A solid electrolyte and solid battery for backup power storage

Abstract

This invention discloses a solid-state electrolyte and a solid-state battery for the field of backup power and energy storage, belonging to the field of battery manufacturing technology. The solid-state electrolyte for backup power and energy storage comprises the following components by weight: 30-40 parts polymer matrix, 18-30 parts lithium salt, 0.8-1.3 parts lithium salt promoter, 1-4 parts binder, 18-26 parts tetrahydrofuran, and 0.8-2.3 parts conductive additive. The solid-state electrolyte prepared using the above substances exhibits excellent ionic conductivity, electrochemical stability, and safety, and its parameters are suitable for backup power and energy storage applications.

Description

Technical Field

[0001] This invention belongs to the field of battery manufacturing technology, specifically relating to a solid electrolyte and solid battery for backup power storage. Background Technology

[0002] In the field of backup power storage, traditional liquid electrolyte batteries face numerous development bottlenecks. Liquid electrolytes are volatile and prone to leakage, posing serious safety hazards such as fire and explosion when exposed to high temperatures, overcharging, or mechanical damage, making it difficult to meet the stringent safety requirements of energy storage systems. Moreover, during charge-discharge cycles, the growth of lithium dendrites in liquid electrolytes can easily puncture the separator, causing internal short circuits and significantly shortening battery life. In contrast, solid-state electrolytes utilize a solid-state ion conduction mechanism, possessing non-flammable and leak-proof characteristics, fundamentally improving battery safety. Simultaneously, their high mechanical strength effectively inhibits lithium dendrite growth, ensuring long-term stable battery operation. With the large-scale integration of renewable energy into the grid, the requirements for energy density, cycle life, and safety of energy storage systems are increasingly stringent. Solid-state electrolytes, with their unique advantages, have become a key material for driving the upgrading of backup power storage technology and achieving large-scale safe energy storage, showing broad development prospects.

[0003] Patent CN118919826A discloses a composite electrolyte for use in solid-state batteries for energy storage, its preparation method, and its application. Step (1): Polyvinylidene fluoride-hexafluoropropylene copolymer and lithium bis(trifluoromethanesulfonyl)imide are mixed and dissolved in a solvent to obtain a polymer solid electrolyte solution; Step (2): Inorganic dielectric nanofiller is added to the polymer solid electrolyte solution, and solvent is added again to obtain a composite solid electrolyte dispersion; Step (3): The composite solid electrolyte dispersion is dried at high temperature to obtain a solid electrolyte. The composite solid electrolyte of this invention achieves large cycle charge / discharge specific capacity and high rate charge / discharge specific capacity characteristics in a full battery assembled with lithium iron phosphate as the positive electrode and lithium metal as the negative electrode. Although the composite solid electrolyte prepared according to the above method exhibits large cycle charge / discharge specific capacity and high rate charge / discharge specific capacity characteristics in a full battery, the performance of this solid-state battery still has certain defects. For example, during long-term cycle use, the battery capacity will show a relatively significant decay, and at high rate charge / discharge, the internal polarization phenomenon of the battery is more severe, leading to a decrease in charge / discharge efficiency. This is mainly because the inorganic dielectric nanofiller has poor dispersion uniformity in the polymer aggregate, and the interfacial bonding between the polymer and the inorganic filler is not tight enough, which affects the smoothness of ion transport and electron conduction. Summary of the Invention

[0004] The purpose of this invention is to provide a solid electrolyte and solid battery for the field of backup power and energy storage, in order to solve the technical problems of poor safety performance and ionic conductivity of solid electrolytes in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a solid electrolyte for backup power storage, which is composed of the following components by weight: 30-40 parts polymer matrix, 18-30 parts lithium salt, 0.8-1.3 parts lithium salt promoter, 1-4 parts binder, 18-26 parts tetrahydrofuran and 0.8-2.3 parts conductive additive.

[0006] Preferably, the method for preparing the polymer matrix includes the following steps: Q1: Add o-phenylenediamine to a container containing ethanol, stir, add ethyl glyoxylate, heat to reflux and react, then stir at room temperature. After the reaction is complete, filter to obtain intermediate 1. Q2: Add intermediate 1, potassium carbonate, 1-bromoheptadecane and N,N-dimethylformamide to a container and stir at room temperature. Then add ethyl acetate and distilled water, stir, extract, combine the organic phases, wash, dry, distill under reduced pressure, and purify to obtain intermediate 2. Q3: Add graphite to tetrahydrofuran, disperse it by ultrasonication, add tetrahydrofuran containing polycarbonate, then add distilled water dropwise, stir, freeze, vacuum dry, immerse in distilled water containing intermediate 2, dry, and obtain the polymer matrix.

[0007] The synthesis reaction formula for intermediate 2 in the above process is as follows:

[0008] The mass spectrometry analysis of intermediate 1 showed the following results: m / z: 146.05 (100.0%), 147.05 (9.5%); the mass spectrometry analysis of intermediate 2 showed the following results: m / z: 384.31 (100.0%), 385.32 (27.5%), 386.32 (3.9%).

[0009] Preferably, in Q1, the ratio of o-phenylenediamine, ethanol, and ethyl glyoxylate is (0.92-1.24) g: (25-32) mL: (1.08-1.16) g, and the mixture is heated to 80-83℃ and refluxed for 4-6 h, then stirred at room temperature for 10-12 h. In Q2, the ratio of intermediate 1, potassium carbonate, 1-bromoheptadecane, N,N-dimethylformamide, ethyl acetate, and distilled water is (0.51-0.68) g: (0.78-0.86) g: (2.43-2.62) g: (20-30) mL: (8-12) mL: (6-10) mL, and the mixture is stirred at room temperature for 10-12 h. The mixture is then extracted with ethyl acetate, washed with saturated ammonium chloride aqueous solution and saturated sodium chloride aqueous solution, and dried with anhydrous sodium sulfate.

[0010] Preferably, in Q3, the ratio of graphite, polycarbonate and intermediate 2 is (0.6-0.8) g: (2.45-2.98) g: (1.2-1.8) g, and the mixture is ultrasonically dispersed for 30-45 min.

[0011] Preferably, the method for preparing the lithium salt accelerator includes the following steps: S1: Add bromododecane, p-hydroxybenzaldehyde, potassium carbonate and potassium iodide to a container containing acetonitrile, heat and stir to react. After the reaction is complete, cool, add hydrochloric acid, extract, dry, and rotary evaporate to obtain white solid a. S2: White solid a and p-hydroxyphenylacetonitrile were added sequentially to a container containing sodium hydroxide and ethanol. After heating and reacting, hydrochloric acid, distilled water and dichloromethane were added, the mixture was extracted, dried and rotary evaporated to obtain yellow solid b. S3: Under nitrogen atmosphere, yellow solid b, 1,3-dibromopropane, potassium carbonate and potassium iodide were added sequentially to a container containing acetonitrile. The mixture was heated and stirred under reflux. After the reaction was completed, the mixture was cooled, and hydrochloric acid, distilled water and dimethyl carbonate were added. The mixture was extracted, dried, filtered, and purified by rotary evaporation to obtain yellow solid c. S4: Add 4,4'-bis(dimethylhydroxysilyl)diphenyl ether to a container containing acetonitrile, stir, add yellow solid c, potassium carbonate and potassium iodide, heat to reflux and react, cool, add hydrochloric acid, distilled water and dimethyl carbonate, extract, dry, filter, rotary evaporate and purify to obtain lithium salt promoter.

[0012] The synthesis reaction formula for the lithium salt accelerator in the above process is as follows:

[0013] Mass spectrometry analysis of white solid a yielded the following results: m / z: 290.22 (100.0%), 291.23 (21.0%), 292.23 (2.5%); mass spectrometry analysis of yellow solid b yielded the following results: m / z: 405.27 (100.0%), 406.27 (29.7%), 407.27 (4.6%); mass spectrometry analysis of yellow solid c yielded the following results: m / z: 525.22 (100.0%), 527.22 (97.4%), 526.23 (33.0%), 528.23 (32.8%), 527.23 (5.7%), 529.23 (5.5%); mass spectrometry analysis of lithium salt accelerator yielded the following result: m / z: 1208.71 (100.0%). 1209.71 (93.8%), 1210.71 (44.4%), 1211.71 (10.9%), 1211.72 (9.5%), 1210.70 (6.8%), 1212.72 (3.3%), 1212.71 (3.0%).

[0014] Preferably, in S1, the ratio of bromododecane, p-hydroxybenzaldehyde, potassium carbonate, potassium iodide, and acetonitrile is (2.32-2.57) g : (1.21-1.46) g : (0.82-1.05) g : (0.48-0.56) g : (40-50) mL, and the mixture is heated to 80-85℃ and stirred for 8-10 h, with a hydrochloric acid concentration of 1 mol / L; in S2, the ratio of white solid a, p-hydroxyphenylacetonitrile, sodium hydroxide, and ethanol is (1.02-1.28) g : (0.82-0.96) g : (0.46-0.52) g : (6-10) mL, and the mixture is heated to 60-62℃ and reacted for 4-6 h, then dried with anhydrous magnesium sulfate.

[0015] Preferably, in step S3, the ratio of yellow solid b, 1,3-dibromopropane, potassium carbonate, potassium iodide, and acetonitrile is (1.12-1.58) g : (0.52-0.68) g : (0.56-0.66) g : (0.41-0.48) g : (20-30) mL. The mixture is heated to 80-84°C and refluxed for 10-12 hours. The concentration of hydrochloric acid is 1 mol / L, and anhydrous magnesium sulfate is used. The mixture is dried. In S4, the ratio of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, acetonitrile, yellow solid c, potassium carbonate and potassium iodide is (2.12-2.48) g : (30-35) mL : (1.02-1.24) g : (0.8-1.1) g : (0.45-0.52) g. The mixture is heated to 78-82℃ and refluxed for 10-12 h. The concentration of hydrochloric acid is 1 mol / L.

[0016] Preferably, the method for preparing a solid electrolyte for backup power storage includes the following steps: Step 1: Add the polymer matrix and binder to a container containing tetrahydrofuran, stir and mix to obtain a viscous solution; Step 2: Add lithium salt to the viscous solution, continue stirring, then add lithium salt accelerator, stir, add conductive additive, and stir to obtain a mixed slurry; Step 3: Let the mixed slurry stand to degas, pour it onto the mold surface to form a thin film, dry it, and obtain a solid electrolyte.

[0017] Preferably, the method for preparing a solid-state battery using the prepared solid-state electrolyte includes the following steps: P1: Mix lithium iron phosphate, conductive agent and binder to make a positive electrode slurry, coat it onto an aluminum foil current collector and dry it to obtain a positive electrode sheet. Mix graphene, conductive agent and binder to make a negative electrode slurry, coat it onto a copper foil current collector and dry it to obtain a negative electrode sheet. P2: The positive electrode, solid electrolyte and negative electrode are stacked together, and the layers are in close contact and hot-pressed to obtain the battery cell; P3: The battery cell is added to an aluminum-plastic film and vacuum-sealed to obtain a solid-state battery.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention applies the obtained polymer matrix to a solid electrolyte, which can effectively improve ionic conductivity, enhance mechanical properties and dimensional stability, and also improve electrochemical stability, thermal stability and safety. Intermediate 2 is rich in nitrogen and oxygen atoms, and as a Lewis base, it can coordinate with lithium ions in lithium salts, weaken the Coulomb force between lithium ions and anions, promote lithium salt dissociation, and increase the concentration of free lithium ions. The polar groups contained in intermediate 2 can aggregate to form nanoscale ion-enriched regions, which synergistically construct a continuous lithium ion transport pathway with the carbonyl groups of polycarbonate, thereby improving ionic conductivity. Graphite, as a nanofiller, combines with polycarbonate, which has high mechanical strength and thermal stability, to form a rigid network, improving the mechanical properties of the polymer matrix. At the same time, intermediate 2 can undergo slight reduction on the electrode surface to form a solid electrolyte interface film, improving electrochemical stability. In addition, polycarbonate has excellent flame retardancy, and the nitrogen atoms contained in intermediate 2 decompose at high temperatures, improving the flame retardancy rating, thereby improving thermal stability and safety.

[0019] 2. This invention adds the prepared lithium salt promoter to a solid electrolyte, which can effectively improve ionic conductivity, reduce interfacial impedance between the solid electrolyte and the electrode, and enhance battery safety. The cyano group contained in the lithium salt promoter has strong polarity and can form coordination with lithium ions, reducing the dissociation energy of the lithium salt, increasing the concentration of free lithium ions, and improving conductivity. The long alkyl chain can increase molecular flexibility, help form amorphous regions, reduce crystallinity, and provide more pathways for lithium ion transport. The siloxane group can form a uniform solid electrolyte interfacial film on the electrode surface, preventing electrolyte decomposition and promoting uniform lithium ion deposition. At the same time, the polar groups contained in the lithium salt promoter can be uniformly distributed on the electrode surface, avoiding local deposition and improving battery safety. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0021] Example 1: This example discloses a method for preparing a polymer matrix, including the following steps: Q1: Add 1.11g of o-phenylenediamine to a container containing 28mL of ethanol, stir, add 1.12g of ethyl glyoxylate, heat to 80℃ and reflux for 6h, then stir at room temperature for 12h. After the reaction is complete, filter to obtain intermediate 1. Q2: Add 0.59g of intermediate 1, 0.82g of potassium carbonate, 2.52g of 1-bromoheptadecane and 25mL of N,N-dimethylformamide to a container and stir at room temperature for 12h. Then add 10mL of ethyl acetate and 8mL of distilled water, stir, extract with ethyl acetate, combine the organic phases, wash with saturated ammonium chloride aqueous solution and saturated sodium chloride aqueous solution, dry with anhydrous sodium sulfate, and purify by vacuum distillation to obtain intermediate 2. Q3: Add 0.7g of graphite to 40mL of tetrahydrofuran, sonicate for 30min, then add 20mL of tetrahydrofuran containing 2.72g of polycarbonate, then add 3mL of distilled water, stir, freeze, vacuum dry, immerse in 80mL of distilled water containing 1.5g of intermediate 2, and dry to obtain the polymer matrix.

[0022] This embodiment discloses a method for preparing a lithium salt accelerator, including the following steps: S1: 2.45 g of bromododecane, 1.33 g of p-hydroxybenzaldehyde, 0.93 g of potassium carbonate and 0.52 g of potassium iodide were added to a container containing 45 mL of acetonitrile. The mixture was heated to 80 °C and stirred for 10 h. After the reaction was completed, the mixture was cooled, 2 mL of 1 mol / L hydrochloric acid was added, the mixture was extracted, dried, and rotary evaporated to obtain a white solid a. S2: 1.15g of white solid a and 0.89g of p-hydroxyphenylacetonitrile were added sequentially to a container containing 0.49g of sodium hydroxide and 8mL of ethanol. After heating to 60℃ and reacting for 6h, 1mL of 1mol / L hydrochloric acid, 1.5mL of distilled water and 1.2mL of dichloromethane were added, and the mixture was extracted. The solid was dried with anhydrous magnesium sulfate and rotary evaporated to obtain yellow solid b. S3: Under nitrogen atmosphere, 1.35g of yellow solid b, 0.6g of 1,3-dibromopropane, 0.61g of potassium carbonate and 0.45g of potassium iodide were added sequentially to a container containing 25mL of acetonitrile. The mixture was heated to 80℃ and refluxed with stirring for 12h. After the reaction was completed, the mixture was cooled, and 1.2mL of 1mol / L hydrochloric acid, 2mL of distilled water and 0.9g of dimethyl carbonate were added. The mixture was extracted, dried with anhydrous magnesium sulfate, filtered, and purified by rotary evaporation to obtain yellow solid c. S4: 2.3 g of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether was added to a container containing 32.5 mL of acetonitrile. After stirring, 1.13 g of yellow solid c, 0.9 g of potassium carbonate and 0.48 g of potassium iodide were added. The mixture was heated to 80 °C and refluxed for 12 h. After cooling, 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried, filtered, and purified by rotary evaporation to obtain the lithium salt promoter.

[0023] This embodiment discloses a solid electrolyte for backup power storage, which is composed of the following components by weight: 35 parts polymer matrix, 24 parts lithium salt, 1.05 parts lithium salt promoter, 2.5 parts binder, 22 parts tetrahydrofuran and 1.5 parts conductive additive.

[0024] This embodiment discloses a method for preparing a solid electrolyte in the field of backup power storage, including the following steps: Step 1: Add the polymer matrix and binder to a container containing tetrahydrofuran, stir and mix to obtain a viscous solution; Step 2: Add lithium salt to the viscous solution, continue stirring, then add lithium salt accelerator, stir, add conductive additive, and stir to obtain a mixed slurry; Step 3: Let the mixed slurry stand to degas, pour it onto the mold surface to form a thin film, dry it, and obtain a solid electrolyte.

[0025] This embodiment discloses a method for preparing a solid-state battery, including the following steps: P1: Mix lithium iron phosphate, conductive agent and binder to make a positive electrode slurry, coat it onto an aluminum foil current collector and dry it to obtain a positive electrode sheet. Mix graphene, conductive agent and binder to make a negative electrode slurry, coat it onto a copper foil current collector and dry it to obtain a negative electrode sheet. P2: The positive electrode, solid electrolyte and negative electrode are stacked together, and the layers are in close contact and hot-pressed to obtain the battery cell; P3: The battery cell is added to an aluminum-plastic film and vacuum-sealed to obtain a solid-state battery.

[0026] Example 2: This example discloses a method for preparing a polymer matrix, including the following steps: Q1: Add 0.92g of o-phenylenediamine to a container containing 25mL of ethanol, stir, add 1.08g of ethyl glyoxylate, heat to 80℃ and reflux for 6h, then stir at room temperature for 12h. After the reaction is complete, filter to obtain intermediate 1. Q2: Add 0.51g of intermediate 1, 0.78g of potassium carbonate, 2.43g of 1-bromoheptadecane and 20mL of N,N-dimethylformamide to a container and stir at room temperature for 12h. Then add 8mL of ethyl acetate and 10mL of distilled water, stir, extract with ethyl acetate, combine the organic phases, wash with saturated ammonium chloride aqueous solution and saturated sodium chloride aqueous solution, dry with anhydrous sodium sulfate, and purify by vacuum distillation to obtain intermediate 2. Q3: Add 0.6g of graphite to 40mL of tetrahydrofuran, sonicate for 30min, then add 20mL of tetrahydrofuran containing 2.45g of polycarbonate, then add 3mL of distilled water, stir, freeze, vacuum dry, immerse in 80mL of distilled water containing 1.2g of intermediate 2, and dry to obtain the polymer matrix.

[0027] This embodiment discloses a method for preparing a lithium salt accelerator, including the following steps: S1: 2.32 g of bromododecane, 1.21 g of p-hydroxybenzaldehyde, 0.82 g of potassium carbonate and 0.56 g of potassium iodide were added to a container containing 40 mL of acetonitrile. The mixture was heated to 80 °C and stirred for 10 h. After the reaction was completed, the mixture was cooled, 2 mL of 1 mol / L hydrochloric acid was added, the mixture was extracted, dried, and rotary evaporated to obtain a white solid a. S2: 1.02 g of white solid a and 0.82 g of p-hydroxyphenylacetonitrile were added sequentially to a container containing 0.46 g of sodium hydroxide and 10 mL of ethanol. After heating to 60 °C and reacting for 6 h, 1 mL of 1 mol / L hydrochloric acid, 1.5 mL of distilled water and 1.2 mL of dichloromethane were added, and the mixture was extracted. The solid was dried with anhydrous magnesium sulfate and rotary evaporated to obtain yellow solid b. S3: Under nitrogen atmosphere, 1.12 g of yellow solid b, 0.52 g of 1,3-dibromopropane, 0.56 g of potassium carbonate and 0.41 g of potassium iodide were added sequentially to a container containing 20 mL of acetonitrile. The mixture was heated to 80 °C and refluxed with stirring for 12 h. After the reaction was completed, the mixture was cooled, and 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried with anhydrous magnesium sulfate, filtered, and purified by rotary evaporation to obtain yellow solid c. S4: 2.12 g of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether was added to a container containing 35 mL of acetonitrile. After stirring, 1.02 g of yellow solid c, 0.8 g of potassium carbonate and 0.45 g of potassium iodide were added. The mixture was heated to 80 °C and refluxed for 12 h. After cooling, 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried, filtered, and purified by rotary evaporation to obtain the lithium salt promoter.

[0028] This embodiment discloses a solid electrolyte for backup power storage, which is composed of the following components by weight: 30 parts polymer matrix, 18 parts lithium salt, 0.8 parts lithium salt promoter, 1 part binder, 26 parts tetrahydrofuran and 0.8 parts conductive additive.

[0029] This embodiment discloses a method for preparing a solid electrolyte in the field of backup power storage, including the following steps: Step 1: Add the polymer matrix and binder to a container containing tetrahydrofuran, stir and mix to obtain a viscous solution; Step 2: Add lithium salt to the viscous solution, continue stirring, then add lithium salt accelerator, stir, add conductive additive, and stir to obtain a mixed slurry; Step 3: Let the mixed slurry stand to degas, pour it onto the mold surface to form a thin film, dry it, and obtain a solid electrolyte.

[0030] This embodiment discloses a method for preparing a solid-state battery, including the following steps: P1: Mix lithium iron phosphate, conductive agent and binder to make a positive electrode slurry, coat it onto an aluminum foil current collector and dry it to obtain a positive electrode sheet. Mix graphene, conductive agent and binder to make a negative electrode slurry, coat it onto a copper foil current collector and dry it to obtain a negative electrode sheet. P2: The positive electrode, solid electrolyte and negative electrode are stacked together, and the layers are in close contact and hot-pressed to obtain the battery cell; P3: The battery cell is added to an aluminum-plastic film and vacuum-sealed to obtain a solid-state battery.

[0031] Example 3: This example discloses a method for preparing a polymer matrix, including the following steps: Q1: Add 1.24g of o-phenylenediamine to a container containing 32mL of ethanol, stir, add 1.16g of ethyl glyoxylate, heat to 80℃ and reflux for 6h, then stir at room temperature for 12h. After the reaction is complete, filter to obtain intermediate 1. Q2: Add 0.68g of intermediate 1, 0.86g of potassium carbonate, 2.62g of 1-bromoheptadecane and 30mL of N,N-dimethylformamide to a container and stir at room temperature for 12h. Then add 12mL of ethyl acetate and 6mL of distilled water, stir, extract with ethyl acetate, combine the organic phases, wash with saturated ammonium chloride aqueous solution and saturated sodium chloride aqueous solution, dry with anhydrous sodium sulfate, and purify by vacuum distillation to obtain intermediate 2. Q3: Add 0.8g of graphite to 40mL of tetrahydrofuran, sonicate for 30min, then add 20mL of tetrahydrofuran containing 2.98g of polycarbonate, then add 3mL of distilled water, stir, freeze, vacuum dry, immerse in 80mL of distilled water containing 1.8g of intermediate 2, and dry to obtain the polymer matrix.

[0032] This embodiment discloses a method for preparing a lithium salt accelerator, including the following steps: S1: 2.57 g of bromododecane, 1.46 g of p-hydroxybenzaldehyde, 1.05 g of potassium carbonate and 0.48 g of potassium iodide were added to a container containing 50 mL of acetonitrile, heated to 80 °C and stirred for 10 h. After the reaction was completed, the mixture was cooled, 2 mL of 1 mol / L hydrochloric acid was added, the mixture was extracted, dried and rotary evaporated to obtain white solid a. S2: 1.28 g of white solid a and 0.96 g of p-hydroxyphenylacetonitrile were added sequentially to a container containing 0.52 g of sodium hydroxide and 6 mL of ethanol. After heating to 60 °C and reacting for 6 h, 1 mL of 1 mol / L hydrochloric acid, 1.5 mL of distilled water and 1.2 mL of dichloromethane were added, and the mixture was extracted. The extract was dried with anhydrous magnesium sulfate and rotary evaporated to obtain yellow solid b. S3: Under nitrogen atmosphere, 1.58 g of yellow solid b, 0.68 g of 1,3-dibromopropane, 0.66 g of potassium carbonate and 0.48 g of potassium iodide were added sequentially to a container containing 30 mL of acetonitrile. The mixture was heated to 80 °C and refluxed with stirring for 12 h. After the reaction was completed, the mixture was cooled, and 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried with anhydrous magnesium sulfate, filtered, and purified by rotary evaporation to obtain yellow solid c. S4: 2.48 g of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether was added to a container containing 30 mL of acetonitrile. After stirring, 1.24 g of yellow solid c, 1.1 g of potassium carbonate and 0.52 g of potassium iodide were added. The mixture was heated to 80 °C and refluxed for 12 h. After cooling, 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried, filtered, and purified by rotary evaporation to obtain the lithium salt promoter.

[0033] This embodiment discloses a solid electrolyte for backup power storage, which is composed of the following components by weight: 40 parts polymer matrix, 30 parts lithium salt, 1.3 parts lithium salt promoter, 4 parts binder, 18 parts tetrahydrofuran and 2.3 parts conductive additive.

[0034] This embodiment discloses a method for preparing a solid electrolyte in the field of backup power storage, including the following steps: Step 1: Add the polymer matrix and binder to a container containing tetrahydrofuran, stir and mix to obtain a viscous solution; Step 2: Add lithium salt to the viscous solution, continue stirring, then add lithium salt accelerator, stir, add conductive additive, and stir to obtain a mixed slurry; Step 3: Let the mixed slurry stand to degas, pour it onto the mold surface to form a thin film, dry it, and obtain a solid electrolyte.

[0035] This embodiment discloses a method for preparing a solid-state battery, including the following steps: P1: Mix lithium iron phosphate, conductive agent and binder to make a positive electrode slurry, coat it onto an aluminum foil current collector and dry it to obtain a positive electrode sheet. Mix graphene, conductive agent and binder to make a negative electrode slurry, coat it onto a copper foil current collector and dry it to obtain a negative electrode sheet. P2: The positive electrode, solid electrolyte and negative electrode are stacked together, and the layers are in close contact and hot-pressed to obtain the battery cell; P3: The battery cell is added to an aluminum-plastic film and vacuum-sealed to obtain a solid-state battery.

[0036] Example 4: This example discloses a method for preparing a polymer matrix, including the following steps: Q1: Add 0.98g of o-phenylenediamine to a container containing 26mL of ethanol, stir, add 1.1g of ethyl glyoxylate, heat to 80℃ and reflux for 6h, then stir at room temperature for 12h. After the reaction is complete, filter to obtain intermediate 1. Q2: Add 0.55g of intermediate 1, 0.8g of potassium carbonate, 2.48g of 1-bromoheptadecane and 22mL of N,N-dimethylformamide to a container and stir at room temperature for 12h. Then add 9mL of ethyl acetate and 9mL of distilled water, stir, extract with ethyl acetate, combine the organic phases, wash with saturated ammonium chloride aqueous solution and saturated sodium chloride aqueous solution, dry with anhydrous sodium sulfate, and purify by vacuum distillation to obtain intermediate 2. Q3: Add 0.65g of graphite to 40mL of tetrahydrofuran, sonicate for 30min, then add 20mL of tetrahydrofuran containing 2.53g of polycarbonate, then add 3mL of distilled water, stir, freeze, vacuum dry, immerse in 80mL of distilled water containing 1.3g of intermediate 2, and dry to obtain the polymer matrix.

[0037] This embodiment discloses a method for preparing a lithium salt accelerator, including the following steps: S1: 2.38 g of bromododecane, 1.28 g of p-hydroxybenzaldehyde, 0.99 g of potassium carbonate and 0.54 g of potassium iodide were added to a container containing 42 mL of acetonitrile. The mixture was heated to 80 °C and stirred for 10 h. After the reaction was completed, the mixture was cooled, 2 mL of 1 mol / L hydrochloric acid was added, the mixture was extracted, dried, and rotary evaporated to obtain a white solid a. S2: 1.08 g of white solid a and 0.84 g of p-hydroxyphenylacetonitrile were added sequentially to a container containing 0.47 g of sodium hydroxide and 7 mL of ethanol. After heating to 60 °C and reacting for 6 h, 1 mL of 1 mol / L hydrochloric acid, 1.5 mL of distilled water and 1.2 mL of dichloromethane were added, and the mixture was extracted. The extract was dried with anhydrous magnesium sulfate and rotary evaporated to obtain yellow solid b. S3: Under nitrogen atmosphere, 1.27 g of yellow solid b, 0.56 g of 1,3-dibromopropane, 0.59 g of potassium carbonate and 0.43 g of potassium iodide were added sequentially to a container containing 22 mL of acetonitrile. The mixture was heated to 80 °C and refluxed with stirring for 12 h. After the reaction was completed, the mixture was cooled, and 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried with anhydrous magnesium sulfate, filtered, and purified by rotary evaporation to obtain yellow solid c. S4: 2.21 g of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether was added to a container containing 32 mL of acetonitrile. After stirring, 1.08 g of yellow solid c, 0.85 g of potassium carbonate and 0.46 g of potassium iodide were added. The mixture was heated to 80 °C and refluxed for 12 h. After cooling, 1.2 mL of 1 mol / L hydrochloric acid, 2 mL of distilled water and 0.9 g of dimethyl carbonate were added. The mixture was extracted, dried, filtered, and purified by rotary evaporation to obtain the lithium salt promoter.

[0038] This embodiment discloses a solid electrolyte for backup power storage, which is composed of the following components by weight: 38 parts polymer matrix, 22 parts lithium salt, 0.9 parts lithium salt promoter, 2 parts binder, 20 parts tetrahydrofuran and 1.2 parts conductive additive.

[0039] This embodiment discloses a method for preparing a solid electrolyte in the field of backup power storage, including the following steps: Step 1: Add the polymer matrix and binder to a container containing tetrahydrofuran, stir and mix to obtain a viscous solution; Step 2: Add lithium salt to the viscous solution, continue stirring, then add lithium salt accelerator, stir, add conductive additive, and stir to obtain a mixed slurry; Step 3: Let the mixed slurry stand to degas, pour it onto the mold surface to form a thin film, dry it, and obtain a solid electrolyte.

[0040] This embodiment discloses a method for preparing a solid-state battery, including the following steps: P1: Mix lithium iron phosphate, conductive agent and binder to make a positive electrode slurry, coat it onto an aluminum foil current collector and dry it to obtain a positive electrode sheet. Mix graphene, conductive agent and binder to make a negative electrode slurry, coat it onto a copper foil current collector and dry it to obtain a negative electrode sheet. P2: The positive electrode, solid electrolyte and negative electrode are stacked together, and the layers are in close contact and hot-pressed to obtain the battery cell; P3: The battery cell is added to an aluminum-plastic film and vacuum-sealed to obtain a solid-state battery.

[0041] Comparative Example 1: Compared with Example 1, Comparative Example 1 uses polycarbonate instead of polymer matrix in the process of preparing solid-state battery, while other conditions remain unchanged.

[0042] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add lithium salt promoters during the preparation of solid-state batteries, and all other conditions remained unchanged.

[0043] Performance testing: The solid-state batteries prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests. The ionic conductivity of the samples was tested according to NB / T 10827-2021, and the safety performance of the samples was tested according to GB 44240-2024. The test results are shown in Table 1.

[0044] As shown in Table 1, the solid electrolytes with excellent ionic conductivity and safety performance can be prepared by using the methods of Examples 1-4. A comparison between Comparative Example 1 and Examples 1-4 reveals that the use of a polymer matrix can effectively improve the ionic conductivity and safety performance of the solid electrolyte; a comparison between Comparative Example 2 and Examples 1-4 reveals that the use of a lithium salt promoter can effectively improve the ionic conductivity and safety performance of the solid electrolyte.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0046] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A solid electrolyte for backup power and energy storage, characterized in that, It consists of the following components by weight: 30-40 parts polymer matrix, 18-30 parts lithium salt, 0.8-1.3 parts lithium salt accelerator, 1-4 parts binder, 18-26 parts tetrahydrofuran and 0.8-2.3 parts conductive additive.

2. The solid electrolyte for backup power storage according to claim 1, characterized in that, The method for preparing the polymer matrix includes the following steps: Q1: Add o-phenylenediamine to a container containing ethanol, stir, add ethyl glyoxylate, heat to reflux and react, then stir at room temperature. After the reaction is complete, filter to obtain intermediate 1. Q2: Add intermediate 1, potassium carbonate, 1-bromoheptadecane and N,N-dimethylformamide to a container and stir at room temperature. Then add ethyl acetate and distilled water, stir, extract, combine the organic phases, wash, dry, distill under reduced pressure, and purify to obtain intermediate 2. Q3: Add graphite to tetrahydrofuran, disperse it by ultrasonication, add tetrahydrofuran containing polycarbonate, then add distilled water dropwise, stir, freeze, vacuum dry, immerse in distilled water containing intermediate 2, dry, and obtain the polymer matrix.

3. A solid electrolyte for backup power storage according to claim 2, characterized in that, In Q1, the ratio of o-phenylenediamine, ethanol, and ethyl glyoxylate is (0.92-1.24) g: (25-32) mL: (1.08-1.16) g; in Q2, the ratio of intermediate 1, potassium carbonate, 1-bromoheptadecane, N,N-dimethylformamide, ethyl acetate, and distilled water is (0.51-0.68) g: (0.78-0.86) g: (2.43-2.62) g: (20-30) mL: (8-12) mL: (6-10) mL.

4. A solid electrolyte for backup power storage according to claim 2, characterized in that, In Q3, the ratio of graphite, polycarbonate and intermediate 2 is (0.6-0.8) g: (2.45-2.98) g: (1.2-1.8) g.

5. A solid electrolyte for backup power storage according to claim 1, characterized in that, The preparation method of the lithium salt accelerator includes the following steps: S1: Add bromododecane, p-hydroxybenzaldehyde, potassium carbonate and potassium iodide to a container containing acetonitrile, heat and stir to react. After the reaction is complete, cool, add hydrochloric acid, extract, dry, and rotary evaporate to obtain white solid a. S2: White solid a and p-hydroxyphenylacetonitrile were added sequentially to a container containing sodium hydroxide and ethanol. After heating and reacting, hydrochloric acid, distilled water and dichloromethane were added, the mixture was extracted, dried and rotary evaporated to obtain yellow solid b. S3: Under nitrogen atmosphere, yellow solid b, 1,3-dibromopropane, potassium carbonate and potassium iodide were added sequentially to a container containing acetonitrile. The mixture was heated and stirred under reflux. After the reaction was completed, the mixture was cooled, and hydrochloric acid, distilled water and dimethyl carbonate were added. The mixture was extracted, dried, filtered, and purified by rotary evaporation to obtain yellow solid c. S4: Add 4,4'-bis(dimethylhydroxysilyl)diphenyl ether to a container containing acetonitrile, stir, add yellow solid c, potassium carbonate and potassium iodide, heat to reflux and react, cool, add hydrochloric acid, distilled water and dimethyl carbonate, extract, dry, filter, rotary evaporate and purify to obtain lithium salt promoter.

6. A solid electrolyte for backup power storage according to claim 5, characterized in that, In S1, the ratio of the amounts of bromododecane, p-hydroxybenzaldehyde, potassium carbonate, potassium iodide, and acetonitrile is (2.32-2.57) g : (1.21-1.46) g : (0.82-1.05) g : (0.48-0.56) g : (40-50) mL; in S2, the ratio of the amounts of white solid a, p-hydroxyphenylacetonitrile, sodium hydroxide, and ethanol is (1.02-1.28) g : (0.82-0.96) g : (0.46-0.52) g : (6-10) mL.

7. A solid electrolyte for backup power storage according to claim 5, characterized in that, In S3, the ratio of yellow solid b, 1,3-dibromopropane, potassium carbonate, potassium iodide, and acetonitrile is (1.12-1.58) g : (0.52-0.68) g : (0.56-0.66) g : (0.41-0.48) g : (20-30) mL; in S4, the ratio of 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, acetonitrile, yellow solid c, potassium carbonate, and potassium iodide is (2.12-2.48) g : (30-35) mL : (1.02-1.24) g : (0.8-1.1) g : (0.45-0.52) g.

8. A method for preparing a solid electrolyte for backup power storage as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Add the polymer matrix and binder to a container containing tetrahydrofuran, stir and mix to obtain a viscous solution; Step 2: Add lithium salt to the viscous solution, continue stirring, then add lithium salt accelerator, stir, add conductive additive, and stir to obtain a mixed slurry; Step 3: Let the mixed slurry stand to degas, pour it onto the mold surface to form a thin film, dry it, and obtain a solid electrolyte.

9. A method for preparing a solid-state battery using the solid-state electrolyte prepared according to claim 8, characterized in that, Includes the following steps: P1: Mix lithium iron phosphate, conductive agent and binder to make a positive electrode slurry, coat it onto an aluminum foil current collector and dry it to obtain a positive electrode sheet. Mix graphene, conductive agent and binder to make a negative electrode slurry, coat it onto a copper foil current collector and dry it to obtain a negative electrode sheet. P2: The positive electrode, solid electrolyte and negative electrode are stacked together, and the layers are in close contact and hot-pressed to obtain the battery cell; P3: The battery cell is added to an aluminum-plastic film and vacuum-sealed to obtain a solid-state battery.

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