A method for recovering lithium is provided. The method includes the following steps. A lithium-containing solution is provided. A manganese oxide adsorbent is immersed in the lithium-containing solution, and a reducing agent is added to carry out an adsorption reaction, and the manganese oxide adsorbent is immersed in a solution containing an oxidizing agent to carry out a desorption reaction.

A fluidized bed reactor according to an embodiment of the present disclosure includes a reactor body, and a dispersion plate coupled to a bottom portion of the reactor body. The dispersion plate may include a base plate and injection columns protruding from a top surface of the base plate. The injection columns include first injection columns arranged at a central portion of the dispersion plate, and second injection columns arranged at a peripheral portion of the dispersion plate. The second injection column has a greater height than a height of the first injection column. A reactive gas is uniformly injected to a wall surface of the reactor through the dispersion plate, thereby increasing a recovery ratio for an active metal of a lithium secondary battery.

This invention provides a method for efficiently separating magnesium and lithium from salt lake brine, and simultaneously preparing high-purity magnesium oxide and battery-grade lithium carbonate. The detailed processing steps are as follows: (1) adding urea into the brine to dissolve, (2) placing the solution into the reactor for hydrothermal reaction, the magnesium ion will precipitate and enter the solid phase; (3) filtering and drying the production to get the magnesium carbonate solid, while the lithium ion remains in the liquid phase; (4) after directly concentration and precipitation, the battery-grade lithium carbonate can be obtained, while the calcination of solid-phase product results in the high-purity magnesium oxide. In this method, urea is used as the precipitant to separate magnesium and lithium in salt lake without introducing any new metal ion, and the brine solution is not diluted. The solid product is white and fluffy powder, which is easy to filter and separate. The extraction rate of lithium is high than 94%, and the purity of MgO obtained by calcination is higher than 99.5%.

This invention provides a method for efficiently separating magnesium and lithium from salt lake brine, and simultaneously preparing high-purity magnesium oxide and battery-grade lithium carbonate. The detailed processing steps are as follows: (1) adding urea into the brine to dissolve, (2) placing the solution into the reactor for hydrothermal reaction, the magnesium ion will precipitate and enter the solid phase; (3) filtering and drying the production to get the magnesium carbonate solid, while the lithium ion remains in the liquid phase; (4) after directly concentration and precipitation, the battery-grade lithium carbonate can be obtained, while the calcination of solid-phase product results in the high-purity magnesium oxide. In this method, urea is used as the precipitant to separate magnesium and lithium in salt lake without introducing any new metal ion, and the brine solution is not diluted. The solid product is white and fluffy powder, which is easy to filter and separate. The extraction rate of lithium is high than 94%, and the purity of MgO obtained by calcination is higher than 99.5%.

A lithium extraction method is disclosed. The lithium extraction method includes: preparing lithium phosphate containing impurities; dissolving the lithium phosphate and the impurities in an acid; and preparing a lithium-containing solution by adding an additive to a solution prepared by dissolving the lithium phosphate and the impurities in the acid, wherein the additive is a substance capable of simultaneously precipitating phosphate anions and the impurities, and the lithium-containing solution prepared through addition of the additive is basic.

A lithium extraction method is disclosed. The lithium extraction method includes: preparing lithium phosphate containing impurities; dissolving the lithium phosphate and the impurities in an acid; and preparing a lithium-containing solution by adding an additive to a solution prepared by dissolving the lithium phosphate and the impurities in the acid, wherein the additive is a substance capable of simultaneously precipitating phosphate anions and the impurities, and the lithium-containing solution prepared through addition of the additive is basic.

Regeneration of degraded cathode particles in lithium-ion batteries is achieved using a combination of hydrothermal treatment of cycled electrode particles followed by short thermal annealing. The methods provide for direct regeneration of Li-ion cathode materials including LiCoO.sub.2, LiMn.sub.2O.sub.4, LiFePO.sub.4, and Li.sub.xNi.sub.y Mn.sub.z Co.sub.1−y−zO.sub.2, in an economical and environmentally-friendly process.

Regeneration of degraded cathode particles in lithium-ion batteries is achieved using a combination of hydrothermal treatment of cycled electrode particles followed by short thermal annealing. The methods provide for direct regeneration of Li-ion cathode materials including LiCoO.sub.2, LiMn.sub.2O.sub.4, LiFePO.sub.4, and Li.sub.xNi.sub.y Mn.sub.z Co.sub.1−y−zO.sub.2, in an economical and environmentally-friendly process.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

Methods and systems for production of lithium hydroxide and lithium carbonate are described. One or more embodiments of the method include producing lithium hydroxide from potassium chloride, lithium chloride, and water. One or more embodiments of the method include producing lithium carbonate from potassium chloride, lithium chloride, water, and a carbon dioxide source. One or more embodiments of the method include producing lithium carbonate from sodium chloride, lithium chloride, water, and a carbon dioxide source.