A flexible solid-state electrolyte membrane and a method of preparing the same

Abstract

The application discloses a kind of flexible solid electrolyte membrane and preparation method thereof, belong to solid battery technical field, specifically related to a kind of preparation method of flexible solid electrolyte membrane, comprising: electrolyte, organic monomer, inorganic electrolyte and initiator are mixed, and electrolytic slurry is obtained;Electrolytic slurry is coated on flexible base film, and crosslinking solidification is obtained, to obtain flexible solid electrolyte membrane.In the application, organic monomer can be polymerized to form polymer electrolyte under the initiation of initiator, flexible base film has loose network structure, can allow inorganic electrolyte to pass through, polymer electrolyte is crosslinked polymerization on flexible base film, polymer electrolyte and flexible base film are crosslinked each other, inorganic electrolyte and electrolyte are dispersed in the crosslinked polymerization structure of polymer electrolyte and flexible base film.The application is a kind of flexible solid electrolyte membrane and preparation method thereof with good conductivity, good charge-discharge performance after being made into battery.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology, specifically relating to a flexible solid-state electrolyte membrane and its preparation method. Background Technology

[0002] Solid-state batteries have attracted widespread attention due to their high energy density and safety. Among these, solid-state electrolytes, as a key component of solid-state batteries, have garnered significant research interest. Among the various solid-state electrolytes available, composite solid-state electrolytes, which combine the advantages of inorganic and polymer electrolytes, show promising prospects for industrial applications. However, composite solid-state electrolytes generally suffer from low ionic conductivity and poor mechanical properties, making it difficult to meet the high-rate and stable cycling requirements of solid-state batteries.

[0003] Traditional composite electrolytes involve adding a small amount (≤10%) of inorganic electrolyte particles to a polymer electrolyte, which can improve ionic conductivity to some extent. However, the ionic conductivity still cannot meet the fast-charging requirements of solid-state batteries. Furthermore, a small amount of inorganic electrolyte is still insufficient to suppress the formation and continuous growth of lithium dendrites during charge-discharge cycles. On the other hand, adding a high proportion of inorganic electrolyte can lead to poor electrolyte flexibility. Summary of the Invention

[0004] The purpose of this invention is to provide a flexible solid electrolyte membrane with good conductivity and good charge / discharge performance after being made into a battery, and a method for preparing the same.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0006] A method for preparing a flexible solid electrolyte membrane includes: mixing an electrolyte, an organic monomer, an inorganic electrolyte, and an initiator to obtain an electrolyte slurry; coating the electrolyte slurry onto a flexible base membrane, and then cross-linking and curing it to obtain a flexible solid electrolyte membrane; the electrolyte contains LiPF6, and the concentration of LiPF6 in the electrolyte is 1-3M. This invention uses a polymer electrolyte, an inorganic electrolyte, and an electrolyte to prepare a flexible solid electrolyte membrane. If the amount of polymer electrolyte used is too small, a flexible solid electrolyte membrane cannot be prepared; if the amount of inorganic electrolyte used is too large, it will lead to poor flexibility. By reasonably dispersing the polymer electrolyte and inorganic electrolyte in the electrolyte, a flexible solid electrolyte membrane with good conductivity and good flexibility is prepared.

[0007] Preferably, the electrolyte also contains EC and DMC, and the volume ratio of EC to DMC in the electrolyte is 1:0.5-2.

[0008] Preferably, the organic monomers include acrylate monomers and / or vinylene carbonate monomers, wherein the acrylate monomers include at least one of ethoxylated trimethylolpropane triacrylate, polyethylene glycol diacrylate, polyethylene glycol methacrylate, and triethylene glycol dimethacrylate.

[0009] More preferably, the organic monomer is ethoxylated trimethylolpropane triacrylate, and the mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate is 1:0.4-2.

[0010] Preferably, the organic monomers include 2-phenoxyethyl acrylate and 2-methylallyl sulfonate. This invention uses 2-phenoxyethyl acrylate and 2-methylallyl sulfonate in combination with ethoxylated trimethylolpropane triacrylate to prepare a polymer electrolyte. Different monomers synthesize polymer electrolytes with different effects on the flexible solid electrolyte membrane. In this invention, the polymer electrolyte prepared from 2-phenoxyethyl acrylate, 2-methylallyl sulfonate, and ethoxylated trimethylolpropane triacrylate, in conjunction with the inorganic electrolyte and electrolyte solution, can improve the conductivity of the flexible solid electrolyte membrane, resulting in improved charge-discharge performance after being fabricated into a battery.

[0011] Preferably, the inorganic electrolyte includes at least one of oxide electrolytes, sulfide electrolytes, and halide electrolytes.

[0012] Preferably, additives are also added during the preparation of the electrolytic slurry, including at least one of cyclic carbonates, organic sulfates, sulfonates, and lithium salts.

[0013] Preferably, the initiator includes a photoinitiator or a thermal initiator.

[0014] This invention discloses a flexible solid electrolyte membrane prepared by the above method.

[0015] The present invention discloses a battery comprising the above-described flexible solid electrolyte membrane.

[0016] Preferably, the battery includes a positive electrode, an electrolyte membrane, and a negative electrode stacked together. The positive electrode and the flexible base membrane are stacked sequentially from bottom to top. After coating the flexible base membrane with a slurry containing electrolyte, polymer monomer, inorganic electrolyte, and initiator, the negative electrode is covered, and the battery is obtained by in-situ crosslinking and curing.

[0017] Preferably, in the preparation of the flexible solid electrolyte membrane, the electrolyte, organic monomer, inorganic electrolyte and initiator are mixed to obtain an electrolyte slurry; the electrolyte slurry is coated on a flexible base membrane and then crosslinked and cured to obtain the flexible solid electrolyte membrane.

[0018] Preferably, in the preparation of the flexible solid electrolyte membrane, the electrolyte, organic monomer and additive are mixed and stirred for 10-60 min to prepare an electrolyte mixture; an inorganic electrolyte is added to the electrolyte mixture and stirred for 4-12 h, then an initiator is added and stirred for 3-10 min to prepare an electrolyte slurry; the electrolyte slurry is coated onto a flexible base membrane to ensure uniform distribution on the flexible base membrane, and then cross-linked and cured to prepare the flexible solid electrolyte membrane.

[0019] More preferably, in the preparation of the flexible solid electrolyte membrane, the electrolyte is composed of a mixture of LiPF6, EC and DMC, the concentration of LiPF6 in the electrolyte is 1-3M, and the volume ratio of EC to DMC in the electrolyte is 1:0.5-2.

[0020] More preferably, in the preparation of the flexible solid electrolyte membrane, the organic monomers include acrylate monomers and / or vinylene carbonate monomers, and the acrylate monomers include at least one of ethoxylated trimethylolpropane triacrylate (ETPTA), polyethylene glycol diacrylate (PEGDA), polyethylene glycol methacrylate (PEGMA), and triethylene glycol dimethacrylate (TEGDA).

[0021] More preferably, in the preparation of the flexible solid electrolyte membrane, the additives include at least one of cyclic carbonates, organic sulfates, sulfonates, and lithium salts; the cyclic carbonates include fluoroethylene carbonate (FEC) or vinylene carbonate (VC); the organic sulfates include ethylene sulfate (DTD); the sulfonates include 1,3-propenesulfonyl lactone (PST), 1,4-butanesulfonyl lactone (BS), or methanedisulfonate methylene (MMDS); and the lithium salts include lithium difluorophosphate (LiPO2F2), lithium bis(oxalato)borate (LiBOB), or lithium difluorooxalato)borate (LiDFOB).

[0022] More preferably, in the preparation of the flexible solid electrolyte membrane, the inorganic electrolyte includes at least one of oxide electrolyte, sulfide electrolyte and halide electrolyte; the inorganic electrolyte includes lithium lanthanum zirconium tantalum oxide (LLZTO), and the particle size of the inorganic electrolyte is preferably 300-800 nm.

[0023] More preferably, in the preparation of the flexible solid electrolyte membrane, the initiator includes a photoinitiator or a thermal initiator; the photoinitiator includes 2-hydroxy-2-methyl-1-phenyl-1-propanone (HMPP); the thermal initiator includes azobisisobutyronitrile (AIBN).

[0024] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, the organic monomer is ethoxylated trimethylolpropane triacrylate, and the mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate is 1:0.4-2.

[0025] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, the additive is fluoroethylene carbonate (FEC), and the mass ratio of LiPF6 to fluoroethylene carbonate is 1:0.66.

[0026] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, the inorganic electrolyte is lithium lanthanum zirconium tantalum oxide (LLZTO), the particle size of the lithium lanthanum zirconium tantalum oxide is 500 nm, and the mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide is 1:3-10.

[0027] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, the initiator is azobisisobutyronitrile (AIBN), and the mass ratio of LiPF6 to azobisisobutyronitrile is 1:0.01-0.05.

[0028] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, and in the crosslinking and curing process, the initiator is the thermal initiator azobisisobutyronitrile, the crosslinking and curing temperature is 60-80℃, and the crosslinking and curing time is 1-4h.

[0029] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, and the organic monomers also include 2-phenoxyethyl acrylate and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate is 1:0.4-2, the mass ratio of LiPF6 to 2-phenoxyethyl acrylate is 1:0.01-0.1, and the mass ratio of LiPF6 to 2-methylallyl sulfonate is 1:0.01-0.1.

[0030] More preferably, in the preparation of the flexible solid electrolyte membrane, the amount of electrolyte used is measured by the amount of LiPF6 used, and the organic monomer also includes glycerol allyl ether, with a mass ratio of LiPF6 to glycerol allyl ether of 1:0.01-0.06. In the preparation of the flexible solid electrolyte membrane, the organic monomer can also include glycerol allyl ether. In the presence of 2-phenoxyethyl acrylate, 2-methylallyl sulfonate, and ethoxylated trimethylolpropane triacrylate, the addition of glycerol allyl ether further improves the conductivity of the flexible solid electrolyte membrane. This indicates that the polymer electrolyte containing glycerol allyl ether and the structures of 2-phenoxyethyl acrylate, 2-methylallyl sulfonate, and ethoxylated trimethylolpropane triacrylate can conduct electricity better under the action of inorganic electrolyte and electrolyte. After the flexible solid electrolyte membrane is prepared into a battery, the charge and discharge performance of the battery is improved.

[0031] This invention employs a method of mixing an electrolyte, organic monomers, and additives to prepare an electrolyte mixture; adding an inorganic electrolyte and an initiator to the electrolyte mixture to prepare an electrolyte slurry; and then coating the electrolyte slurry onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thereby preparing a flexible solid electrolyte membrane. The electrolyte contains LiPF6, EC, and DMC; the organic monomers include ethoxylated trimethylolpropane triacrylate; the additives include fluoroethylene carbonate; the inorganic electrolyte is lithium lanthanum zirconium tantalum oxide; and the initiator is azobisisobutyronitrile. The organic monomers can polymerize under the initiator to form a polymer electrolyte. The flexible base membrane has a loose network structure that allows the inorganic electrolyte to pass through. The polymer electrolyte cross-links and polymerizes on the flexible base membrane, and there is mutual cross-linking between the polymer electrolyte and the flexible base membrane. The inorganic electrolyte and electrolyte are dispersed within the cross-linked polymer structure of the polymer electrolyte and the flexible base membrane. Therefore, this invention has the following beneficial effects: the flexible solid electrolyte has good conductivity, resulting in good charge and discharge performance after being made into a battery. Therefore, the present invention relates to a flexible solid electrolyte membrane with good conductivity and good charge-discharge performance after being made into a battery, and a method for preparing the same. Attached Figure Description

[0032] Figure 1 This is a graph showing the ionic conductivity at room temperature.

[0033] Figure 2 This is a discharge capacity diagram. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0036] Example 1: A method for preparing a flexible solid electrolyte

[0037] Preparation of flexible solid electrolyte: The electrolyte, organic monomer and additives are mixed and stirred for 30 min to prepare an electrolyte mixture; the inorganic electrolyte is added to the electrolyte mixture and stirred for 8 h, then the initiator is added and stirred for 5 min to prepare an electrolyte slurry; the electrolyte slurry is coated onto a flexible base film to make the electrolyte slurry uniformly distributed on the flexible base film, crosslinked and cured to prepare a flexible solid electrolyte membrane. The electrolyte is a mixture of LiPF6, EC, and DMC, with a LiPF6 concentration of 1M and a volume ratio of EC to DMC of 1:1. The amount of electrolyte used is measured by the amount of LiPF6 used. The organic monomer is ethoxylated trimethylolpropane triacrylate, with a LiPF6 to ethoxylated trimethylolpropane triacrylate mass ratio of 1:1.32. The additive is fluoroethylene carbonate, with a LiPF6 to fluoroethylene carbonate mass ratio of 1:0.66. The inorganic electrolyte is lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm and a LiPF6 to lithium lanthanum zirconium tantalum oxide mass ratio of 1:5.92. The initiator is azobisisobutyronitrile (AIBN), with a LiPF6 to AIBN mass ratio of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile is used, the crosslinking and curing temperature is 70℃, and the crosslinking and curing time is 2 hours.

[0038] Example 2: A method for preparing a flexible solid electrolyte

[0039] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.08, and the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.09. The additive was fluoroethylene carbonate, with a mass ratio of LiPF6 to fluoroethylene carbonate of 1:0.66. The inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and a mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide of 1:5.92. The initiator was azobisisobutyronitrile, with a mass ratio of LiPF6 to azobisisobutyronitrile of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0040] Example 3: A method for preparing a flexible solid electrolyte

[0041] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.08, and the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.02. The additive was fluoroethylene carbonate, with a mass ratio of LiPF6 to fluoroethylene carbonate of 1:0.66. The inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and a mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide of 1:5.92. The initiator was azobisisobutyronitrile, with a mass ratio of LiPF6 to azobisisobutyronitrile of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0042] Example 4: A method for preparing a flexible solid electrolyte

[0043] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.03, the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.09, the additive was fluoroethylene carbonate, and the mass ratio of LiPF6 to fluoroethylene carbonate was 1:0.66; the inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and the mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide was 1:5.92; the initiator was azobisisobutyronitrile, and the mass ratio of LiPF6 to azobisisobutyronitrile was 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0044] Example 5: A method for preparing a flexible solid electrolyte

[0045] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.03, and the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.02. The additive was fluoroethylene carbonate, with a mass ratio of LiPF6 to fluoroethylene carbonate of 1:0.66. The inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and a mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide of 1:5.92. The initiator was azobisisobutyronitrile, with a mass ratio of LiPF6 to azobisisobutyronitrile of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0046] Example 6: A method for preparing a flexible solid electrolyte

[0047] The electrolyte is a mixture of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte is 1M, and the volume ratio of EC to DMC in the electrolyte is 1:1. The amount of electrolyte used is measured by the amount of LiPF6 used. The organic monomers are ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, 2-methylallyl sulfonate ammonium chloride, and glyceryl allyl ether. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate is 1:1.32. The mass ratio of LiPF6 to 2-methylallylsulfonic acid amine was 1:0.08, the mass ratio of LiPF6 to glyceryl allyl ether was 1:0.02, the additive was fluoroethylene carbonate, and the mass ratio of LiPF6 to fluoroethylene carbonate was 1:0.66; the inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and the mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide was 1:5.92; the initiator was azobisisobutyronitrile, and the mass ratio of LiPF6 to azobisisobutyronitrile was 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0048] Example 7: A method for preparing a flexible solid electrolyte

[0049] The electrolyte is a mixture of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte is 1M, and the volume ratio of EC to DMC in the electrolyte is 1:1. The amount of electrolyte used is measured by the amount of LiPF6 used. The organic monomers are ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, 2-methylallyl sulfonate ammonium chloride, and glyceryl allyl ether. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate is 1:1.32. The mass ratio of LiPF6 to 2-methylallylsulfonic acid amine was 1:0.08, the mass ratio of LiPF6 to glyceryl allyl ether was 1:0.05, the additive was fluoroethylene carbonate, and the mass ratio of LiPF6 to fluoroethylene carbonate was 1:0.66; the inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and the mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide was 1:5.92; the initiator was azobisisobutyronitrile, and the mass ratio of LiPF6 to azobisisobutyronitrile was 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0050] Comparative Example 1: A method for preparing a flexible solid electrolyte

[0051] Preparation of flexible solid electrolyte: The electrolyte, organic monomer and additives are mixed and stirred for 30 min to prepare an electrolyte mixture; the inorganic electrolyte is added to the electrolyte mixture and stirred for 8 h, then the initiator is added and stirred for 5 min to prepare an electrolyte slurry; the electrolyte slurry is coated onto a flexible base film to make the electrolyte slurry uniformly distributed on the flexible base film, crosslinked and cured to prepare a flexible solid electrolyte membrane. The electrolyte is a mixture of LiPF6, EC, and DMC, with a LiPF6 concentration of 1M and a volume ratio of EC to DMC of 1:1. The amount of electrolyte used is measured by the amount of LiPF6 used. The organic monomer is ethoxylated trimethylolpropane triacrylate, with a LiPF6 to ethoxylated trimethylolpropane triacrylate mass ratio of 1:0.2. The additive is fluoroethylene carbonate, with a LiPF6 to fluoroethylene carbonate mass ratio of 1:0.66. The inorganic electrolyte is lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm and a LiPF6 to lithium lanthanum zirconium tantalum oxide mass ratio of 1:5.92. The initiator is azobisisobutyronitrile (AIBN), with a LiPF6 to AIBN mass ratio of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile is used, the crosslinking and curing temperature is 70℃, and the crosslinking and curing time is 2 hours.

[0052] Comparative Example 2: A method for preparing a flexible solid electrolyte

[0053] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.08, and the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.006. The additive was fluoroethylene carbonate, with a mass ratio of LiPF6 to fluoroethylene carbonate of 1:0.66. The inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and a mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide of 1:5.92. The initiator was azobisisobutyronitrile, with a mass ratio of LiPF6 to azobisisobutyronitrile of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0054] Comparative Example 3: A method for preparing a flexible solid electrolyte

[0055] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.005, the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.09, the additive was fluoroethylene carbonate, and the mass ratio of LiPF6 to fluoroethylene carbonate was 1:0.66; the inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and the mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide was 1:5.92; the initiator was azobisisobutyronitrile, and the mass ratio of LiPF6 to azobisisobutyronitrile was 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0056] Comparative Example 4: A method for preparing a flexible solid electrolyte

[0057] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane, ensuring uniform distribution and cross-linking curing to obtain a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of ethyl acrylate was 1:0.005, the mass ratio of LiPF6 to 2-methylallylsulfonic acid amine was 1:0.006, the additive was fluoroethylene carbonate, and the mass ratio of LiPF6 to fluoroethylene carbonate was 1:0.66; the inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and the mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide was 1:5.92; the initiator was azobisisobutyronitrile, and the mass ratio of LiPF6 to azobisisobutyronitrile was 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0058] Comparative Example 5: A method for preparing a flexible solid electrolyte

[0059] Preparation of flexible solid electrolyte: Electrolyte, organic monomers, and additives were mixed and stirred for 30 min to prepare an electrolyte mixture. Inorganic electrolyte was added to the electrolyte mixture and stirred for 8 h. Then, an initiator was added and stirred for 5 min to prepare an electrolyte slurry. The electrolyte slurry was coated onto a flexible base membrane to ensure uniform distribution and cross-linking curing, thus preparing a flexible solid electrolyte membrane. The electrolyte was composed of LiPF6, EC, and DMC. The concentration of LiPF6 in the electrolyte was 1 M, and the volume ratio of EC to DMC was 1:1. The amount of electrolyte used was measured based on the amount of LiPF6 used. The organic monomers were ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate was 1:1.32. The mass ratio of methyl ethyl acrylate was 1:0.15, and the mass ratio of LiPF6 to 2-methylallyl sulfonamide was 1:0.16. The additive was fluoroethylene carbonate, with a mass ratio of LiPF6 to fluoroethylene carbonate of 1:0.66. The inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, with a particle size of 500 nm, and a mass ratio of LiPF6 to lithium lanthanum zirconium tantalum oxide of 1:5.92. The initiator was azobisisobutyronitrile, with a mass ratio of LiPF6 to azobisisobutyronitrile of 1:0.02. During crosslinking and curing, the thermal initiator azobisisobutyronitrile was used, the crosslinking and curing temperature was 70℃, and the crosslinking and curing time was 2 hours.

[0060] Experimental example:

[0061] In this invention, flexible solid-state electrolytes prepared in various embodiments and comparative examples were assembled into blocking batteries with a stainless steel / electrolyte / stainless steel structure, and impedance tests were performed. The results of room temperature ionic conductivity are as follows: Figure 1As shown, S1 is Example 1, S2 is Example 2, S3 is Example 3, S4 is Example 4, S5 is Example 5, S6 is Example 6, S7 is Example 7, D1 is Comparative Example 1, D2 is Comparative Example 2, D3 is Comparative Example 3, D4 is Comparative Example 4, and D5 is Comparative Example 5. In this invention, an electrolyte, organic monomer, and additives are mixed to prepare an electrolyte mixture; an inorganic electrolyte and an initiator are added to the electrolyte mixture and mixed to prepare an electrolyte slurry; the electrolyte slurry is coated onto a flexible base film, so that the electrolyte slurry is coated onto the flexible base film. A flexible solid electrolyte membrane was prepared by uniform distribution and cross-linking curing. The electrolyte contained LiPF6, EC, and DMC. The organic monomers included ethoxylated trimethylolpropane triacrylate, and the additives included fluoroethylene carbonate. The inorganic electrolyte was lithium lanthanum zirconium tantalum oxide, and the initiator was azobisisobutyronitrile. The organic monomers could polymerize under the initiation of the initiator to form a polymer electrolyte. The flexible base membrane had a loose network structure that allowed the inorganic electrolyte to pass through. The polymer electrolyte cross-linked and polymerized on the flexible base membrane, and there was cross-linking between the polymer electrolyte and the flexible base membrane. The organic electrolyte and electrolyte solution are dispersed in the cross-linked polymer structure of the polymer electrolyte and the flexible base membrane. When preparing the polymer electrolyte using organic monomers, the amount of organic monomers used should not be too low. If the amount of organic monomers is too low, a flexible solid electrolyte membrane cannot be prepared. In the polymerization of the polymer electrolyte, 2-phenoxyethyl acrylate and 2-methylallyl sulfonate amine can also be added to the organic monomers. Under reasonable usage, the conductivity of the flexible solid electrolyte membrane can be improved. If the amount of 2-phenoxyethyl acrylate or 2-methylallyl sulfonate amine used is too low, while the amount of the other is within a suitable range, the conductivity of the flexible solid electrolyte membrane cannot be improved. If the amounts of both 2-phenoxyethyl acrylate and 2-methylallyl sulfonate amine are too low, the conductivity of the flexible solid electrolyte membrane also cannot be improved. In this invention, glycerol allyl ether can be added. With the use of ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate amine in the organic monomers, the use of glycerol allyl ether further improves the conductivity of the flexible solid electrolyte membrane.

[0062] Solid-state battery preparation: Lithium iron phosphate, carbon nanotubes, and polyvinylidene fluoride were premixed at a mass ratio of 8:1:1, and then N-methylpyrrolidone was added. The mixture was then hand-milled for 30 minutes to obtain a uniform positive electrode slurry. This positive electrode slurry was coated onto a carbon-coated aluminum foil current collector and then dried in a vacuum oven at 80°C for 12 hours to obtain the lithium iron phosphate positive electrode. Using lithium iron phosphate as the positive electrode, lithium metal as the negative electrode, and a flexible solid-state electrolyte as the electrolyte, CR2025 coin cells were assembled. The entire assembly process was carried out in an argon-filled glove box. In preparing the CR2025 coin cells, the positive and negative electrodes were used as two plates to apply pressure and evenly distribute the electrolyte slurry on a flexible base film. Crosslinking and curing were then performed according to the crosslinking curing conditions, and finally, the cells were encapsulated to obtain the CR2025 coin cells. The flexible solid-state electrolyte was prepared using the methods described in Examples 1-7 and Comparative Examples 1-3.

[0063] This invention presents constant current charge-discharge tests on CR2025 coin cells prepared from the flexible solid electrolytes of Examples 1-7 and Comparative Examples 1-3 on an electrochemical workstation. The charge-discharge range is 2.5-4.2V, and the rate test current density is 1C. The discharge capacity results are as follows: Figure 2As shown, S1 is Example 1, S2 is Example 2, S3 is Example 3, S4 is Example 4, S5 is Example 5, S6 is Example 6, S7 is Example 7, D1 is Comparative Example 1, D2 is Comparative Example 2, D3 is Comparative Example 3, D4 is Comparative Example 4, and D5 is Comparative Example 5. This invention prepares CR2025... The difference in this invention compared to button cell batteries lies in the preparation of the flexible solid electrolyte. In this invention, an electrolyte, organic monomers, and additives are mixed to prepare an electrolyte mixture. An inorganic electrolyte and an initiator are added to the electrolyte mixture to prepare an electrolyte slurry. The electrolyte slurry is then coated onto a flexible base film, ensuring uniform distribution and cross-linking to obtain a flexible solid electrolyte membrane. The electrolyte contains LiPF6, EC, and DMC. The organic monomers include ethoxylated trimethylolpropane triacrylate, and the additives include fluoroethylene carbonate. The inorganic electrolyte is lithium lanthanum zirconium tantalum oxide, and the initiator is azobisisobutyronitrile. The organic monomers can polymerize under the initiation of the initiator to form a polymer electrolyte. The flexible base film has a loose network structure that allows the inorganic electrolyte to pass through. The polymer electrolyte cross-links and polymerizes on the flexible base film, and the polymer electrolyte and the flexible base film cross-link with each other. The inorganic electrolyte and electrolyte are dispersed within the cross-linked polymer structure of the polymer electrolyte and the flexible base film. When preparing polymer electrolytes through monomer polymerization, the amount of organic monomers used should not be too low. If the amount of organic monomers is too low, a flexible solid electrolyte membrane cannot be prepared, and therefore cannot be used to prepare batteries. In the polymerization of polymer electrolytes, 2-phenoxyethyl acrylate and 2-methylallyl sulfonate can also be added to the organic monomers. Under reasonable usage, the charge-discharge performance of the battery can be improved. If the amount of 2-phenoxyethyl acrylate or 2-methylallyl sulfonate is too low, while the amount of the other is within a suitable range, the charge-discharge performance of the battery cannot be improved. If the amounts of both 2-phenoxyethyl acrylate and 2-methylallyl sulfonate are too low, the charge-discharge performance of the battery cannot be improved either. In this invention, glycerol allyl ether can be added. With the use of ethoxylated trimethylolpropane triacrylate, 2-phenoxyethyl acrylate, and 2-methylallyl sulfonate in the organic monomers, the use of glycerol allyl ether further improves the charge-discharge performance of the battery.

[0064] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0065] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for preparing a flexible solid electrolyte membrane, characterized in that, include: Electrolyte, organic monomer, inorganic electrolyte and initiator are mixed to obtain electrolytic slurry; Electrolytic slurry is coated onto a flexible base membrane and then cross-linked and cured to obtain a flexible solid electrolyte membrane; The electrolyte contains LiPF6, and the concentration of LiPF6 in the electrolyte is 1-3M; The organic monomers include 2-phenoxyethyl acrylate, ethoxylated trimethylolpropane triacrylate, 2-methylallyl sulfonate amine, and glycerol allyl ether. The mass ratio of LiPF6 to ethoxylated trimethylolpropane triacrylate is 1:0.4-2, the mass ratio of LiPF6 to 2-phenoxyethyl acrylate is 1:0.01-0.1, the mass ratio of LiPF6 to 2-methylallyl sulfonate amine is 1:0.01-0.1, and the mass ratio of LiPF6 to glycerol allyl ether is 1:0.01-0.

06.

2. The preparation method according to claim 1, characterized in that, The electrolyte also contains EC and DMC, and the volume ratio of EC to DMC in the electrolyte is 1:0.5-2.

3. The preparation method according to claim 1, characterized in that, The inorganic electrolyte includes at least one of oxide electrolytes, sulfide electrolytes, and halide electrolytes.

4. The preparation method according to claim 1, characterized in that, Additives are also added during the preparation of the electrolytic slurry. The additives include at least one of cyclic carbonates, organic sulfates, sulfonates, and lithium salts.

5. The preparation method according to claim 1, characterized in that, The initiator includes a photoinitiator or a thermal initiator.

6. The flexible solid electrolyte membrane prepared by any one of claims 1-5.

7. A battery comprising the flexible solid electrolyte membrane of claim 6.

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