A method of manufacturing a solid-state battery with integrated electrodes

Abstract

The present application relates to a kind of preparation method of solid-state battery with integrated electrode, belong to metal secondary battery field.The purpose of the present application is to use lithiumated cellulose as positive ion transmission accelerator, which can transport lithium ion and limit the movement of lithium salt anion, and combined with electrode electrolyte integrated design, provide a kind of preparation method of solid-state battery with integrated electrode, the method is applied on battery positive pole piece with composite solid-state electrolyte slurry, integrated electrode is obtained after drying, and negative pole piece is placed on its surface to obtain solid-state battery by pressing;Integrated electrode greatly reduces the interface resistance of solid-state battery, accelerates the migration rate of ion in the interior and interface of solid-state battery positive pole, so that solid-state battery with integrated electrode obtains excellent electrochemical performance;Integrated electrode prepared by the method has simple process and is easy to operate, which has great significance for the development of solid-state battery.

Description

Technical Field

[0001] This invention relates to a method for preparing a solid-state battery with integrated electrodes, belonging to the field of metal secondary batteries. Background Technology

[0002] Solid electrolytes, with their high mechanical strength, high room temperature ionic conductivity, ideal high temperature stability, and low volatility, are ideal alternatives to organic electrolytes. They are also one of the best choices for solving problems such as the easy reaction between lithium metal anodes and electrolytes, and the easy formation of lithium dendrites. Therefore, they have attracted extensive research.

[0003] As research has deepened, it has been discovered that solid-state electrolytes, due to their high mechanical properties, are very hard, resulting in a solid-solid contact with the positive electrode. This leads to a high interfacial resistance in solid-state batteries, limiting ion transport and directly affecting the battery's energy density. In recent years, many methods have emerged to address the poor interfacial contact in solid-state batteries, such as adding organic electrolytes, ionic liquids, or plastic crystals to the interface between the solid electrolyte and the positive and negative electrodes to improve interfacial contact and increase ion transport efficiency. However, these methods still leave safety risks associated with the operation of solid-state batteries.

[0004] Another difference between solid-state batteries and conventional liquid batteries lies in the composition of their positive electrodes. Conventional battery positive electrodes consist of active materials, conductive agents, and polymers. Due to the wetting effect of organic electrolytes with high ionic conductivity, ions can be normally transported on the positive electrode side. However, in solid-state batteries, the solid electrolyte cannot wet the positive electrode, which causes solid-state batteries using conventional battery positive electrode formulations to malfunction. Therefore, it is necessary to optimize the composition of solid-state battery positive electrodes to promote rapid ion transport within the electrode. Thus, developing novel solid-state battery positive electrodes and constructing tight interfacial contacts are of great practical significance. Summary of the Invention

[0005] The purpose of this invention is to utilize lithium cellulose, which can transport lithium ions and restrict the movement of lithium salt anions, as a positive electrode ion transport accelerator, and combine it with an integrated electrode-electrolyte design to provide a method for preparing a solid-state battery with an integrated electrode. The integrated electrode greatly reduces the interfacial resistance of the solid-state battery and accelerates the migration rate of ions inside the positive electrode and at the interface of the solid-state battery. Therefore, the solid-state battery with an integrated electrode achieves excellent electrochemical performance.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A method for preparing a solid-state battery with an integrated electrode involves coating a composite solid electrolyte slurry onto the positive electrode of the battery, drying it to obtain an integrated electrode, placing a negative electrode on its surface, and pressing it to obtain a solid-state battery.

[0008] A method for preparing a solid-state battery with integrated electrodes, wherein the positive electrode sheet is obtained by adding lithium cellulose, polymer, conductive agent, lithium salt and active material to solvent A and stirring, coating it onto a current collector using a scraper, and drying. The stirring time is controlled between 6 and 36 h, the stirring rate is controlled between 200 and 1500 r / min, preferably 800 r / min, the drying temperature is maintained between 50 and 120 ℃, preferably 80 ℃, and the drying time is controlled between 6 and 36 h, preferably 24 h.

[0009] The molar concentration of the lithium salt is between 0.1 and 0.3 mol / L, preferably 0.1 mol / L;

[0010] The mass ratio of the polymer to the solvent is between 1:100 and 1:10, preferably 1:25;

[0011] The content of the lithium cellulose in the polymer does not exceed 8 wt% by weight.

[0012] The mass ratio of the conductive agent to the polymer is between 10:3 and 1:3, preferably 1:1;

[0013] A method for preparing a solid-state battery with integrated electrodes, wherein the method for preparing the composite solid electrolyte slurry is as follows: lithium cellulose, lithium salt and polymer are added to solvent B, and the mixture is stirred to obtain the electrolyte slurry. The stirring time is controlled between 6 and 36 h, preferably 24 h, and the stirring rate is controlled between 200 and 1500 r / min, preferably 800 r / min.

[0014] The mass ratio of the polymer to the solvent is between 1:100 and 3:10, preferably 1:10;

[0015] The molar concentration of the lithium salt is between 0.125 and 0.5 mol / L, preferably 0.2 mol / L;

[0016] The content of the lithium cellulose in the polymer does not exceed 8 wt% by weight.

[0017] A method for preparing a solid-state battery with an integrated electrode, wherein the specific preparation method of the integrated electrode is as follows: a composite solid electrolyte slurry is coated onto the positive electrode sheet of the solid-state battery and dried under vacuum. The drying temperature is maintained between 50 and 120°C, preferably 80°C, and the drying time is controlled between 6 and 36 h, preferably 24 h.

[0018] The polymer is one or more of polyethylene oxide, polyvinylidene fluoride (PVDF), polyacrylonitrile, polyvinylidene fluoride-hexafluoropropylene, polymethyl methacrylate, polyethylene succinate, polypropylene oxide, polyethyleneimine, and polyvinylidene chloride, preferably PVDF;

[0019] The lithium salt is one or more of lithium perchlorate, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, lithium hexafluoroarsenate, and lithium hexafluorophosphate, with LiTFSI being preferred.

[0020] The solvent A is one or more of N-methylpyrrolidone (NMP), N-dimethylformamide, N-dimethylacetamide (DMAc), triethyl phosphate, dimethyl sulfoxide ethanol, methanol, acetonitrile and acetone, preferably NMP;

[0021] The solvent B is one or more of N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, triethyl phosphate, dimethyl sulfoxide ethanol, methanol, acetonitrile and acetone, preferably DMAc;

[0022] The conductive agent is one or more of acetylene black, conductive carbon black (Super-P), Ketjen black, conductive graphite, conductive graphite, vapor-grown carbon fibers, carbon nanotubes and graphene and their composite conductive agents, preferably Super-P.

[0023] The active material is one or more of lithium cobalt oxide, lithium nickel oxide, nickel-cobalt-manganese ternary materials, lithium nickel-cobalt-aluminum oxide, lithium-rich manganese-based materials, lithium manganese oxide, lithium nickel-manganese oxide, iron tetroxide, lithium vanadium oxide, lithium iron phosphate (LiFePO4), lithium manganese phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxyphosphate, lithium cobalt phosphate, lithium nickel phosphate, lithium iron silicate, lithium iron fluorosulfate, lithium iron borate, lithium iron titanate, iron trifluoride, cobalt trifluoride, nickel trifluoride, titanium disulfide, iron disulfide, molybdenum disulfide, and niobium triselenide, preferably LiFePO4;

[0024] A method for preparing a solid-state battery with integrated electrodes, wherein the method for preparing the lithium-ionized cellulose includes the following steps:

[0025] Step 1: Add nanocellulose particles to DMAc solvent and stir magnetically until some hydrogen bonds are broken; then centrifuge to obtain wet pre-dissolved nanocellulose; after drying, obtain pre-dissolved nanocellulose particles; the mass ratio of nanocellulose particles to DMAc is between 0.05 and 0.2, preferably 0.1;

[0026] Step 2: Add anhydrous lithium chloride (LiCl) to the DMAc solvent and stir until the LiCl is completely dissolved to obtain a DMAc / LiCl solution; the LiCl / DMAc molar ratio is between 0:1 and 0.22:1, preferably 0.17;

[0027] Step 3: Add the pre-dissolved nanocellulose particles obtained in Step 1 to the DMAc / LiCl solution obtained in Step 2, and stir until homogeneous to obtain lithium-ionized cellulose; the mass fraction of the pre-dissolved nanocellulose particles is between 4 wt% and 30 wt%, preferably 20 wt%;

[0028] The nanocellulose particles are prepared and purified from various types of cellulose nanocrystals, cellulose nanofibers, cellulose nanosheets, and nanocellulose particles from trees, bamboo, cotton, crops, marine algae, and marine bacteria, preferably nanocellulose particles purified from cotton.

[0029] The stirring rate in step one is controlled between 200 and 1500 r / min, preferably 800 r / min, and the stirring time is controlled between 6 and 36 h, preferably 24 h;

[0030] The centrifugal speed for centrifugation in step one is controlled within 2000~12000 r / min, preferably 10000 r / min;

[0031] The drying temperature in step one is maintained between 50 and 120 °C, preferably 80 °C, and the drying time is controlled between 6 and 36 hours, preferably 24 hours.

[0032] The stirring rate in step two is controlled between 200 and 1500 r / min, preferably 800 r / min, and the stirring time is controlled between 6 and 36 h, preferably 24 h.

[0033] The stirring rate in step three is controlled between 200 and 1500 r / min, preferably 800 r / min, and the stirring time is controlled between 6 and 36 h, preferably 24 h.

[0034] A method for preparing a solid-state battery with integrated electrodes, wherein the main material of the negative electrode sheet is one or more of the following: artificial graphite negative electrode material, natural graphite negative electrode material, central phase carbon microsphere negative electrode material, petroleum coke negative electrode material, carbon fiber negative electrode material, pyrolytic resin carbon negative electrode material, hard carbon negative electrode material, soft carbon negative electrode material, graphene negative electrode material, tin oxide negative electrode material, tin-based composite oxide negative electrode material, lithium-containing transition metal nitride negative electrode material, carbon nanotube negative electrode material, nano-alloy negative electrode material, silicon-carbon negative electrode material, potassium metal negative electrode material, sodium metal negative electrode material, aluminum metal negative electrode material, magnesium metal negative electrode material, lithium metal negative electrode material, and lithium alloy negative electrode material, preferably lithium metal negative electrode material. Beneficial effects

[0035] 1. In this invention, lithium cellulose with numerous oxygen-containing groups is added to the positive electrode of a solid-state battery. By stirring, the lithium cellulose is coated on the surface of lithium iron phosphate, which enables lithium ions to migrate rapidly in the positive electrode of the solid-state battery.

[0036] 2. The lithium-ionized cellulose introduced in this invention has good flexibility and can interact with the polymer substrate, promoting the movement of polymer chain segments and greatly improving the ion transport efficiency of solid-state batteries.

[0037] 3. The integrated electrode prepared by this invention greatly reduces the interface resistance of solid-state batteries and improves the ion transport efficiency at the interface.

[0038] 4. The integrated electrode prepared by this invention uses lithium cellulose as a bridge to accelerate the ion transport rate between the positive electrode and the solid electrolyte of the solid battery, which is of great significance to the research and development of solid batteries.

[0039] 5. This invention provides a highly stable solid-state battery with integrated electrodes, achieving excellent cycle stability of solid-state lithium iron phosphate batteries at room temperature. Attached Figure Description

[0040] Figure 1 This is a SEM image of an integrated lithium iron phosphate electrode.

[0041] Figure 2 The impedance diagrams are of a solid-state battery with 7.2% lithium cellulose and an integrated lithium iron phosphate electrode before and after 200 cycles at room temperature and 0.5C.

[0042] Figure 3 It is an impedance diagram of a solid-state battery with lithium iron phosphate integrated electrode containing 8% lithium cellulose.

[0043] Figure 4 This is an impedance diagram of a solid-state battery with an integrated lithium iron phosphate electrode containing 5.5% lithium cellulose. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the embodiments. However, the present invention is not limited to the following embodiments.

[0045] The analytical testing methods used in the following embodiments include:

[0046] AC impedance spectroscopy and linear cyclic voltammetry: Electrochemical workstation (CHI660D), Shanghai;

[0047] Scanning electron microscope (SEM) test: Model HITACHI S-4800, Japan

[0048] Electrochemical performance testing: LAND, Wuhan. Comparative Example 1

[0049] 15 g of nanocellulose particles were added to 100 mL of DMAc and magnetically stirred for 24 h. The mixture was then centrifuged at 10000 r / min and transferred to a vacuum oven at 80 °C for 24 h to obtain pre-dissolved nanocellulose particles. A certain amount of anhydrous lithium chloride was added to the DMAc solvent until the anhydrous lithium chloride was completely dissolved, and the mixture was stirred continuously for 24 h, maintaining a molar ratio of 0.15:1 to obtain a DMAc / LiCl solution. 10 g of the pre-dissolved nanocellulose particles were taken and added to 50 mL of the DMAc / LiCl solution and stirred evenly to obtain lithium-ionized cellulose. 0.8 g of PVDF and 0.2 mol / L LiTFSI were added to 8 mL of DMAc solvent, followed by the addition of 1.5% (w / w) of lithium-ionized cellulose PVDF. The mixture was stirred for 24 h to obtain a composite solid electrolyte slurry. The composite solid electrolyte slurry was coated onto a glass slide with a scraper height of 1000 μm and vacuum dried to obtain a composite solid electrolyte. The drying temperature was maintained at 80 °C and the drying time was controlled at 24 h. 11 mg of PVDF, 11 mg of Super-P, and 88 mg of lithium iron phosphate were added to 400 mg of NMP and stirred overnight. The mixture was then coated onto an aluminum current collector with a scraper height of 200 μm and dried at 80 °C for 24 h to obtain a solid-state battery positive electrode. The solid-state battery positive electrode, composite solid electrolyte, and lithium sheet were sequentially placed in a coin cell and encapsulated under a pressure of 900 Pa to form a solid-state battery.

[0050] The solid-state battery prepared in this experimental example was tested, and the results are as follows:

[0051] Tests showed that the solid-state lithium iron phosphate battery prepared in this embodiment has a high interface resistance and cannot cycle stably under conditions of 30 °C and 0.5 C. Comparative Example 2

[0052] 12 g of nanocellulose particles were added to 100 mL of DMAc and magnetically stirred for 24 h. After centrifugation at 10000 r / min, the particles were transferred to a vacuum oven at 80 °C and dried for 24 h to obtain pre-dissolved nanocellulose particles. A certain amount of anhydrous lithium chloride was added to the DMAc solvent until the anhydrous lithium chloride was completely dissolved and stirred continuously for 24 h, maintaining a molar ratio of 0.13:1 to obtain a DMAc / LiCl solution. 10 g of the pre-dissolved nanocellulose particles were added to 50 mL of the DMAc / LiCl solution and stirred evenly to obtain lithium-ionized cellulose. 0.9 g of PVDF and 0.2 mol / L LiTFSI were added to 8 mL of DMAc solvent, followed by the addition of 3.5% (w / w) lithium cellulose containing PVDF. The mixture was stirred for 24 h to obtain a composite solid electrolyte slurry. The composite solid electrolyte slurry was coated onto a glass slide with a scraper height of 1000 μm and vacuum dried to obtain a composite solid electrolyte. The drying temperature was maintained at 80 ℃ and the drying time was controlled at 24 h. 2.8 mg of lithium cellulose, 11 mg of PVDF, 11 mg of Super-P, and 88 mg of lithium iron phosphate were added to 400 mg of NMP and stirred overnight. The mixture was then coated onto an aluminum current collector with a scraper height of 200 μm and dried at 80 ℃ for 24 h to obtain a solid-state battery positive electrode. The solid-state battery positive electrode, composite solid electrolyte, and lithium sheet were sequentially placed in a coin cell and encapsulated under a pressure of 900 Pa to form a solid-state battery.

[0053] The solid-state battery prepared in this experimental example was tested, and the results are as follows:

[0054] Tests show that the solid-state lithium iron phosphate battery prepared in this comparative example has an interfacial impedance of about 400 Ω at 30 ℃, and can be stably cycled for 100 cycles at 30 ℃ and 0.5 C with a capacity retention of 80%. Example 1

[0055] 10 g of nanocellulose particles were added to 100 mL of DMAc and magnetically stirred for 24 h. The mixture was then centrifuged at 10000 r / min and transferred to a vacuum oven at 80 °C for 24 h to obtain pre-dissolved nanocellulose particles. A certain amount of anhydrous lithium chloride was added to the DMAc solvent until the anhydrous lithium chloride was completely dissolved, and the mixture was stirred continuously for 24 h, maintaining a molar ratio of 0.17:1 to obtain a DMAc / LiCl solution. 10 g of the pre-dissolved nanocellulose particles were taken and added to 50 mL of the DMAc / LiCl solution and stirred evenly to obtain lithium-ionized cellulose. 0.8 g of PVDF and 0.2 mol / L LiTFSI were added to 8 mL of DMAc solvent and magnetically stirred for 24 h. Then, 7.2% (w / w) of lithium cellulose PVDF was added, and the mixture was stirred for 24 h to obtain a composite solid electrolyte slurry. 2.2 mg of lithium cellulose PVDF, 7 mg of PVDF, 11 mg of Super-P, 4 mg of LiTFSI, and 88 mg of lithium iron phosphate were added to 400 mg of NMP and stirred overnight. The mixture was then coated onto an aluminum current collector with a scraper height of 200 μm and dried at 80 ℃ for 24 h to obtain a solid-state battery cathode. The composite solid electrolyte slurry was coated onto the solid-state battery cathode and vacuum dried with a scraper height of 1000 μm to obtain an integrated electrode. The drying temperature was maintained at 80 ℃ and the drying time was controlled at 24 h. A lithium sheet was placed on the surface of the integrated electrode with an area ratio of 1:1, and the electrode was placed in a coin cell and encapsulated at 900 Pa pressure to form a solid-state battery.

[0056] The solid-state battery with integrated electrodes prepared in this experimental example was tested, and the results are as follows:

[0057] like Figure 1 As shown in the SEM image of the integrated electrode cross-section, it can be clearly seen that the solid electrolyte and the positive electrode of the solid battery are in close contact without obvious separation, which ensures the good operation of the solid battery at room temperature. The test results show that the solid Li|lithium iron phosphate battery prepared in this embodiment has an interfacial impedance of about 100 Ω at 30℃ and can be stably cycled for 200 cycles at 30℃ and 0.5 C with a capacity retention of 95%. Example 2

[0058] 15 g of nanocellulose particles were added to 100 mL of DMAc and magnetically stirred for 24 h. The mixture was then centrifuged at 10000 r / min and transferred to a vacuum oven at 80 °C for 24 h to obtain pre-dissolved nanocellulose particles. A certain amount of anhydrous lithium chloride was added to the DMAc solvent until the anhydrous lithium chloride was completely dissolved, and the mixture was stirred continuously for 24 h, maintaining a molar ratio of 0.15:1 to obtain a DMAc / LiCl solution. 12 g of the pre-dissolved nanocellulose particles were taken and added to 50 mL of the DMAc / LiCl solution and stirred evenly to obtain lithium-ionized cellulose. 0.6 g of PVDF and 0.2 mol / L LiTFSI were added to 8 mL of DMAc solvent and magnetically stirred for 24 h. Then, 8% (w / w) of lithium cellulose (PVDF) was added, and the mixture was stirred for 24 h to obtain a composite solid electrolyte slurry. 2.5 mg of lithium cellulose, 7 mg of PVDF, 11 mg of Super-P, 4 mg of LiTFSI, and 88 mg of lithium iron phosphate were added to 400 mg of NMP and stirred overnight. The mixture was then coated onto an aluminum current collector using a 200 μm high scraper. The drying temperature was maintained at 80 °C for 24 h to obtain a solid-state battery cathode. The composite solid electrolyte slurry was coated onto the solid-state battery cathode and vacuum dried using a 1000 μm high scraper to obtain an integrated electrode. The drying temperature was maintained at 80 °C for 24 h. A lithium sheet was placed on the surface of the integrated electrode with a 1:1 area ratio. The electrode was then placed in a coin cell and encapsulated at 900 Pa pressure to form a solid-state battery.

[0059] The solid-state battery with integrated electrodes prepared in this experimental example was tested, and the results are as follows:

[0060] Because the integrated electrode makes close contact between the solid electrolyte and the positive electrode of the solid battery, the interfacial impedance is about 120 Ω at 30°C. As tested, the solid Li|lithium iron phosphate battery prepared in this embodiment can be stably cycled 200 times at 30°C and 0.5 C with a capacity retention of 93%. Example 3

[0061] 12 g of nanocellulose particles were added to 100 mL of DMAc and magnetically stirred for 24 h. After centrifugation at 10000 r / min, the particles were then transferred to a vacuum oven at 80 °C and dried for 24 h to obtain pre-dissolved nanocellulose particles. A certain amount of anhydrous lithium chloride was added to the DMAc solvent until the anhydrous lithium chloride was completely dissolved and stirred continuously for 24 h, maintaining a molar ratio of 0.12:1 to obtain a DMAc / LiCl solution. 15 g of the pre-dissolved nanocellulose particles were taken and added to 50 mL of the DMAc / LiCl solution and stirred evenly to obtain lithiumized cellulose. 1 g of PVDF and 0.2 mol / L LiTFSI were added to 10 mL of DMAc solvent and magnetically stirred for 24 h. Then, 5.5% (w / w) of lithium cellulose PVDF was added, and the mixture was stirred for 24 h to obtain a composite solid electrolyte slurry. 2 mg of lithium cellulose phosphate, 7 mg of PVDF, 11 mg of Super-P, 3 mg of LiTFSI, and 88 mg of lithium iron phosphate were added to 400 mg of NMP and stirred overnight. The mixture was then coated onto an aluminum current collector using a 200 μm high scraper. The drying temperature was maintained at 80 °C for 24 h to obtain a solid-state battery positive electrode. The composite solid electrolyte slurry was coated onto the solid-state battery positive electrode and vacuum dried using a 1000 μm high scraper to obtain an integrated electrode. The drying temperature was maintained at 80 °C for 24 h. A lithium sheet was placed on the surface of the integrated electrode with an area ratio of 1:1. The electrode was then placed in a coin cell and encapsulated at 900 Pa pressure to form a solid-state battery.

[0062] The solid-state battery with integrated electrodes prepared in this experimental example was tested, and the results are as follows:

[0063] Because the integrated electrode makes close contact between the solid electrolyte and the positive electrode of the solid battery, the interfacial impedance is about 150 Ω at 30°C. As tested, the solid Li|lithium iron phosphate battery prepared in this embodiment can be stably cycled 200 times at 30°C and 0.5 C with a capacity retention of 90%.

[0064] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for fabricating a solid-state battery with integrated electrodes, characterized in that: A composite solid electrolyte slurry is coated onto the positive electrode of a battery, dried to obtain an integrated electrode, and a negative electrode is placed on its surface and pressed to obtain a solid battery. The positive electrode is obtained by adding lithium cellulose, polymer, conductive agent, lithium salt and active material into solvent A and stirring, then coating it onto a current collector with a scraper and drying. The stirring time is controlled between 6 and 36 hours, the stirring rate is controlled between 200 and 1500 r / min, the drying temperature is maintained between 50 and 120°C, and the drying time is controlled between 6 and 36 hours. The molar concentration of the lithium salt is between 0.1 and 0.3 mol / L; The mass ratio of the polymer to the solvent is between 1:100 and 1:10; The content of the lithium cellulose as a percentage of the polymer weight does not exceed 8 wt%. The mass ratio of the conductive agent to the polymer is between 10:3 and 1:3; The method for preparing the lithium-ionized cellulose includes the following steps: Step 1: Add nanocellulose particles to DMAc solvent and stir magnetically until some hydrogen bonds are broken; then centrifuge to obtain wet pre-dissolved nanocellulose; after drying, obtain pre-dissolved nanocellulose particles; the mass ratio of nanocellulose particles to DMAc is between 0.05 and 0.

2. Step 2: Add anhydrous lithium chloride to DMAc solvent and stir until LiCl is completely dissolved to obtain DMAc / LiCl solution; the molar ratio of LiCl / DMAc is between 0:1 and 0.22:

1. Step 3: Add the pre-dissolved nanocellulose particles obtained in Step 1 to the DMAc / LiCl solution obtained in Step 2, stir evenly, and obtain lithium cellulose; the mass fraction of the pre-dissolved nanocellulose particles is between 4wt% and 30wt%.

2. The method for fabricating a solid-state battery with integrated electrodes as described in claim 1, characterized in that: The preparation method of the composite solid electrolyte slurry is as follows: lithium cellulose, lithium salt and polymer are added to solvent B and stirred to obtain electrolyte slurry. The stirring time is controlled between 6 and 36 h and the stirring rate is controlled between 200 and 1500 r / min. The mass ratio of the polymer to the solvent is between 1:100 and 3:10; The molar concentration of the lithium salt is between 0.125 and 0.5 mol / L; The lithium cellulose content accounts for no more than 8 wt% of the polymer weight.

3. The method for fabricating a solid-state battery with integrated electrodes as described in claim 1, characterized in that: The specific preparation method of the integrated electrode is as follows: the composite solid electrolyte slurry is coated on the positive electrode sheet of the solid battery and dried under vacuum. The drying temperature is maintained between 50 and 120°C and the drying time is controlled between 6 and 36 hours.

4. The method for fabricating a solid-state battery with integrated electrodes as described in claim 2, characterized in that: The polymer is one or more of the following: polyethylene oxide, polyvinylidene fluoride, polyacrylonitrile, polyvinylidene fluoride-hexafluoropropylene, polymethyl methacrylate, polyethylene succinate, polypropylene oxide, polyethyleneimine, and polyvinylidene chloride. The lithium salt is one or more of lithium perchlorate, lithium bis(trifluoromethanesulfonylimide) and lithium bis(fluorosulfonylimide), lithium tetrafluoroborate, lithium hexafluoroarsenate and lithium hexafluorophosphate. Solvent A is one or more of N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, triethyl phosphate, dimethyl sulfoxide ethanol, methanol, acetonitrile, and acetone; The solvent B is one or more of N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, triethyl phosphate, dimethyl sulfoxide ethanol, methanol, acetonitrile, and acetone; The conductive agent is one or more of acetylene black, conductive carbon black, Ketjen black, conductive graphite, vapor-grown carbon fiber, carbon nanotubes and graphene and their composite conductive agents. The active material is one or more of the following: lithium cobalt oxide, lithium nickel oxide, nickel-cobalt-manganese ternary materials, lithium nickel-cobalt-aluminum oxide, lithium-rich manganese-based materials, lithium manganese oxide, lithium nickel-manganese oxide, iron tetroxide, lithium vanadium oxide, lithium iron phosphate, lithium manganese phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxyphosphate, lithium cobalt phosphate, lithium nickel phosphate, lithium iron silicate, lithium iron fluoride, lithium iron borate, lithium iron titanate, iron trifluoride, cobalt trifluoride, nickel trifluoride, titanium disulfide, iron disulfide, molybdenum disulfide, and niobium triselenide.

5. A method for fabricating a solid-state battery with integrated electrodes as described in claim 1 or 2, characterized in that: The nanocellulose particles are one of various cellulose nanofibers, cellulose nanosheets, and nanocellulose particles prepared and purified from trees, bamboo, cotton, marine algae, and marine bacteria.

6. The method for fabricating a solid-state battery with integrated electrodes as described in claim 1, characterized in that: The stirring rate in step one is controlled between 200 and 1500 r / min, and the time is controlled between 6 and 36 h. The centrifugal speed for centrifugation in step one is controlled within 2000–12000 r / min; The drying temperature in step one is maintained between 50 and 120°C, and the drying time is controlled between 6 and 36 hours. The stirring rate in step two is controlled between 200 and 1500 r / min, and the stirring time is controlled between 6 and 36 h. The stirring rate in step three is controlled between 200 and 1500 r / min, and the stirring time is controlled between 6 and 36 h.

7. The method for fabricating a solid-state battery with integrated electrodes as described in claim 1, characterized in that: The main material of the negative electrode sheet is one or more of the following: artificial graphite negative electrode material, natural graphite negative electrode material, central phase carbon microsphere negative electrode material, petroleum coke negative electrode material, carbon fiber negative electrode material, hard carbon negative electrode material, soft carbon negative electrode material, graphene negative electrode material, tin oxide negative electrode material, tin-based composite oxide negative electrode material, lithium-containing transition metal nitride negative electrode material, carbon nanotube negative electrode material, nano-alloy negative electrode material, silicon-carbon negative electrode material, potassium metal negative electrode material, sodium metal negative electrode material, aluminum metal negative electrode material, magnesium metal negative electrode material, and lithium metal negative electrode material.

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