ACTIVE MATERIAL FOR SECONDARY BATTERIES, ELECTRODE FOR SECONDARY BATTERIES, SECONDARY BATTERY, BATTERY PACK, ELECTRIC VEHICLE, ELECTRICAL ENERGY STORAGE SYSTEM, ELECTRIC TOOL AND ELECTRONIC DEVICE

摘要

This secondary battery is provided with a positive electrode, a negative electrode and an electrolyte solution. The positive electrode contains a lithium-containing compound that has an average composition represented by Li1+a(CobNicMdMne)1-aO2-f. (In the formula, M represents one or more metal elements other than manganese, cobalt and nickel; and a-e satisfy 0.05 < a < 0.2, 0.45 ≤ b ≤ 0.7, 0 < c ≤ 0.1, 0 ≤ d ≤ 0.1, e ≤ b, b + c + d + e = 1 and -0.1 ≤ f ≤ 0.2.)