| abstract |
The present invention relates to secondary batteries, battery packs, electric vehicles, and power storage systems. The secondary battery includes: a positive electrode of a lithium-oxygen-containing compound, a negative electrode, and a non-aqueous electrolyte solution including one or more first anions represented by the formula (1): B(XY) x F y R z - ( 1), wherein, X is a kind of in divalent chain hydrocarbon group, divalent fluorinated chain hydrocarbon group, and no group; Y is cyano group (-C≡N) and isocyano group (-N + ≡C- ) one of; R is one of a monovalent fluorinated chain hydrocarbon group and a monovalent fluorinated cyclic hydrocarbon group; and x to z satisfy x>0, y≥0, z≥0, (x+y+z)=4 and an integer of (y+z)>0. |