LITHIUM SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a lithium secondary battery excellent in output in a low SOC region, and resistant to degradation associated with charge-discharge cycles.SOLUTION: The lithium secondary battery comprises a positive electrode containing a positive electrode active material composed of secondary particles made of primary particles composed of a lithium transition metal oxide; and a negative electrode. The positive electrode active material contains at least one of Ni, Co, and Mn, further contains W, Ca, and Mg, and satisfies 2≤(m/m)≤50, (m+m)≥0.26, and (m/m)≥1.5, where mrepresents the mole percentage of W, mrepresents the mole percentage of Ca, and mrepresents the mole percentage of Mg, with the total amount of Ni, Co, and Mn being taken as 100 mol%. The W is concentrated at the surfaces of the primary particles.