Solid-state electrolyte battery and method of making the same

Abstract

The application discloses a kind of solid electrolyte battery and preparation method thereof, it is related to battery technical field, comprising: positive sheet;Negative sheet;Solid electrolyte layer is set between the positive sheet and negative sheet, the solid electrolyte layer includes the following raw materials: organic polymer 30~70wt%, lithium salt 10~50wt%, additive 1~10wt%, binder 1~10wt%, wetting agent 1~5wt% and the solvent of balance amount.The beneficial effects of the application is that the solid electrolyte prepared in the application can increase the transmission channel of lithium ion, to reduce the transmission impedance of solid-solid interface, so as to have higher ionic conductivity battery;The battery prepared by using the solid electrolyte not only has excellent thermal stability, safe to use, but also has good electrical performance, and battery cycle performance is good.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a solid electrolyte battery and its preparation method. Background Technology

[0002] Currently, lithium-ion batteries have a significant impact on people's daily lives and the national economy, with applications spanning commercial electronic products such as mobile phones, computers, and digital cameras, automotive power systems, and energy storage in renewable energy power plants. Improvements and refinements in lithium-ion battery technology have further expanded its application areas, while simultaneously placing more stringent demands on its performance.

[0003] Currently, commercially available lithium-ion batteries widely use organic liquid electrolytes. These electrolytes easily corrode the positive and negative electrodes, causing irreversible capacity loss. Furthermore, during charging and discharging, they decompose to produce flammable gases, potentially leading to fires and explosions. In contrast, solid-state lithium-ion batteries, using solid electrolytes, have significant potential to improve energy density, extend lifespan, and enhance safety.

[0004] Currently, inorganic ceramic solid electrolytes and organic polymer solid electrolytes are commonly used, but both have relative limitations. Inorganic ceramic solid electrolytes require high-temperature sintering during preparation, resulting in excessive energy consumption and increased costs. Organic polymer electrolytes generally have poor strength and cannot suppress dendrite formation in lithium metal anodes, making them difficult to meet practical requirements. Therefore, existing solid electrolytes are limited by grain boundary barriers, preventing the improvement of lithium-ion migration rates and resulting in low conductivity that fails to meet practical requirements. Thus, improving the conductivity of solid electrolytes is currently a key focus of industry research. Summary of the Invention

[0005] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a solid electrolyte battery and its preparation method.

[0006] The technical solution of the present invention is as follows:

[0007] A solid electrolyte battery, comprising:

[0008] Positive electrode plate;

[0009] Negative electrode plate;

[0010] A solid electrolyte layer is disposed between the positive electrode and the negative electrode. The solid electrolyte layer comprises the following raw materials: 30-70 wt% organic polymer, 10-50 wt% lithium salt, 1-10 wt% additives, 1-10 wt% binder, 1-5 wt% wetting agent, and the balance being solvent.

[0011] In a preferred embodiment of the present invention, the additive comprises the following raw materials: 20-60 wt% modified zeolite powder / alumina composite material, 20-60 wt% modified diatomaceous earth / pearl clay composite material, 5-10 wt% sodium lignosulfonate, and 5-10 wt% graphene oxide.

[0012] In a preferred embodiment of the present invention, the preparation method of the additive includes: adding modified zeolite powder / alumina composite material to a graphene oxide solution and stirring at a speed of 500-1000 r / min for 30-60 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at a speed of 500-1000 r / min for 30-60 min, washing with water, and drying; heating to 80-90°C at a rate of 1-5°C / min and treating under a vacuum of -0.01--0.05 MPa for 10-20 min, then heating to 100-110°C at a rate of 1-5°C / min and treating under a vacuum of -0.05--0.1 MPa for 10-20 min, and cooling to room temperature to obtain the additive.

[0013] In a preferred embodiment of the present invention, the preparation method of the modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200-250℃ and calcining it for 1-2 hours, then heating it to 450-500℃ and calcining it for 1-2 hours, continuing to heat it to 900-950℃ and calcining it for 1-2 hours, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding the composite material to distilled water, placing it in an ice-water bath, adding concentrated hydrochloric acid while stirring, adding TiCl4 solution dropwise, and then continuing to add ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 80-85℃, and holding it at that temperature for 40-60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5-6.7, filtering, washing, and drying the reactants; adding a silane coupling agent to the dried reactants and mixing them evenly.

[0014] In a preferred embodiment of the present invention, the preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the solution to alkaline; adding fatty acids and zeolite powder to the solution and heating; adjusting the system to acidic; filtering and washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina and grinding it in a grinder to obtain a mixture; adding a silane coupling agent to the mixture and mixing it evenly.

[0015] In a preferred embodiment of the present invention, the organic polymer is at least one selected from polyoxyethylene, polyvinylidene fluoride, and polyethylene oxide.

[0016] In a preferred embodiment of the present invention, the lithium salt is at least one selected from lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxoborate, and lithium difluoroborate oxalate.

[0017] In a preferred embodiment of the present invention, the wetting agent is sodium dodecylbenzenesulfonate, the binder is styrene-butadiene rubber, and the solvent is at least one selected from acetonitrile, acetone, butanone, ethanol, and propanol.

[0018] A method for preparing a solid-state electrolyte battery includes the following steps:

[0019] S1. Making the positive electrode plate;

[0020] S2. Fabricate the negative electrode plate;

[0021] S3. Fabrication of a solid electrolyte layer: The organic polymer, lithium salt, additives, binder, wetting agent and solvent are formulated into a solid electrolyte slurry; the solid electrolyte slurry is coated on one side surface of the positive electrode and / or negative electrode to form at least one solid electrolyte layer;

[0022] S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode to obtain a solid electrolyte battery.

[0023] In a preferred embodiment of the present invention, in step S3, the additive is added to the solvent and stirred at a speed of 500-1000 r / min for 2-4 hours under a vacuum of -0.01 to -0.05 MPa; organic polymer is then added and stirred at a speed of 500-1000 r / min for 1-2 hours under a vacuum of -0.01 to -0.05 MPa; lithium salt is then added and stirred at a speed of 500-1000 r / min for 2-4 hours under a vacuum of -0.01 to -0.05 MPa; finally, binder and wetting agent are added and stirred evenly at a speed of 500-1000 r / min to prepare a solid electrolyte slurry.

[0024] This invention has at least one of the following beneficial effects:

[0025] The solid electrolyte of this invention comprises an organic polymer, a lithium salt, additives, a binder, and a wetting agent. The organic polymer forms the matrix of the organic polymer electrolyte, thus avoiding problems such as electrolyte leakage, poor safety, and short circuits that are common in liquid lithium-ion batteries. The lithium salt enables the directional movement of ions, thereby facilitating the conduction of positive and negative ions. The additives of this invention include modified zeolite powder / alumina composite material, modified diatomaceous earth / pearl clay composite material, sodium lignosulfonate, and graphene oxide. These additives not only interact with the organic polymer and lithium salt, thereby increasing lithium-ion transport channels and providing a smooth path for lithium-ion conduction, improving conductivity and ion transport number, resulting in better battery cycle performance, but also ensure uniform lithium-ion transfer distribution, reduce lithium-ion loss caused by lithium dendrite formation, improve the interfacial stability and electrochemical operating window between the separator and the cathode material, and enhance lithium-ion cycle performance. Specifically, by modifying zeolite powder and alumina, on the one hand, cellulose ether and alumina are used to fill the zeolite powder, ensuring thorough mixing and exposing the ether groups in the pore channels. The ether groups then combine with lithium salts to fill the pores of the zeolite powder. On the other hand, surface modification of zeolite powder and alumina reduces agglomeration and increases the interfacial affinity between zeolite powder, alumina, and polymers, allowing for thorough and uniform mixing with organic polymers and lithium salts. Modifying diatomaceous earth and perlite, by coating their surfaces with titanium dioxide, reduces agglomeration. The synergistic effect of various filler components such as silica, alumina, and titanium dioxide lowers the order of the polymer chains and inhibits polymer crystallization. Graphene oxide has abundant negatively charged oxygen-containing functional groups on its surface, exhibiting a strong affinity for positively charged sodium ions, accelerating their migration and resulting in high ionic conductivity. Sodium lignosulfonate can improve dispersibility. Wetting agents can further improve the mixing effect of additives with organic polymers and lithium salts. In summary, the solid electrolyte of this invention enables uniform lithium-ion transfer and distribution, reduces lithium-ion loss caused by lithium dendrite formation, thereby improving the interfacial stability and electrochemical operating window between the separator and the cathode material, and enhancing lithium-ion cycle performance.

[0026] The solid electrolyte prepared by this invention can increase the lithium ion transport channels to reduce the transport impedance at the solid-solid interface, thereby producing a battery with high ionic conductivity. The battery made using this solid electrolyte not only has excellent thermal stability and is safe to use, but also has good electrical performance and good battery cycle performance. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following specific embodiments.

[0028] Example 1

[0029] A method for preparing a solid electrolyte battery includes the following steps:

[0030] S1. Making the positive electrode sheet: Mix lithium cobalt oxide, LiTFSI, PVDF and conductive carbon black in a ratio of 95:1:2:2 evenly, coat it onto the surface of the aluminum current collector, and dry it under vacuum at 120°C.

[0031] S2. Making the negative electrode: Mix graphite, LiTFSI, carboxymethyl cellulose and conductive carbon black in a ratio of 93:2:2:3 evenly, coat it onto the surface of the copper current collector as the negative electrode, and dry it at 80°C.

[0032] S3. Fabrication of the solid electrolyte layer:

[0033] Weigh the following raw materials: 30 wt% organic polymer, 50 wt% lithium salt, 5 wt% additive, 5 wt% binder, 1 wt% wetting agent, and the balance solvent; add the additive to the solvent and stir at 500 r / min for 2 h under a vacuum of -0.01 MPa; continue adding organic polymer and stir at 500 r / min for 1 h under a vacuum of -0.01 MPa; continue adding lithium salt and stir at 500 r / min for 2 h under a vacuum of -0.01 MPa; finally add binder and wetting agent and stir evenly at 500 r / min to prepare a solid electrolyte slurry; coat one side of the positive and negative electrode sheets with the solid electrolyte slurry to form a solid electrolyte layer;

[0034] The organic polymer is polyethylene oxide; the lithium salt is lithium hexafluorophosphate; the wetting agent is sodium dodecylbenzene sulfonate; the binder is styrene-butadiene rubber; and the solvent is acetonitrile.

[0035] The additives include the following raw materials: 20wt% modified zeolite powder / alumina composite material, 60wt% modified diatomaceous earth / pearl clay composite material, 10wt% sodium lignosulfonate, and 10wt% graphene oxide.

[0036] The preparation method of the additive includes: adding modified zeolite powder / alumina composite material to graphene oxide solution and stirring at 500 r / min for 60 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at 500 r / min for 60 min, washing with water and drying; heating to 80℃ at a rate of 1℃ / min and treating under a vacuum of -0.01 MPa for 20 min, then heating to 100℃ at a rate of 1℃ / min and treating under a vacuum of -0.05 MPa for 20 min, and cooling to room temperature to obtain the additive.

[0037] The preparation method of modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay at a mass ratio of 1:1, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200℃ and calcining it for 2 hours, then heating it to 500℃ and calcining it for 1 hour, continuing to heat it to 900℃ and calcining it for 1 hour, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding 1g of the composite material to 5 times its weight of distilled water, placing it in an ice-water bath, stirring while adding 0.5mL of concentrated hydrochloric acid, adding 1.5mL of 1.5mol / L TiCl4 solution, and then adding 1.2mL of 1.5mol / L ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 85℃ and holding it at that temperature for 60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5, filtering, washing, and drying the reactants; adding 0.01% of the total weight of diatomaceous earth and pearl clay of silane coupling agent to the dried reactants, and mixing them evenly.

[0038] The preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the pH of the solution to 10.5; adding fatty acids and zeolite powder to the solution, heating at 100℃ for 90 min, with a mass ratio of cellulose ether, fatty acids and zeolite powder of 30:3:10; adjusting the pH of the system to 3; filtering, washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina, with a mass ratio of zeolite powder to alumina of 1.5:1, and grinding in a grinder to obtain a mixture; adding 0.01% of the total weight of zeolite powder / alumina silane coupling agent to the mixture, and mixing evenly.

[0039] S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode. The positive electrode and the ceramic separator, and the negative electrode and the layer are wound in sequence to form a lithium-ion cell. The cell is then installed in a casing, injected with an organic electrolyte (containing 1 mol / L LiPF6, wherein the solvent is dimethyl carbonate: diethyl carbonate: propylene carbonate = 1:1:1), sealed, and formed to obtain a solid electrolyte battery.

[0040] Example 2

[0041] A method for preparing a solid electrolyte battery includes the following steps:

[0042] S1. Making the positive electrode sheet: Mix lithium cobalt oxide, LiTFSI, PVDF and conductive carbon black in a ratio of 95:1:2:2 evenly, coat it onto the surface of the aluminum current collector, and dry it under vacuum at 120°C.

[0043] S2. Making the negative electrode: Mix graphite, LiTFSI, carboxymethyl cellulose and conductive carbon black in a ratio of 93:2:2:3 evenly, coat it onto the surface of the copper current collector as the negative electrode, and dry it at 80°C.

[0044] S3. Fabrication of the solid electrolyte layer:

[0045] Weigh the following raw materials: 40 wt% organic polymer, 40 wt% lithium salt, 3 wt% additive, 3 wt% binder, 2 wt% wetting agent, and the balance solvent; add the additive to the solvent and stir at 600 r / min for 4 h under a vacuum of -0.02 MPa; continue adding organic polymer and stir at 600 r / min for 2 h under a vacuum of -0.02 MPa; continue adding lithium salt and stir at 6000 r / min for 2 h under a vacuum of -0.01 MPa; finally add binder and wetting agent and stir evenly at 600 r / min to prepare a solid electrolyte slurry; coat one side of the positive and negative electrode sheets with the solid electrolyte slurry to form a solid electrolyte layer;

[0046] The organic polymer is polyethylene oxide; the lithium salt is lithium hexafluorophosphate; the wetting agent is sodium dodecylbenzene sulfonate; the binder is styrene-butadiene rubber; and the solvent is acetonitrile.

[0047] The additives include the following raw materials: 35 wt% modified zeolite powder / alumina composite material, 50 wt% modified diatomaceous earth / pearl clay composite material, 8 wt% sodium lignosulfonate, and 7 wt% graphene oxide.

[0048] The preparation method of the additive includes: adding modified zeolite powder / alumina composite material to graphene oxide solution and stirring at 600 r / min for 60 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at 700 r / min for 50 min, washing with water and drying; heating to 85℃ at a rate of 2℃ / min and treating under vacuum of -0.02 MPa for 15 min, then heating to 105℃ at a rate of 3℃ / min and treating under vacuum of -0.06 MPa for 15 min, and cooling to room temperature to obtain the additive.

[0049] The preparation method of modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay at a mass ratio of 1:1, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200℃ and calcining it for 2 hours, then heating it to 500℃ and calcining it for 1 hour, continuing to heat it to 900℃ and calcining it for 1 hour, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding 1g of the composite material to 5 times its weight of distilled water, placing it in an ice-water bath, stirring while adding 0.5mL of concentrated hydrochloric acid, adding 1.5mL of 1.5mol / L TiCl4 solution, and then adding 1.2mL of 1.5mol / L ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 85℃ and holding it at that temperature for 60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5, filtering, washing, and drying the reactants; adding 0.01% of the total weight of diatomaceous earth and pearl clay of silane coupling agent to the dried reactants, and mixing them evenly.

[0050] The preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the pH of the solution to 10.5; adding fatty acids and zeolite powder to the solution, heating at 100℃ for 90 min, with a mass ratio of cellulose ether, fatty acids and zeolite powder of 30:3:10; adjusting the pH of the system to 3; filtering, washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina, with a mass ratio of zeolite powder to alumina of 1.5:1, and grinding in a grinder to obtain a mixture; adding 0.01% of the total weight of zeolite powder / alumina silane coupling agent to the mixture, and mixing evenly.

[0051] S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode. The positive electrode and the ceramic separator, and the negative electrode and the layer are wound in sequence to form a lithium-ion cell. The cell is then installed in a casing, injected with an organic electrolyte (containing 1 mol / L LiPF6, wherein the solvent is dimethyl carbonate: diethyl carbonate: propylene carbonate = 1:1:1), sealed, and formed to obtain a solid electrolyte battery.

[0052] Example 3

[0053] A method for preparing a solid electrolyte battery includes the following steps:

[0054] S1. Making the positive electrode sheet: Mix lithium cobalt oxide, LiTFSI, PVDF and conductive carbon black in a ratio of 95:1:2:2 evenly, coat it onto the surface of the aluminum current collector, and dry it under vacuum at 120°C.

[0055] S2. Making the negative electrode: Mix graphite, LiTFSI, carboxymethyl cellulose and conductive carbon black in a ratio of 93:2:2:3 evenly, coat it onto the surface of the copper current collector as the negative electrode, and dry it at 80°C.

[0056] S3. Fabrication of the solid electrolyte layer:

[0057] Weigh the following raw materials: 50 wt% organic polymer, 30 wt% lithium salt, 5 wt% additive, 5 wt% binder, 3 wt% wetting agent, and the balance solvent; add the additive to the solvent and stir at 700 r / min for 3 h under a vacuum of -0.03 MPa; continue adding the organic polymer and stir at 700 r / min for 1.5 h under a vacuum of -0.03 MPa; continue adding the lithium salt and stir at 7000 r / min for 3 h under a vacuum of -0.03 MPa; finally add the binder and wetting agent and stir evenly at 700 r / min to prepare a solid electrolyte slurry; coat one side of the positive and negative electrode sheets with the solid electrolyte slurry to form a solid electrolyte layer;

[0058] The organic polymer is at least one of polyoxyethylene, polyvinylidene fluoride, and polyethylene oxide; the lithium salt is at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxoborate, and lithium difluoroborate oxalate; the wetting agent is sodium dodecylbenzene sulfonate; the binder is styrene-butadiene rubber; and the solvent is at least one of acetonitrile, acetone, butanone, ethanol, and propanol.

[0059] The additives include the following raw materials: 40wt% modified zeolite powder / alumina composite material, 45wt% modified diatomaceous earth / pearl clay composite material, 7wt% sodium lignosulfonate, and 8wt% graphene oxide.

[0060] The preparation method of the additive includes: adding modified zeolite powder / alumina composite material to graphene oxide solution and stirring at 700 r / min for 45 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at 700 r / min for 45 min, washing with water and drying; heating to 85℃ at a rate of 3℃ / min and treating under vacuum of -0.03 MPa for 15 min, then heating to 105℃ at a rate of 3℃ / min and treating under vacuum of -0.07 MPa for 15 min, and cooling to room temperature to obtain the additive.

[0061] The preparation method of modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay at a mass ratio of 1:1, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200℃ and calcining it for 2 hours, then heating it to 500℃ and calcining it for 1 hour, continuing to heat it to 900℃ and calcining it for 1 hour, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding 1g of the composite material to 5 times its weight of distilled water, placing it in an ice-water bath, stirring while adding 0.5mL of concentrated hydrochloric acid, adding 1.5mL of 1.5mol / L TiCl4 solution, and then adding 1.2mL of 1.5mol / L ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 85℃ and holding it at that temperature for 60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5, filtering, washing, and drying the reactants; adding 0.01% of the total weight of diatomaceous earth and pearl clay of silane coupling agent to the dried reactants, and mixing them evenly.

[0062] The preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the pH of the solution to 10.5; adding fatty acids and zeolite powder to the solution, heating at 100℃ for 90 min, with a mass ratio of cellulose ether, fatty acids and zeolite powder of 30:3:10; adjusting the pH of the system to 3; filtering, washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina, with a mass ratio of zeolite powder to alumina of 1.5:1, and grinding in a grinder to obtain a mixture; adding 0.01% of the total weight of zeolite powder / alumina silane coupling agent to the mixture, and mixing evenly.

[0063] S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode. The positive electrode and the ceramic separator, and the negative electrode and the layer are wound in sequence to form a lithium-ion cell. The cell is then installed in a casing, injected with an organic electrolyte (containing 1 mol / L LiPF6, wherein the solvent is dimethyl carbonate: diethyl carbonate: propylene carbonate = 1:1:1), sealed, and formed to obtain a solid electrolyte battery.

[0064] Example 4

[0065] A method for preparing a solid electrolyte battery includes the following steps:

[0066] S1. Making the positive electrode sheet: Mix lithium cobalt oxide, LiTFSI, PVDF and conductive carbon black in a ratio of 95:1:2:2 evenly, coat it onto the surface of the aluminum current collector, and dry it under vacuum at 120°C.

[0067] S2. Making the negative electrode: Mix graphite, LiTFSI, carboxymethyl cellulose and conductive carbon black in a ratio of 93:2:2:3 evenly, coat it onto the surface of the copper current collector as the negative electrode, and dry it at 80°C.

[0068] S3. Fabrication of the solid electrolyte layer:

[0069] Weigh the following raw materials: 40 wt% organic polymer, 40 wt% lithium salt, 8 wt% additives, 2 wt% binder, 2 wt% wetting agent, and the balance solvent; add the additives to the solvent and stir at 900 r / min for 2 h under a vacuum of -0.04 MPa; continue adding organic polymer and stir at 900 r / min for 1 h under a vacuum of -0.04 MPa; continue adding lithium salt and stir at 900 r / min for 2 h under a vacuum of -0.04 MPa; finally add the binder and wetting agent and stir evenly at 900 r / min to prepare a solid electrolyte slurry; coat one side of the positive and negative electrode sheets with the solid electrolyte slurry to form a solid electrolyte layer;

[0070] The organic polymer is at least one of polyoxyethylene, polyvinylidene fluoride, and polyethylene oxide; the lithium salt is at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxoborate, and lithium difluoroborate oxalate; the wetting agent is sodium dodecylbenzene sulfonate; the binder is styrene-butadiene rubber; and the solvent is at least one of acetonitrile, acetone, butanone, ethanol, and propanol.

[0071] The additives include the following raw materials: 50 wt% modified zeolite powder / alumina composite material, 40 wt% modified diatomaceous earth / pearl clay composite material, 5 wt% sodium lignosulfonate, and 5 wt% graphene oxide.

[0072] The preparation method of the additive includes: adding modified zeolite powder / alumina composite material to graphene oxide solution and stirring at 900 r / min for 30 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at 1000 r / min for 30 min, washing with water and drying; heating to 88℃ at a rate of 4℃ / min and treating under vacuum of -0.04 MPa for 10 min, then heating to 105℃ at a rate of 4℃ / min and treating under vacuum of -0.08 MPa for 15 min, and cooling to room temperature to obtain the additive.

[0073] The preparation method of modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay at a mass ratio of 1:1, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200℃ and calcining it for 2 hours, then heating it to 500℃ and calcining it for 1 hour, continuing to heat it to 900℃ and calcining it for 1 hour, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding 1g of the composite material to 5 times its weight of distilled water, placing it in an ice-water bath, stirring while adding 0.5mL of concentrated hydrochloric acid, adding 1.5mL of 1.5mol / L TiCl4 solution, and then adding 1.2mL of 1.5mol / L ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 85℃ and holding it at that temperature for 60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5, filtering, washing, and drying the reactants; adding 0.01% of the total weight of diatomaceous earth and pearl clay of silane coupling agent to the dried reactants, and mixing them evenly.

[0074] The preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the pH of the solution to 10.5; adding fatty acids and zeolite powder to the solution, heating at 100℃ for 90 min, with a mass ratio of cellulose ether, fatty acids and zeolite powder of 30:3:10; adjusting the pH of the system to 3; filtering, washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina, with a mass ratio of zeolite powder to alumina of 1.5:1, and grinding in a grinder to obtain a mixture; adding 0.01% of the total weight of zeolite powder / alumina silane coupling agent to the mixture, and mixing evenly.

[0075] S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode. The positive electrode and the ceramic separator, and the negative electrode and the layer are wound in sequence to form a lithium-ion cell. The cell is then installed in a casing, injected with an organic electrolyte (containing 1 mol / L LiPF6, wherein the solvent is dimethyl carbonate: diethyl carbonate: propylene carbonate = 1:1:1), sealed, and formed to obtain a solid electrolyte battery.

[0076] Example 5

[0077] A method for preparing a solid electrolyte battery includes the following steps:

[0078] S1. Making the positive electrode sheet: Mix lithium cobalt oxide, LiTFSI, PVDF and conductive carbon black in a ratio of 95:1:2:2 evenly, coat it onto the surface of the aluminum current collector, and dry it under vacuum at 120°C.

[0079] S2. Making the negative electrode: Mix graphite, LiTFSI, carboxymethyl cellulose and conductive carbon black in a ratio of 93:2:2:3 evenly, coat it onto the surface of the copper current collector as the negative electrode, and dry it at 80°C.

[0080] S3. Fabrication of the solid electrolyte layer:

[0081] Weigh the following raw materials: 70 wt% organic polymer, 10 wt% lithium salt, 5 wt% additive, 5 wt% binder, 2 wt% wetting agent, and the balance solvent; add the additive to the solvent and stir at 1000 r / min for 1 h under a vacuum of -0.05 MPa; continue adding organic polymer and stir at 1000 r / min for 1 h under a vacuum of -0.05 MPa; continue adding lithium salt and stir at 1000 r / min for 2 h under a vacuum of -0.05 MPa; finally add the binder and wetting agent and stir evenly at 1000 r / min to prepare a solid electrolyte slurry; coat one side of the positive and negative electrode sheets with the solid electrolyte slurry to form a solid electrolyte layer;

[0082] The organic polymer is at least one of polyoxyethylene, polyvinylidene fluoride, and polyethylene oxide; the lithium salt is at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxoborate, and lithium difluoroborate oxalate; the wetting agent is sodium dodecylbenzene sulfonate; the binder is styrene-butadiene rubber; and the solvent is at least one of acetonitrile, acetone, butanone, ethanol, and propanol.

[0083] The additives include the following raw materials: 60wt% modified zeolite powder / alumina composite material, 30wt% modified diatomaceous earth / pearl clay composite material, 5wt% sodium lignosulfonate, and 5wt% graphene oxide.

[0084] The preparation method of the additive includes: adding modified zeolite powder / alumina composite material to graphene oxide solution and stirring at 1000 r / min for 30 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at 1000 r / min for 30 min, washing with water and drying; heating to 90℃ at a rate of 3℃ / min and treating under a vacuum of -0.05 MPa for 10 min, then heating to 110℃ at a rate of 5℃ / min and treating under a vacuum of -0.1 MPa for 10 min, and cooling to room temperature to obtain the additive.

[0085] The preparation method of modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay at a mass ratio of 1:1, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200℃ and calcining it for 2 hours, then heating it to 500℃ and calcining it for 1 hour, continuing to heat it to 900℃ and calcining it for 1 hour, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding 1g of the composite material to 5 times its weight of distilled water, placing it in an ice-water bath, stirring while adding 0.5mL of concentrated hydrochloric acid, adding 1.5mL of 1.5mol / L TiCl4 solution, and then adding 1.2mL of 1.5mol / L ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 85℃ and holding it at that temperature for 60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5, filtering, washing, and drying the reactants; adding 0.01% of the total weight of diatomaceous earth and pearl clay of silane coupling agent to the dried reactants, and mixing them evenly.

[0086] The preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the pH of the solution to 10.5; adding fatty acids and zeolite powder to the solution, heating at 100℃ for 90 min, with a mass ratio of cellulose ether, fatty acids and zeolite powder of 30:3:10; adjusting the pH of the system to 3; filtering, washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina, with a mass ratio of zeolite powder to alumina of 1.5:1, and grinding in a grinder to obtain a mixture; adding 0.01% of the total weight of zeolite powder / alumina silane coupling agent to the mixture, and mixing evenly.

[0087] S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode. The positive electrode and the ceramic separator, and the negative electrode and the layer are wound in sequence to form a lithium-ion cell. The cell is then installed in a casing, injected with an organic electrolyte (containing 1 mol / L LiPF6, wherein the solvent is dimethyl carbonate: diethyl carbonate: propylene carbonate = 1:1:1), sealed, and formed to obtain a solid electrolyte battery.

[0088] Comparative Example 1

[0089] No additives were added to the solid electrolyte layer; otherwise, it was the same as in Example 1.

[0090] Comparative Example 2

[0091] The additives do not include modified zeolite powder / alumina composite material, and are otherwise the same as in Example 1.

[0092] Comparative Example 3

[0093] The additives do not include modified diatomaceous earth / pearl clay composite material, and are otherwise the same as in Example 1.

[0094] Comparative Example 4

[0095] The additive does not contain graphene oxide, but otherwise it is the same as in Example 1.

[0096] Performance testing

[0097] (1) Ionic conductivity test:

[0098] The composite solid electrolytes prepared in Examples 1-5 and Comparative Examples 1-4 were punched into discs and subjected to electrochemical impedance spectroscopy at 25°C in a frequency range of 1 Hz to 8 MHz. Based on the measured electrolyte impedance and the formula, the room-temperature ionic conductivity of the electrolyte was calculated as follows: σ = L / RS, where L is the thickness of the solid electrolyte (cm), R is the measured ohmic impedance (Ω), and S is the area of ​​the solid electrolyte (cm²). 2 ).

[0099] (2) Battery performance test:

[0100] Ten batteries from Examples 1-5 and Comparative Examples 1-4 were randomly selected and subjected to cycle performance testing after being fully charged. The batteries were charged and discharged at a 1C rate at room temperature for 500 cycles. The battery capacity before and after each cycle was recorded, and the average value of the data from the ten batteries was taken.

[0101] Capacity retention rate after n cycles = (Battery capacity after n cycles / Battery capacity before cycles) × 100%.

[0102] The test results are shown in Table 1.

[0103] Table 1

[0104]

[0105]

[0106] As shown in Table 1, the solid electrolytes prepared in Examples 1-5 exhibit high ionic conductivity. This is consistent with the batteries prepared in Examples 1-5, which also show high capacity retention after 500 cycles. This indicates that the solid electrolytes prepared in Examples 1-5 possess high ionic conductivity, resulting in batteries with good cycle performance. Comparing Examples 1-5 with Comparative Examples 1-4, it can be seen that the ionic conductivity of the solid electrolytes in Examples 1-5 and the capacity retention after 500 cycles are significantly better than those in Comparative Examples 1-4. This suggests that the addition of additives to the solid electrolyte, and the inclusion of modified zeolite / alumina composite materials, modified diatomaceous earth / pearl clay composite materials, and graphene oxide in the additives, all affect the ionic conductivity of the solid electrolyte, thereby influencing the battery capacity retention.

[0107] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A solid-state electrolyte battery, characterized in that, include: Positive electrode plate; Negative electrode plate; A solid electrolyte layer is disposed between the positive electrode and the negative electrode. The solid electrolyte layer comprises the following raw materials: 30-70 wt% organic polymer, 10-50 wt% lithium salt, 1-10 wt% additives, 1-10 wt% binder, 1-5 wt% wetting agent, and the balance being solvent. The additive comprises the following raw materials: 20-60 wt% modified zeolite powder / alumina composite material, 20-60 wt% modified diatomaceous earth / pearl clay composite material, 5-10 wt% sodium lignosulfonate, and 5-10 wt% graphene oxide; The preparation method of the additive includes: adding modified zeolite powder / alumina composite material to graphene oxide solution and stirring at 500~1000 r / min for 30~60 min; continuing to add modified diatomaceous earth / pearl clay composite material and sodium lignosulfonate, stirring at 500~1000 r / min for 30~60 min, washing with water and drying; heating to 80~90℃ at a rate of 1~5℃ / min and treating under a vacuum of -0.01~-0.05 MPa for 10~20 min, then heating to 100~110℃ at a rate of 1~5℃ / min and treating under a vacuum of -0.05~-0.1 MPa for 10~20 min, and cooling to room temperature to obtain the additive; The preparation method of the modified diatomaceous earth / pearl clay composite material includes: mixing diatomaceous earth and pearl clay, grinding them in a grinder to obtain a mixture; placing the mixture in a muffle furnace, first heating it to 200~250℃ and calcining it for 1~2 hours, then heating it to 450~500℃ and calcining it for 1~2 hours, then continuing to heat it to 900~950℃ and calcining it for 1~2 hours, cooling it to room temperature with the furnace, and grinding it to obtain the composite material; adding the composite material to distilled water, placing it in an ice-water bath, adding concentrated hydrochloric acid while stirring, adding TiCl4 solution dropwise, then continuing to add ammonium sulfate solution, mixing and stirring, heating the mixture in a water bath to 80~85℃, and holding it at that temperature for 40~60 minutes; then adding a prepared ammonia solution dropwise until the pH reaches 6.5~6.7, filtering, washing, and drying the reactants; adding a silane coupling agent to the dried reactants and mixing them evenly. The preparation method of the modified zeolite powder / alumina composite material includes: preparing a solution using cellulose ether and ethanol, and adjusting the solution to alkaline; adding fatty acids and zeolite powder to the solution and heating; adjusting the system to acidic; filtering and washing with deionized water until neutral to obtain modified zeolite powder; mixing the modified zeolite powder with alumina and grinding it in a grinder to obtain a mixture; adding a silane coupling agent to the mixture and mixing evenly. The method for preparing the solid-state electrolyte battery includes the following steps: S1. Making the positive electrode plate; S2. Fabricate the negative electrode plate; S3. Fabrication of a solid electrolyte layer: The organic polymer, lithium salt, additives, binder, wetting agent and solvent are formulated into a solid electrolyte slurry; the solid electrolyte slurry is coated on one side surface of the positive electrode and / or negative electrode to form at least one solid electrolyte layer; S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode to obtain a solid electrolyte battery.

2. A solid-state electrolyte battery according to claim 1, characterized in that, The organic polymer is at least one of polyoxyethylene, polyvinylidene fluoride, and polyethylene oxide.

3. A solid-state electrolyte battery according to claim 1, characterized in that, The lithium salt is at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium dioxoborate, and lithium difluoroborate oxalate.

4. A solid-state electrolyte battery according to claim 1, characterized in that, The wetting agent is sodium dodecylbenzenesulfonate, the binder is styrene-butadiene rubber, and the solvent is at least one selected from acetonitrile, acetone, butanone, ethanol, and propanol.

5. The method for preparing a solid-state electrolyte battery according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Making the positive electrode plate; S2. Fabricate the negative electrode plate; S3. Fabrication of a solid electrolyte layer: The organic polymer, lithium salt, additives, binder, wetting agent and solvent are formulated into a solid electrolyte slurry; the solid electrolyte slurry is coated on one side surface of the positive electrode and / or negative electrode to form at least one solid electrolyte layer; S4. The positive electrode and the negative electrode are bonded together, so that the solid electrolyte layer is sandwiched between the positive electrode and the negative electrode to obtain a solid electrolyte battery.

6. The method for preparing a solid electrolyte according to claim 5, characterized in that: In step S3, the additive is added to the solvent and stirred at a speed of 500-1000 r / min for 2-4 hours under a vacuum of -0.01 to -0.05 MPa; then the organic polymer is added and stirred at a speed of 500-1000 r / min for 1-2 hours under a vacuum of -0.01 to -0.05 MPa. Continue adding lithium salt and stirring at 500-1000 r / min for 2-4 hours under a vacuum of -0.01 to -0.05 MPa. Finally, add binder and wetting agent and stir evenly at 500-1000 r / min to prepare a solid electrolyte slurry.

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