Methods of pretreating an electroactive material comprising lithium titanate oxide (LTO) include contacting a surface of the electroactive material with a pretreatment composition. In one variation, the pretreatment composition includes a salt of lithium fluoride salt selected from the group consisting of: lithium hexafluorophosphate (LiPF.sub.6), lithium tetrafluoroborate (LiBF.sub.4), and combinations thereof, and a solvent. In another variation, the pretreatment composition includes an organophosphorus compound. In this manner, a protective surface coating forms on the surface of the electroactive material. The protective surface coating comprises fluorine, oxygen, phosphorus or boron, as well as optional elements such as carbon, hydrogen, and listed metals, and combinations thereof.

Methods of pretreating an electroactive material comprising lithium titanate oxide (LTO) include contacting a surface of the electroactive material with a pretreatment composition. In one variation, the pretreatment composition includes a salt of lithium fluoride salt selected from the group consisting of: lithium hexafluorophosphate (LiPF.sub.6), lithium tetrafluoroborate (LiBF.sub.4), and combinations thereof, and a solvent. In another variation, the pretreatment composition includes an organophosphorus compound. In this manner, a protective surface coating forms on the surface of the electroactive material. The protective surface coating comprises fluorine, oxygen, phosphorus or boron, as well as optional elements such as carbon, hydrogen, and listed metals, and combinations thereof.

A positive electrode for an all-solid secondary battery, comprising a positive electrode active material expressed by A.sub.2S.AX, wherein

A is an alkali metal; and

X is selected from I, Br, Cl, F, BF.sub.4, BH.sub.4, SO.sub.4, BO.sub.3, PO.sub.4, O, Se, N, P, As, Sb, PF.sub.6, AsF.sub.6, ClO.sub.4, NO.sub.3, CO.sub.3, CF.sub.3SO.sub.3, CF.sub.3COO, N(SO.sub.2F).sub.2 and N(CF.sub.3SO.sub.2).sub.2.

A positive electrode for an all-solid secondary battery, comprising a positive electrode active material expressed by A.sub.2S.AX, wherein

A is an alkali metal; and

X is selected from I, Br, Cl, F, BF.sub.4, BH.sub.4, SO.sub.4, BO.sub.3, PO.sub.4, O, Se, N, P, As, Sb, PF.sub.6, AsF.sub.6, ClO.sub.4, NO.sub.3, CO.sub.3, CF.sub.3SO.sub.3, CF.sub.3COO, N(SO.sub.2F).sub.2 and N(CF.sub.3SO.sub.2).sub.2.

A positive electrode material for a lithium-ion secondary battery which has high capacity and excellent charge and discharge cycle performance, and a manufacturing method thereof are provided, or a method of manufacturing a positive electrode material with high productivity is provided. The positive electrode material for a lithium-ion secondary battery includes a crystal represented by a crystal structure with a space group R-3m, a first region, and a second region, which is in contact with at least part of an outer side of the first region and whose outer edge corresponds to a surface of the first particle. The ratio of manganese atoms to cobalt atoms in the first region is lower than the ratio of manganese atoms to cobalt atoms in the second region. The ratio of fluorine atoms to oxygen atoms in the first region is lower than the ratio of fluorine atoms to oxygen atoms in the second region.

A method for forming a cathode includes milling a suspension of precursors via a micromedia mill to form a mixture of primary particles in the suspension. The precursors include one or more metal compounds. The method includes spray drying the suspension after the milling to form secondary particles. The secondary particles are agglomerations of the primary particles. The method also includes annealing the secondary particles to form a disordered rocksalt powder.

A method for forming a cathode includes milling a suspension of precursors via a micromedia mill to form a mixture of primary particles in the suspension. The precursors include one or more metal compounds. The method includes spray drying the suspension after the milling to form secondary particles. The secondary particles are agglomerations of the primary particles. The method also includes annealing the secondary particles to form a disordered rocksalt powder.

Disclosed are a cathode active material for high voltage and a lithium secondary battery including the same. More particularly, a cathode active material including spinel-type compound particles having a composition represented by Formula 1 below;
Li.sub.1+aM.sub.xMn.sub.2−xO.sub.4−zA.sub.z  (1) where a, x and z are defined in a specification of the present invention, and metal oxides or metal hydroxides present on surfaces of the spinel-type compound particles, and a lithium secondary battery including the same.

Disclosed are a cathode active material for high voltage and a lithium secondary battery including the same. More particularly, a cathode active material including spinel-type compound particles having a composition represented by Formula 1 below;
Li.sub.1+aM.sub.xMn.sub.2−xO.sub.4−zA.sub.z  (1) where a, x and z are defined in a specification of the present invention, and metal oxides or metal hydroxides present on surfaces of the spinel-type compound particles, and a lithium secondary battery including the same.

The present disclosure relates to a positive electrode material including a spinel-structured lithium manganese-based first positive electrode active material and a lithium nickel-manganese-cobalt-based second positive electrode active material, wherein the first positive electrode active material includes a lithium manganese oxide represented by Formula 1 and a coating layer which is disposed on a surface of the lithium manganese oxide, the second positive electrode active material is represented by Formula 2, and an average particle diameter of the second positive electrode active material is greater than an average particle diameter of the first positive electrode active material, and a positive electrode and a lithium secondary battery which include the positive electrode material:
Li.sub.1+aMn.sub.2−bM.sup.1.sub.bO.sub.4−cA.sub.c  [Formula 1]
Li.sub.1+x[Ni.sub.yCo.sub.zMn.sub.wM.sup.2.sub.v]O.sub.2−pB.sub.p  [Formula 2]