Patent ID: 9692085
Date: 2017-06-27
CPC Classifications: H01M,Y02E,Y02T

Claim:
1. A lithium ion secondary battery comprising a positive electrode and a negative electrode which are capable of intercalating and deintercalating lithium, a separator between the positive electrode and the negative electrode, and an electrolytic solution containing a nonaqueous electrolytic solvent, wherein the positive electrode comprises a positive electrode active material operating at a potential of 4.5 V or more versus lithium, the separator comprises cellulose, or a cellulose derivative, the nonaqueous electrolytic solvent comprises a fluorinated solvent in an amount ranging from 5 to 80% by volume, wherein said fluorinated solvent comprises a fluorinated ether represented by the following formula (1-1); wherein R the porosity of the separator ranges from at least 50% through 95%, and the positive electrode active material comprises lithium manganese complex oxide represented by the following formula (A), wherein 0.4≦x≦1.2, 0≦y<0.3, x+y<2, 0≦a≦1.2, and 0≦w≦1 are satisfied; M is at least one selected from Co, Ni, Fe, Cr, and Cu; Y is at least one selected from Li, B, Na, Mg, Al, Ti, Si, K, and Ca; and Z is at least one selected from F and Cl.