An embodiment of the present invention provides a method for preparing a solid lithium salt from a lithium solution including the steps of, preparing a mixture in which a phosphorus-containing material is added to a lithium solution in step 1; adding a basic solution to the prepared mixture to adjust the pH in step 2; making the pH-adjusted mixture react by raising its temperature and filtering to recover lithium phosphate in step 3; preparing an acid lithium solution in which distilled water and acid are added to the recovered lithium phosphate, in step 4; and recovering a solid lithium salt by evaporative concentration of the acid lithium solution, in step 5.

The present invention provides a method for the preparation of multi-nutrient potassic fertilizer, by recovering potassium from sugarcane molasses based alcohol distillery effluent (commonly known as spent wash). The process involves pre-treatment of spent wash to clarify the aqueous phase and utilization of the treated spent wash in production of potassic fertilizer. The present invention enables utilisation of spent wash for recovery of value-added product (viz., potash fertiliser of >99% purity) and improves ease of Zero Liquid Discharge compliance by subjecting the relatively benign process effluent to industrially practiced techniques for water recovery and salt reclamation.

The present application relates to an electrolyte, an electrochemical device and an electronic device comprising the same. The electrolyte of the present application includes a cyclic N-containing sulfonyl-compound and at least one of vinylene carbonate, fluoroethylene carbonate, lithium tetrafluoroborate, lithium difluoro(oxalato)borate or lithium difluorophosphate. The electrolyte of the present application may further include a sulfur-oxygen double bond containing compound and a silicon-containing carbonate. Compared with the prior art, using the electrolyte provided by the present application can effectively improve the high-temperature storage, cycle performance and overcharge performance of an electrochemical device, such as a lithium-ion battery.

A positive electrode active material including a nickel-containing lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of transition metals excluding lithium, and a coating layer which is formed on a surface of the nickel-containing lithium transition metal oxide and includes a lithium-containing inorganic compound, a nickel oxide, and a nickel oxyhydroxide is provided. A method of preparing the positive electrode active material, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the positive electrode active material are also provided.

Metal (II) phosphate powders, lithium metal phosphate powders for a Li-ion battery and methods for manufacturing the same are provided. The lithium metal phosphate powders are represented by the following formula (II):

LiFe.sub.1-aM.sub.aPO.sub.4(II)

wherein M comprises at least one metal selected from the group consisting of Mn, Co, Ni, Cu, Cr, V, Mo, Ti, Zn, Zr, Tc, Ru, Rh, Pd, Ag, Cd, Pt, Au, Al, Ga, In, Be, Mg, Ca, Sr, B and Nb, 0.5<a1, the lithium metal phosphate powders are composed of plural flake powders, and a length of each of the flake powders is ranged from 50 nm to 10 m.

A lithium manganese iron phosphate positive electrode active material, preparation method, a positive electrode plate, a secondary battery and an electrical apparatus are disclosed. The method comprises: mixing and grinding an iron source, a solid base and optionally a source of doping element M After grinding, impurities are removed to obtain a nanoscale iron-containing oxide; mixing the obtained nanoscale iron-containing oxide with a solvent, a lithium source, a manganese source, a phosphorus source, optionally a source of doping element N, optionally a source of doping element Q and optionally a source of doping element R in a predetermined ratio and then grinding. After grinding, granulating to obtain a powder; and sintering the powder to obtain the lithium manganese iron phosphate positive electrode active material. A lithium manganese iron phosphate positive electrode active material having both good electrochemical performance and high tap density can be obtained.

A lithium manganese iron phosphate positive electrode active material, preparation method, a positive electrode plate, a secondary battery and an electrical apparatus are disclosed. The method comprises: mixing and grinding an iron source, a solid base and optionally a source of doping element M After grinding, impurities are removed to obtain a nanoscale iron-containing oxide; mixing the obtained nanoscale iron-containing oxide with a solvent, a lithium source, a manganese source, a phosphorus source, optionally a source of doping element N, optionally a source of doping element Q and optionally a source of doping element R in a predetermined ratio and then grinding. After grinding, granulating to obtain a powder; and sintering the powder to obtain the lithium manganese iron phosphate positive electrode active material. A lithium manganese iron phosphate positive electrode active material having both good electrochemical performance and high tap density can be obtained.

The present invention relates to a method of manufacturing lithium hydroxide, which includes adding at least one acid selected from hydrochloric acid, sulfuric acid, and nitric acid into lithium phosphate slurry including a lithium phosphate particle, adding an alkali material to the lithium phosphate slurry including the acid, and converting it into a lithium hydroxide aqueous solution.

A solid electrolyte, in which an occupied impurity level that is formed by a part of elements contained in a mobile ion-containing material being substituted and that is occupied by electrons is included in a band gap of the mobile ion-containing material, and an amount of charge retention per composition formula of the occupied impurity level is equal to or greater than an amount of charge retention of mobile ions per composition formula of the mobile ion-containing material.

A positive electrode active material includes: a particle including a lithium composite oxide; a first layer that is provided on a surface of the particle and includes a lithium composite oxide; and a second layer that is provided on a surface of the first layer. The lithium composite oxide included in the particle and the lithium composite oxide included in the first layer have the same composition or almost the same composition, the second layer includes an oxide or a fluoride, and the lithium composite oxide included in the first layer has lower crystallinity than the lithium composite oxide included in the particle.