A si-o-m based solid state electrolyte, method of making and battery applications thereof

Abstract

The application provides a Si-O-M-based solid-state electrolyte, a preparation method thereof and battery application. First, raw materials for synthesizing the Si-O-M-based solid-state electrolyte are prepared into a solid-state electrolyte embryo, and then phase inversion is performed under a specific atmosphere; finally, high-temperature calcination and ion exchange treatment are performed to prepare the Si-O-M-based solid-state electrolyte. The solid-state electrolyte forms a network structure between solid phases, and a continuous through channel is constructed. The continuous through channel provides active sites for ion adsorption and a fast and accurate transmission channel, improves ion transmission efficiency, reduces the generation of dendrites, avoids various side reactions, improves the ion conductivity and stability of the battery, is suitable for lithium / zinc / sodium / magnesium / aluminum secondary batteries, and has important theoretical research and practical value.

Description

Technical Field

[0001] This application belongs to the field of battery electrolyte technology, and particularly relates to a Si-OM-based solid electrolyte, its preparation method and battery application. Background Technology

[0002] Secondary batteries are of great significance for environmental protection and efficient energy utilization. Currently, secondary battery systems mainly use liquid electrolytes, which are prone to leakage and short circuits, potentially leading to dangerous accidents such as battery combustion and explosion. In contrast, the use of solid-state electrolytes can effectively reduce the proportion of flammable materials in the battery and, to some extent, inhibit the growth of dendrites on the negative electrode, thereby avoiding short circuits and thus offering higher safety.

[0003] Solid-state electrolytes can be broadly classified into three categories: inorganic, polymeric, and composite. However, each type of solid-state electrolyte has its own advantages and limitations in practical applications. For example, traditional solid-state electrolytes have limited ion conductivity and poor performance stability. The room-temperature ionic conductivity of existing solid-state electrolytes is generally low, and the energy barrier for ion transport within the electrolyte is high, preventing ions from moving freely as they would in an electrolyte solution. Ion movement in the solid-phase system is highly dependent on the crystal structure and the movement of polymer chains, thus failing to meet the requirements of fast charging and discharging in commercial applications. Furthermore, due to the inherently high interfacial energy between solid materials, multilayer solids are difficult to wet with each other, typically maintaining very limited point contact with a small effective contact area, making it difficult to construct an ideal electrode-solid-state electrolyte interface structure and hindering ion transport across interfaces. Ion diffusion within the positive electrode active material is another critical issue. If the solid electrolyte material cannot permeate the composite electrode sufficiently, the electrochemical reaction cannot proceed effectively. The nucleation and growth of dendrites within the solid-state electrolyte can also cause short circuits in the battery. Moreover, the manufacturing cost of solid-state batteries is relatively high, and the preparation process of solid-state electrolytes is complex, requiring more stringent equipment and technology.

[0004] Therefore, solid-state batteries assembled using existing solid-state electrolytes face problems such as short cycle life, low energy density, and high cost, which seriously restrict the application and development of solid-state energy storage devices and affect their industrialization process. Summary of the Invention

[0005] This application provides a Si-OM-based solid electrolyte, its preparation method, and its battery application to address the problems existing in related technologies. The technical solution is as follows:

[0006] In a first aspect, embodiments of this application provide a method for preparing a Si-OM-based solid electrolyte, comprising the following steps:

[0007] The raw materials for synthesizing Si-OM-based solid electrolytes are made into solid electrolyte preforms;

[0008] The embryo is subjected to phase transformation using hydrothermal conversion, solvothermal conversion, or solvent-free conversion;

[0009] The embryo after phase transformation is subjected to high-temperature calcination and / or ion exchange treatment to prepare the Si-OM-based solid electrolyte.

[0010] The raw materials for synthesizing the Si-OM-based solid electrolyte include one or more of the following: silicon source, aluminum source, germanium source, titanium source, or alkaline source.

[0011] In one embodiment, the silicon source is one or a combination of two or more of silicates, silicon tetrachloride, silica sol, tetraethyl orthosilicate, fumed silica, or silica.

[0012] In one embodiment, the aluminum source is one or a combination of two or more of aluminum isopropoxide, sodium aluminate, aluminum chloride, aluminum sulfate, aluminum nitrate, boehmite, aluminum sol, boehmite, aluminum hydroxide, or aluminum oxide.

[0013] In one embodiment, the titanium source is one or a combination of two or more of titanium tetrachloride, tetrabutyl titanate, tetraethyl titanate, titanium isopropoxide, titanium sulfate, titanium oxysulfate, titanium silicate, strontium titanate, titanium bromide, aluminum titanate, lithium titanate, titanium oxalate, and titanium dioxide.

[0014] In one embodiment, the germanium source is one or a combination of two or more of tetramethyl germanium, tetraethyl germanium, germanium oxalate, germanium oxide, orthogermate, digermate, tetragermate, germanium silicate, trimethyl germanium chloride, germanium sulfide, germanium sulfate, germanium chloride, germanium nitrate, or germanium phosphate.

[0015] In one embodiment, the alkali source is one or a combination of two or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, or organic amines.

[0016] In one embodiment, the raw materials of the Si-OM-based solid electrolyte further contain a pore-forming agent and / or an activator.

[0017] In one embodiment, the activator is one or a combination of two or more of the following: ammonia, dimethylamine, trimethylamine, diethylamine, triethylamine, ammonium chloride, sodium chloride, ammonium iodide, ammonium fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluorosilicate, ammonium fluoroaluminate, aluminum fluorosilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, lithium carbonate, sodium carbonate, potassium bicarbonate, lithium bicarbonate, sodium bicarbonate, lithium phosphate, sodium phosphate, potassium phosphate, potassium hydrogen phosphate, lithium hydrogen phosphate, sodium hydrogen phosphate, potassium dihydrogen phosphate, lithium dihydrogen phosphate, or sodium dihydrogen phosphate.

[0018] In one embodiment, the raw material of the Si-OM-based solid electrolyte further contains an ion migration element precursor; the ion migration element is a zinc precursor, a lithium precursor, or a sodium precursor.

[0019] In one embodiment, the ion migration element precursor is one or more of zinc sulfate, zinc carbonate, zinc chloride, zinc iodide, zinc nitrate, zinc bromide, zinc gluconate, zinc octanoate, zinc thiophosphate dioctyl alkyl salt, amino acid chelate zinc, metallic zinc, zinc hydroxide, or zinc oxide.

[0020] In one embodiment, the ion migration element precursor is one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium carbonate, lithium sulfate, lithium chloride, lithium nitrate, lithium chloride, lithium bromide, lithium oxide, or lithium hydroxide.

[0021] In one embodiment, the ion migration element precursor is one or more of sodium chloride, sodium carbonate, sodium sulfate, sodium nitrate, sodium thiosulfate, sodium perrhenate, sodium fluoride, sodium bromide, sodium benzoate, sodium acetate, sodium oxide, or sodium hydroxide.

[0022] In one embodiment, the raw materials of the Si-OM-based solid electrolyte also contain additives and dispersants.

[0023] In one embodiment, the additive is one or more of the following: metal oxides, metal hydroxides, metal salts, and organic salts of magnesium, calcium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc.

[0024] In one embodiment, the dispersant is one or more of water, methanol, ethanol, propanol, ethylene glycol, propylene glycol, butanediol, acetone, tetrahydrofuran, dimethyl ether, N-methylpyrrolidone, or N,N-dimethylformamide.

[0025] In one embodiment, the solid electrolyte preform is prepared by extrusion, pressing, coating, scraping, or self-assembly.

[0026] In one embodiment, the hydrothermal conversion involves dissolving the raw materials of the Si-OM-based solid electrolyte in water to prepare an aqueous synthesis solution, then placing the solid electrolyte preform in the synthesis solution, followed by a phase conversion.

[0027] In one embodiment, the solvothermal conversion involves dissolving the raw materials of the Si-OM-based solid electrolyte in an organic solvent or a mixed solvent consisting of water and an organic solvent to prepare a solvent synthesis solution, then placing the solid electrolyte preform in the synthesis solution, and then performing a phase conversion.

[0028] In one embodiment, the solvent-free conversion involves placing a solid electrolyte preform in a crystallization vessel for direct phase conversion.

[0029] In one embodiment, the solventless conversion involves placing a solid electrolyte preform in a crystallization vessel containing water, ammonia, organic amines, or ammonium salts, without contact between the vessel and the solid electrolyte preform, followed by phase conversion.

[0030] In one embodiment, the phase transformation temperature is 60℃-280℃, and the crystallization transformation time is 0.5h-160h.

[0031] In one embodiment, the calcination temperature is 300-2000℃ and the calcination time is 0.5h-24h.

[0032] In one embodiment, the ion exchange process involves immersing the baked electrolyte preform in a zinc, lithium, or sodium salt solution for 1-96 hours.

[0033] Secondly, embodiments of this application provide a Si-OM-based solid electrolyte, which is prepared by the Si-OM-based solid electrolyte preparation method described above.

[0034] Thirdly, embodiments of this application provide a battery including the Si-OM-based solid electrolyte as described above.

[0035] The advantages or beneficial effects of the above technical solutions include at least the following:

[0036] The Si-OM-based material proposed in this application is an amorphous or microcrystalline macromolecular inorganic material composed of silicon and other elements linked by oxygen. The interconnected macromolecular inorganic materials form a network structure, which not only avoids the intergranular spacing caused by the contact between traditional particulate materials but also improves the mechanical strength of the material. The network structure creates continuous interconnected channels, providing active sites and rapid, precise transport channels for ion adsorption. This avoids the disorder and randomness caused by the transport of ions through crystal defects in traditional electrolytes, improving ion transport efficiency, reducing dendrite formation, preventing various side reactions, and enhancing the ionic conductivity and stability of the battery. Furthermore, this solid-state electrolyte also has advantages such as wide availability of materials, simple preparation process, energy saving, and environmental friendliness.

[0037] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of this application will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0038] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0039] Figure 1 SEM image of the Si-O-Al solid electrolyte prepared in Example 1

[0040] Figure 2 The XRD pattern of the Si-O-Al solid electrolyte prepared in Example 1;

[0041] Figure 3 The graph shows the cycling performance of the Si-O-Al solid electrolyte prepared in Example 1 in a zinc-zinc symmetric battery.

[0042] Figure 4 SEM image of the Si-O-Al(Ti) solid electrolyte prepared in Example 2;

[0043] Figure 5 SEM image of the Si-O-Ge solid electrolyte prepared in Example 3;

[0044] Figure 6 The cycling performance results of the Si-O-Ge solid electrolyte prepared in Example 3 for zinc-zinc symmetric batteries are shown.

[0045] Figure 7 The image shows a SEM image of the Si-O-Ti solid electrolyte prepared in Example 5. Detailed Implementation

[0046] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0047] To address the shortcomings of traditional solid-state electrolytes, Si-OM-based materials, such as SiO2, Al2O3, clay, and zeolite, are added as coatings or fillers to battery separators, liquid electrolytes, or organic solid-state electrolytes. This enhances the wettability, ionic conductivity, thermal stability, and mechanical strength of the separator or electrolyte, thereby optimizing battery safety, cycle life, and energy density. Furthermore, structural control can activate the inherent ion transport capabilities of Si-OM-based materials, leading to the fabrication of inexpensive solid-state electrolytes with high-efficiency ion transport and low interfacial transport resistance. Therefore, this application provides a Si-OM-based solid-state electrolyte, a solid-state battery, and a method for its fabrication.

[0048] A method for preparing a Si-OM-based solid electrolyte includes the following steps:

[0049] The raw materials for synthesizing Si-OM-based solid electrolytes are made into solid electrolyte preforms;

[0050] The embryo is subjected to phase transformation using hydrothermal conversion, solvothermal conversion, or solvent-free conversion;

[0051] The embryo after phase transformation is subjected to high-temperature calcination and / or ion exchange treatment to prepare the Si-OM-based solid electrolyte.

[0052] The raw materials for synthesizing the Si-OM-based solid electrolyte include one or more of the following: silicon source, aluminum source, germanium source, titanium source, or alkaline source.

[0053] Si-OM-based materials are composite materials with Si-O bonds as the core structure and containing M elements (usually metallic elements). During the phase transformation process of the raw materials, the solid powder particles gradually lose their crystal structure and react with adjacent substances to form a network structure, eliminating the intergranular spacing between particles. The network structure is interconnected, forming a continuous channel structure. These interconnected channels provide active sites for ion adsorption. When the battery is working, ions detach from the adsorption sites and are rapidly and accurately transported within the channels, improving ion transport efficiency, reducing dendrite formation, avoiding various side reactions, and improving ionic conductivity and stability. Therefore, this invention, by constructing a three-dimensional network-like Si-OM-based solid electrolyte, effectively overcomes the low ionic conductivity and poor stability of powder molecular sieve-pressed solid electrolytes, thus improving the performance of solid electrolytes.

[0054] On the other hand, the raw materials for Si-OM-based materials are generally similar to those for molecular sieves, so they are widely available and inexpensive, which can effectively reduce production costs.

[0055] In one embodiment, the silicon source is one or a combination of two or more of silicates, silicon tetrachloride, silica sol, tetraethyl orthosilicate, fumed silica, or silica.

[0056] In one embodiment, the aluminum source comprises 0%-70% by mass in the raw materials of the Si-OM-based material. When the aluminum source comprises 0% by mass, the solid electrolyte preform does not contain aluminum. The aluminum source comprises 0%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, or 70% by mass, or any combination thereof.

[0057] In one embodiment, the aluminum source is one or a combination of two or more of aluminum isopropoxide, sodium aluminate, aluminum chloride, aluminum sulfate, aluminum nitrate, boehmite, aluminum sol, boehmite, aluminum hydroxide, or aluminum oxide.

[0058] In one embodiment, the titanium source comprises 0%-50% by mass in the raw materials of the Si-OM-based material. When the titanium source comprises 0% by mass, the solid electrolyte preform does not contain the titanium source. The titanium source comprises 0%, 2%, 4%, 6%, 8%, 10%, 15%, 20%, 30%, 40%, or 50% by mass, or any combination thereof.

[0059] In one embodiment, the titanium source is one or a combination of two or more of titanium tetrachloride, tetrabutyl titanate, tetraethyl titanate, titanium isopropoxide, titanium sulfate, titanium oxysulfate, titanium silicate, strontium titanate, titanium bromide, aluminum titanate, lithium titanate, titanium oxalate, and titanium dioxide.

[0060] In one embodiment, the germanium source has a mass percentage content of 0%-50% in the raw materials of the Si-OM-based material. When the mass percentage content of the germanium source is 0%, the solid electrolyte preform does not contain the germanium source. The mass percentage content of the germanium source in the raw materials of the Si-OM-based material is one or any two of the following values: 0%, 5%, 10%, 15%, 20%, 25%, 30%, 40%, or 50%.

[0061] In one embodiment, the germanium source is one or a combination of two or more of tetramethyl germanium, tetraethyl germanium, germanium oxalate, germanium oxide, orthogermate, digermate, tetragermate, germanium silicate, trimethyl germanium chloride, germanium sulfide, germanium sulfate, germanium chloride, germanium nitrate, or germanium phosphate.

[0062] In one embodiment, the alkali source has a mass percentage content of 0%-30% in the raw materials of the Si-OM-based material. When the mass percentage content of the alkali source is 0%, the solid electrolyte preform does not contain the alkali source. The mass percentage content of the alkali source in the raw materials of the Si-OM-based material is a range of one or both of 0%, 2%, 4%, 6%, 8%, 10%, 15%, 20%, or 30%.

[0063] The alkali source is one or a combination of two or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, or organic amines.

[0064] In one embodiment, the raw materials of the Si-OM-based solid electrolyte further contain a pore-forming agent and / or an activator. The pore-forming agent is a conventionally used pore-forming agent in the art, and those skilled in the art can select and use such agents to produce the corresponding pore-forming effect. Examples include starch and methylcellulose.

[0065] In one embodiment, the pore-forming agent has a mass percentage content of 0%-30% in the raw materials of the Si-OM-based material. When the mass percentage content of the pore-forming agent is 0%, the solid electrolyte preform does not contain the pore-forming agent. The mass percentage content of the pore-forming agent in the raw materials of the Si-OM-based material is one or any two of the following: 0%, 2%, 4%, 6%, 8%, 10%, 15%, 20%, or 30%.

[0066] In one embodiment, the activator is one or a combination of two or more of the following: ammonia, dimethylamine, trimethylamine, diethylamine, triethylamine, ammonium chloride, sodium chloride, ammonium iodide, ammonium fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluorosilicate, ammonium fluoroaluminate, aluminum fluorosilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, lithium carbonate, sodium carbonate, potassium bicarbonate, lithium bicarbonate, sodium bicarbonate, lithium phosphate, sodium phosphate, potassium phosphate, potassium hydrogen phosphate, lithium hydrogen phosphate, sodium hydrogen phosphate, potassium dihydrogen phosphate, lithium dihydrogen phosphate, or sodium dihydrogen phosphate.

[0067] In one embodiment, the activator has a mass percentage content of 0%-50% in the raw materials of the Si-OM-based material. When the mass percentage content of the activator is 0%, the solid electrolyte preform does not contain the activator. The mass percentage content of the activator in the raw materials of the Si-OM-based material is one or any two of the following values: 0%, 2%, 4%, 6%, 8%, 10%, 15%, 20%, 25%, 30%, 40%, or 50%.

[0068] In one embodiment, the raw materials of the Si-OM-based solid electrolyte also contain ion migration element precursors; the ion migration elements are mainly metal salts added to ensure that the solid electrolyte contains the elements that need to migrate.

[0069] In one embodiment, the ion migration element precursor has a mass percentage content of 0%-20% in the raw materials of the Si-OM-based material. When the mass percentage content of the ion migration element precursor is 0%, the solid electrolyte preform does not contain the ion migration element precursor. The mass percentage content of the ion migration element precursor in the raw materials of the Si-OM-based material is a range of 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, or 20%, or any combination thereof.

[0070] In one embodiment, the ion migration element is a zinc precursor, a lithium precursor, or a sodium precursor.

[0071] In one embodiment, the ion migration element precursor is one or more of zinc sulfate, zinc carbonate, zinc chloride, zinc iodide, zinc nitrate, zinc bromide, zinc gluconate, zinc octanoate, zinc thiophosphate dioctyl alkyl salt, amino acid chelate zinc, metallic zinc, zinc hydroxide, or zinc oxide.

[0072] In one embodiment, the ion migration element precursor is one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium carbonate, lithium sulfate, lithium chloride, lithium nitrate, lithium chloride, lithium bromide, lithium oxide, or lithium hydroxide.

[0073] In one embodiment, the ion migration element precursor is one or more of sodium chloride, sodium carbonate, sodium sulfate, sodium nitrate, sodium thiosulfate, sodium perrhenate, sodium fluoride, sodium bromide, sodium benzoate, sodium acetate, sodium oxide, or sodium hydroxide.

[0074] In one embodiment, the raw materials of the Si-OM-based solid electrolyte also contain additives and dispersants.

[0075] In one embodiment, the additive is one or more of the following: metal oxides, metal hydroxides, metal salts, and organic salts of magnesium, calcium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc.

[0076] In one embodiment, the additive contains 0%-20% by mass in the raw materials of the Si-OM-based material. When the additive contains 0% by mass, the solid electrolyte preform does not contain the additive. The additive contains 0% by mass in the raw materials of the Si-OM-based material within a range of one or both of the following: 0%, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, or 20%.

[0077] In one embodiment, the dispersant is one or a combination of two or more of water, methanol, ethanol, propanol, ethylene glycol, propylene glycol, butanediol, acetone, tetrahydrofuran, dimethyl ether, N-methylpyrrolidone, or N,N-dimethylformamide. The dispersant facilitates the uniform dispersion and mixing of the raw materials and the formation of the preform.

[0078] In one embodiment, the solid electrolyte preform is prepared by extrusion, pressing, coating, blade coating, or self-assembly. Extrusion, pressing, coating, blade coating, or self-assembly are all conventional methods for preparing preforms in the art. By selecting appropriate parameters and conditions using the above methods, preforms that meet the requirements of solid electrolytes can be prepared.

[0079] In one embodiment, the hydrothermal synthesis involves dissolving the raw materials of the Si-OM-based solid electrolyte in water to prepare an aqueous synthesis solution, then placing the solid electrolyte preform in the synthesis solution, and then crystallizing and transforming it.

[0080] In this embodiment, the raw materials for the Si-OM-based solid electrolyte in the aqueous synthesis solution are raw materials prepared according to the ratio of the embryo material. One part of the two raw materials is used to prepare an embryo, and the other part is dissolved in water to prepare the aqueous synthesis solution. The mass concentration of the synthesis solution is generally 0.05-0.2 g / ml.

[0081] In one embodiment, the solvothermal synthesis involves dissolving the raw materials of the Si-OM-based solid electrolyte in an organic solvent or a mixed solvent consisting of water and an organic solvent to prepare a solvent synthesis solution, then placing the solid electrolyte preform in the synthesis solution, and then crystallizing and transforming it.

[0082] The organic solvent is one or more of the following: alcohols, ketones, ethers, or amides, which are miscible with water.

[0083] Preferably, the organic solvent is one or more of acetone, tetrahydrofuran, N,N-dimethylformamide, methanol, ethanol, propanol, ethylene glycol, propylene glycol, or butanediol. In one embodiment, the solvent-free synthesis is to directly crystallize the solid electrolyte preform in a crystallization reactor.

[0084] In one embodiment, the solvent-free synthesis involves placing a solid electrolyte preform in a crystallization vessel containing water, ammonia, organic amines, or ammonium salts, without contact between the vessel and the solid electrolyte preform, followed by crystallization transformation.

[0085] Preferably, the mass content of ammonia, organic amine or ammonium salt in solvent-free synthesis is 0.01%-99%.

[0086] In one embodiment, the crystallization transformation temperature is 60℃-280℃, and the crystallization transformation time is 0.5h-160h.

[0087] In one embodiment, the calcination temperature is 300-2000℃ and the calcination time is 0.5h-24h.

[0088] In one embodiment, the ion exchange process involves immersing the baked electrolyte preform in a zinc, lithium, or sodium salt solution for 1-120 hours. The primary purpose of ion exchange is to introduce the desired migrating elements into the solid electrolyte.

[0089] This application provides a Si-OM-based solid electrolyte, prepared by the method described above. The Si-OM-based solid electrolyte is amorphous or microcrystalline, and contains a large number of channels for ion transport.

[0090] This application provides a battery including a Si-OM-based solid electrolyte as described above.

[0091] The following specific examples will provide further details.

[0092] Example 1

[0093] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0094] 1) Mix and grind 3 g of sodium aluminate, 12 g of fumed silica and 0.5 g of starch until completely mixed and homogeneous, and then press them into solid electrolyte preforms using a tablet press.

[0095] 2) Place the solid electrolyte preform in a crystallization vessel, and add 1 ml of ammonia water to the crystallization vessel without contacting the solid electrolyte preform. After sealing the crystallization vessel, perform phase conversion at 180℃ for 24 hours.

[0096] 3) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace and calcined at 450°C for 6 hours. Then, it is immersed in a 2 mol / L zinc sulfate solution for 6 hours, and then dried to obtain Si-O-Al solid electrolyte.

[0097] SEM image of Si-O-Al solid electrolyte as shown in Figure 1 Figure 1 As shown; XRD pattern as shown Figure 2 As shown; the cycle performance results of the zinc-zinc symmetric battery are as follows. Figure 3 As shown.

[0098] from Figure 2 As can be seen, the Si-O-Al solid electrolyte has an amorphous structure. From... Figure 1 The SEM images show that the Si-O-Al solid electrolyte has a porous network structure.

[0099] Figure 3 Cycling performance results showed that the zinc ion migration rate was 6.32 mS / cm, the ion transference number was 0.68, and the zinc-zinc symmetric cell operated at 1 mA·cm⁻¹. -2 Current density, 1 mAh·cm -2 It can cycle stably for 1800 hours at its capacity. It has good electron migration capability and battery stability.

[0100] Example 2

[0101] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0102] 1) Mix 15 g sodium aluminate, 3 g tetrabutyl titanate, 27 g fumed silica and 1 g methylcellulose and grind until completely homogeneous, then press into a solid electrolyte preform using a tablet press.

[0103] 2) Place the solid electrolyte preform in a crystallization vessel, and add 1 ml of ammonia water to the crystallization vessel. After sealing the crystallization vessel, perform phase conversion at 140℃ for 12 hours.

[0104] 3) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace and calcined at 400°C for 6 hours. Then, it is immersed in a 1 mol / L lithium chloride solution for 24 hours, and after drying, Si-O-Al(Ti) solid electrolyte is obtained.

[0105] SEM image of Si-O-Al(Ti) solid electrolyte as shown in Figure Figure 4 As shown.

[0106] The prepared solid electrolyte exhibits a lithium-ion migration rate of 3.27 mS / cm and an ion transference number of 0.57. The full cell operates at 0.5 mA·cm⁻¹. -2 Current density, 0.5 mAh·cm -2 It can stably cycle for 1000 hours at its capacity.

[0107] Example 3

[0108] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0109] 1) Mix and grind 8.8 g of tetraethylgermanium and 30.5 g of sodium silicate nonahydrate until they are completely mixed and homogeneous, and then prepare a solid electrolyte preform by a scraping method;

[0110] 2) The solid electrolyte preform was placed in a crystallization vessel, and after the crystallization vessel was sealed, it underwent phase transformation at 140℃ for 12 hours;

[0111] 3) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace at 600°C for 10 hours. Then, it is immersed in a 0.5 mol / L sodium nitrate solution for 8 hours. After drying, Si-O-Ge solid electrolyte is obtained.

[0112] SEM images of Si-O-Ge solid electrolytes are shown below. Figure 5 As shown, the cycle performance results of the zinc-zinc symmetric battery are as follows: Figure 6 As shown.

[0113] The prepared solid electrolyte exhibits a lithium-ion migration rate of 2.47 mS / cm and an ion transference number of 0.59. The full cell operates at 1 mA·cm⁻¹. -2 Current density, 1 mAh·cm -2 It can stably cycle for 2000 hours at its capacity.

[0114] Example 4

[0115] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0116] 1) Mix and grind 6.5 g sodium aluminate, 7.2 g sodium silicate nonahydrate, 1.2 g sodium hydroxide, 1.4 g potassium titanium oxalate and 1.5 g copper chloride until they are completely mixed and homogeneous, and then use a scraping method to prepare a solid electrolyte preform;

[0117] 2) Place the solid electrolyte preform in a crystallization vessel, and add a small amount of water so that the water just covers the solid electrolyte preform. After sealing the crystallization vessel, perform a phase transformation at 200℃ for 24 hours.

[0118] 3) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace and calcined at 700°C for 6 hours. Then, it is immersed in a 2 mol / L zinc sulfate solution for 8 hours. After drying, copper-modified Si-O-Al(Ti) solid electrolyte is obtained.

[0119] The prepared solid electrolyte exhibits a zinc ion migration rate of 4.15 mS / cm and an ion transference number of 0.79. The full cell operates at 1 mA·cm⁻¹. -2 Current density, 1 mAh·cm -2 It can stably cycle for 1200 hours at its capacity.

[0120] Example 5

[0121] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0122] 1) Mix 7.2 g sodium silicate nonahydrate, 1.2 g sodium hydroxide, 1.4 g potassium titanium oxalate and 1.5 g nickel nitrate with 1 g PTFE and 2 g water and grind until completely mixed and uniform. Then, use a roller method to prepare a solid electrolyte preform.

[0123] 2) The solid electrolyte preform was placed in a crystallization vessel, and after the crystallization vessel was sealed, it underwent phase transformation at 80°C for 5 hours;

[0124] 3) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace and calcined at 500°C for 5 hours. Then, it is immersed in a 2 mol / L LiFSI solution for 24 hours. After drying, nickel-modified Si-O-Ti solid electrolyte is obtained.

[0125] SEM images of Si-O-Ti solid electrolytes are shown below. Figure 7 As shown.

[0126] The prepared solid electrolyte exhibits a lithium-ion migration rate of 3.77 mS / cm and an ion transference number of 0.63. The full cell operates at 1 mA·cm⁻¹. -2 Current density, 1 mAh·cm -2 It can stably cycle for 1100 hours at its capacity.

[0127] Example 6

[0128] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0129] 1) Mix 14 g of fumed silica, 0.3 g of lithium chloride, 7.5 g of sodium hydroxide, 1 g of PVDF and 10 g of water and grind until completely homogeneous, then use a roller method to prepare a solid electrolyte preform;

[0130] 2) The solid electrolyte preform was placed in a crystallization vessel, and after the crystallization vessel was sealed, it underwent phase transformation at 140℃ for 96 hours;

[0131] 3) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace at 800°C for 5 hours. Then, it is immersed in a 2 mol / L zinc sulfate solution for 24 hours. After drying, Si-O-Si solid electrolyte is obtained.

[0132] The prepared solid electrolyte exhibits a lithium-ion migration rate of 1.03 mS / cm and an ion transference number of 0.51. The full cell operates at 1 mA·cm⁻¹. -2 1 mAh·cm -2 It can stably cycle for 1050 hours at its capacity.

[0133] Example 7

[0134] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0135] 1) Mix and grind 5.5 g sodium aluminate, 6.2 g sodium silicate nonahydrate, 1.2 g sodium hydroxide, 1.4 g tetrabutyl titanate and 1.5 g chromium chloride until completely mixed and homogeneous, and then prepare a solid electrolyte preform by a scraping method;

[0136] 2) Add 2.5 g sodium aluminate, 3.2 g sodium silicate nonahydrate, 0.4 g sodium hydroxide and 0.6 g tetrabutyl titanate to 50 g water to prepare a synthesis solution;

[0137] 3) Place the solid electrolyte preform in a crystallization vessel, and simultaneously add the synthesis solution to cover the solid electrolyte preform. After sealing the crystallization vessel, perform a phase transformation at 100°C for 24 hours.

[0138] 4) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace at 50°C for 6 hours. Then, it is immersed in a 2 mol / L zinc sulfate solution for 8 hours. After drying, the chromium-modified Si-O-Al(Ti) solid electrolyte is obtained.

[0139] The prepared solid electrolyte exhibits a zinc ion migration rate of 5.16 mS / cm and an ion transference number of 0.71. The full cell operates at 1.5 mA·cm⁻¹. -2 Current density, 1.5 mAh·cm -2 It can stably cycle for 1300 hours at its capacity.

[0140] Example 8

[0141] A Si-OM-based solid electrolyte and its preparation method, comprising the following steps:

[0142] 1) Mix and grind 6.8 g of tetramethylgermanium and 30.5 g of sodium silicate nonahydrate until they are completely mixed and homogeneous, and then prepare a solid electrolyte preform by a scraping method;

[0143] 2) Add 1.8 g of tetramethylgermanium and 6.5 g of tetraethyl orthosilicate to methanol to prepare a methanol synthesis solution;

[0144] 3) Place the solid electrolyte preform in a crystallization reactor and add methanol synthesis solution at the same time. After sealing the crystallization reactor, perform phase conversion at 140℃ for 12 hours.

[0145] 4) After the crystallization vessel cools down, the solid electrolyte preform is taken out and placed in a muffle furnace and calcined at 500°C for 8 hours. Then, it is immersed in a 0.5 mol / L lithium nitrate solution for 8 hours, and then dried to obtain Si-O-Ge solid electrolyte.

[0146] The prepared solid electrolyte exhibits a lithium-ion migration rate of 2.77 mS / cm and an ion transference number of 0.69. The full cell operates at 0.5 mA·cm⁻¹. -2 Current density, 0.5 mAh·cm -2 It can stably cycle for 2000 hours at its capacity.

[0147] Comparative Example 1

[0148] A solid electrolyte and its preparation method, comprising the following steps:

[0149] 1) Mix 3 g of sodium aluminate with 12 g of fumed silica and 0.5 g of starch until completely mixed, and then press the mixture into a solid electrolyte morphology using a tablet press.

[0150] 2) It was placed in a muffle furnace and calcined at 450°C for 6 hours, and then immersed in a 2 mol / L zinc sulfate solution for 6 hours to obtain a solid electrolyte compared with Example 1.

[0151] The zinc ion migration rate of the prepared solid electrolyte is 0.009 mS / cm, which cannot meet the battery performance requirements.

[0152] Comparative Example 2

[0153] A solid electrolyte and its preparation method, comprising the following steps:

[0154] 1) Mix and grind 3 g germanium oxalate, 12 g fumed silica and 0.5 g methylcellulose until completely homogeneous, and then press into a solid electrolyte preform using a tablet press;

[0155] 2) Place the solid electrolyte preform in a crystallization vessel, and add 1 ml of ammonia water to the crystallization vessel without contacting the solid electrolyte preform. After sealing the crystallization vessel, crystallize at 180°C for 24 hours.

[0156] 3) After the crystallization vessel has cooled, the solid electrolyte preform is taken out and placed in a muffle furnace and calcined at 450°C for 6 hours to obtain the control solid electrolyte.

[0157] Since the solid electrolyte does not contain any ion-migrating elements, the zinc ions in the prepared solid electrolyte have an almost undetectable ion migration rate.

[0158] Comparative Example 3

[0159] A solid electrolyte and its preparation method, comprising the following steps:

[0160] 1) Mix and grind 2 g of titanium sulfate and 5 g of fumed silica until they are completely and evenly mixed, and then press them into solid electrolyte preforms using a tablet press.

[0161] 2) Place the solid electrolyte preform in a crystallization vessel, and add 1 ml of ammonia water to the crystallization vessel without contacting the solid electrolyte preform. After sealing the crystallization vessel, crystallize at 240℃ for 24 hours.

[0162] 3) Immerse in a 2 mol / L zinc sulfate solution for 6 hours, remove and dry to obtain a control solid electrolyte.

[0163] The lithium-ion migration rate of the prepared solid electrolyte is 0.004 mS / cm.

[0164] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0165] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0166] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a Si-OM-based solid electrolyte, characterized in that, Includes the following steps: The raw materials for synthesizing Si-OM-based solid electrolytes are made into solid electrolyte preforms; The embryo is subjected to phase transformation using hydrothermal conversion, solvothermal conversion, or solvent-free conversion; The embryo after phase transformation is subjected to high-temperature calcination and ion exchange treatment to prepare the Si-OM-based solid electrolyte; the Si-OM-based solid electrolyte is amorphous or microcrystalline. The raw materials for synthesizing the Si-OM-based solid electrolyte include one or more of the following: silicon source, aluminum source, germanium source, titanium source, or alkaline source. The hydrothermal conversion involves dissolving the raw materials of the Si-OM-based solid electrolyte in water to prepare an aqueous synthesis solution, then placing the solid electrolyte preform in the synthesis solution, followed by a phase inversion. The solvothermal conversion involves dissolving the raw materials of the Si-OM-based solid electrolyte in an organic solvent or a mixed solvent consisting of water and an organic solvent to prepare a solvent synthesis solution, then placing the solid electrolyte preform in the synthesis solution, and then performing a phase conversion. Alternatively, a solid electrolyte preform may be placed in a crystallization vessel containing water, ammonia, organic amines, or ammonium salts, wherein the container does not come into contact with the solid electrolyte preform, and then a phase transformation occurs. The phase transformation temperature is 60℃-280℃, and the phase transformation time is 0.5h-160h; The roasting temperature is 300-2000℃, and the roasting time is 0.5h-24h; The ion exchange process involves immersing the calcined electrolyte preform in a zinc, lithium, or sodium salt solution for 1-120 hours.

2. The method for preparing Si-OM-based solid electrolyte according to claim 1, characterized in that, The silicon source is one or a combination of two or more of silicates, silicon tetrachloride, silica sol, tetraethyl orthosilicate, or silicon dioxide. The aluminum source is one or a combination of two or more of the following: aluminum isopropoxide, sodium aluminate, aluminum chloride, aluminum sulfate, aluminum nitrate, boehmite, aluminum sol, boehmite, aluminum hydroxide, or aluminum oxide. The titanium source is one or a combination of two or more of the following: titanium tetrachloride, tetrabutyl titanate, tetraethyl titanate, titanium isopropoxide, titanium sulfate, titanium oxysulfate, titanium silicate, strontium titanate, titanium bromide, aluminum titanate, lithium titanate, titanium oxalate, and titanium dioxide. The germanium source is one or a combination of two or more of the following: tetramethyl germanium, tetraethyl germanium, germanium oxalate, germanium oxide, orthogermate, digermate, tetragermate, germanium silicate, trimethyl germanium chloride, germanium sulfide, germanium sulfate, germanium chloride, germanium nitrate, or germanium phosphate. The alkali source is one or a combination of two or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, or organic amines.

3. The method for preparing the Si-OM-based solid electrolyte according to claim 1, characterized in that, The raw materials for Si-OM-based solid electrolytes also contain pore-forming agents and / or activators; The activator is one or a combination of two or more of the following: ammonia, dimethylamine, trimethylamine, diethylamine, triethylamine, ammonium chloride, sodium chloride, ammonium iodide, ammonium fluoride, sodium fluoride, potassium fluoride, lithium fluoride, ammonium fluorosilicate, ammonium fluoroaluminate, aluminum fluorosilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, lithium carbonate, sodium carbonate, potassium bicarbonate, lithium bicarbonate, sodium bicarbonate, lithium phosphate, sodium phosphate, potassium phosphate, potassium hydrogen phosphate, lithium hydrogen phosphate, sodium hydrogen phosphate, potassium dihydrogen phosphate, lithium dihydrogen phosphate, or sodium dihydrogen phosphate.

4. The method for preparing Si-OM-based solid electrolyte according to claim 1, characterized in that, The raw materials for Si-OM-based solid electrolytes also contain ion migration element precursors; the ion migration elements are zinc precursors, lithium precursors, or sodium precursors. The ion migration element precursor is one or more of zinc sulfate, zinc carbonate, zinc chloride, zinc iodide, zinc nitrate, zinc bromide, zinc gluconate, zinc octanoate, zinc thiophosphate dioctyl alkyl salt, amino acid chelate zinc, metallic zinc, zinc hydroxide, or zinc oxide. The ion migration element precursor is one or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium bis(fluorosulfonyl)imide, lithium carbonate, lithium sulfate, lithium chloride, lithium nitrate, lithium bromide, lithium oxide, or lithium hydroxide. The ion migration element precursor is one or more of sodium chloride, sodium carbonate, sodium sulfate, sodium nitrate, sodium thiosulfate, sodium perrhenate, sodium fluoride, sodium bromide, sodium benzoate, sodium acetate, sodium oxide, or sodium hydroxide.

5. The method for preparing Si-OM-based solid electrolyte according to claim 1, characterized in that, The raw materials for Si-OM-based solid electrolytes also contain additives and / or dispersants; The additive is one or more of the following: metal oxides, metal hydroxides, and metal salts of magnesium, calcium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc. The dispersant is one or more of the following: water, methanol, ethanol, propanol, ethylene glycol, propylene glycol, butanediol, acetone, tetrahydrofuran, dimethyl ether, N-methylpyrrolidone, or N,N-dimethylformamide.

6. The method for preparing Si-OM-based solid electrolyte according to claim 1, characterized in that, The solid electrolyte preform can be prepared by extrusion, pressing, coating, scraping or self-assembly.

7. A Si-OM-based solid electrolyte, characterized in that, It is prepared by the method for preparing Si-OM-based solid electrolyte according to any one of claims 1-6.

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