The present invention relates to a novel method for preparing lithium oxide. In the present invention, the particle size and shape of lithium oxide may be controlled during the preparing process. In addition, the present invention relates to lithium oxide with controlled particle size and shape prepared by this preparing method.

The present invention relates to a novel method for preparing lithium oxide. In the present invention, the particle size and shape of lithium oxide may be controlled during the preparing process. In addition, the present invention relates to lithium oxide with controlled particle size and shape prepared by this preparing method.

Systems and methods use ion exchange to extract lithium from a lithium-containing feed solution such as a salar brine. Lithium ions are loaded into an ion exchange resin and then eluted while recharging the resin. Sodium hydroxide or sodium bicarbonate may be used to recharge the resin but are not directly mixed with the lithium-containing feed solution. An eluate stream is produced containing lithium hydroxide or lithium bicarbonate. Lithium hydroxide can be precipitated as lithium hydroxide or in a hydrate form. Lithium bicarbonate may be converted to lithium carbonate. The system and method optionally includes processing an eluate stream to recover one or more compounds for re-use in regenerating the resin bed.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

A hybrid electro-pressure driven method for the recovery, purification, and concentration of lithium salts is described. A fractionating electrodialysis stack equipped with selective ion exchange membranes is s used to separate a lithium containing brine into a monovalent enriched fraction and a divalent enriched fraction. The monovalent enriched fraction is further processed to remove remaining impurities by use of pressure driven nanofiltration. An optional concentrating electrodialysis device may further concentrate the monovalent enriched fraction in lithium content. The method may be combined with a subsequent solvent extraction and electrolysis step to produce lithium hydroxide, a Li+ selective sorbent step for producing purified lithium chloride, or a Li+ selective sorbent and precipitative step to produce lithium carbonate.

A hybrid electro-pressure driven method for the recovery, purification, and concentration of lithium salts is described. A fractionating electrodialysis stack equipped with selective ion exchange membranes is s used to separate a lithium containing brine into a monovalent enriched fraction and a divalent enriched fraction. The monovalent enriched fraction is further processed to remove remaining impurities by use of pressure driven nanofiltration. An optional concentrating electrodialysis device may further concentrate the monovalent enriched fraction in lithium content. The method may be combined with a subsequent solvent extraction and electrolysis step to produce lithium hydroxide, a Li+ selective sorbent step for producing purified lithium chloride, or a Li+ selective sorbent and precipitative step to produce lithium carbonate.

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.

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 secondary battery includes a positive electrode, a negative electrode including a negative electrode active material, and an electrolytic solution. The negative electrode active material includes a lithium-silicon-containing oxide that includes lithium and silicon as constituent elements and includes magnesium present on a surface layer of the lithium-silicon-containing oxide. The lithium-silicon-containing oxide includes a phase including silicon and a phase including at least one kind of lithium silicate represented by Formula (1). A range in which magnesium is present is within a range of greater than or equal to 10 nm and less than or equal to 3000 nm from a surface of the lithium-silicon-containing oxide in a depth direction. Magnesium forms at least one kind of magnesium silicate represented by Formula (2). A ratio of a number of moles of magnesium to a number of moles of lithium is greater than or equal to 0.1 mol % and less than or equal to 20 mol %,

Li.sub.aSi.sub.bO.sub.c  (1) where a, b, and c satisfy 1≤a≤6, 1≤b≤3, and 1≤c≤7, respectively,

Mg.sub.xSi.sub.yO.sub.z  (2) where x, y, and z satisfy 1≤x≤3, 1≤y≤2, and 1≤z≤4, respectively.