In-situ photocured double salt polymer solid-state electrolyte, preparation method thereof and lithium ion battery

Abstract

The application discloses an in-situ photocuring double-salt polymer solid-state electrolyte and a preparation method and a lithium ion battery, relates to the technical field of solid-state lithium battery electrolytes, and the preparation method of the solid-state electrolyte is as follows: lithium nitrate is dissolved in a solvent under an inert atmosphere to obtain a lithium nitrate solution; a polymer monomer, a crosslinking agent, a film forming agent and butanedinitrile are mixed, lithium bistrifluoromethanesulfonimide and a photoinitiator are added, the mixture is uniformly mixed, and then the lithium nitrate solution is added to obtain a double-salt polymer solid-state electrolyte precursor solution; a diaphragm is soaked in the double-salt polymer solid-state electrolyte precursor solution, the diaphragm is taken out and is cured by ultraviolet light, and thus the double-salt polymer solid-state electrolyte is obtained. The application constructs a novel polymer solid-state electrolyte system which can have safety and high performance, realizes effective regulation of the interface behavior of lithium ion batteries and lithium metal batteries, and thus improves the cycle stability and use reliability of the whole system under room temperature conditions.

Description

Technical Field

[0001] This invention relates to the field of solid-state lithium battery electrolyte technology, and particularly to in-situ photocurable dual-salt polymer solid electrolyte and its preparation method, and lithium-ion batteries. Background Technology

[0002] With the rapid popularization of energy storage systems, electric vehicles, and portable electronic devices, lithium-ion batteries have gained widespread application due to their high energy density, long cycle life, and environmental friendliness. Currently, liquid carbonate electrolytes are still the dominant electrolyte system. However, liquid electrolytes have inherent safety defects such as flammability, easy leakage, and susceptibility to violent exothermic reactions under external abuse conditions. Several energy storage fires in recent years have demonstrated that liquid systems have significant safety bottlenecks in the high energy density direction, limiting the further application of lithium batteries in scenarios with higher safety levels.

[0003] Solid-state electrolytes are considered a fundamental solution to the safety issues of liquid electrolytes due to their high thermal stability and excellent safety. Among them, polymer solid-state electrolytes have become an important development direction for room-temperature solid-state batteries due to their advantages such as good flexibility, low cost, excellent film-forming properties, and strong compatibility with electrode interfaces. However, traditional polymer electrolytes such as PEO systems have low ionic conductivity and limited electrochemical stability windows at room temperature, making it difficult to meet the high voltage and high current density requirements of high-nickel cathodes or lithium metal anodes.

[0004] Succinate (SN), as a typical crystalline succinate, exhibits high ionic conductivity at room temperature, a wide electrochemical window, and cost advantages, demonstrating significant potential as a room-temperature solid-state electrolyte. However, a violent spontaneous reaction occurs between SN and lithium metal, leading to rapid degradation of the solid-state electrolyte / electrode interface, resulting in high interfacial impedance and even the risk of short circuits due to dendrite growth. Furthermore, the mechanical retention and interfacial stability of SN-based electrolytes are still insufficient to support long-term cycling, necessitating improvements through the construction of interfacial stabilizing layers or the introduction of synergistic systems.

[0005] Current research indicates that ion conduction and interfacial chemical stability of solid-state electrolytes can be effectively improved through multi-lithium salt synergy, solvation regulation, and in-situ polymerization strategies. Lithium nitrate (LiNO3) stands out for its ability to form a stable SEI layer rich in Li3N, demonstrating excellent interfacial stabilization properties. However, its low solubility and uneven dispersion in polymer matrices limit its application in solid-state systems. Furthermore, traditional thermosetting methods are inefficient and have long preparation cycles, making them unsuitable for large-scale applications.

[0006] Therefore, there is an urgent need to develop a novel dual-salt polymer solid electrolyte with good interface stability, rapid curing capability, and suitability for lithium metal batteries, so as to improve the safety performance and application reliability of solid-state batteries. Summary of the Invention

[0007] Based on the technical problems existing in the background technology, this invention proposes an in-situ photocurable dual-salt polymer solid electrolyte and its preparation method, as well as a lithium-ion battery, to achieve effective control of the interface behavior of lithium-ion batteries and lithium metal batteries, thereby improving the cycle stability and reliability of the whole system under room temperature conditions.

[0008] The present invention proposes a method for preparing an in-situ photocurable dual-salt polymer solid electrolyte, the method steps of which are as follows: S1: Lithium nitrate is dissolved in a solvent under an inert atmosphere to obtain a lithium nitrate solution; S2: Mix the polymer monomer, crosslinking agent, film-forming agent and succinate, add lithium bis(trifluoromethanesulfonylimide) and photoinitiator, mix well and then add lithium nitrate solution to obtain a dual-salt polymer solid electrolyte precursor solution. S3: Immerse the membrane in the precursor solution of the dual-salt polymer solid electrolyte, remove the membrane and cure it under ultraviolet light to obtain the dual-salt polymer solid electrolyte.

[0009] Preferably, the solvent is one or more selected from dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, tetraethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; And / or, the mass ratio of lithium nitrate to solvent is 0.1-0.2:1.

[0010] Preferably, the mass ratio of polymeric monomer to crosslinking agent is 0.8-1.2:1, and the amount of crosslinking agent added is 5-10% of the total mass of the precursor solution; And / or, the amount of LiNO3 added is 1-5 wt% relative to the total mass of the precursor solution.

[0011] Preferably, the polymerization monomer is one or more of the following acrylate or methacrylate monomers: ethyl acrylate, methyl acrylate, butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, etc.

[0012] Preferably, the crosslinking agent is one or more of the following multifunctional acrylate crosslinking agents: ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol tri / tetraacrylate, etc.

[0013] Preferably, the film-forming agent is one or more of lithium anode interface film-forming agents such as fluoroethylene carbonate, vinylene carbonate, dimethyl fluorocarbonate, and difluoroethylene carbonate. And / or, the amount of film-forming agent added is 1-5 wt% of the total mass of the precursor solution.

[0014] Preferably, the photoinitiator is one or more of the following pyrolysis-type photoinitiators: diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylacetone-1, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide. And / or, the amount of photoinitiator added is 0.5-2 wt% of the total mass of the precursor solution.

[0015] Preferably, the wavelength of the ultraviolet light is 320-420 nm, and the irradiation intensity is 10-20 mW·cm. -2 .

[0016] The present invention proposes an in-situ photocurable dual-salt polymer solid electrolyte, which is prepared by the above-described preparation method.

[0017] The present invention proposes a lithium-ion battery comprising the above-mentioned in-situ photocured dual-salt polymer solid electrolyte.

[0018] Beneficial technical effects of the present invention: 1. The in-situ dual-salt photocuring preparation route used in this invention is simple to operate, has a fast curing speed, and low material cost, and can obtain a polymer solid electrolyte with a uniform structure in a short time. This electrolyte system has a significant promoting effect on improving the cycle durability of solid-state lithium batteries under room temperature conditions.

[0019] 2. This invention utilizes DMSO to construct a stable solvation structure, significantly improving the dispersibility and solubility of LiNO3 in polymer systems; simultaneously, the composite SEI formed at the interface of the LiTFSI / LiNO3 dual-salt system effectively enhances the dispersibility of LiNO3. + Migration uniformity. The resulting solid electrolyte can form a tight contact interface with the electrode, possessing both a wide electrochemical stability range and excellent interfacial compatibility. It can also form a dense and stable interfacial film on the lithium anode surface, thereby suppressing side reactions.

[0020] 3. In traditional SN-type solid electrolytes, SN reacts violently with metallic lithium, causing rapid interfacial instability. The dual-salt regulation strategy proposed in this invention can mitigate the aforementioned adverse reactions. The Li3N / inorganic SEI structure formed by LiNO3 can effectively block chemical erosion of the lithium surface, allowing the electrolyte to maintain structural integrity during cycling and fundamentally reducing the risk of interfacial damage.

[0021] 4. The solid-state lithium battery based on the electrolyte system of this invention exhibits excellent cycle life at room temperature, which helps to improve the actual reliability of the battery in high-safety-level applications (such as energy storage systems and power batteries). Attached Figure Description

[0022] Figure 1 XPS spectra and peak division results of solid electrolytes prepared under different LiNO3 addition amounts (0-5wt%, relative to the total mass of the precursor solution) proposed in this invention at different etching depths at the negative electrode interface after cycling, including the N1s and F1s regions.

[0023] Figure 2 This is a comparison of the lithium deposition / stripping stability of the liquid electrolyte proposed in this invention and different solid electrolytes in lithium symmetric batteries; Figure 3 This is a comparison chart of the exchange current density of the solid electrolyte proposed in this invention; Figure 4 The graph shows the lithium-ion transference number test results of the solid electrolyte proposed in this invention. Figure 5 This is a comparison diagram of the oxidative decomposition potentials of the solid electrolyte proposed in this invention; Figure 6 A comparison diagram of the interface impedance of the NCM811 / Li coin cell proposed in this invention; Figure 7 This is a comparison chart of the cycle performance of the NCM811 / Li coin cell proposed in this invention; Figure 8 This is a comparison of the heat flow curves of the solid electrolyte and lithium metal anode proposed in this invention. Detailed Implementation

[0024] The present invention will be further explained below with reference to specific embodiments.

[0025] In an argon-filled glove box environment (O2 and H2O content both <1ppm), weigh 0.18g of LiNO3 and add it to 1mL of dimethyl sulfoxide (DMSO). Stir at 500rpm for 12h at room temperature until it is completely dissolved and forms a transparent and homogeneous LiNO3 solution for later use.

[0026] Example 1 0.178 g of ethyl acrylate (EA), 0.178 g of ethylene glycol dimethacrylate (EGDMA) and 0.018 g of fluoroethylene carbonate (FEC) were added to 0.9 g of succinate (SN) and stirred to form a homogeneous and transparent solution. Then, 0.54 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.02 g of photoinitiator TPO were added to the solution and stirred at room temperature until completely dissolved. Finally, 0.498 g of LiNO3 solution was added dropwise and stirred at 1000 rpm for 5 min to obtain a dual-salt polymer solid electrolyte precursor solution.

[0027] The glass fiber membrane was immersed in a dual-salt polymer solid electrolyte precursor solution to ensure it was fully wetted. Then, the wetted glass fiber membrane was irradiated under an ultraviolet light source for about 30 seconds to allow the precursor system to rapidly crosslink and solidify, resulting in a transparent dual-salt polymer solid electrolyte.

[0028] Example 2 0.191 g of ethyl acrylate (EA), 0.178 g of ethylene glycol dimethacrylate (EGDMA) and 0.018 g of fluoroethylene carbonate (FEC) were added to 0.9 g of succinate (SN) and stirred to form a homogeneous and transparent solution. Then, 0.54 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.02 g of photoinitiator TPO were added to the solution and stirred at room temperature until completely dissolved. Finally, 0.498 g of LiNO3 solution was added dropwise and stirred at 1000 rpm for 5 min to obtain a dual-salt polymer solid electrolyte precursor solution.

[0029] The glass fiber membrane was immersed in a dual-salt polymer solid electrolyte precursor solution to ensure it was fully wetted. Then, the wetted glass fiber membrane was irradiated under an ultraviolet light source for about 30 seconds to allow the precursor system to rapidly crosslink and solidify, resulting in a transparent dual-salt polymer solid electrolyte.

[0030] Example 3 0.160 g of ethyl acrylate (EA), 0.178 g of ethylene glycol dimethacrylate (EGDMA) and 0.018 g of fluoroethylene carbonate (FEC) were added to 0.9 g of succinate (SN) and stirred to form a homogeneous and transparent solution. Then, 0.54 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.025 g of photoinitiator TPO were added to the solution and stirred at room temperature until completely dissolved. Finally, 0.498 g of LiNO3 solution was added dropwise and stirred at 1000 rpm for 5 min to obtain a dual-salt polymer solid electrolyte precursor solution.

[0031] The glass fiber membrane was immersed in a dual-salt polymer solid electrolyte precursor solution to ensure it was fully wetted. Then, the wetted glass fiber membrane was irradiated under an ultraviolet light source for about 30 seconds to allow the precursor system to rapidly crosslink and solidify, resulting in a transparent dual-salt polymer solid electrolyte.

[0032] Comparative Example 1 The difference between this comparative example and Example 1 is that LiNO3 is not added; all other conditions are the same as in Example 1.

[0033] Comparative Example 2 The difference between this comparative example and Example 1 is that the amount of LiNO3 solution added was adjusted from 0.498g in Example 1 to 0.140g; all other conditions are the same as in Example 1.

[0034] Comparative Example 3 The difference between this comparative example and Example 1 is that the amount of LiNO3 solution added was adjusted from 0.498g in Example 1 to 1.012g; all other conditions are the same as in Example 1.

[0035] Comparative Example 4 This comparative example uses a baseline liquid electrolyte system, with a commercially available electrolyte as a reference: 1 mol / L LiPF6 / EC:DEC = 1:1 (mass ratio) commercially available electrolyte.

[0036] NCM811 positive electrode active material, acetylene black conductive agent and PVDF binder were mixed and ground evenly at a ratio of 8:1:1 (mass ratio); an appropriate amount of NMP was added to prepare a slurry, and the slurry was stirred until it was stable and free of particles; the slurry was evenly coated onto an aluminum foil current collector through a 200μm doctor blade, dried under vacuum at 80℃ for 12h, rolled into sheets and cut into circular electrodes for later use.

[0037] Inside a glove box, the positive electrode, the solid electrolyte prepared in Examples 1 and Comparative Examples 1-4, and the lithium metal negative electrode were placed sequentially in a CR2032 button casing and sealed using a sealing machine. After the battery was sealed, it was left to stand in the glove box for a period of time to allow the solid electrolyte to fully contact the electrode interface. This solid-state battery can be used for subsequent testing.

[0038] Figure 1 XPS spectra and peak division results of solid electrolytes prepared under different LiNO3 addition amounts (0-5 wt%, relative to the total mass of the precursor solution) proposed in this invention at different etching depths at the negative electrode interface after cycling, including the N 1s and F 1s regions. In Example 1, the N 1s spectral region corresponds to the nitrogen-containing inorganic component (LiN... x The characteristic peaks of LiNxOy and Li3Nx were most prominent, indicating the formation of a stable and dense interfacial inert layer under appropriate LiNOx conditions. In Comparative Example 1 (without LiNOx), the nitrogen-containing species signal was weak, and the interface was dominated by organic decomposition products, lacking an effective protective layer. Comparative Example 2 (low concentration LiNOx) showed some nitrogen-containing inorganic components, but the interfacial structure was still incomplete. In Comparative Example 3 (high concentration LiNOx), the relevant inorganic components tended to increase, but the increase was limited. Furthermore, in the F1s spectral region, Example 1 exhibited a higher proportion of stable inorganic products such as LiNxOy and LiF. The results indicate that, in the presence of both LiTFSI and FEC, the introduction of an appropriate amount of LiNOx can construct a LiNx-based inert layer on the lithium anode surface. x A stable interface layer characterized by Oy, Li3N, and LiF groups effectively inhibits the decomposition reactions of succinate and LiTFSI, and improves interface stability.

[0039] Figure 2 The Li||Li symmetric cells assembled in Example 1 and Comparative Examples 1-4 at 2mA·cm -2 Cyclic stability curves at current density. It can be seen that Example 1 exhibits the lowest and most stable polarization voltage, with almost no significant fluctuations during cycling, indicating optimal interface stability. Comparative Example 1 (without LiNO3) and Comparative Example 2 (low concentration of LiNO3) both show significant voltage oscillations and increased polarization, indicating poor interface stability. Comparative Examples 3 and 4 show even more pronounced polarization voltage fluctuations during cycling, which continuously increase over time, exhibiting typical characteristics of interface instability. Therefore, the dual-salt photocurable solid electrolyte with an appropriate amount of LiNO3 (Example 1) demonstrates optimal interface stability and cycling performance at high current densities.

[0040] Figure 3 This is a comparison of the exchange current density of the solid / liquid electrolytes prepared in Example 1 and Comparative Examples 1-4. As can be seen from the figure, the curve corresponding to Example 1 has the steepest slope, indicating that it has the highest exchange current density and the strongest interfacial charge transfer capability, which is beneficial to Li… + Uniform deposition and stripping on the electrode surface. Comparative Example 1 (no LiNO3), Comparative Example 3 (high concentration LiNO3), and Comparative Example 4 (liquid electrolyte) all exhibited low exchange current densities, indicating limited interfacial kinetics; the improvement in Comparative Example 2 (low concentration LiNO3) was limited and still lower than that in Example 1. This shows that solvation regulation of an appropriate amount of LiNO3 in the solid system can more effectively improve interfacial reactivity. Therefore, the photocurable dual-salt solid electrolyte of Example 1 has the best performance in terms of interfacial kinetics.

[0041] Figure 4 The results show the lithium-ion transport number (LTU) test results for the solid / liquid electrolytes of Examples 1 and 1-4. Example 1 showed an excellent LTU of 0.824. After introducing lithium nitrate, the LTU of the system decreased slightly compared to Comparative Example 1 (without LiNO3) and Comparative Example 2 (low concentration LiNO3). This can be attributed to the weaker lithium-ion conduction kinetics after lithium nitrate dissociation compared to the base lithium salt. Even with this slight decrease, the LTU still meets the performance requirements for efficient lithium-ion transport in energy storage devices. With increasing lithium nitrate content, the LTU of Comparative Example 3 (high concentration LiNO3) continued to decrease, while Comparative Example 4 (liquid electrolyte) exhibited the lowest LTU. These results demonstrate that the dual-salt photocurable solid electrolyte can achieve efficient selective lithium-ion transport.

[0042] Figure 5Linear sweep voltammetry plots of Example 1 and Comparative Examples 1-4 are shown to evaluate the electrochemical stability window of the electrolyte. As can be seen from the figures, the oxidation decomposition potential of Example 1 is higher than that of the other comparative systems, indicating that the synergistic effect of an appropriate amount of LiNO3 and the EA / EGDMA photocurable network can improve the antioxidant stability of the electrolyte. The introduction of DMSO has a slight effect on the oxidation potential, but the oxidation potential of Example 1 is still higher than 4.8V. The results show that the dual-salt photocurable solid electrolyte of Example 1 is suitable for high-voltage cathode systems.

[0043] Figure 6 The figure shows the AC impedance spectra of the NCM811 / Li coin cells assembled in Example 1 and Comparative Examples 1-4. As can be seen from the figure, Example 1 has the lowest overall impedance. Figure 1 The conclusions indicate that the stable solvation structure constructed with an appropriate amount of LiNO3 can effectively reduce interfacial impedance and improve the contact compatibility between the solid electrolyte and the cathode material. Comparative Example 1 (without LiNO3) and Comparative Example 3 (high concentration of LiNO3) both exhibited higher impedance, indicating limited interfacial reaction kinetics; Comparative Example 2 (low concentration of LiNO3) showed some improvement, but was still significantly higher than Example 1. Comparative Example 4 (liquid electrolyte) showed a large impedance change in the low-frequency range, indicating poor interfacial stability. The results demonstrate that the dual-salt photocurable solid electrolyte of Example 1 has significant advantages in both interfacial contact and ion transport.

[0044] Figure 7 This figure compares the cycling performance of the NCM811 / Li coin cells assembled in Example 1 and Comparative Examples 1-4 at room temperature. As shown in the figure, Example 1 exhibits the highest capacity retention and the slowest capacity decay during cycling, demonstrating the best cycling stability. Comparative Examples 1 (without LiNO3) and 3 (high concentration of LiNO3) both showed significant and rapid capacity decline in the later stages of cycling, indicating insufficient interfacial stability. Comparative Example 2 (low concentration of LiNO3) showed some improvement, but its stability was still lower than that of Example 1. Comparative Example 4 (liquid electrolyte) showed even more significant capacity decay during long-term cycling, making it difficult to maintain stable output. The results indicate that an appropriate amount of LiNO3 combined with a photocurable polymer network can effectively enhance interfacial stability, thereby significantly improving the cycle life of solid-state batteries at room temperature.

[0045] Figure 8This figure compares the thermal stability of Example 1 with that of Comparative Examples 1-4, using a lithium metal anode. As can be seen from the figure, the thermal stability of Example 1 is significantly improved compared to Comparative Example 4 (liquid electrolyte), exhibiting a higher heat release onset temperature, a lower peak heat flux, and a shorter heat generation range. The thermal stability of the other comparative examples is basically similar to that of the Example 1. The results indicate that an appropriate amount of LiNO3 combined with a photocurable polymer network can effectively improve the thermal stability of the solid electrolyte, thereby significantly improving the cycle life of the solid-state battery at room temperature.

[0046] In summary, this invention proposes an in-situ photocurable dual-salt polymer solid electrolyte. By introducing a LiNO3-DMSO solvation structure and a LiTFSI / LiNO3 dual-salt system, combined with an EA / EGDMA photocuring network, the electrolyte effectively suppresses interfacial side reactions while maintaining excellent thermal stability. An appropriate amount of LiNO3 can form a stable interfacial environment in the photocurable electrolyte system, thereby reducing polarization, increasing lithium-ion transference number, and enhancing the interfacial compatibility between the electrolyte and the electrode. The solid electrolyte prepared by this invention exhibits good cycle stability, lower interfacial impedance, and a wider electrochemical stability window in both lithium symmetric batteries and NCM811 / Li full cells, demonstrating its performance advantages. The photocurable dual-salt solid electrolyte system constructed in this invention features simple preparation, in-situ curing capability, and high interfacial stability, providing a new technical approach for the development of room-temperature solid-state batteries and possessing broad application prospects.

[0047] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application. The scope of this application is defined by the appended claims and their equivalents, all of which should be included within the protection scope of this application.

Claims

1. A method for preparing an in-situ photocurable dual-salt polymer solid electrolyte, characterized in that, The steps are as follows: S1: Lithium nitrate is dissolved in a solvent under an inert atmosphere to obtain a lithium nitrate solution; S2: Mix the polymer monomer, crosslinking agent, film-forming agent and succinate, add lithium bis(trifluoromethanesulfonylimide) and photoinitiator, mix well and then add lithium nitrate solution to obtain a dual-salt polymer solid electrolyte precursor solution. S3: Immerse the membrane in the dual-salt polymer solid electrolyte precursor solution, remove the membrane and cure it under ultraviolet light to obtain the dual-salt polymer solid electrolyte. The amount of lithium nitrate added is 1-5 wt% of the total mass of the precursor solution.

2. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The solvent is one or more of dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, tetraethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; And / or, the mass ratio of lithium nitrate to solvent is 0.1-0.2:

1.

3. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The mass ratio of polymeric monomer to crosslinking agent is 0.8-1.2:1, and the amount of crosslinking agent added is 5-10% of the total mass of the precursor solution.

4. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The polymer monomers are one or more of the following: ethyl acrylate, methyl acrylate, butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, methyl methacrylate, butyl methacrylate, and hydroxyethyl methacrylate.

5. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The crosslinking agent is one or more of ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, and pentaerythritol tri / tetraacrylate.

6. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The film-forming agent is one or more of fluoroethylene carbonate, vinylene carbonate, dimethyl fluorocarbonate, and difluoroethylene carbonate; And / or, the amount of film-forming agent added is 1-5 wt% of the total mass of the precursor solution.

7. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The photoinitiator is one or more of the following: diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methylphenylacetone, 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylacetone-1, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; And / or, the amount of photoinitiator added is 0.5-2 wt% of the total mass of the precursor solution.

8. The method for preparing the in-situ photocurable dual-salt polymer solid electrolyte according to claim 1, characterized in that, The wavelength of ultraviolet light is 320-420 nm, and the irradiation intensity is 10-20 mW·cm. -2 .

9. An in-situ photocurable dual-salt polymer solid electrolyte, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. A lithium-ion battery, characterized in that, It includes the in-situ photocurable dual-salt polymer solid electrolyte as described in claim 9.

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