-cutting, multiple positive electrode sheets and multiple composite negative electrode sheets are sequentially heated and composited. Then, using existing stacking processes, the positive and composite negative electrode sheets are alternately stacked and hot-pressed to obtain an all-solid-state battery cell. Using the negative electrode current collector as a carrier enables continuous stacking of the battery cell, thereby achieving continuous and stable manufacturing and significantly improving efficiency. The stacking process provided in this invention greatly reduces the handling and transfer of individual sheets, improving yield and making it easier to control.

[0108] In some embodiments, the drying temperature of the oven is 60℃-200℃, and the drying time is 0.5min-30min; the operating pressure during composite roller pressing is 0.5T-10T, and the pressing temperature is 60℃-150℃.

[0109] like Figure 4 and Figure 5As shown, positive electrode sheets and composite negative electrode sheets are stacked alternately, with copper foil coated with insulating adhesive (i.e., negative electrode current collector) at the bends. After stacking, the cell is hot-pressed and shaped by upper and lower pressure plates, with the hot-pressing temperature controlled at 60℃-120℃, the pressure at 2T-12T, and the hot-pressing time at 5S-60S.

[0110] This invention also provides an all-solid-state battery cell, comprising a positive active layer, a negative active layer, and an electrolyte membrane. The positive active layer is bonded to the negative active layer via the electrolyte membrane. An ionic liquid treatment layer is provided between the electrolyte membrane and the positive and / or negative active layers. Cured insulating adhesive is attached to the edge of the positive active layer to fill the dimensional difference between the positive and negative active layers.

[0111] like Figure 4 and Figure 5 As shown, the ends of the positive and negative active layers are flush, avoiding problems such as collapse and short circuits caused by the size difference between the positive and negative active agents; the insulating adhesive at the edge can bond with the negative electrode under high pressure conditions, and when the positive electrode is charged and discharged, it can effectively alleviate the problem of poor cycle performance caused by the volume change of the positive electrode sheet during charging and discharging, and improve the cycle performance of the battery; it can also effectively prevent the occurrence of problems such as material falling off the edge of the positive electrode sheet.

[0112] In some embodiments, the all-solid-state battery cell further includes a positive current collector and a negative current collector. A positive active layer is attached to both sides of the positive current collector to form a positive electrode sheet, and a negative active layer is attached to both sides of the negative current collector to form a negative electrode sheet. An electrolyte membrane is attached to both sides of the negative electrode sheet to form a composite negative electrode sheet. Multiple positive electrode sheets and composite negative electrode sheets are used. The positive electrode sheets and composite negative electrode sheets are alternately stacked, and the cured insulating adhesive on the positive electrode sheet fills the size difference between the positive and negative active layers. Adjacent negative electrode sheets are connected by a negative current collector, and both sides of the negative current collector connecting the two adjacent negative electrode sheets are coated with cured insulating adhesive. By first bonding the electrolyte membrane to the negative electrode sheet, problems such as the inability to grasp and back-and-forth movement caused by the poor physical strength characteristics of the electrolyte membrane are solved.

[0113] In some embodiments, the width of the cured insulating adhesive attached to the positive electrode sheet is 0.5μm-1.5μm, such as 0.5μm, 1.0μm, 1.5μm, etc. As described in S2, the width of the positive electrode marking groove is 1mm-3mm, then the width of the insulating adhesive is 1mm-3mm. After the insulating adhesive is cut in the middle, the width of the cured insulating adhesive attached to the positive electrode sheet on the product is 0.5μm-1.5μm.

[0114] It should be noted that the preparation method provided in this embodiment of the invention is carried out through steps S1-S5, which can reduce physical contact and handling during the cell stacking process, increase the insulating adhesive layer to prevent edge short circuits, and the electrode sheet after composite treatment also has the ability to be continuously stacked. The entire solid-state cell manufacturing method has reliable guarantees in terms of quality risk control and production stability, and can realize the mass production of solid-state cells.

[0115] This invention also provides a lithium-ion battery, including the above-mentioned all-solid-state cells, the number of which is unlimited, which are assembled to form a complete battery structure.

[0116] This invention also provides an electrical device, including the aforementioned lithium-ion battery, which is used for power supply. The form of the electrical device is not limited.

[0117] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0118] Example 1

[0119] This embodiment provides a method for preparing an all-solid-state battery cell, including the following steps:

[0120] (1) Preparation of positive electrode tape, negative electrode tape and solid electrolyte tape

[0121] NCM811@Li2TiO3 (i.e., NCM811 cathode particles coated with 3nm thick Li2TiO3, self-made) was used as the cathode active material, Li6PS5Cl as the cathode electrolyte, CNT as the conductive agent, and modified polytetrafluoroethylene (PTFE with functional group substitution, purchased from DuPont TE3885, the same below) as the cathode binder. These materials were mixed at a mass ratio of 75:22:2:1, and subjected to low-speed (100r / min) mixing for 0.1h, followed by high-speed shearing (1000r / min) for 0.15h. The mixture was then hot-rolled at 110℃ to a 220μm cathode active layer. This cathode active layer was then composited with 11μm carbon-coated aluminum foil to form a cathode strip.

[0122] Silicon carbide material (Si / C-450, the same below), Li6PS5Cl, VGCF (purchased from Kejing, the same below) and polytetrafluoroethylene (PTFE) were mixed in a mass ratio of 70:25:3:2. The mixture was then mixed at a low speed (100 r / min) for 0.1 h and sheared at a high speed (1000 r / min) for 0.3 h. The mixture was then hot-rolled at 100 °C to a negative electrode active layer with a thickness of 220 μm. The negative electrode active layer was then composited with a 7 μm double-sided carbon-coated copper foil and die-cut to prepare the negative electrode strip.

[0123] Xylene, n-heptane, and PVDF were mixed to prepare a mixed adhesive solution. This solution was then ball-milled with Li6PS5Cl at a mass ratio of 2:98, with a solid content of 45%, to obtain an electrolyte slurry. This slurry was coated onto an 11 μm thick PET substrate and dried at 80°C to form a 40 μm thick electrolyte film. The film was then die-cut to obtain an electrolyte sheet. An ionic liquid was prepared using 1-ethyl-3-methylimidazolium sulfate. The electrolyte sheet was placed in a vapor deposition assembly, and the ionic liquid was used to deposit a 50 nm thick electrolyte strip onto the surface of the electrolyte film, yielding a solid electrolyte strip. The deposition process parameters are as follows: existing conventional vapor deposition methods can be used.

[0124] (2) Markings on positive electrode strip

[0125] like Figure 1 As shown, based on the dimensions of the positive electrode product (preset dimensions are 71mm*180mm), double-sided texturing is performed on the positive electrode active layer to form positive electrode texturing grooves. The positions of the positive electrode texturing grooves on both sides of the active coating correspond, the texturing depth is equal to the thickness of the positive electrode active layer, and the width of the positive electrode texturing groove is 2mm. Insulating adhesive is injected into the positive electrode texturing groove and then cured.

[0126] The raw materials for the injected insulating adhesive include an adhesive and a viscoelastic material, with a mass ratio of 1:1. The adhesive is polyacrylic acid (PAA), purchased from Hubei Junrui Biotechnology Co., Ltd., model number 9007-20-9, and the viscoelastic material is ethylene-vinyl acetate copolymer (EVA), purchased from DuPont, USA, model number 250 low temperature resistant.

[0127] (3) Bonding of negative electrode tape and solid electrolyte tape

[0128] like Figure 2 As shown, the electrolyte membrane is first transferred and bonded to the negative electrode material on one side of the copper foil. During the transfer process, the base film (i.e., Figure 2 (Mera membrane); After one side of the transfer is completed, the negative electrode material on the other side of the copper foil is transferred and bonded to the electrolyte membrane. During the transfer process, the base film is peeled off simultaneously, achieving electrolyte stripping and electrolyte bonding at the same time. Specifically, the electrolyte membrane is transferred and bonded to both sides of the negative electrode strip using multiple rollers. During the multi-roller bonding, the multi-roller bonding line pressure is controlled at 1MPa and the roller temperature is 120℃. After the transfer is completed, the strip is wound up to obtain the composite negative electrode strip.

[0129] (4) Marking of composite negative electrode strip

[0130] like Figure 3As shown, a negative electrode groove is formed on the composite negative electrode strip, penetrating the negative electrode active layer and the electrolyte membrane. Insulating adhesive is injected into the negative electrode groove and cured to form multiple composite negative electrode sheets spaced apart by insulating adhesive. The type of insulating adhesive is the same as in step (2), and the thickness of the injected insulating adhesive is 100 μm.

[0131] (5) Positive electrode die-cutting, positive and negative electrode superposition

[0132] like Figure 4 As shown, the positive electrode sheet is cut, heated, laminated, stacked, and hot-pressed in sequence. After curing in step (2), the positive electrode strip is die-cut at the position of the insulating adhesive to obtain a positive electrode sheet with the required size. The positive electrode sheet is fed into the oven through the feeding roller, and the composite negative electrode strip also enters the oven. The positive electrode sheet is attached to both sides of the composite negative electrode strip. The electrode sheet is heated in the oven and laminated by the composite roller. The negative current collector is used as a carrier for continuous stacking of the battery cell, followed by hot pressing.

[0133] The drying temperature in the oven is 100℃, and the drying time is 1 minute. The operating pressure during composite roller pressing is 5T, and the pressing temperature is 120℃. After stacking, the battery cells are hot-pressed and shaped using upper and lower pressure plates, with the hot-pressing temperature controlled at 100℃, the pressure at 8T, and the hot-pressing time at 1 minute.

[0134] Example 2

[0135] The only difference from Example 1 is that the insulating adhesive is made of a single type of polyacrylic acid.

[0136] Example 3

[0137] The only difference from Example 1 is that the insulating adhesive uses a single ethylene-vinyl acetate copolymer material.

[0138] Example 4

[0139] The only difference from Example 1 is that no ionic liquid treatment layer is formed during the preparation of the solid electrolyte strip.

[0140] Comparative Example 1

[0141] This comparative example provides an existing method for preparing an all-solid-state battery cell. The specific steps are as follows: (1) the positive electrode sheet is sliced ​​and prepared according to the design size; (2) the electrolyte membrane is composited onto both sides of the negative electrode sheet; (3) the composite negative electrode sheet is sliced ​​and prepared according to the design size; (4) the positive electrode sheet and the composite negative electrode sheet are stacked into a battery cell according to the conventional stacking method.

[0142] Experimental Example 1

[0143] Assembly success rate of cells prepared by test examples and comparative examples: No short circuit after battery assembly. (2) Cycle performance: Soft pack batteries are assembled by stacking, and continuously charged and discharged at 0.5C rate at 45℃ until the capacity retention rate is 80%.

[0144] Table 1. Assembly success rate and electrochemical performance test results of the positive electrode.

[0145] sample Assembly success rate Cyclic performance (capacity maintained at 80%) Example 1 95％ 800 laps Example 2 94％ 780 laps Example 3 95％ 750 laps Example 4 90％ 700 laps Comparative Example 1 60％ 300 laps

[0146] As can be seen from Table 1, the preparation method provided in this embodiment of the invention can significantly improve the assembly success rate compared with the comparative example, and the cycle performance is also significantly improved.

[0147] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An all-solid-state battery cell, characterized by, The full solid-state battery cell comprises a positive electrode active layer, a negative electrode active layer and an electrolyte film, the positive electrode active layer is attached to the negative electrode active layer through the electrolyte film; an ionic liquid treatment layer is arranged between the electrolyte film and the positive electrode active layer and / or the negative electrode active layer; A cured insulating adhesive is attached to the edge of the positive electrode active layer to fill the size difference between the positive electrode active layer and the negative electrode active layer; The preparation process of the full solid-state battery cell comprises: A positive electrode material belt is provided, which comprises a positive electrode current collector and a positive electrode active layer attached to the positive electrode current collector; According to the size of the positive electrode sheet product, a positive electrode mark groove is formed on the positive electrode active layer by marking, insulating adhesive is injected at the positive electrode mark groove, and is cured and formed; after curing and forming, die cutting is performed at the position of the insulating adhesive to obtain the positive electrode sheet with the required size; The positive electrode sheet, the electrolyte film and the negative electrode sheet are attached, and the electrolyte film is located between the positive electrode sheet and the negative electrode sheet; The raw material of the insulating adhesive comprises a first binder and a viscoelastic material, the first binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile; the mass ratio of the first binder and the viscoelastic material is 1: (0.5-1.5); the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, polyester, epoxy resin, polyurethane, polybutadiene acid, silicone resin, styrene-butadiene copolymer, polyester imine and polyimide.

2. The all-solid-state battery cell of claim 1, wherein, The positive electrode active layer is attached to both sides of the positive electrode current collector to form a positive electrode sheet, the negative electrode active layer is attached to both sides of the negative electrode current collector to form a negative electrode sheet, the electrolyte film is attached to both sides of the negative electrode sheet to form a composite negative electrode sheet, and the positive electrode sheet and the composite negative electrode sheet are both multiple; The positive electrode sheet and the composite negative electrode sheet are alternately stacked; The negative electrode current collector is used to connect adjacent two negative electrode sheets.

3. The all-solid-state battery cell of claim 2, wherein, The width of the cured insulating adhesive attached to the positive electrode sheet is 0.5-1.5 μm.

4. The all-solid-state battery cell of claim 2, wherein, The cured insulating adhesive is attached to both sides of the negative electrode current collector connecting adjacent two negative electrode sheets.

5. The all-solid-state battery cell of claim 1, wherein, The positive electrode active layer comprises a positive electrode active material, a second binder and a conductive agent; the second binder is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid and polyacrylonitrile.

6. The all-solid-state battery cell of claim 5, wherein, The first binder and the second binder are the same type.

7. The all-solid-state battery cell of claim 5, wherein, The positive electrode active layer further comprises an electrolyte, and the electrolyte is selected from at least one of a sulfide electrolyte, an oxide electrolyte and a halide electrolyte.

8. The all-solid-state battery cell of claim 1, wherein, The ionic liquid treatment layer is prepared by depositing ionic liquid on the surface of the electrolyte film.

9. The all-solid-state battery cell of claim 8, wherein, The ionic liquid treatment layer is prepared by depositing ionic liquid on the surface of the electrolyte film by gas phase deposition.

10. The all-solid-state battery cell of claim 8, wherein, The ionic liquid used in the preparation of the ionic liquid treatment layer is selected from at least one of 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium diamine, 1-ethyl-3-methylimidazolium acetate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium bis-trifluoromethyl sulfonimide, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate.

11. The all-solid-state battery cell of claim 10, wherein, The thickness of the ionic liquid treatment layer is 5 nm-1000 nm, and the thickness of the electrolyte film is 10 μm-100 μm.

12. The all-solid-state battery cell of claim 11, wherein, The electrolyte film comprises a sulfide electrolyte and a third binder, the mass ratio of the sulfide electrolyte is 80%-99%; wherein the sulfide electrolyte is selected from at least one of Li3PS4, Li7P3S 11 10 GeP2S 12 , Li6PS5Cl, Li6PS5I, Li6PS5Br and Li 3.875 Sn 0.875 As 0.125 S4 and Li4SnS4; the third binder in the electrolyte film is selected from at least one of polyvinylidene fluoride binder, silicone rubber, styrene butadiene rubber, polyvinyl alcohol, acrylate and butadiene rubber.​ 13. A method of producing the all-solid-state battery cell according to any one of claims 1 to 12, characterized by, The method comprises the following steps: A positive electrode material belt is provided, which comprises a positive electrode current collector and a positive electrode active layer attached to the positive electrode current collector; According to the size of the positive electrode sheet product, a mark is made on the positive electrode active layer to form a positive electrode mark groove, insulation glue is injected at the positive electrode mark groove, and is cured and formed; After curing and forming, die cutting is performed at the position of the insulation glue to obtain the positive electrode sheet with a size meeting the requirements; The positive electrode sheet, the electrolyte film, and a negative electrode sheet are attached, with the electrolyte film located between the positive electrode sheet and the negative electrode sheet; The raw material of the insulation glue comprises a first adhesive and a viscoelastic material, the first adhesive is selected from at least one of polytetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, carboxymethyl cellulose, polyacrylic acid, and polyacrylonitrile; the mass ratio of the first adhesive and the viscoelastic material is 1: (0.5-1.5); the viscoelastic material is selected from at least one of ethylene-vinyl acetate copolymer, polyester, epoxy resin, polyurethane, polybutadiene acid, silicone resin, styrene-butadiene copolymer, polyester imine, and polyimide.

14. The method of claim 13, wherein, The method comprises the following steps: A negative electrode material belt and a solid-state electrolyte material belt are also provided, the negative electrode material belt comprises a negative electrode current collector and a negative electrode active layer attached to the negative electrode current collector, and the solid-state electrolyte material belt comprises a base film and an electrolyte film attached to the base film; The solid-state electrolyte material belt is transferred to the negative electrode active layer of the negative electrode material belt, and the base film is separated, so that the negative electrode material belt is attached with the electrolyte film on both sides, to obtain a composite negative electrode material belt; A mark is made on the composite negative electrode material belt to form a negative electrode mark groove penetrating through the negative electrode active layer and the electrolyte film, insulation glue is injected at the negative electrode mark groove, and is cured and formed, to obtain a plurality of composite negative electrode sheets arranged at intervals; The plurality of positive electrode sheets obtained after die cutting are combined with the plurality of composite negative electrode sheets, and then are alternately stacked and hot-pressed to be shaped, to obtain a full-solid-state battery cell.

15. The preparation method according to claim 14, characterized in that, The thickness of the insulation glue injected at the negative electrode mark groove is less than or equal to the thickness of the negative electrode active layer.

16. The method of claim 15, wherein, The preparation method meets at least one of the following conditions: Condition one, before the solid-state electrolyte material belt is transferred to the negative electrode active layer of the negative electrode material belt, an ionic liquid treatment layer is arranged on the side surface of the electrolyte film away from the base film. Condition two, after separating the base film, an ionic liquid treatment layer is arranged on the side surface of the electrolyte film away from the negative active layer.

17. The method of claim 16, wherein the method further comprises, The forming process of the electrolyte film comprises: mixing sulfide electrolyte, third binder and electrolyte solvent according to the composition of the electrolyte film to obtain electrolyte slurry, coating the electrolyte slurry on one side of the base film, and drying to form the electrolyte film.

18. The method of claim 17, wherein, The electrolyte solvent is selected from the group consisting of butyl butyrate, isobutyl isobutyrate, n-hexane, n-heptane, toluene, xylene, anisole, cyclohexanone and 1,3,5 at least one of mesitylene.

19. The preparation method according to claim 17, characterized in that, The material of the base film is selected from at least one of polyethylene terephthalate, polyamide, polyimide, polypropylene, aluminum foil and stainless steel foil.

20. A lithium-ion battery, characterized by, The all-solid-state battery core prepared by the preparation method of any one of claims 13-19.

21. An electrical device, comprising: The lithium ion battery of claim 20.

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