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; and the positive electrode contains an active material that is capable of absorbing and desorbing an electrode reactive substance. The ratio of the intensity (IS) of a peak assigned to SO2 - to the intensity (IF) of a peak assigned to LiF2 -, namely IS/IF as obtained by a negative ion analysis of the active material using time-of-flight secondary ion mass spectrometry is 0.04 or more. Since a secondary battery according to the present invention has an intensity ratio IS/IF of 0.04 or more as obtained by a negative ion analysis of the active material using time-of-flight secondary ion mass spectrometry, the secondary battery is able to achieve excellent battery characteristics.