NON-AQUEOUS LIQUID ELECTROLYTE AND NON-AQUEOUS LIQUID ELECTROLYTE SECONDARY BATTERY

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 LiPF6 and/or LiBF4 (first lithium salt) and lithium salt different from said first one, represented by formula below (second lithium salt).Lil(αmXan)(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. Xa represents functional group having atom selected from 14th to 17th groups of periodic table at its binding-position to α. Two or more of Xa may be connected to each other to form a ring structure. However, such a case where α is boron and Xa is compound represented by(CiH2(i-2)O4)(CjH2(j-2)O4)is omitted (i and j represent integers of 2 or larger.)