The present invention relates to a method of preparing a vanadium electrolyte solution and a battery including the vanadium electrolyte solution. According to the present invention, the present invention has an effect of providing a method of preparing a vanadium electrolyte solution that allows control of the reduction reaction rate of a vanadium compound, provides an effect of omitting separation and recovery processes by not generating by-products, and provides reproducibility of a single manufacturing process and a battery including the vanadium electrolyte solution.

The present invention relates to a method of preparing a vanadium electrolyte solution and a battery including the vanadium electrolyte solution. According to the present invention, the present invention has an effect of providing a method of preparing a vanadium electrolyte solution that allows control of the reduction reaction rate of a vanadium compound, provides an effect of omitting separation and recovery processes by not generating by-products, and provides reproducibility of a single manufacturing process and a battery including the vanadium electrolyte solution.

Methods and systems for removing impurities from electrolyte solutions having three or more valence states. In some embodiments, a method includes electrochemically reducing an electrolyte solution to lower its valence state to a level that causes impurities to precipitate out of the electrolyte solution and then filtering the precipitate(s) out of the electrolyte solution. In embodiments in which the electrolyte solution is desired to be at a valence state higher than the precipitation valence state, a method of the disclosure includes oxidizing the purified electrolyte solution to the target valence.

Methods and systems for removing impurities from electrolyte solutions having three or more valence states. In some embodiments, a method includes electrochemically reducing an electrolyte solution to lower its valence state to a level that causes impurities to precipitate out of the electrolyte solution and then filtering the precipitate(s) out of the electrolyte solution. In embodiments in which the electrolyte solution is desired to be at a valence state higher than the precipitation valence state, a method of the disclosure includes oxidizing the purified electrolyte solution to the target valence.

The present invention relates to a method for converting and separating vanadium, titanium, and iron from the vanadium-titanium-iron concentrate in one step, which includes the steps as below. (1) The vanadium-titanium-iron concentrate is mixed and roasted together with addition agent and reducing agent, and thereby vanadium-containing pig iron and vanadium enriched slag are obtained. (2) The vanadium titanium enriched slag is leached in water and filtered, and thereby vanadium-containing solution and titanium slag are obtained. The technical features of the present invention are as below. By the new process of sodium reduction coupling, a new system of low-temperature smelting multiphase reaction separation is constructed. The reduction of iron, sodiumizing of vanadium, and the melting separation process of the vanadium titanium enriched slag and the iron are achieved in one step. Three products, i.e., the vanadium-containing pig iron, the vanadium-containing solution, and the titanium slag are produced.

The present invention provides a method for producing a solution of nanosheets, comprising the step of contacting an intercalated layered material with a polar aprotic solvent to produce a solution of nanosheets, wherein the intercalated layered material is prepared from a layered material selected from the group consisting of a transition metal dichalcogenide, a transition metal monochalcogenide, a transition metal trichalcogenide, a transition metal oxide, a metal halide, an oxychalcogenide, an oxypnictide, an oxyhalide of a transition metal, a trioxide, a perovskite, a niobate, a ruthenate, a layered III-VI semiconductor, black phosphorous and a V-VI layered compound. The invention also provides a solution of nanosheets and a plated material formed from nanosheets.

The present invention provides a method for producing a solution of nanosheets, comprising the step of contacting an intercalated layered material with a polar aprotic solvent to produce a solution of nanosheets, wherein the intercalated layered material is prepared from a layered material selected from the group consisting of a transition metal dichalcogenide, a transition metal monochalcogenide, a transition metal trichalcogenide, a transition metal oxide, a metal halide, an oxychalcogenide, an oxypnictide, an oxyhalide of a transition metal, a trioxide, a perovskite, a niobate, a ruthenate, a layered III-VI semiconductor, black phosphorous and a V-VI layered compound. The invention also provides a solution of nanosheets and a plated material formed from nanosheets.

Proposed are a metal-substituted titanium oxide which has a composition other than conventional Ti.sub.3O.sub.5 while having a property of being able to undergo phase transition from a crystal structure in a paramagnetic metal state to a crystal structure of a nonmagnetic semiconductor upon application of pressure or light and which can also be used in fields other than conventional technical fields, and a method for producing a metal-substituted titanium oxide sintered body. According to the present invention, it is possible to provide a metal-substituted titanium oxide having a crystal structure which does not undergo phase transition to a crystal structure having the properties of a nonmagnetic semiconductor even at 460 [K] or lower but maintains a paramagnetic metal state over the entire temperature range of 0 to 800 [K] and which undergoes phase transition to a crystal structure of a nonmagnetic semiconductor upon application of pressure or light, the metal-substituted titanium oxide having a composition in which some of Ti sites of Ti.sub.3O.sub.5 are substituted with any one of Mg, Mn, Al, V and Nb.

Provided are forward osmosis processes to increase the concentration of a dilute metal salt solution, e.g., a vanadium electrolyte solution. In embodiments, such a process comprises: (a) delivering a draw solution to a draw chamber of a forward osmosis module, the draw solution comprising water and sulfuric acid at a draw acid concentration, wherein the draw solution is free of vanadium cations; and (b) delivering a feed solution to a feed chamber of the forward osmosis module, the draw and feed chambers separated by a membrane, the feed solution comprising water, vanadium cations, and sulfuric acid at a feed acid concentration that is lower than the draw acid concentration, wherein water passes across the membrane from the feed solution to the draw solution, thereby providing a concentrated vanadium electrolyte solution as a feed chamber output and a diluted acid solution as a draw chamber output.

Provided are forward osmosis processes to increase the concentration of a dilute metal salt solution, e.g., a vanadium electrolyte solution. In embodiments, such a process comprises: (a) delivering a draw solution to a draw chamber of a forward osmosis module, the draw solution comprising water and sulfuric acid at a draw acid concentration, wherein the draw solution is free of vanadium cations; and (b) delivering a feed solution to a feed chamber of the forward osmosis module, the draw and feed chambers separated by a membrane, the feed solution comprising water, vanadium cations, and sulfuric acid at a feed acid concentration that is lower than the draw acid concentration, wherein water passes across the membrane from the feed solution to the draw solution, thereby providing a concentrated vanadium electrolyte solution as a feed chamber output and a diluted acid solution as a draw chamber output.