A method of fabricating an in-situ solid state battery structure

Abstract

The application discloses a preparation method of an in-situ solid-state battery structure, and comprises the following steps: 1, mixing a polymer monomer, an initiator and an electrolyte to obtain an in-situ solid-state electrolyte precursor I, mixing the in-situ solid-state electrolyte precursor I with an inorganic solid-state electrolyte to obtain an in-situ solid-state electrolyte precursor II and an in-situ solid-state electrolyte precursor III; 2, preparing a positive electrode sheet and a negative electrode sheet; 3, coating the in-situ solid-state electrolyte precursor I on surfaces of the positive electrode sheet and the negative electrode sheet, and obtaining a solidified positive electrode and a solidified negative electrode through static solidification and rolling; 4, coating the in-situ solid-state electrolyte precursor II on a surface of the solidified positive electrode and coating the in-situ solid-state electrolyte precursor III on a surface of the solidified negative electrode, and obtaining a composite positive electrode and a composite negative electrode through static solidification; and 5, solidifying the composite positive electrode and the composite negative electrode after being attached. The preparation method effectively improves the contact area of the in-situ solid-state electrolyte and the positive electrode sheet and the negative electrode sheet, improves the ion conduction efficiency, and is suitable for the technical field of battery preparation.

Description

Technical Field

[0001] This invention belongs to the field of battery manufacturing technology, and in particular relates to a method for preparing an in-situ solid-state battery structure. Background Technology

[0002] Traditional lithium-ion batteries suffer from safety issues due to the flammability of their liquid electrolytes and the risk of thermal runaway (such as fires and explosions) during short circuits. Liquid electrolytes and graphite anodes cannot meet the higher energy density requirements of future electric vehicles and high-energy electronic devices. Furthermore, liquid electrolytes are prone to side reactions during long-term cycling, leading to capacity decay and affecting battery stability. To address these problems, researchers have proposed using solid-state electrolytes to replace traditional liquid electrolytes.

[0003] Solid electrolytes are safe and have good thermal stability, making them suitable for extreme temperature environments. At the same time, solid interface reactions are relatively slow and there are fewer side reactions. Polymer electrolytes, on the other hand, form solid electrolytes in situ inside the battery through chemical reactions or heat treatment, achieving efficient contact between the electrolyte and electrode materials, thereby improving ionic conductivity and interface stability.

[0004] While in-situ solid-state battery technology is considered a potential solution to the challenges of solid-state batteries, it still faces several problems. Current technologies typically involve first fabricating the battery cell, then injecting the in-situ solid electrolyte precursor into the cell and curing it through methods such as thermal initiation and ultraviolet light irradiation. This method can lead to uneven curing of the solid electrolyte precursor and high internal resistance in the battery. Furthermore, the porosity of the electrode sheets is further reduced after rolling, making it difficult for the in-situ solid electrolyte precursor to penetrate into the electrode sheets and form continuous ion transport channels, affecting battery performance. Additionally, the in-situ solid electrolyte cannot fully contact the positive and negative electrode materials, resulting in interfacial gaps and reduced ion conduction efficiency. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing an in-situ solid-state battery structure. This method involves coating an in-situ solid electrolyte precursor onto the surfaces of unrolled positive and negative electrode sheets, then increasing the contact area between the in-situ solid electrolyte and the positive and negative electrode sheets through curing and rolling, and improving the density of the positive and negative electrode sheets. Further coating the positive and negative electrode sheets with the in-situ solid electrolyte precursor again helps control the thickness of the in-situ solid electrolyte (cured in-situ solid electrolyte precursor) on the positive and negative electrode surfaces. This solves the problem in the prior art where directly injecting the in-situ solid electrolyte precursor into the battery cell results in insufficient contact between the cured in-situ solid electrolyte and the electrode sheets, leading to reduced ion conduction efficiency.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing an in-situ solid-state battery structure, characterized in that the preparation method includes the following steps:

[0007] Step 1: Mix the polymer monomer, initiator, and electrolyte to obtain in-situ solid electrolyte precursor I. Mix in-situ solid electrolyte precursor I with two inorganic solid electrolytes respectively to obtain in-situ solid electrolyte precursor II and in-situ solid electrolyte precursor III.

[0008] Step 2: Coat the positive electrode slurry onto the surface of the current collector to obtain the positive electrode sheet, and coat the negative electrode slurry onto the surface of the current collector to obtain the negative electrode sheet;

[0009] Step 3: Coat the surface of the positive and negative electrode sheets obtained in Step 2 with the in-situ solid electrolyte precursor I obtained in Step 1, let it stand to cure, and then roll it to obtain the cured positive and cured negative electrodes.

[0010] Step 4: Coat the in-situ solid electrolyte precursor II obtained in Step 1 onto the surface of the cured positive electrode obtained in Step 3, and coat the in-situ solid electrolyte precursor III obtained in Step 1 onto the surface of the cured negative electrode obtained in Step 3. After static curing, a composite positive electrode and a composite negative electrode with a gel-like solid electrolyte layer are obtained.

[0011] Step 5: Bond the composite positive electrode and composite negative electrode obtained in Step 4 together, and after curing, obtain the in-situ solid-state battery structure.

[0012] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the mass ratio of inorganic solid electrolyte to polymer monomer in electrolyte precursor II and electrolyte precursor III in step one is not greater than 3:5.

[0013] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the inorganic solid-state electrolyte in the in-situ solid-state electrolyte precursor II in step one is an oxidation-resistant inorganic solid-state electrolyte, and the inorganic solid-state electrolyte in the in-situ solid-state electrolyte precursor III is a reduction-resistant inorganic solid-state electrolyte.

[0014] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the oxidation-resistant inorganic solid electrolyte is one of LATP, LLZO, LISICON, and Li3YCl6, and the reduction-resistant inorganic solid electrolyte is one of LLTO, Li3PS4, and Li2ZrCl6.

[0015] This invention utilizes oxidation-resistant LATP (lithium aluminum titanium phosphate), LLZO (lithium lanthanum titanium oxide), LISICON (lithium superion conductor), and Li3YCl6 (halide solid electrolyte) to coat the surface of the solidified positive electrode. This achieves compatibility with high-voltage positive electrode materials, enhances thermal stability and safety, broadens the electrochemical window, suppresses interfacial side reactions, and improves the battery's cycle life. Conversely, by using reduction-resistant LLTO (lithium lanthanum titanium oxide), Li3PS4 (sulfide solid electrolyte), and Li2ZrCl6 (halide solid electrolyte) to coat the surface of the solidified negative electrode, this invention inhibits electrolyte decomposition, reduces interfacial impedance, increases battery energy density, improves wide-temperature stability, and simplifies interface engineering.

[0016] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the polymer monomer in step one is one or more of ester monomers, carbonate monomers, amide monomers, nitrile monomers, fluorinated monomers, ether compounds, and oligomers containing ether segments; the initiator is one or more of azo initiators, peroxide initiators, and cationic and anionic initiators; and the electrolyte includes a solvent and a lithium salt.

[0017] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the solvent is one or more of ethylene carbonate, fluoroethylene carbonate, propylene carbonate, and ethylene glycol dimethyl ether.

[0018] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the resting time in step three is 8h to 24h, and the curing method is: irradiation with ultraviolet light with a wavelength of 250nm to 400nm for 100s to 400s.

[0019] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the thickness of both the positive and negative electrodes after rolling and curing in step three is reduced by not less than 50 μm.

[0020] This invention improves the battery's electrical performance and energy density by controlling the thickness of the roll forming process, thereby making the contact between the components inside the in-situ solid electrolyte and between the in-situ solid electrolyte and the positive and negative electrode sheets closer.

[0021] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the standing time in step four is 5h to 12h, the curing method is: irradiation with ultraviolet light with a wavelength of 250nm to 400nm for 50s to 200s, and the thickness of the gel-like solid electrolyte layer is 60μm to 200μm.

[0022] This invention enables the inorganic solid electrolytes in the in-situ solid electrolyte precursor II and III to settle onto the positive and negative electrode surfaces, respectively, by controlling the settling time. This forms an asymmetric electrolyte layer on the positive and negative electrode surfaces, which helps to mitigate the side reactions between the in-situ solid electrolyte and the positive and negative electrode surfaces. By controlling the mass ratio of inorganic solid electrolyte to polymer monomer and the thickness of the gel-like solid electrolyte layer (60μm~200μm), the thickness of the settled inorganic solid electrolyte is 2μm~40μm. This avoids the inorganic solid electrolyte being too thin or unable to completely cover the electrode surface, which would make it difficult to achieve the expected battery design performance. It also avoids the inorganic solid electrolyte being too thick, which would result in poor adhesion between the positive and negative electrode surfaces, causing excessive spacing between the positive and negative electrodes and making ion transport difficult.

[0023] The above-mentioned method for preparing an in-situ solid-state battery structure is characterized in that the curing method in step five is: standing for 80s to 240s in an environment with a temperature of 50℃~100℃ and a pressure of 30PSI~60PSI.

[0024] This invention, by controlling the curing process in a heated and pressurized environment, enables the composite positive and negative electrode surfaces to be completely bonded, the in-situ solid electrolyte to be in closer contact with the positive and negative electrode sheets, and the in-situ solid electrolyte to be more uniform inside and on the surface of the positive and negative electrode sheets. This effectively increases the ion transport channels of the battery and reduces the interfacial impedance between the in-situ solid electrolyte and the positive and negative electrode sheets.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. This invention coats the surface of unrolled positive and negative electrode sheets with an in-situ solid electrolyte precursor. Since the unrolled positive and negative electrode sheets have a large number of pores, the in-situ solid electrolyte precursor can be injected into the gaps between the active material particles of the positive and negative electrode sheets, increasing the contact area between the positive and negative electrode sheets and the in-situ solid electrolyte precursor, which is conducive to the formation of continuous ion transport channels. Then, rolling is used to improve the compactness of the positive and negative electrode sheets and the in-situ solid electrolyte, thereby improving the electrical performance and energy density of the in-situ solid battery.

[0027] 2. This invention controls the thickness of the in-situ solid electrolyte on the positive and negative electrode surfaces by recoating and curing an in-situ solid electrolyte precursor on the positive and negative electrode surfaces, and improves the thickness difference in various parts of the positive and negative electrode surfaces caused by rolling, resulting in a larger contact area after the positive and negative electrode sheets are bonded together. At the same time, the recoated in-situ solid electrolyte precursor contains inorganic solid electrolyte. During the standing process, the inorganic solid electrolyte will settle under the action of gravity and form an asymmetric electrolyte layer on the surface of the positive and negative electrode sheets, which helps to alleviate the side reactions between the in-situ solid electrolyte and the positive and negative electrode sheets.

[0028] 3. The present invention enables the composite positive and negative electrodes to be tightly bonded by forming a gel-like solid electrolyte layer on the surface of the composite positive and negative electrodes. Then, it is cured by heating and pressurizing to reduce the resistance of the bonding surface. It can also remove the separator between the positive and negative electrodes of the battery in the prior art, which is beneficial to improving the integrity of the in-situ solid battery structure.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the in-situ solid-state battery structure of the present invention. Detailed Implementation

[0031] Example 1

[0032] The preparation method of this embodiment includes the following steps:

[0033] Step 1: By mass, mix 5 parts pentaerythritol tetraacrylate, 0.05 parts azobisisobutyronitrile (AIBN), and 50 parts electrolyte to obtain in-situ solid electrolyte precursor I; mix 5 parts pentaerythritol tetraacrylate, 0.05 parts AIBN, and 50 parts electrolyte with 1 part LLZO to obtain in-situ solid electrolyte precursor II; mix 5 parts pentaerythritol tetraacrylate, 0.05 parts AIBN, and 50 parts electrolyte with 1 part LLTO to obtain in-situ solid electrolyte precursor III; the electrolytes are all composed of lithium hexafluorophosphate, fluoroethylene carbonate, ethylene carbonate, and lithium difluorooxalate borate.

[0034] Step 2: By mass, mix 95 parts lithium cobalt oxide, 2 parts polyvinylidene fluoride, and 3 parts carbon black in N-methylpyrrolidone, coat the mixture onto the surface of aluminum foil, and dry it to obtain the positive electrode sheet; mix 95 parts graphite, 2 parts styrene-butadiene rubber, 2 parts carbon black, and 1 part carbon nanotubes in water and N-methylpyrrolidone, coat the mixture onto the surface of copper foil current collector, and dry it to obtain the negative electrode sheet;

[0035] Step 3: Coat the in-situ solid electrolyte precursor I obtained in Step 1 onto the surfaces of the positive and negative electrode sheets. After standing for 12 hours, irradiate the positive and negative electrode sheets with ultraviolet light at a wavelength of 250 nm for 400 seconds to obtain a solidified positive electrode with a thickness of 200 μm and a solidified negative electrode with a thickness of 170 μm. Then roll press to obtain a solidified positive electrode with a thickness of 150 μm and a solidified negative electrode with a thickness of 120 μm.

[0036] Step 4: Coat the in-situ solid electrolyte precursor II obtained in Step 1 onto the surface of the cured positive electrode obtained in Step 3, and coat the in-situ solid electrolyte precursor III obtained in Step 1 onto the surface of the cured negative electrode obtained in Step 3. Let stand at 40°C for 5 hours, and then irradiate the cured positive electrode and the cured negative electrode with ultraviolet light of wavelength 250nm for 200s to obtain a composite positive electrode and a composite negative electrode with a gel-like solid electrolyte layer. The thickness of the gel-like solid electrolyte layer is 60μm and 70μm, respectively, and the thickness of the inorganic solid electrolyte is 13μm.

[0037] Step 5: Completely bond the composite positive and composite negative electrodes obtained in Step 4, and cure them at 100°C under a pressure of 30 PSI for 80 seconds to obtain the desired result. Figure 1 The in-situ solid-state battery structure shown is cut and assembled into a solid-state battery.

[0038] In step one of this embodiment, pentaerythritol tetraacrylate can be replaced with one or more of the following: ester monomers, carbonate monomers, amide monomers, nitrile monomers, fluorinated monomers, ether compounds, and oligomers containing ether segments, excluding pentaerythritol tetraacrylate. Azobisisobutyronitrile can be replaced with one or more of the following: azo initiators, peroxide initiators, and anionic and cationic initiators, excluding azobisisobutyronitrile. LLZO can be replaced with LISICON or Li3YCl6, and LLTO can be replaced with Li3PS4. Fluorinated ethylene carbonate and ethylene carbonate can be replaced with ethylene carbonate and / or ethylene glycol dimethyl ether. Lithium hexafluorophosphate and lithium difluorooxalate borate can be replaced with one or more of the following: lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, and lithium bis(trifluoromethanesulfonyl)imide.

[0039] The solid-state battery prepared in this embodiment has an interface impedance of no more than 100 ohms and a capacity retention of no less than 90% after 100 cycles.

[0040] Example 2

[0041] The preparation method of this embodiment includes the following steps:

[0042] Step 1: By mass, mix 5 parts pentaerythritol tetraacrylate, 0.05 parts azobisisobutyronitrile (AIBN), and 50 parts electrolyte to obtain in-situ solid electrolyte precursor I; mix 5 parts pentaerythritol tetraacrylate, 0.05 parts AIBN, and 50 parts electrolyte with 2 parts LLZO to obtain in-situ solid electrolyte precursor II; mix 5 parts pentaerythritol tetraacrylate, 0.05 parts AIBN, and 50 parts electrolyte with 2 parts Li₂ZrCl₆ to obtain in-situ solid electrolyte precursor III; the electrolytes are all composed of lithium hexafluorophosphate, fluoroethylene carbonate, ethylene carbonate, and lithium difluorooxalate borate.

[0043] Step 2: By mass, mix 95 parts lithium cobalt oxide, 2 parts polyvinylidene fluoride, and 3 parts carbon black in N-methylpyrrolidone, coat the mixture onto the surface of aluminum foil, and dry to obtain the positive electrode sheet; mix 95 parts silicon carbide, 2 parts styrene-butadiene rubber, 2 parts carbon black, and 1 part carbon nanotubes in water and N-methylpyrrolidone, coat the mixture onto the surface of copper foil current collector, and dry to obtain the negative electrode sheet;

[0044] Step 3: Coat the in-situ solid electrolyte precursor I obtained in Step 1 onto the surfaces of the positive and negative electrode sheets. After standing for 10 hours, irradiate the positive and negative electrode sheets with ultraviolet light at a wavelength of 280 nm for 300 seconds to obtain a solidified positive electrode with a thickness of 210 μm and a solidified negative electrode with a thickness of 160 μm. Then roll press to obtain a solidified positive electrode with a thickness of 150 μm and a solidified negative electrode with a thickness of 90 μm.

[0045] Step 4: Coat the in-situ solid electrolyte precursor II obtained in Step 1 onto the surface of the cured positive electrode obtained in Step 3, and coat the in-situ solid electrolyte precursor III obtained in Step 1 onto the surface of the cured negative electrode obtained in Step 3. Let stand at 28°C for 10 hours, and then irradiate the cured positive electrode and the cured negative electrode with ultraviolet light of wavelength 280nm for 150s to obtain a composite positive electrode and a composite negative electrode with a gel-like solid electrolyte layer. The thickness of the gel-like solid electrolyte layer is 80μm and 90μm, respectively, and the thickness of the inorganic solid electrolyte is 26μm.

[0046] Step 5: Completely bond the composite positive electrode and composite negative electrode obtained in Step 4, and cure them at 80°C with a pressure of 40 PSI for 150 seconds to obtain an in-situ solid-state battery structure. After cutting, assemble it into a solid-state battery.

[0047] The solid-state battery prepared in this embodiment has an interface impedance of no more than 100 ohms and a capacity retention of no less than 90% after 100 cycles.

[0048] Example 3

[0049] The preparation method of this embodiment includes the following steps:

[0050] Step 1: By mass, mix 5 parts maleic anhydride, 0.05 parts azobisisobutyronitrile (AIBN), and 100 parts electrolyte to obtain in-situ solid electrolyte precursor I; mix 5 parts maleic anhydride, 0.05 parts AIBN, and 100 parts electrolyte with 2.5 parts LATP to obtain in-situ solid electrolyte precursor II; mix 5 parts maleic anhydride, 0.05 parts AIBN, and 100 parts electrolyte with 2.5 parts LLTO to obtain in-situ solid electrolyte precursor III; the electrolytes are all composed of lithium hexafluorophosphate, fluoroethylene carbonate, ethylene carbonate, and lithium difluorooxalate borate.

[0051] Step 2: By mass, mix 95 parts lithium iron phosphate, 2 parts polyvinylidene fluoride, and 3 parts carbon nanotubes evenly in N-methylpyrrolidone, coat the mixture onto the surface of aluminum foil, and dry it to obtain the positive electrode sheet; mix 95 parts graphite, 2 parts styrene-butadiene rubber, 2 parts carbon black, and 1 part carbon nanotubes evenly in water and N-methylpyrrolidone, coat the mixture onto the surface of copper foil, and dry it to obtain the negative electrode sheet;

[0052] Step 3: Coat the in-situ solid electrolyte precursor I obtained in Step 1 onto the surfaces of the positive and negative electrode sheets. After standing for 8 hours, irradiate the positive and negative electrode sheets with ultraviolet light with a wavelength of 300 nm for 200 seconds to obtain a solidified positive electrode with a thickness of 215 μm and a solidified negative electrode with a thickness of 150 μm. Then roll press to obtain a solidified positive electrode with a thickness of 160 μm and a solidified negative electrode with a thickness of 80 μm.

[0053] Step 4: Coat the in-situ solid electrolyte precursor II obtained in Step 1 onto the surface of the cured positive electrode obtained in Step 3, and coat the in-situ solid electrolyte precursor III obtained in Step 1 onto the surface of the cured negative electrode obtained in Step 3. Let stand at 30°C for 7 hours, and then irradiate the cured positive electrode and the cured negative electrode with ultraviolet light with a wavelength of 300nm for 100s to obtain a composite positive electrode and a composite negative electrode with a gel-like solid electrolyte layer. The thickness of the gel-like solid electrolyte layer is 120μm and 80μm, respectively, and the thickness of the inorganic solid electrolyte is 33μm.

[0054] Step 5: Completely bond the composite positive electrode and composite negative electrode obtained in Step 4, and cure them at 60°C with a pressure of 50 PSI for 200 seconds to obtain an in-situ solid-state battery structure. After cutting, assemble it into a battery.

[0055] The solid-state battery prepared in this embodiment has an interface impedance of no more than 100 ohms and a capacity retention of no less than 90% after 100 cycles.

[0056] Example 4

[0057] The preparation method of this embodiment includes the following steps:

[0058] Step 1: By mass, mix 5 parts maleic anhydride, 0.05 parts azobisisobutyronitrile (AIBN), and 100 parts electrolyte to obtain in-situ solid electrolyte precursor I; mix 5 parts maleic anhydride, 0.05 parts AIBN, 100 parts electrolyte, and 3 parts LATP to obtain in-situ solid electrolyte precursor II; mix 5 parts maleic anhydride, 0.05 parts AIBN, 100 parts electrolyte, and 3 parts Li₂ZrCl₆ to obtain in-situ solid electrolyte precursor III; the electrolytes are all composed of lithium hexafluorophosphate, fluoroethylene carbonate, ethylene carbonate, and lithium difluorooxalate borate.

[0059] Step 2: By mass, mix 95 parts lithium iron phosphate, 2 parts polyvinylidene fluoride, and 3 parts carbon nanotubes evenly in N-methylpyrrolidone, coat the mixture onto the surface of aluminum foil, and dry it to obtain the positive electrode sheet; mix 95 parts silicon carbide, 2 parts styrene-butadiene rubber, 2 parts carbon black, and 1 part carbon nanotubes evenly in water and N-methylpyrrolidone, coat the mixture onto the surface of copper foil, and dry it to obtain the negative electrode sheet;

[0060] Step 3: Coat the in-situ solid electrolyte precursor I obtained in Step 1 onto the surfaces of the positive and negative electrode sheets. After standing for 24 hours, irradiate the positive and negative electrode sheets with ultraviolet light of wavelength 400nm for 100s to obtain a solidified positive electrode with a thickness of 220μm and a solidified negative electrode with a thickness of 170μm. Then roll press to obtain a solidified positive electrode with a thickness of 120μm and a solidified negative electrode with a thickness of 70μm.

[0061] Step 4: Coat the in-situ solid electrolyte precursor II obtained in Step 1 onto the surface of the cured positive electrode obtained in Step 3, and coat the in-situ solid electrolyte precursor III obtained in Step 1 onto the surface of the cured negative electrode obtained in Step 3. Let stand at 25°C for 12 hours, and then irradiate the cured positive electrode and the cured negative electrode with ultraviolet light with a wavelength of 400nm for 50s to obtain a composite positive electrode and a composite negative electrode with a gel-like solid electrolyte layer. The thickness of the gel-like solid electrolyte layer is 200μm and 100μm, respectively, and the thickness of the inorganic solid electrolyte is 40μm.

[0062] Step 5: Completely bond the composite positive electrode and composite negative electrode obtained in Step 4, and cure them at 50°C with a pressure of 60 PSI for 240 seconds to obtain an in-situ solid-state battery structure. After cutting, assemble it into a battery.

[0063] The solid-state battery prepared in this embodiment has an interface impedance of no more than 100 ohms and a capacity retention of no less than 90% after 100 cycles.

[0064] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing an in-situ solid-state battery structure, characterized in that, The preparation method includes the following steps: Step 1: Mix the polymer monomer, initiator, and electrolyte to obtain in-situ solid electrolyte precursor I. Mix in-situ solid electrolyte precursor I with two inorganic solid electrolytes respectively to obtain in-situ solid electrolyte precursor II and in-situ solid electrolyte precursor III. The mass ratio of inorganic solid electrolyte to polymer monomer in both electrolyte precursor II and electrolyte precursor III is no greater than 3:

5. The inorganic solid electrolyte in in-situ solid electrolyte precursor II is an oxidation-resistant inorganic solid electrolyte, and the inorganic solid electrolyte in in-situ solid electrolyte precursor III is a reduction-resistant inorganic solid electrolyte. The oxidation-resistant inorganic solid electrolyte is one of LATP, LLZO, LISICON, and Li3YCl6, and the reduction-resistant inorganic solid electrolyte is one of LLTO, Li3PS4, and Li2ZrCl6. Step 2: Coat the positive electrode slurry onto the surface of the current collector to obtain the positive electrode sheet, and coat the negative electrode slurry onto the surface of the current collector to obtain the negative electrode sheet; Step 3: Coat the in-situ solid electrolyte precursor I obtained in Step 1 onto the surface of the positive and negative electrode sheets obtained in Step 2, let it stand and cure, and then roll it to obtain the cured positive and negative electrodes; the standing time is 8h~24h, and the curing method is: irradiate with ultraviolet light with a wavelength of 250nm~400nm for 100s~400s; Step 4: Coat the in-situ solid electrolyte precursor II obtained in Step 1 onto the surface of the cured positive electrode obtained in Step 3, and coat the in-situ solid electrolyte precursor III obtained in Step 1 onto the surface of the cured negative electrode obtained in Step 3. After standing and curing, a composite positive electrode and a composite negative electrode with a gel-like solid electrolyte layer are obtained. The standing time is 5h~12h, and the curing method is: irradiate with ultraviolet light with a wavelength of 250nm~400nm for 50s~200s. The thickness of the gel-like solid electrolyte layer is 60μm~200μm. Step 5: Bond the composite positive electrode and composite negative electrode obtained in Step 4 together and cure them to obtain an in-situ solid-state battery structure; the curing method is to let it stand for 80s to 240s in an environment with a temperature of 50℃~100℃ and a pressure of 30PSI~60PSI.

2. The method for preparing an in-situ solid-state battery structure according to claim 1, characterized in that, The polymer monomers mentioned in step one are one or more of the following: ester monomers, carbonate monomers, amide monomers, nitrile monomers, fluorinated monomers, ether compounds, and oligomers containing ether segments; the initiator is one or more of the following: azo initiator, peroxide initiator, and cationic / anionic initiator; and the electrolyte includes a solvent and a lithium salt.

3. The method for preparing an in-situ solid-state battery structure according to claim 2, characterized in that, The solvent is one or more of ethylene carbonate, fluoroethylene carbonate, propylene carbonate, and ethylene glycol dimethyl ether.

4. The method for preparing an in-situ solid-state battery structure according to claim 1, characterized in that, In step three, the thickness of both the cured positive and negative electrodes after rolling is reduced by no less than 50 μm.

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