Patent ID: 7238453

Claim:
A secondary battery comprising: a. an anode b. a cathode, and, c. an electrolytic solution, comprising i. a non-aqueous solvent, wherein the non-aqueous solvent comprises ethylene carbonate and ethylmethyl carbonate in a volume ratio of about 1:4 to about 1:1, ii. a first salt comprising lithium bis(oxalato)borate in a concentration of greater than 0.15 M to about 2.0 M and iii. a second salt in a concentration of about 0.1 M to about 1.6 M, wherein the second salt is selected from the group consisting of LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiTaF 6 , LiAlCl 4 , Li 2 B 10 Cl 10 , LiCF 3 SO 3 , LiE(C n F 2n+1 SO 2 ) m , wherein m=2 or 3, wherein E=N when m=2, and wherein E=C when m=3, and n=1–10; LiPF x (R F ) 6−x , and LiBF y (R F ) 4−y , wherein R F represents perfluorinated C 1 –C 20 alkyl groups or perfluorinated aromatic groups, x=0–5, and y=0–3, and combinations thereof.