Positive electrode active material for secondary battery, positive electrode for secondary battery, secondary battery and method for producing positive electrode active material for secondary battery

摘要

A life of a secondary battery is extended, increase in a resistance when storing a secondary battery at an elevated temperature is prevented, and increase in a resistance during a charge-discharge cycle is prevented. A positive electrode active material comprising a lithium manganate and a lithium nickelate are used. The lithium manganate is a compound represented by the following formula (1) or the compound in which some of Mn or O sites are replaced with another element: <?in-line-formulae description="In-line Formulae" end="lead"?>Li1+xMn2-xO4 (1)<?in-line-formulae description="In-line Formulae" end="tail"?> (in the above-shown formula (1), 0.15<=x<=0.24).