A positive electrode active material includes positive electrode active material particles including a composite oxide with a hexagonal crystal structure. The composite oxide includes Li, Co, and at least one element M1 selected from the group consisting of Ni, Fe, Pb, Mg, Al, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Mn and Cr, and the at least one element M1 is provided on a surface of the positive electrode active material particles. An atomic ratio of a total amount of the at least one element M1 to an amount of Co on the surface of the positive electrode active material particles is from 0.6 to 1.3.

A method for recovering an active metal of a lithium secondary battery according to an embodiment of the present application whereby a cathode active material mixture obtained from a used cathode of a lithium secondary battery is prepared, and the cathode active material mixture is reacted in a fluidized bed reactor to form a preliminary precursor mixture. A lithium precursor is recovered from the preliminary precursor mixture. Yield and selectivity of a lithium precursor can be improved using the fluidized bed reactor.

A method for recovering an active metal of a lithium secondary battery according to an embodiment of the present application whereby a cathode active material mixture obtained from a used cathode of a lithium secondary battery is prepared, and the cathode active material mixture is reacted in a fluidized bed reactor to form a preliminary precursor mixture. A lithium precursor is recovered from the preliminary precursor mixture. Yield and selectivity of a lithium precursor can be improved using the fluidized bed reactor.

A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

Provided is a cobalt precursor for preparing a lithium cobalt oxide of a layered structure which is included in a positive electrode active material, wherein the cobalt precursor is cobalt oxyhydroxide (CoMOOH) doped with, as dopants, magnesium (Mg) and M different from the magnesium.

Provided is a cobalt precursor for preparing a lithium cobalt oxide of a layered structure which is included in a positive electrode active material, wherein the cobalt precursor is cobalt oxyhydroxide (CoMOOH) doped with, as dopants, magnesium (Mg) and M different from the magnesium.

The present application relates to a metal oxide and synthesis of a lithium ion battery. Specifically, the present application selects a cobalt oxide compound, which uses Co.sub.3O.sub.4 as a main body, as a precursor of lithium cobalt oxide, and anion doping is performed in particles of Co.sub.3O.sub.4 to obtain a doped precursor for lithium cobalt oxide. The general formula of the precursor can be expressed as Co.sub.3(O.sub.1-yM.sub.y).sub.4, where about 0<y<about 0.2, and wherein the anion M comprises at least one of F, P, S, Cl, N, As, Se, Br, Te, I or At. The lithium ion battery with a cathode made of lithium cobalt oxide material prepared by using the precursor presents good cycle stability in a high voltage charge-discharge environment.

A method for preparing a transition-metal adamantane carboxylate salt is presented. The method includes mixing a transition-metal hydroxide and a diamondoid compound having at least one carboxylic acid moiety to form a reactant mixture, where M is a transition metal. Further, the method includes hydrothermally treating the reactant mixture at a reaction temperature for a reaction time to form the transition-metal adamantane carboxylate salt.

A method for preparing a transition-metal adamantane carboxylate salt is presented. The method includes mixing a transition-metal hydroxide and a diamondoid compound having at least one carboxylic acid moiety to form a reactant mixture, where M is a transition metal. Further, the method includes hydrothermally treating the reactant mixture at a reaction temperature for a reaction time to form the transition-metal adamantane carboxylate salt.

Further described herein are extensions to the basic concept of LHs as electrode materials, include both new materials for use with LHs and higher order poly-layer hydroxides (PLHs) as well as methods for synthesizing improved LH material such as with conductive supports or through the use of cross-linking. Finally, also described herein are embodiments enabling the use of LHs as flow electrodes as well as the use of 2-d LH materials for surface redox reactions.