LITHIUM ION SECONDARY BATTERY EXCELLENT IN RATE CHARACTERISTIC AND CYCLE CHARACTERISTIC, AND HAVING HIGH SAFETY EVEN IN HIGH ENERGY DENSITY

摘要

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery.SOLUTION: In a lithium ion secondary battery, a negative electrode binder comprises a composition including a butadiene copolymer and a cellulose-based compound, and an electrolytic solution comprises an electrolyte including a polymer. The lithium ion secondary battery is excellent in rate characteristics and cycle characteristics, and has high safety even in high energy density.