| abstract |
An object is to provide a non-aqueous electrolyte solution, a non-aqueous secondary battery, a battery pack, and a hybrid system that improve desired battery performance, particularly in an acetonitrile electrolyte solution. The non-aqueous electrolyte solution of the present invention is characterized by containing a non-aqueous solvent, PO 2 F 2 anion, and a cyclic acid anhydride. The non-aqueous secondary battery of the present invention includes: a positive electrode having a positive electrode active material layer on one or both surfaces of a current collector; a negative electrode having a negative electrode active material layer on one or both surfaces of the current collector; An aqueous electrolyte solution, characterized in that the non-aqueous electrolyte solution contains acetonitrile and LiPO 2 F 2 , and the value calculated by dividing the volume resistance at -30°C measured by FRA of the non-aqueous secondary battery by the internal resistance value is 0.05 to 0.05 0.7 range. In addition, the capacity retention rate calculated by dividing the 5C discharge capacity by the 1C discharge capacity after the 4-hour storage test of the non-aqueous secondary battery at 85°C was 70% or more. |