624results about "Lithium compounds" patented technology

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 discloses a lithium supplement additive and a preparation method and application thereof. The lithium supplement additive comprises a lithium sulfinate compound, and the lithium sulfinate compound contains an electron withdrawing group. An electron withdrawing group contained in the lithium sulfinate compound in the lithium supplement additive can effectively change electron cloud distribution around sulfur atoms, so that the lithium sulfinate compound is endowed with relatively high lithium supplement capacity; meanwhile, due to the existence of the electron withdrawing group, the electron energy of the lowest unoccupied molecular orbital (LUMO) of the lithium sulfinate compound is reduced, and the energy gap between the highest occupied molecular orbital (HOMO) and the LUMO of the lithium sulfinate compound is reduced, so that the lithium supplement additive can be arranged in an electrode plate to exert the lithium supplement capacity and also can be used as an electrolyte additive; and the material can participate in electrode / electrolyte interface formation.

The invention discloses a preparation method of a crown ether functionalized anti-pollution nanofiltration membrane, which comprises the following steps: soaking a membrane of a commercial nanofiltration membrane in pure water, and coating the surface with a double-end epoxy compound ethanol solution; uniformly coating the surface of the membrane with an aza 12-crown-4 methanol solution; and drying the membrane in an atmosphere of 40-90 DEG C to obtain the crown ether functionalized anti-pollution nanofiltration membrane. The nano-filtration membrane is realized by chemically grafting aza 12-crown-4 on the membrane surface of a commercial nano-filtration membrane by utilizing a double-end epoxy compound; compared with a traditional nanofiltration membrane, the crown ether functionalized nanofiltration membrane provided by the invention has the advantages that the electronegativity of the surface is reduced, and the surface is similar to an aquatic plant molecular brush structure, so that the deposition of pollutants on the surface of the membrane can be effectively improved, and the anti-pollution performance of the membrane is enhanced; meanwhile, due to the complexing effect of 12-crown-4 molecules on lithium ions, the lithium ions can be effectively captured, concentration polarization of the lithium ions on the surface of the diaphragm is improved, and then the magnesium-lithium separation efficiency of the diaphragm is improved.

To provide an efficient method of preparing high-purity lithium sulfide.SOLUTION: In a method for preparing lithium sulfide, a solid sulfur layer and a lithium source layer are sequentially arranged in a reactor. A gas feed is injected into the reactor in a single direction to obtain a lithium sulfide-containing product. The lithium sulfide-containing product is dissolved in an anhydrous solvent to form a lithium sulfide-containing solution. Lithium sulfide is separated from the lithium sulfide-containing solution. The gas feed sequentially passes through the solid sulfur layer and the lithium source layer, such that high-purity lithium sulfide may be efficiently prepared.SELECTED DRAWING: Figure 1

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 discloses a high-initial-efficiency fast-charge graphite composite material and a preparation method thereof, the composite material is of a core-shell structure, the core is graphite, and the shell is lithium sulfonate / lithium molybdate and an amorphous carbon coating layer thereof; the mass ratio of the shell is 5-15 wt% according to the mass ratio of the composite material being 100%. The preparation method comprises the following steps: adding a molybdenum compound into a solvent to prepare a solution, adding graphite oxide, an inorganic lithium salt and a carbon nanotube conductive solution, reacting for 2-12 hours at the temperature of 50-120 DEG C, filtering, carbonizing filter residues to obtain a lithium molybdate conductive agent coated graphite material, and depositing a lithium sulfonate derivative on the surface of the lithium molybdate conductive agent coated graphite material by an atomization method to obtain the lithium molybdate conductive agent coated graphite material. The electron and ion conductivity of the material can be improved, and the rate and the first efficiency of the material can be improved.

The invention relates to the technical field of electrochemistry, and provides a sulfide solid electrolyte, a preparation method thereof, a battery and application. The chemical formula of the sulfide solid electrolyte is Li7-aPS6-aXa, X is halogen, and a is greater than or equal to 1 and less than or equal to 2; wherein the peak area of a diffraction peak corresponding to a (111) crystal plane of the sulfide solid electrolyte is I1, the peak area of a diffraction peak corresponding to a (311) crystal plane of the sulfide solid electrolyte is I2, and I1 / I2 is larger than or equal to 0.2 and smaller than or equal to 0.3. The I1 / I2 of the sulfide solid electrolyte disclosed by the invention is within the range, a good crystal structure and a relatively large interface area can be provided, and ion movement is promoted, so that relatively high ionic conductivity is obtained. Furthermore, according to the method disclosed by the invention, the high ionic conductivity of the product is ensured by reducing the solvent dosage and optimizing the sintering step, and meanwhile, the environmental pollution, the energy consumption and the production cost are remarkably reduced.

The invention provides a sulfide solid electrolyte and a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The preparation method comprises the following steps: S1, carrying out dry ball milling treatment on raw materials Li2S, P2S5 and LiX according to a required stoichiometric ratio, so that the raw materials are amorphized; s2, adding a solvent into the non-crystallized raw material obtained in the step S1, and carrying out wet ball-milling treatment to obtain a precursor with the particle size of 0.05-0.5 mu m; s3, the solvent is removed from the precursor slurry, the sulfide solid electrolyte is obtained through solid-phase sintering, all the steps are carried out in an inert atmosphere, and X is a halogen element. According to the present invention, the non-crystallization of the raw material is achieved through the dry ball milling, the uniform precursor slurry with the small particle size is obtained by combining the wet ball milling, and the sub-micron / nano-scale pure phase electrolyte material can be obtained after the sintering treatment, such that the electrode / electrolyte interface contact is improved, the impedance is reduced, and the battery performance is significantly improved.

The invention discloses a hydrogel-based water-energy-resource co-production solar evaporator and application thereof, and belongs to the technical field of chemistry and environment, the hydrogel-based water-energy-resource co-production solar evaporator is prepared by taking sodium alginate hydrogel as a matrix, adding carbon nanotubes and a titanium-based lithium ion sieve or a metal-doped titanium-based lithium ion sieve into a solution of the sodium alginate hydrogel, taking polyurethane sponge as a carrier frame, and preparing the hydrogel-based water-energy-resource co-production solar evaporator. Ca2 + is adopted as a cross-linking agent to construct a solar evaporator with a flexible size (centimeter-level to meter-level components can be prepared according to application scenes), the solar evaporator is used for the solar driven evaporation process of lithium-containing water resources such as salt lake seawater, and Li + selective enrichment, fresh water collection and waste heat power generation are synchronously achieved. Moreover, the evaporator has the characteristics of simple preparation process, low cost and excellent environmental compatibility, also has a good removal effect on salt ions, and keeps stable fresh water collection performance in a long-time operation process.

The invention belongs to the technical field of electrolyte, and particularly relates to a method for preparing liquid lithium hexafluorophosphate from sodium hexafluorophosphate. The method comprises the following steps: adding a sodium source into a hexafluorophosphoric acid aqueous solution for neutralization reaction to obtain a sodium hexafluorophosphate aqueous solution, then extracting to remove water, drying to obtain a sodium hexafluorophosphate solid, and heating and decomposing the sodium hexafluorophosphate solid to obtain phosphorus pentafluoride gas; the phosphorus pentafluoride gas is not mixed with SO3, POF3, HF and other impurity gases, a complex refining and purifying process is not needed, and the phosphorus pentafluoride gas with the purity exceeding 99.9% can be obtained after simple purification and can be directly used for synthesizing liquid lithium hexafluorophosphate. The method does not generate waste acid, does not need a complicated phosphorus pentafluoride gas purification process, is particularly suitable for the requirements of the lithium battery industry on high-purity electrolyte, and has the remarkable advantages of high product purity, small environmental pollution, low production cost and the like.

A cathode active material, a cathode including the cathode active material, an all-solid secondary battery including the cathode, and a method of preparing the cathode active material are provided. The cathode active material includes primary particles including a Li2S-containing composite, secondary particles including the primary particles agglomerated therein, wherein a D10 size of the secondary particles is 5 µm or more.

The present invention relates to a method for co - processing and resource utilization of overhaul slag, fly ash, and desulfurized gypsum. The method comprises the following steps: Step 1) dehydrate and then dry the desulfurized gypsum, add calcium carbonate to the dried desulfurized gypsum, and collect SO3 gas; Step 2) carry out an autoclave reaction on the SO3 gas obtained in Step 1, water, and fly ash. After solid - liquid separation, silicon dioxide and an aluminum sulfate solution are obtained; Step 3) crush and ball - mill the overhaul slag, and carry out first - stage roasting with a peroxide at high temperature to obtain clinker 1; leach out sodium fluoride from clinker 1 by water immersion, and then add it to the aluminum sulfate for second - stage roasting to obtain clinker 2; Step 4) mix clinker 2 with water for leaching to obtain a filtrate and a filter residue; Step 5) calcine calcium oxide and the filter residue to obtain calcium aluminate. The beneficial effect of the present invention aims to synergistically utilize the sodium, aluminum, fluorine, and lithium elements, the aluminum and silicon elements of fly ash, and the calcium element in desulfurized gypsum to achieve the purpose of resource conversion.

The utility model discloses a salt lake lithium extraction adsorbent scrubbing system which comprises a scrubbing tower and an adsorption tower, and a sunken water distributor is arranged at the bottom end in the scrubbing tower; the middle position of the bottom of the concave water distributor penetrates through the bottom of the scrubbing tower and is connected with a runner opening; a water replenishing opening is formed in the middle of the bottom of the scrubbing tower; two feed ports are formed in the positions, close to the water inlet, of one side of the scrubbing tower, and a water outlet is formed in the position, close to the top, of one side of the scrubbing tower; the flow channel port is sequentially connected with a pneumatic valve j, a diaphragm pump B and an adsorption column through a pipeline; according to the system, crushed resin particles and impurities are effectively removed by cleaning an adsorbent, so that the adsorption performance and the flowability of a resin bed layer are recovered, and it is ensured that the resin bed layer is always in the optimal working state. In the process of scrubbing the adsorbent, the adsorbent does not need to be manually carried except for necessary adsorption tower pipeline connection operation, so that the scrubbing efficiency is remarkably improved.

The invention relates to the technical field of electrochemistry, and provides a sulfide solid electrolyte and an all-solid-state lithium battery, the chemical formula of the sulfide solid electrolyte is Li < 7-2x-y > PMxS < 6-x-y > OxCl < 0.7-y > Br < 0.3 y >, M is at least one of Ca, Mg and Cu, x is more than or equal to 0.01 and less than or equal to 0.3, y is more than or equal to 0.5 and less than or equal to 2, x / y is more than or equal to 0.008 and less than or equal to 0.24, the molar ratio of the element M to the element O is 1: 1, and the molar ratio of the element Cl to the element Br is 7: 3; the grain boundary impedance of the sulfide solid electrolyte at 25 DEG C is 20 Omega to 100 Omega. Through the arrangement, the sulfide solid electrolyte disclosed by the invention has relatively low grain boundary impedance while maintaining high ionic conductivity and good air stability. Furthermore, when the sulfide solid electrolyte is applied to the all-solid-state lithium battery, the electrochemical performance of the all-solid-state lithium battery can be improved.

The application relates to the field of electrochemistry, and provides a sulfide solid electrolyte and a full-solid-state lithium battery. The chemical formula of the sulfide solid electrolyte is Li 7+3x‑y P 1‑x M x S 6‑x‑y O x Cl 0.7y Br 0.3y , M is at least one of Ca, Mg and Cu, 0.01<=x<=0.3, 0.5<=y<=2, 0.008<=x / y<=0.24; the fracture toughness of the sulfide solid electrolyte is 0.8 MPa.m 1 / 2 2.5 MPa.m 1 / 2 . Through the above setting, the fracture toughness of the sulfide solid electrolyte is significantly improved, the sulfide solid electrolyte of the application can also maintain high ionic conductivity and good air stability, the synergistic optimization between mechanical reliability and electrochemical performance of the sulfide solid electrolyte is realized, and the electrochemical performance of the full-solid-state lithium battery is improved.

The invention provides a treatment method for removing EDTA-Ca in a high-salt and high-chlorine lithium-containing mother solution, and belongs to the technical field of lithium salt preparation. The treatment method sequentially comprises the following steps: S100, adjusting the pH value of the lithium-containing mother liquor to be treated to be acidic, and stirring to react for a period of time; s200, after stirring reaction, standing for a period of time, filtering to remove precipitate, and collecting filtrate; s300, adjusting the pH value of the filtrate to be alkaline, adding an oxidizing agent, and stirring to react for a period of time; and S400, heating for a period of time after stirring reaction, filtering to remove precipitate, and collecting filtrate to obtain treated lithium-containing mother liquor. The treatment method can effectively break complexation of EDTA-Ca in the high-salt and high-chlorine lithium-containing mother liquor, effectively remove calcium ions and reduce the EDTA content and solution complexation ability, and has the advantages of less lithium ion loss, low cost, simple and safe process and less impurity introduction.

The invention relates to the technical field of electrochemistry, and provides a sulfide solid electrolyte and an all-solid-state lithium battery, the chemical formula of the sulfide solid electrolyte is Li < 7 + 3x-y > P < 1-x > M < x > S < 6-x-y > O < x > Cl < 0.7 y > Br < 0.3 y >, M is at least one of Ca, Mg and Cu, x is more than or equal to 0.01 and less than or equal to 0.3, y is more than or equal to 0.5 and less than or equal to 2, and x / y is more than or equal to 0.008 and less than or equal to 0.24; the fracture toughness of the sulfide solid electrolyte is 0.8 MPa.m < 1 / 2 > to 2.5 MPa.m < 1 / 2 >. Through the arrangement, the fracture toughness of the sulfide solid-state electrolyte is remarkably improved, and the sulfide solid-state electrolyte disclosed by the invention also can maintain relatively high ionic conductivity and good air stability, so that collaborative optimization of the sulfide solid-state electrolyte between mechanical reliability and electrochemical performance is realized; further, the electrochemical performance of the all-solid-state lithium battery is improved.

Provided is a method for efficiently producing a sulfide solid electrolyte which has high ionic conductivity and in which an increase of particle diameters and a spread of particle size distribution are suppressed, the method including mixing, in a first solvent, a raw material-containing substance that contains a plurality of raw materials each containing at least one atom selected from a lithium atom, a phosphorus atom, a sulfur atom, and a halogen atom to obtain a solution containing an electrolyte precursor, removing the solvent from the solution to obtain the electrolyte precursor, bringing the electrolyte precursor into contact with a second solvent, and subsequently heating the mixture, wherein the second solvent differs from the first solvent and is a hydrocarbon solvent.

The application relates to the field of electrochemistry, and provides a sulfide solid electrolyte, a preparation method thereof, a battery and an application. 7‑ A PS 6‑A X A The application also provides a sulfide solid electrolyte selected from any one of compounds of a chemical formula Li 7‑ A PS 6‑A X A X is halogen, and 1<=A<=2; wherein the sulfide solid electrolyte has a fracture toughness of 0.5-2 MPa m 1 / 2 The sulfide solid electrolyte has high fracture toughness and ionic conductivity. Further, the preparation method controls the particle size of a substrate, reduces the solvent consumption and optimizes the sintering step, thereby improving the fracture toughness, high purity and high ionic conductivity of the product, and significantly reducing environmental pollution, energy consumption and production cost.

The invention relates to the technical field of electrochemistry, and provides a sulfide solid electrolyte, a preparation method thereof, a battery and application. The sulfide solid electrolyte disclosed by the invention is selected from any one of a compound with a chemical formula of Li7-APS6-AXA and a Li7-APS6-AXA compound coated or doped with other elements, X is halogen, and A is greater than or equal to 1 and less than or equal to 2; wherein the fracture toughness of the sulfide solid electrolyte is 0.5-2 MPa m < 1 / 2 >. The sulfide solid electrolyte disclosed by the invention has relatively high fracture toughness and ionic conductivity. Furthermore, according to the preparation method disclosed by the invention, by controlling the particle size of the substrate, reducing the solvent dosage and optimizing the sintering step, the fracture toughness, high purity and high ionic conductivity of the product are improved, and meanwhile, the environmental pollution, the energy consumption and the production cost are remarkably reduced.

The invention relates to the technical field of lithium adsorbents, in particular to a preparation and application method of a porous microsphere adsorbent for extracting lithium, and the preparation method comprises the following steps: preparing a water phase solution containing methacrylic acid, water and an emulsifier; the preparation method comprises the following steps: preparing an oil phase solution containing a fluorinated methacrylate monomer containing beta-diketone, cyclohexyl methacrylate, methoxyethyl methacrylate, N, N-bis (acryloyl) cystamine, ethylene glycol dimethacrylate, azodiisobutyronitrile and a solvent; dropwise adding the oil-phase solution into the water-phase solution for gradient emulsification, adding sodium persulfate to initiate polymerization, and performing centrifugal drying to obtain porous microspheres; and immersing the porous microspheres into a NaOH solution for hydrolysis activation, and drying to obtain the porous microsphere adsorbent for selective adsorption of lithium ions. Wherein the beta-diketone can enhance the targeted adsorption effect of the adsorbent on lithium ions and has relatively high selectivity and adsorption capacity, and the strong electron-withdrawing property of CF3 further polarizes carbonyl and enhances the coordination ability of the lithium ions.

The invention discloses a preparation method of a sulfide solid electrolyte, and relates to the field of solid-state batteries, the preparation method comprises the following steps: preparing Li2S-coated LiCl core-shell nanoparticles, and carrying out airflow collision grinding on the Li2S-coated LiCl core-shell nanoparticles and P2S5 nanopowder to obtain composite powder; the composite powder is placed in a reaction furnace for heating deposition, then heating crystallization is carried out, and Li6PS5Cl nanoparticles are obtained; the Li6PS5Cl nanoparticles are placed in a ball milling tank to be treated, then annealing treatment is conducted, and the sulfide solid electrolyte is obtained after treatment is completed. Through combination of the core-shell structure precursor and the vapor deposition technology, the core contradiction that nanocrystallization and high ionic conductivity are difficult to consider at the same time in the sulfide solid electrolyte field is effectively solved, and the problems of interface contact defects caused by micron-sized particles and crystal defects caused by mechanical refinement in a traditional process are effectively solved; the problem is solved through construction of Li2S-coated LiCl core-shell nanoparticles and activation treatment of airflow on collision and grinding.

The invention provides a modified separation membrane as well as a preparation method and application thereof, the preparation method of the modified separation membrane comprises the following steps: obtaining a mixed system of a mineral aggregate and a polar solvent, performing ultrasonic liquid phase stripping on the mixed system to obtain a to-be-treated liquid, and the mass volume ratio of the mineral aggregate to the polar solvent is (50-100) mg: (30-60) ml; performing centrifugal treatment on the to-be-treated liquid, and collecting supernatant liquid to obtain nano suspension liquid; a cross-linking agent is mixed with the nano suspension to obtain modified liquid, the modified liquid contains the modified nanosheets, and the mass of the cross-linking agent is 2%-30% of the mass of the mineral aggregate; the modified liquid is filtered through a filter membrane, the modified nanosheets are evenly loaded on the surface of the filter membrane, and the modified separation membrane is prepared. The modified separation membrane prepared by the invention is a modified separation membrane material with high separation coefficient, high rejection rate and high flux, and has excellent performance.

The application belongs to the technical field of porous adsorption membrane materials, and discloses a titanium lithium ion porous adsorption membrane material and a self-assembly preparation method and application thereof. The preparation method comprises the following steps: dissolving a film-forming polymer in a dispersion liquid containing MXene nanosheets to form a uniform precursor liquid; the MXene nanosheet is a carbide, nitride or carbonitride of a transition metal with a single-layer structure; dispersing a titanium lithium composite oxide in the precursor liquid to form a casting solution; coating the casting solution on a support, and then performing phase inversion by using pure water to obtain a matrix film; placing the matrix film in a lithium elution liquid for immersion washing, replacing lithium ions in the matrix film, and causing a self-assembly reaction of the titanium lithium composite oxide in the matrix film, so that the titanium lithium ion porous adsorption membrane material is obtained. The application innovatively introduces MXene nanosheets and a polysulfone matrix film, fixes the MXene nanosheets on the polysulfone matrix film as an in-situ growth substrate of the titanium lithium composite oxide, and the obtained membrane material has a high adsorption capacity.

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 relates to a method for producing solid lithium salt through extraction-liquid-liquid-solid three-phase reverse extraction from a lithium-containing solution, which comprises the following steps: (1) mixing the lithium-containing solution with a composite extraction agent, and carrying out extraction treatment to obtain a lithium-loaded first organic phase and a raffinate phase; (2) carrying out impurity removal treatment on the first organic phase to obtain a second organic phase; and (3) mixing the second organic phase with a stripping agent, carrying out stripping treatment to obtain an oil-water-solid three-phase mixed phase containing solid lithium salt, and carrying out phase separation on the mixed phase to obtain the solid lithium salt, wherein the stripping agent is an acid solution containing a lithium salt solid. According to the method, efficient separation of lithium and a large number of impurities is achieved through extraction and washing treatment, the solid lithium salt is directly obtained after reverse extraction treatment, the battery-grade solid lithium salt product can be obtained after impurity removal treatment, and the method has the advantages of being simple in preparation technology, short in process, high in product purity and low in production cost.

Systems and methods are provided for multiplexed extraction of target minerals from a variety of separate or combined desalination brines and / or wastewater sources. The use of multiple pretreatment, extraction, and posttreatment apparatuses with intelligent, directed flow control can allow for a single system to extract multiple target minerals. Improved extraction methods including zwitterionic simulated moving bed chromatography with target-specific zwitterions can allow for improved extraction efficiency and recovery rates with a dramatically reduced environmental footprint compared to existing methods.

The invention relates to the field of obtaining inorganic and organoelement sorbents. The proposed method comprises obtaining a chlorine-containing modification of aluminum lithium double hydroxide (DHAL-Cl) from a solution of aluminum chloride, comprising lithium, with addition of sodium hydroxide to control pH. The obtained DHAL-Cl is mixed with the polyvinyl alcohol aqueous solution instead of separating from the reaction mixture. Resulting product is dried to a paste-like state and extruded. The extrudate is pelletized for forming a rounded shape of the granules, the granules are heat-treated, and their color changes from white to black. Prior to the use the sorbent is washed with water. The technical result is providing a production method for a sorbent having increased capacity and high mechanical strength.

The invention discloses a preparation method and application of a polyvinylidene fluoride-containing polymer hydrogel adsorbent. The method comprises the following steps: (1) modifying PVDF powder with a KOH / ethanol solution to obtain an active group containing double bonds, (2) grafting polyacrylic acid (PAA) through free radical polymerization to form a PVDF-g-PAA amphiphilic polymer, and (3) crosslinking with acrylamide (AM) to construct the three-dimensional interpenetrating network hydrogel. The efficient lithium ion adsorbent can be obtained only through three simple steps, the raw materials are low in price, and the method is suitable for large-scale preparation. The adsorbent realizes efficient lithium adsorption, the lithium ion adsorption capacity in a salt lake brine alkaline environment reaches 33.48 mg / g, and the lithium-magnesium selectivity coefficient reaches 45. Experiments show that the adsorption capacity of the adsorbent is still kept at 82% after multiple times of circulation, and the adsorbent has excellent mechanical stability and cyclic regeneration capacity and is particularly suitable for lithium resource extraction of salt lake brine with a high magnesium-lithium ratio.

In the method for preparing lithium sulfide, a solid sulfur layer and a lithium source layer are sequentially arranged in a reactor. And injecting gas into the reactor along a single direction to obtain a product containing lithium sulfide. The lithium sulfide-containing product is dissolved in an anhydrous solvent to form a lithium sulfide-containing solution. And separating the lithium sulfide from the solution containing the lithium sulfide. And the gas sequentially passes through the solid sulfur layer and the lithium source layer, so that high-purity lithium sulfide can be effectively prepared.