| abstract |
A non-aqueous liquid electrolyte secondary battery using negative-electrode active material having Si, Sn and/or Pb, with high charge-capacity, superior characteristics including discharge-capacity retention rate over long is provided. Its non-aqueous liquid electrolyte contains carbonate having unsaturated bond and/or halogen and compounds like LiPF 6 and/or LiBF 4 (first lithium salt) and lithium salt different from said first one, represented by formula below (second lithium salt). n n Li 1 (α m X a n ) n n(In the formula, l, m and n represent integers of 1 to 10, 1 to 100 and 1 to 200, respectively. α represents boron, carbon, nitrogen, oxygen or phosphorus. X a represents functional group having atom selected from 14th to 17th groups of periodic table at its binding-position to α. Two or more of X a may be connected to each other to form a ring structure. However, such a case where α is boron and X a is compound represented by n n (C i H 2(i-2) O 4 ) (C j H 2(j-2) O 4 ) n nis omitted (i and j represent integers of 2 or larger.) |