153 results about "Lithium sulphate" patented technology

The invention relates to the technical field of preparation of lithium sulfide, in particular to a method for preparing lithium sulfide through hydrogen reduction of lithium sulfate. According to the specific technical scheme, the method for preparing the lithium sulfide by reducing the lithium sulfate through the hydrogen comprises the steps that the lithium sulfate is smashed to be micron-sized and then fed into a fluidized bed reactor, then high-purity hydrogen preheated to 850 DEG C is introduced into the fluidized bed reactor from the bottom of the fluidized bed reactor, the reaction temperature is controlled to be 850 + / -20 DEG C, and the reaction time is controlled to be 5-10 min. The hydrogen reduction method is relatively low in reaction temperature (700-900 DEG C), hydrogen is used as a clean reducing agent, a reaction byproduct is only water, and the problems of insufficient purity, high energy consumption, serious environmental pollution and the like in a traditional lithium sulfide preparation method can be avoided. The introduction of the fluidized bed technology can greatly enhance the gas-solid phase heat and mass transfer efficiency, realizes the continuity and automation of the process, and is an important path for realizing the industrialization of the reaction.

The application discloses a method for preparing high-purity battery-grade lithium sulfide by reducing lithium sulfate with a reducing gas. The specific steps are as follows: raw material lithium sulfate and inert wave-absorbing substances are mixed, uniformly mechanically ball-milled, tablet-pressed, sieved, put into a microwave reactor, and then a reducing gas is introduced for microwave heating reaction; after cooling to room temperature, the mixture is discharged into another reactor, ethanol is added for dissolution, mechanical stirring is carried out, and then standing and filtration are performed; the inert wave-absorbing substances are recycled and reused; an ethanol solution of dissolved lithium sulfide is obtained; crude lithium sulfide is obtained by heating and distillation; after freeze-drying, the crude lithium sulfide is heated and secondarily calcined in a rotary furnace under the protection of inert gas, and finally battery-grade high-purity lithium sulfide is obtained. By mixing the inert wave-absorbing substances with the lithium sulfate and heating by the microwave method, the contact surface of the lithium sulfate and the gas can be improved, and in addition, the internal heating method can be used to avoid the lithium sulfide formed on the outer surface from wrapping the raw material lithium sulfate, so as to affect the hydrogen reduction efficiency.

The invention discloses a method for separating and recycling phosphorus, iron and lithium in battery black powder, and relates to the technical field of battery recycling. The method comprises the following steps: carrying out acid leaching on battery black powder to obtain a battery black powder leaching solution and filter residues; an oxidizing agent is added into the battery black powder leaching solution, the pH of the solution is adjusted to 1.8-2.5, solid-liquid separation is conducted after the reaction is completed, and iron phosphate sediment and a lithium-containing solution are obtained; adjusting the pH value of the lithium-containing solution to 10-12, and carrying out solid-liquid separation after the reaction is completed to obtain a metal precipitate and a lithium sulfate solution; dissolving the iron phosphate precipitate in a sulfuric acid solution, adding a reducing agent to reduce ferric iron into ferrous iron, separating out ferrous sulfate by adopting an alcohol precipitation method or an ammonium sulfate crystallization method, and performing solid-liquid separation after the reaction is completed to obtain ferrous sulfate precipitate or ammonium ferrous sulfate crystals and mother liquor; and evaporating and concentrating the mother liquor, and extracting to obtain a phosphoric acid solution. According to the method, the three elements of phosphorus, iron and lithium in the battery black powder can be recycled, and the environmental problem caused by stacking of the lithium extraction slag can be avoided.

The invention discloses a lithium dihydrogen phosphate preparation method, which comprises: S1, mixing a refined lithium sulfate solution with an extraction agent solution, and carrying out standing layering to obtain an upper layer solution; s2, mixing the upper-layer solution with a detergent, washing, and separating to obtain a washing solution; s3, mixing the washing liquid with a phosphoric acid solution, and standing for layering to obtain a lower-layer solution; s4, mixing the lower-layer solution with a component regulator; and carrying out solid-liquid separation. An extracting agent in the extracting agent solution comprises at least one of benzoyl trifluoroacetone, trialkyl phosphine oxide and sulfonated calixarene. The specific extraction agent efficiently selects lithium ions to separate impurities, lithium dihydrogen phosphate is obtained through direct reverse extraction after washing, lithium dihydrogen phosphate does not need to be converted into other lithium products to prepare lithium dihydrogen phosphate, and the process production period is shortened. In addition, lithium dihydrogen phosphate is prepared through washing and reverse extraction after impurities are efficiently selected and separated through an extraction agent; the purity is high; the battery grade lithium dihydrogen phosphate can be obtained.

The invention discloses a quick-hardening early-strength concrete mineral additive and a preparation method thereof, and belongs to the technical field of building materials. The additive comprises the following components in parts by weight: 50-75 parts of a mineral active material (compounded by silica fume, slag powder and metakaolin), 15-30 parts of a composite activator (sodium silicate, lithium sulfate and triethanolamine synergistically), 5-10 parts of a sustained-release microcapsule (calcium sulphoaluminate coated with nano-silica) and 2-5 parts of an auxiliary thickening agent (compounded by HPMC and a water reducing agent). The preparation method comprises the steps of mineral activation, excitant reaction and mixing of the microcapsule and the thickening agent. After the additive is doped into concrete, the 3h compressive strength is greater than or equal to 15MPa, the initial setting time is less than or equal to 5min, and the additive has low resilience (less than or equal to 13%), high durability (impermeability is greater than or equal to P11) and environmental adaptability (-5 DEG C strength fluctuation ratio is less than or equal to 9%). And compared with the prior art, the cost is reduced by 40%, and the method has remarkable economic and social benefits.

The invention discloses a method for directly preparing high-purity Li2S by utilizing carbothermal reduction, which comprises the following steps: ball-milling and mixing Li2SO4.H2O and a carbon source, and carrying out first-step calcination in an air atmosphere at the calcination temperature of 450-550 DEG C to obtain a first-step calcination product; carrying out ball-milling mixing on the first-step calcined product and sublimed sulfur powder, tabletting, and carrying out second-step calcination at the calcination temperature of 700-800 DEG C under the protection of inert gas to obtain a second-step calcined product; and continuously performing third-step calcination on the second-step calcination product under the protection of inert gas at the calcination temperature of 850-950 DEG C to obtain the product Li2S. Lithium sulfate and a high-purity carbon source are adopted as main raw materials, sublimed sulfur powder is introduced in the second-step calcination process to inhibit generation of Li2O, after the carbon source is consumed in the second-step calcination process, a mixture of lithium sulfide and residual lithium sulfate is obtained, the temperature continues to rise, third-step calcination is conducted, the residual lithium sulfate is molten, volatilized and removed, and the lithium sulfide is obtained. And discharging the mixture out of the tubular furnace along with the gas flow of the inert gas to obtain high-purity lithium sulfide.

The invention discloses a preparation method of high-purity lithium sulfide based on a carbon reduction method, and belongs to the technical field of material preparation. Comprising the following steps: S1, mixing anhydrous lithium sulfate with a reducing agent, and adding absolute ethyl alcohol as a solvent, S2, drying a material subjected to wet grinding, removing the absolute ethyl alcohol solvent and water, and transferring the material into a tubular furnace or an atmosphere sintering furnace to obtain a dried material; s3, the environment temperature in the furnace is increased to 600-800 DEG C at the heating rate of 5-12 DEG C / min, heat preservation is conducted for 30-60 min, and a reduction reaction is conducted; s4, after a reduction reaction product is cooled to the room temperature, adding absolute ethyl alcohol, stirring until the absolute ethyl alcohol is fully dissolved, completing solid-liquid separation through a suction filtration device, collecting filtrate and distilling; and S5, drying the distilled product to obtain the high-purity lithium sulfide. By accurately controlling the raw material purity, the reaction parameters and the purification process, the product purity is greater than or equal to 99.5%, the yield is greater than or equal to 89%, and the high-performance application requirements of solid-state batteries and the like are completely met; the method is simple in process steps, moderate in equipment requirements and suitable for large-scale industrial production.

The invention belongs to the technical field of building materials, and provides an early-strength cement-based grouting material and a preparation method thereof.The early-strength cement-based grouting material is prepared from, by weight, 500-600 parts of sulphoaluminate cement, 200-300 parts of Portland cement, 40-100 parts of lithium slag, 1-3 parts of a coagulant, 0.5-1 part of an early strength agent, 5-8 parts of a water reducing agent, 0.5-2.5 parts of a thickening agent, 0.3-0.9 part of a defoaming agent and 260-310 parts of water; the coagulant is sodium metaaluminate and / or potassium metaaluminate; the early strength agent is selected from one or more than two of lithium carbonate, lithium sulfate, calcium formate, calcium acetate, calcium propionate, calcium butyrate and nano silicon dioxide. According to the technical scheme, the problems of poor dispersion resistance and low early strength of a cement-based grouting material in a flowing water environment in the prior art are solved.

A method for producing lithium sulfide according to the present invention is characterized by having a raw material mixing step (S1) in which lithium sulfate and a carbon material are mixed to form a mixed raw material, and a thermal reduction step (S2) in which the mixed raw material is heat-treated in a non-oxidizing atmosphere and the lithium sulfate is thermally reduced to generate lithium sulfide, the method also being characterized in that a carbon powder having a specific surface area measured by the BET method of 55 m2 / g or greater is used as the carbon material. A method for producing a sulfide-based solid electrolyte according to the present invention is characterized in that lithium sulfide produced through the method for producing lithium sulfide according to the present invention is used as a raw material.

The present disclosure is directed to systems and methods of leaching lithium sources using sodium sulfate. The process can include mixing a lithium source, a first sodium sulfate, and lithium hydroxide in a reactor and leaching the lithium source in the mixture in the reactor to form residual solids and a lithium sulfate leachate.

The invention discloses a lead-lithium battery negative electrode material composite formula and a processing technology, and belongs to the technical field of lead-lithium batteries, the lead-lithium battery negative electrode material composite formula comprises the following components by weight: 80-90 parts of a high-entropy lead powder composite material, 2-5 parts of a novel composite expanding agent, 1-3 parts of a conductive reinforcing agent, 5-8 parts of a lithium sulfate-MOF electrolyte with a concentration of 0.5-1.5 mol / L, and 3-6 parts of a binder, the negative electrode material has the advantages of being capable of effectively dispersing the additive and avoiding overgrowth of lead sulfate crystals, and the problems that an existing negative electrode material composite formula of the lead-lithium battery cannot avoid overgrowth of the lead sulfate crystals and an existing processing technology cannot ensure uniform dispersion of the additive, and then the discharge performance and the overall service life of the lead-lithium battery are affected are solved.

The present invention relates to a method for recovering lithium from a lithium-containing waste liquid, the method including the steps of: filtering a cathode material wash solution to separate solid metals contained in the basic waste liquid; adding sulfuric acid to the cathode material wash solution from which the solid metals have been filtered to acidify it and convert lithium carbonate or lithium hydroxide into lithium sulfate; concentrating the wash solution converted into lithium sulfate to obtain a high-concentration lithium sulfate solution; and mixing the high-concentration lithium sulfate solution with a resultant product obtained by leaching from an ore.

The invention provides a method for preparing high-purity lithium sulfate from a lithium-sodium mixed solution. The method comprises the following steps: providing a lithium-sodium mixed sulfate solution; the method comprises the following steps: based on a Li2SO4-Na2SO4-H2O ternary system phase diagram, evaporating and concentrating a lithium-sodium mixed sulfate solution to be saturated, and then freezing and denitrifying to obtain a denitrified solution; evaporating the denitrated solution to a co-saturation point of lithium-sodium mixed sulfate, carrying out lithium precipitation, and separating to obtain a lithium precipitation mother solution and a lithium sulfate monohydrate crude product; purifying the lithium sulfate monohydrate crude product to obtain a high-purity lithium sulfate product; freezing and crystallizing the lithium precipitation mother solution, and separating to obtain a lithium-sodium mixed sulfate hydrate and a frozen solution; the lithium-sodium mixed sulfate hydrate is returned to the lithium-sodium mixed sulfate solution, and the frozen liquid is returned to the denitrated liquid. According to the method, the process is simplified, the lithium recovery rate is increased, cost reduction and efficiency improvement are achieved, material recycling can be achieved in the whole process, and the development prospect is good.

This invention provides a method and apparatus for lithium recovery from a high-sodium, low-lithium solution via cryogenic sodium precipitation and targeted extraction. The method comprises the following steps: S1, weighing sodium sulfate and lithium sulfate samples, dissolving them in deionized water to prepare a high-sodium, low-lithium solution; S2, determining the lithium and sodium ion content of the high-sodium, low-lithium solution using ICP-MS and atomic absorption spectroscopy; S3, freezing the high-sodium, low-lithium solution prepared in step S1 in a circulating freezer to obtain a solid-liquid mixture. The method and apparatus provided by this invention achieve low lithium carryover during sodium precipitation from a high-sodium, low-lithium solution, further realizing high-efficiency lithium resource recovery. Compared with traditional processes, the lithium carryover rate during sodium precipitation can be reduced to 0.2%, reducing energy consumption and operational difficulty while improving lithium recovery rate, making it suitable for industrial production.

A method for producing battery-grade lithium dihydrogen phosphate using lithium-containing brine includes the following steps: (1) adding sodium hydroxide solution to lithium-containing mother liquor, adding the mixed solution to sodium dihydrogen phosphate solution, maintaining the pH of the system at 9-11, reacting, separating the solid and liquid phases to obtain lithium phosphate precipitate and mother liquor; (2) adjusting the slurry, adding concentrated sulfuric acid to react, separating the solid and liquid phases to obtain a mixed solution of liquid-phase lithium dihydrogen phosphate and lithium sulfate; (3) vacuum cooling and crystallization separation to obtain lithium dihydrogen phosphate crystals. This invention achieves efficient recovery of lithium ions from low-concentration lithium-containing brine, eliminating the need for conventional processes such as electrodialysis and MVR for further concentration of lithium-containing mother liquor. It also avoids the use of phosphoric acid in the acidification process, saving raw material costs, reducing the amount of water added in the acidification process, and reducing energy consumption in the crystallization separation process. The resulting battery-grade lithium dihydrogen phosphate is of stable quality, uniformly distributed, and bright white in color, suitable for preparing lithium-ion battery cathode materials, and has a low cost.

The application discloses a method for preparing battery-grade lithium phosphate based on step-by-step precipitation and double washing and application thereof. The method takes crude lithium sulfate as raw material, and through an integrated process of step-by-step precipitation and double washing, the problem of the wrapping of impurity sodium ions and sulfate in the lithium precipitation process of the crude lithium sulfate is solved, and the production cost of the lithium phosphate is reduced, so that the method is suitable for the industrialized production of lithium ion battery positive material precursors. The application mainly controls the impurity content from two aspects. Through step-by-step precipitation and crystal type induced generation, the wrapping of impurities in the product crystal grains can be reduced, and the double washing scheme can remove the residual impurities in the crystal grain gaps. The purpose of the crystal type induced generation is to guide the generation of large crystals and reduce the specific surface area, so that the Na adsorption amount is reduced.

The invention discloses a lithium source impurity removal method, lithium phosphate and a preparation method thereof, and belongs to the technical field of battery materials. The invention solves the problem of how to provide a method for preparing high-purity lithium phosphate from a lithium source in lithium ore. The method comprises the step of removing impurities from a lithium source, and specifically comprises the following steps: roasting lithium ore, and leaching a product obtained after roasting to obtain a lithium sulfate solution; adding one or more of ammonia water, ammonia gas or liquid ammonia into the lithium sulfate solution to adjust the pH value to 8-11, and then filtering to obtain primary purified mother liquor; adding monoammonium phosphate or / and diammonium phosphate into the primary purified mother liquor, adjusting the pH value to 8-11 again, reacting under the stirring condition, and filtering to obtain secondary purified mother liquor; and adding EDTA (Ethylene Diamine Tetraacetic Acid) into the secondary purified mother liquor to obtain the lithium sulfate purified mother liquor. And adding one or more of ammonia water, ammonia gas or liquid ammonia into the monoammonium phosphate solution to adjust the pH value to 8-11, and adding the purified lithium sulfate mother liquor into the monoammonium phosphate solution to obtain the high-purity lithium phosphate.

A process for preparing metal oxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprising:reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum with lithium hydroxide and optionally a chelating agent to obtain a solid comprising a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum, and a liquid comprising lithium sulfate, the metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum;separating the liquid and the solid from one another to obtain the metal hydroxide;submitting the liquid comprising lithium sulfate to an electromembrane process for converting the lithium sulfate into lithium hydroxide; andreusing at least a first portion of said lithium hydroxide obtained by the electromembrane process for reacting with the metal sulfate;reacting at least a second portion of said lithium hydroxide obtained by the electromembrane process with the obtained metal hydroxide to obtain a mixture of metal hydroxides; androasting said mixture of metal hydroxides to obtain the metal oxide.

The invention relates to the technical field of piping inverted filter bricks, in particular to a cement-based piping inverted filter brick and a preparation method thereof. Which comprises Portland cement, mineral powder, fly ash, silica fume, recycled aggregate and an additive. The method comprises the following steps: mixing the recycled aggregate, the Portland cement, the mineral powder and the silica fume; sequentially adding latex powder, a water reducing agent, sodium citrate, tartaric acid, lithium sulfate or lithium carbonate, cellulose ether, a defoaming agent and a dispersing wetting agent, and uniformly stirring; after being uniformly stirred to prepare mortar, the mortar and tap water are uniformly stirred and mixed at a high speed, and the addition amount of the water is 8-10% of the total mass of the mortar; the cement-based piping anti-filtration mortar is poured into a mold to prepare the high-strength piping anti-filtration brick, and the high-strength piping anti-filtration brick is used after being cured to a specified age after being demolded, so that the effects of increasing the manufacturing speed of the piping anti-filtration well, reusing the materials and not preparing the materials of the piping anti-filtration well are realized, and the manpower and the time are saved.

The application belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a MXene two-dimensional material, a graphite negative electrode material and a preparation method of the MXene two-dimensional material, the preparation method of the MXene two-dimensional material being as follows: lithium sulfate solution is added into a MXene dispersion liquid, stirred uniformly, vacuum dried, calcined at 300-500 DEG C, and the MXene two-dimensional material is obtained; and the application can effectively improve lithium ion conductivity and improve the performance of a battery.

Capture mixtures and activated capture mixtures are provided that are useful for nucleic acid separation and purification are provided. The mixtures comprise lithium lauryl sulfate, lithium hydroxide, a zwitterionic sulfonic acid buffering agent, and optionally, proteinase K, capture probes comprising a first specific binding partner (SBP), and a second specific binding partner immobilized to a solid support. Related combinations, methods, uses, and kits, are also provided.

The invention relates to the technical field of drain valves, in particular to an improved drain valve for a lithium sulfate evaporative crystallization system, which comprises a valve body, a valve inner layer, a vapor-liquid pipe, a vapor stopping device, a valve cover, a backflow device, a backflow pipe and a filtrate box, a valve outer layer is arranged in the valve body, a vapor-liquid pipe is arranged on the outer surface of the valve body, a floating ball is arranged in the valve inner layer, a magnetic ball is arranged in the floating ball, a liquid supply pipe is arranged in the valve inner layer, and a magnetic ring is arranged at the end of the liquid supply pipe. The device has the advantages of being good in continuous drainage or exhaust capacity, stable in internal pressure, good in sealing performance, beneficial to separate exhaust and drainage, good in stability, light in overall weight and convenient to install.

The application discloses a mine filling and plugging material quick-setting additive and a preparation method thereof. The water-retaining agent in the quick-setting additive is a composite water-retaining system formed by hydroxypropyl methyl cellulose and modified starch. The hydroxypropyl methyl cellulose physically wraps free water in the slurry; the modified starch adsorbs water molecules through hydrogen bonding, and the double mechanism significantly reduces the bleeding rate; the coagulation accelerator adopts a spray drying wrapping technology, and a core-shell structure composite particle is constructed, in which aluminum lithium sulfate is used as a 'quick-release core', and active calcium silicate gel slurry obtained by the reaction of nano calcium silicate and sodium silicate is used as a'slow-release wrapping layer', so that the coagulation accelerator can promote coagulation, prevent sodium silicate from being consumed too early, and realize sustained coagulation. The early strength agent adopts a gel-gelling method, so that the early strength agent can provide persistent early strength excitation and solve the problem of weak late strength growth. The interface reinforcing agent can make the interface transition zone structure more strong and tough, and improve the integrity and damage resistance after the slurry coagulation and hardening.

The application discloses a preparation and purification method of high-purity radioiodine-labeled antigen. The method comprises the following steps: pre-activating carrier-free sodium iodine[125I] solution in an orthogonal solvation sensitization buffer containing lithium sulfate, 18-crown-6 and beta-cyclodextrin; adding antigen and chloramine-T for a labeling reaction; and performing magnetic separation and purification by using a suspension containing adamantane-modified magnetic microspheres and quaternary ammonium salt-modified strong anion exchange magnetic microspheres after the reaction. The orthogonal solvation effect is used to enhance the nucleophilic activity of iodine ions, and the amount of oxidizing agent is reduced to reduce protein damage; impurities are quickly removed through the double mechanisms of electrostatic adsorption and host-guest recognition. The application has the advantages of high labeling efficiency, high radiochemical purity of the product and complete retention of biological activity.

A method for recycling lithium dihydrogen phosphate to treat lithium sinking mother liquor, comprising the following steps: (1) adding a mixed solution of lithium dihydrogen phosphate and lithium sulfate into the lithium sinking mother liquor to obtain lithium phosphate precipitate and low-lithium mother liquor; (2) separating the lithium phosphate precipitate obtained in step (1), then adding the lithium phosphate precipitate into a sulfuric acid solution to react, obtaining a mixed solution of lithium dihydrogen phosphate and lithium sulfate, and simultaneously precipitating lithium sulfate monohydrate crystals; (3) separating, washing and collecting the lithium sulfate monohydrate crystals obtained in step (2); and returning the mixed solution of lithium dihydrogen phosphate and lithium sulfate obtained in step (2) to step (1) for recycling. The method realizes high-content and low-impurity recovery of lithium ions in the lithium sinking mother liquor, consumes an amount of sulfuric acid equivalent to that consumed in the acidification process of the lithium sinking mother liquor, recycles phosphate, only needs to supplement the loss of dissolution, the lithium recovery rate reaches more than 95%, and secondary lithium sinking is not needed, thus simplifying the process and reducing the production cost.

The invention provides a preparation method of lithium sulfide, a product and application, and belongs to the technical field of synthesis of inorganic compounds. According to the method, anhydrous lithium hydroxide or lithium oxide is taken as a lithium source, sulfur dioxide is taken as an acidifying agent, hydrogen or methane is taken as a reducing gas, and lithium sulfide with high product purity and low carbon content is obtained through four steps of lithium source pretreatment, lithium sulfite intermediate synthesis, lithium sulfite reduction and product post-treatment in sequence; the method can be directly applied to high-end fields such as all-solid-state batteries and lithium-sulfur batteries, and particularly has important significance and wide industrial application prospects for breaking through the industrialization bottleneck of all-solid-state batteries.

The present invention relates to a method for recycling all-solid-state rechargeable battery materials, the method comprising: heat-treating all-solid-state rechargeable battery materials, including lithium-containing materials and sulfide-based solid electrolytes, to convert same into lithium-recovery materials including lithium sulfate; and mixing the product of the heat treatment with an aqueous solvent to extract the lithium-recovery materials.

Provided is a method for producing a lithium carbonate from a basic lithium- and aluminum-containing waste liquid generated during a positive electrode material production process, the method comprising the steps of: (a) filtering the waste liquid to remove metal solids; (b) injecting carbon dioxide into the waste liquid removed of the metal solids, thereby converting a lithium hydroxide into a lithium bicarbonate; (c) adding an anion exchange resin to the lithium bicarbonate-containing waste liquid to convert a lithium sulfate into a lithium hydroxide; (d) injecting carbon dioxide into the lithium hydroxide-containing waste liquid to convert the lithium hydroxide into a lithium carbonate; and (e) concentrating the lithium carbonate-containing waste liquid using an evaporator and then recovering a solid lithium carbonate.

This invention belongs to the field of lithium sulfide technology and discloses a method and apparatus for preparing lithium sulfide by hydrothermal reduction. The method includes: mixing and dispersing lithium sulfate with a pore-forming agent to form a composite precursor; subjecting the composite precursor to hydrothermal reduction in a hydrogen-containing reducing atmosphere, with plasma used for external field enhancement during the hydrothermal reduction process, to obtain crude lithium sulfide. This invention can improve the preparation efficiency of lithium sulfide and obtain high-purity, high-yield lithium sulfide products.

The application discloses a preparation method for synthesizing sulfide solid-state batteries by using lithium sulfide, and belongs to the technical field of sulfide solid electrolytes. High-activity lithium sulfide is prepared by carbon thermal reduction of lithium sulfate monohydrate and graphite, and then, the high-activity lithium sulfide is mixed with lithium chloride, phosphorus pentasulfide and hyperbranched amphiphilic grinding aids as raw materials to obtain high-purity Li6PS5Cl electrolyte powder through pre-mixing, high-energy ball milling and high-temperature sintering, and then, the electrolyte film is prepared by pressing and molding, and a symmetrical battery is assembled. The high-activity lithium sulfide is prepared in situ by carbon thermal reduction, the raw material conversion rate is significantly improved, the synthesis cycle is shortened, and the generation of impurities is reduced; the powder dispersion is strengthened by the hyperbranched amphiphilic grinding aids, the obtained electrolyte has high cycle stability, long service life, high raw material utilization rate and excellent electrochemical performance, the process is efficient and simple, the conditions are controllable, and the process is suitable for industrialized production of high-performance full solid-state lithium batteries.