CATHODE ACTIVE MATERIAL, CATHODE, SECONDARY BATTERY, BATTERY PACK, ELECTRIC VEHICLE, ELECTRIC POWER STORAGE SYSTEM, ELECTRIC POWER TOOL, AND ELECTRONIC APPARATUS

摘要

A secondary battery capable of obtaining superior battery characteristics is provided. The cathode according to the technology includes a lithium-containing compound. The lithium-containing compound is a compound obtained by inserting an element M2 different from an element M1 in a crystal structure of a surface layer region of a composite oxide represented by a general formula of Li1+a(MnbCocNi1−b−c)1−aM1dO2−c (the element M2 is Mg or the like). A mole fraction R1 represented by [R1 (percent)=(a substance amount of the element M2/sum of substance amounts of Mn, Co, Ni, and the element M2)×100] on a central side of the lithium-containing compound is smaller than the mole fraction R1 on a surface layer side of the lithium-containing compound.

主权项

1. A secondary battery comprising:
a cathode; an anode; and an electrolytic solution, wherein the cathode includes a lithium-containing compound, the lithium-containing compound is a compound obtained by inserting an element M2 different from an element M1 in a crystal structure of a surface layer region of a composite oxide represented by a following Formula (1), the element M2 is at least one of Mg, Ca, Ti, Zr, S, F, Fe, Cu, B, Al, P, C, Mn, Ni, and Co, and a mole fraction R1 represented by a following Formula (2) on a central side of the lithium-containing compound is smaller than the mole fraction R1 on a surface layer side of the lithium-containing compound,
Li1+a(MnbCocNi1−b−c)1−aM1dO2−e  (1)where M1 is at least one of Al, Mg, Zr, Ti, Ba, B, Si, and Fe; and a to e satisfy 0 R1 (percent)=(a substance amount of the element M2/sum of substance amounts of Mn, Co, Ni, and the element M2)×100  (2).