LITHIUM-ION SECONDARY BATTERY, AND BATTERY PACK AND POWER STORAGE DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a lithium-ion secondary battery and a power storage device which are more stable and safer even in an overcharged state due to a large current.SOLUTION: The lithium-ion secondary battery according to the present invention includes: a cathode comprising a cathode active material containing a lithium transition metal phosphate; an anode facing the cathode and having such an anode capacity that a ratio of the anode capacity to a cathode capacity per unit area is 105-180% inclusive; and a lithium fluoroborate.