SECONDARY BATTERY, BATTERY PACK, ELECTRONIC DEVICE, ELECTRICALLY DRIVEN VEHICLE, STORAGE DEVICE, AND POWER SYSTEM

摘要

This secondary battery contains the following: a positive electrode that has a positive-electrode active-material layer that contains a positive-electrode active material; a negative electrode that has a negative-electrode active-material layer that contains a negative-electrode active material; and an electrolyte. The positive-electrode active material contains a lithium-iron-phosphate compound that has an olivine structure and/or a lithium-manganese composite oxide that has a spinel structure. The negative-electrode active material contains a titanium-containing inorganic oxide. The surface area of the positive electrode, the surface area of the negative electrode, the irreversible capacity and initial charging capacity per unit surface area of the positive electrode, and the irreversible capacity and initial charging capacity per unit surface area of the negative electrode satisfy a prescribed relation.