493 results about "Lithium sulfide" patented technology

The embodiment of the invention provides a synthesis method and application of lithium sulfide. The synthesis method of the lithium sulfide comprises the following steps: providing a sulfur source and a lithium source; performing first treatment on the sulfur source to obtain sulfur vapor; performing second treatment on the lithium source to obtain molten metal lithium; and in an inert atmosphere, introducing the sulfur vapor into the molten metal lithium, and reacting to generate lithium sulfide. According to the synthesis method and application of the lithium sulfide provided by the embodiment of the invention, the sulfur source is converted into the sulfur vapor, the lithium source is converted into the molten metal lithium, and the gas-liquid out-phase reaction is carried out in the inert atmosphere, so that the reaction efficiency and the purity are improved, the process is simplified, the cost is reduced, and the high-purity requirement can be met; the purity can be improved through raw material pretreatment of sulfur steam and molten metal lithium, and the strict requirement of a solid-state battery for high-purity lithium sulfide is met.

The invention discloses high-purity lithium sulfide as well as a preparation method and application thereof. The preparation method comprises the step that lithium hydride, lithium hydroxide and a sulfur source are subjected to a heating reaction in a dry inert atmosphere, and the high-purity lithium sulfide is obtained. The molar ratio of lithium hydride to lithium hydroxide is X: (10-X), and X is 1-6. The invention also discloses the prepared high-purity lithium sulfide and application of the high-purity lithium sulfide in preparation of sulfide solid electrolyte. Lithium hydroxide and lithium hydride are mixed to serve as a lithium source in lithium sulfide preparation, the lithium hydroxide quickly and uniformly reaches the reaction temperature by means of the characteristic that the lithium hydride reacts with a sulfur source to release heat and produce gas, the lithium hydride reacts to produce gas, meanwhile, discharging of product water vapor is facilitated, and oxygen in the environment is isolated; and hardening and generation of a side reaction product lithium sulfate are prevented, the conversion rate of lithium hydroxide to lithium sulfide is improved, and the raw material and process cost for preparing lithium sulfide is remarkably reduced.

The invention belongs to the technical field of lithium battery materials, and particularly relates to a preparation method of high-purity lithium sulfide. Comprising the following steps: putting lithium hydroxide and pure water into a reaction kettle, replacing air in the reaction kettle with nitrogen, starting the reaction kettle, and stirring and heating; introducing quantitative hydrogen sulfide gas from the bottom of the reaction kettle, and circulating the gas in the reaction kettle between liquid in the reaction kettle and a gas space through a gas circulating pump; and after the temperature of the reaction liquid in the kettle is reduced to 20-30 DEG C, filtering in a nitrogen atmosphere, washing the residual solid with quantitative ammonia water, transferring the filtered solid into a drying box, and purging and drying with nitrogen until no water exists, thereby obtaining the high-purity lithium sulfide. In the solvent method, water is used for replacing an organic solvent for reaction, the problems of organic solvent separation and recovery, hazardous waste treatment and the like are avoided, the cost is reduced, and the method is environment-friendly.

The invention provides a preparation method and application of lithium sulfide. The preparation method comprises the following steps: reacting a lithium source with a sulfur source; the lithium source is a solid lithium-containing substance with the purity of 99% or above and the whiteness of 86 or above; the solid lithium-containing substance is selected from one or more of anhydrous lithium hydroxide, lithium hydroxide monohydrate, lithium carbonate, lithium chloride, lithium bromide and lithium nitrate. According to the method, a solid lithium-containing substance with the purity of 99% or above and the whiteness of 86 or above is used as a lithium source and reacts with a sulfur source, and the ionic conductivity value of the Li6PS5Cl solid electrolyte prepared from the obtained lithium sulfide is stable. Experimental results show that the ionic conductivity can stably reach more than 2mS / cm.

The invention belongs to the technical field of solid-state batteries, and provides a lithium-sulfur-phosphorus-chlorine-bromine solid-state electrolyte, a preparation method thereof and an all-solid-state battery. The preparation method comprises the following steps: mixing lithium sulfide and phosphorus sulfide, and carrying out ball milling to obtain a lithium-sulfur-phosphorus ternary mixture; in protective gas, the lithium-sulfur-phosphorus ternary mixture, lithium chloride and lithium bromide are mixed and then subjected to ball milling, and a lithium-sulfur-phosphorus-chlorine-bromine mixture is obtained; and carrying out heat treatment on the lithium-sulfur-phosphorus-chlorine-bromine mixture in protective gas to obtain the lithium-sulfur-phosphorus-chlorine-bromine solid electrolyte. The lithium-sulfur-phosphorus-chlorine-bromine solid electrolyte provided by the invention not only improves the electrochemical stability, but also maintains the high ionic conductivity characteristic.

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 invention relates to the technical field of battery raw materials, in particular to a preparation method of lithium sulfide powder, the lithium sulfide powder and application, and the preparation method comprises the following steps: uniformly mixing lithium sulfate and a carbon source according to a preset proportion to obtain a first mixture; performing first heat treatment on the first mixture in inert gas to obtain a second mixture; and performing second heat treatment on the second mixture in reducing gas to obtain the lithium sulfide powder. The product obtained by the preparation method disclosed by the invention is the lithium sulfide powder, and the obtained lithium sulfide powder has the advantages of less oxygen and carbon impurities, higher purity and high reaction activity, and meets the synthesis requirements of the electrolyte; according to the preparation method, in the process of preparing lithium sulfide, toxic gas and organic solvent are not used, the reaction temperature is low, the energy consumption is low, the requirement on production equipment is low, the process is simple, the cost is low, harmful gas emission is avoided, safety and environment friendliness are achieved, and industrialization is easy to achieve.

The invention relates to a solid-phase preparation method and application of battery-grade lithium sulfide, and the preparation method comprises the following steps: (1) firstly, adopting industrial-grade lithium carbonate as a raw material, and carrying out pretreatment purification to remove sodium-calcium-magnesium metal ion impurities; (2) carrying out ball-milling mixing on the purified lithium carbonate raw material and sulfur powder, and carrying out low-temperature melting pre-sintering; (3) performing primary high-temperature calcination on the lithium carbonate and sulfur powder mixture under a protective atmosphere to synthesize a lithium sulfide crude product; (4) carrying out secondary high-temperature calcination on the lithium sulfide crude product in a protective atmosphere to remove excessive sulfur impurities and lithium polysulfide impurities so as to obtain purified lithium sulfide; and (5) carrying out ball milling and crushing on the obtained lithium sulfide, and screening to obtain the battery-grade lithium sulfide with different particle sizes. According to the preparation method, a high-temperature solid-phase synthesis method is adopted, and low-temperature melting pre-sintering and high-temperature two-step calcining methods are adopted, so that reaction byproducts are gas and are easy to remove, production and preparation of high-purity battery-grade lithium sulfide can be realized, and the product has excellent electrochemical performance.

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.

A method for synergistically preparing lithium sulfide by vacuum molten salt based on hydrogen sulfide-lithium salt reaction belongs to the technical field of battery materials, and comprises the following steps: placing a lithium salt solid in a reactor, introducing a molten salt medium on the surface of the lithium salt or in a reaction system, introducing purified hydrogen sulfide gas under a vacuum auxiliary condition, controlling the reaction temperature to be 200-500 DEG C, and reacting for 1-2 hours; and adjusting the flow rate of hydrogen sulfide to be 50-1000mL / min and the retention time to be 5-180min, continuously exhausting gas to discharge water vapor in the reaction process, stopping introducing hydrogen sulfide gas after the reaction is finished, cooling the system to room temperature under the protection of inert gas, taking out the product, washing to remove residual fused salt, and carrying out vacuum drying to obtain the high-purity lithium sulfide. The prepared lithium sulfide has high purity (greater than or equal to 99.90%), low defect density and an excellent crystal structure, and can be widely applied to lithium-sulfur batteries, all-solid-state batteries and novel energy storage technologies, so that the energy density is improved, the cycle life is prolonged, and the energy consumption is reduced.

The invention discloses a preparation method of lithium trifluoromethanesulfinate, and belongs to the field of lithium ion battery materials. The preparation method of the lithium trifluoromethanesulfinate comprises the following steps: 1, mixing trifluoromethanesulfonyl chloride, lithium sulfite, lithium bicarbonate and a first solvent, and heating to react; 2, dissolving the concentrated crude product in a second solvent, and filtering and separating a lithium sulfate solid; and 3, concentrating the filtrate, adding a third solvent, uniformly stirring, filtering and separating the lithium chloride solid, and concentrating to obtain the lithium trifluoromethanesulfinate. According to the method for preparing the lithium trifluoromethanesulfinate, the yield can reach 94%, the operation is simple, byproducts are easy to separate, and the method is suitable for industrial production. In addition, the obtained by-product lithium sulfate can be used for preparing lithium sulfide, the by-product lithium chloride can be used for preparing solid electrolyte, and resource utilization is achieved.

The invention discloses electronic-grade lithium sulfide as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing lithium sulfate with hydrogen under a vacuum condition, and carrying out a reduction reaction to prepare the electronic-grade lithium sulfide. According to the preparation method of the electronic-grade lithium sulfide, lithium sulfate is reduced through hydrogen, no waste gas or waste water is generated in the process, environment friendliness is achieved, unreacted hydrogen and water vapor return to the hydrogen storage tank, hydrogen can be reused, the water vapor settles to the bottom of the tank to be recycled after being condensed, the technological process is short, and the product purity is high; the method is suitable for large-scale popularization and application.

The invention relates to lithium sulfide and a preparation method thereof.The preparation method includes the following steps that sublimed sulfur powder and a lithium source are mixed and subjected to a heating reaction, and the lithium source comprises at least one of anhydrous lithium hydroxide, lithium hydroxide monohydrate, lithium oxide, lithium hydride and lithium carbonate; a reducing gas is introduced while the heating reaction is performed, or the reducing gas is introduced after the heating reaction is finished, and a reduction reaction is performed; and after the reaction is finished, introducing protective gas for calcining to prepare the lithium sulfide. The preparation method provided by the invention can realize low-cost and high-purity production of lithium sulfide, and ensures the safety and environmental protection of the production process.

The invention belongs to the field of solid-state battery manufacturing, and particularly relates to a low-cost method for synthesizing high-purity lithium sulfide, which comprises the steps of synthesizing high-purity lithium oxide and synthesizing high-purity lithium sulfide. The process for synthesizing Li2O is unique, lithium salt can be chemically reacted into lithium oxide in a plasma environment, and the method has the advantages of high energy efficiency, short process time, good process controllability, high conversion rate, high product purity and the like. According to the method, self-made low-cost high-purity lithium oxide is adopted as a raw material and continuously reacts with hydrogen sulfide gas at a proper temperature (200-400 DEG C) for 20-60 minutes, so that high-purity lithium sulfide can be obtained. According to the process, the synthesis cost is greatly reduced, so that the large-scale commercial production of the sulfide solid electrolyte becomes possible.

The invention provides a preparation method of lithium sulfide, and relates to the technical field of lithium sulfide. According to the preparation method of the lithium sulfide, the lithium sulfide is obtained by reducing the sulfur salt component and the lithium sulfide in the atmosphere of the reducing gas, so that the process conditions are relatively mild, and the industrial large-scale production is facilitated.

An electrode composite material and a method of making same are disclosed. A mixture that includes lithium sulfide (Li2S) particles containing a Li2S compound, carbon particles, and halogenated lithium phosphorous sulfide (LPS-X) particles containing an LPS-X (X is F, Cl, Br, and / or I) compound are provided. The LPS-X particles have crystallinity which can be confirmed with XRD of the LPS-X particles or the mixture showing XRD peaks indicative of crystalline LPS-X. The mixture does not include lithium phosphorous sulfide (LPS) particles made of an LPS compound. The mixture is ball-milled to provide a ball-milled composite material. At least part of the LPS-X compound contained in at least part of the LPS-X particles is converted to the LPS compound. XRD of the ball-milled composite material shows none of the XRD peaks indicative of crystalline LPS-X.

The invention relates to a method for preparing lithium sulfide at low temperature by microwave molten salt assisted carbon disulfide-lithium salt reaction, and belongs to the technical field of key materials of lithium-sulfur batteries and solid-state batteries. The technical problems of high energy consumption, difficulty in inhibiting by-products, insufficient purity and crystal phase stability, difficulty in continuous amplification and the like in the existing lithium sulfide preparation process are solved. Comprising the following steps: step 1, performing crushing, screening and grading treatment on lithium source powder; step 2, placing the treated lithium source powder and molten salt in a closed reactor, and introducing CS2 in a gas or liquid form; 3, applying microwave radiation, and reacting at a gas-solid-liquid multiphase interface to generate lithium sulfide; and 4, cooling the material after the reaction to room temperature, separating and recovering the fused salt to obtain the lithium sulfide powder. The method is low in reaction temperature, low in energy consumption, high in reaction rate, high in product purity and suitable for continuous and industrial production.

The invention provides a process for preparing high-purity lithium sulfide based on industrial waste salt recycling, which comprises the following steps: S1, mixing sulfur-containing waste salt and a waste carbon material, granulating, reducing, calcining, separating and purifying to obtain solid sodium sulfide; s2, mixing and ball-milling the obtained solid sodium sulfide and lithium chloride, adding a mixture of a catalyst and ethanol, and performing catalytic reaction to obtain a lithium sulfide crude product; and S3, purifying and drying the obtained lithium sulfide crude product to obtain the lithium sulfide. The method not only can break through the bottleneck of the existing production route, but also can realize the strategic direction of high-value utilization of bulk solid wastes, and has far-reaching significance for promoting sustainable development and green transformation of the battery industry.

The present invention relates to a method for preparing lithium sulfide, according to the present invention, when preparing lithium sulfide by a reaction between a lithium raw material and hydrogen sulfide, the reaction is carried out under relatively mild conditions compared to the prior art, so that frequent maintenance or replacement due to corrosion and failure of a reactor and various pipes is not required, thereby improving the economical efficiency of the process. Further, by reusing the unreacted hydrogen sulfide from which moisture has been removed and the solvent, process costs can be reduced, and economical efficiency can be ensured during mass production. Furthermore, moisture and water vapor generated in the lithium sulfide generation reaction are effectively removed, thereby preventing a reverse reaction for generating lithium hydroxide, promoting a positive reaction, and producing high-quality lithium sulfide with high purity and high yield. In addition, the particle size can be adjusted in units, and a separate pulverizing space or pulverizing table is not required, so that convenience and mass productivity are excellent.

The utility model provides a device suitable for preparing lithium sulfide by a continuous double decomposition method. The device mainly comprises a material stirring reaction kettle, a solvent storage tank, continuous solid-liquid separation equipment, continuous solvent evaporation equipment, a first condensing tower and continuous dynamic vacuum calcination equipment, the device disclosed by the utility model can smoothly realize continuous production and preparation of lithium sulfide, and is simple in operation process and free from harmful gas pollution; in the preparation process, a single solvent is used and the solvent is recycled, so that the preparation method has the advantages of energy conservation and low cost, and cross contamination of multiple solvents is avoided; in addition, during continuous production of lithium sulfide, only one-time high-temperature calcination operation is carried out, and a lithium sulfide product with high purity and small particle size is successfully prepared; the composite cathode material can be directly used for preparing a sulfide solid electrolyte and a lithium-sulfur battery. The method has high industrial application value.

The utility model discloses a liquid-phase synthesis system of lithium sulfide. Comprising a first lithium sulfate dissolving device, a first barium sulfide dissolving device, a chemical combination reaction device, a first separation device and a second separation device, the liquid phase after-treatment unit is used for concentrating, purifying and drying the liquid phase to obtain lithium sulfide, and the solid phase after-treatment unit is used for washing and drying the solid phase to obtain barium sulfate; the first lithium sulfate dissolving device and the first barium sulfide dissolving device are both connected with a raw material inlet of the combination reaction device; and a reaction product outlet of the combination reaction device is connected with the first separation device. The liquid-phase synthesis system of the lithium sulfide has the advantages that products are easy to separate, the purity of the lithium sulfide products is high, the liquid-phase synthesis system of the lithium sulfide is very suitable for industrial-scale production, and the produced high-purity anhydrous lithium sulfide is very suitable for solid-state battery anode materials and has huge potential economic benefits.

The invention discloses lithium sulfide, a two-step double decomposition preparation method and application of the lithium sulfide in an all-solid-state battery, and belongs to the technical field of solid-state batteries. According to the preparation method, a two-step decomposition synthesis technology is adopted, lithium carbonate and ammonium thiocyanate are used as raw materials, the raw materials are uniformly mixed and then placed in a high-temperature reactor, a step heating sintering procedure is completed in an inert gas atmosphere, and the purpose of fully decomposing and converting the raw materials is achieved by accurately controlling the temperature and the time; after a product is obtained through reaction, the high-purity lithium sulfide material is obtained after the product is cooled to the room temperature. The method for preparing the lithium sulfide is low in raw material cost, simple in reactant formula and free of side reaction in the reaction process, and the finally generated product is few in impurity, high in purity and good in crystallinity.

The invention discloses a method for preparing high-purity lithium sulfide from a lithium sulfate mother liquor, which comprises the following steps: preparing a lithium sulfate concentrated liquor: adding 98% concentrated sulfuric acid into the lithium sulfate mother liquor to adjust the pH value, adjusting the pH value to 6-7, carrying out precise filtration to filter out possible impurities to obtain a filtrate, introducing the filtrate into an MVR evaporation system, and concentrating the mother liquor to obtain a concentrated liquor, performing freezing crystallization on the concentrated solution by using a cooling crystallizer, and then performing centrifugal separation under the action of a centrifugal machine to obtain solid slag which is mirabilite and a solution which is lithium sulfate concentrated solution; and preparing crude lithium sulfide: performing evaporative crystallization on the obtained lithium sulfate concentrated solution, adding pure water for slurrying, and performing centrifugal filtration and cleaning for 2-3 times. The impurity content is effectively controlled through a multi-stage purification process, the Li2S product with the purity larger than or equal to 99.95% is finally obtained, the key technical problem of direct conversion from a liquid battery recycling material to a solid battery positive electrode raw material is solved, and core material support is provided for lithium battery industry closed loop and industrial product iteration.

The invention relates to the technical field of battery materials, in particular to a preparation method of a lithium sulfide material. The preparation method of the lithium sulfide material comprises the following steps: S1, mixing lithium carbonate and sodium sulfide, heating to a first heating temperature to melt lithium carbonate and react with sodium sulfide, separating out a solid phase, and collecting a first solid; s2, the first solid is heated to a second heating temperature, the second heating temperature is higher than the melting point of sodium carbonate and lower than the melting points of lithium sulfide and sodium sulfide, a solid phase is separated out, and a second solid is collected; s3, the second solid is heated to a third heating temperature, the third heating temperature is higher than the melting point of lithium sulfide and lower than the melting point of sodium sulfide, a liquid phase is separated out, and a liquid lithium sulfide material is prepared; and S4, carrying out curing treatment on the liquid lithium sulfide material to prepare a solid lithium sulfide material. The preparation method improves the reaction conversion rate, simplifies the process flow, reduces the cost and improves the product purity.

The invention relates to the technical field of lithium-sulfur battery diaphragm materials and preparation thereof, and discloses a preparation method of a lithium-sulfur battery diaphragm modified material, which comprises the following steps: (1) preparing two MOF materials, namely Co-MOF and Mn-MOF, by a solvothermal method; (2) taking the Co-MOF and the Mn-MOF as raw materials, and preparing a CoSe / MnSe-N-C composite material derived from the Co-MOF and the Mn-MOF by utilizing a high-temperature sintering method; and (3) taking a CoSe / MnSe-N-C composite material derived from Co-MOF and Mn-MOF as a modifier, and adopting a coating method to obtain the modified PP diaphragm of the lithium-sulfur battery. According to the lithium-sulfur battery modified PP diaphragm provided by the invention, sulfur-loving sites, lithium-loving sites and catalytic electrode reaction active sites in the modifier CoSe / MnSe-N-C composite material can be utilized to effectively inhibit the shuttle effect of lithium polysulfide and the growth of lithium dendrites, the electrode reaction kinetics of the lithium polysulfide can be accelerated, and the overall electrochemical performance of the lithium-sulfur battery is greatly improved.

The invention provides a sulfide electrolyte material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing lithium sulfide, phosphorus pentasulfide, rare earth sulfide and a solvent, and reacting to obtain a sulfide electrolyte precursor; and carrying out pressing treatment on the sulfide electrolyte precursor, and carrying out low-temperature sintering on the material obtained by pressing at 250-500 DEG C to obtain the sulfide electrolyte material. According to the method disclosed by the invention, the synthesis of the rare earth element doped sulfide precursor is realized by adopting a pure liquid phase method, particles are dispersed in a liquid phase solvent, and the particle uniformity and dispersity of the obtained finished product are obviously superior to those of a solid phase method. After the precursor obtained by the liquid phase method is pressed and sintered at low temperature, the crystal boundary between crystals of the electrolyte material is relatively small, the energy barrier of ion transmission is remarkably enhanced, the conductivity of the electrolyte is optimized, and the long-cycle stability of the all-solid-state battery is improved.

The invention belongs to the technical field of chemical materials, and particularly discloses a method for preparing lithium sulfide, which comprises the following steps: mixing lithium salt and ammonium sulfide for reaction to obtain lithium sulfide; wherein the lithium salt comprises at least one of lithium hexafluorophosphate, lithium difluorophosphate and lithium tetrafluoroborate. According to the method for preparing the lithium sulfide, the lithium salt and the ammonium sulfide can fully react under the mild condition, the reaction time is short, the reaction yield is high, and meanwhile the purity of the obtained lithium sulfide is high.

The invention discloses lithium sulfide and a preparation method thereof. The preparation method comprises the following steps: (1) carrying out ball-milling mixing on iron powder, sodium sulfide and lithium sulfate in a first inert atmosphere to obtain a mixture; (2) calcining the mixture in a second inert atmosphere for the first time to obtain a reaction material; (3) stirring and washing the reaction material with an alcohol solvent in a third inert atmosphere, filtering to obtain filtrate and a filter cake, performing reduced pressure distillation on the filtrate to obtain a lithium sulfide crude product, washing the filter cake with deionized water, and filtering to obtain a solid by-product; and (4) carrying out secondary calcination on the lithium sulfide crude product in a fourth inert atmosphere to obtain lithium sulfide. The preparation method provided by the invention has the advantages of few synthesis steps, simple product purification and environmental protection.

The invention relates to a digestion method for lithium sulfide impurity element analysis and a content determination method thereof, the digestion method comprises the following steps: (A1) pre-digestion: weighing a lithium sulfide sample, and adding ultrapure water to obtain a sample aqueous solution; dropwise adding oxidizing acid into the sample aqueous solution, and heating to enable the lithium sulfide sample in the sample aqueous solution to fully react, so as to obtain a pre-digested sample; (A2) microwave digestion: carrying out microwave digestion on the pre-digested sample under a closed condition to obtain a microwave digested sample, and fixing the volume to obtain a to-be-detected sample solution. Compared with a conventional multi-time acid-adding digestion method, the digestion method has the advantages that oxidizing acid does not need to be added repeatedly, so that the operation steps are simple, the digestion time is short, and compared with the multi-time acid-adding digestion method, the method can meet quantitative analysis of most impurity elements in lithium sulfide.

The application provides a sulfide solid electrolyte and a preparation method thereof, and particularly relates to the technical field of secondary batteries. The sulfide solid electrolyte is a lithium phosphorus oxysulfide, and the chemical formula of the lithium phosphorus oxysulfide is Li7P3S 7.5+x‑5y O 3.5‑x+5y ; wherein, 0<=x<=3.5, 0<=y<=1.5, -7.5