Abstract: The object is to provide a nonaqueous-electrolyte battery having high charge/discharge efficiency and excellent high-rate performance. This subject is accomplished by using a nonaqueous electrolyte which comprises an organic solvent and a lithium salt dissolved therein and is characterized by containing at least one quaternary ammonium salt in an amount of 0.06 mol/L or larger and 0.5 mol/L or smaller. This effect is thought to be attributable to the following mechanism: in a relatively early stage (stage in which the negative-electrode potential is relatively noble) in a first charge step, a satisfactory protective coating film is formed on the negative electrode by the action of the quaternary ammonium salt and, hence, the organic solvent employed in the nonaqueous electrolyte is inhibited from decomposing.

Abstract: A nonaqueous electrolyte includes an organic solvent and a lithium salt dissolved in the organic solvent, and a quaternary ammonium salt in an amount of 0.06 mol/L or greater and 0.5 mol/L or less, the quaternary ammonium salt having a structure represented by (chemical formula 3): wherein R is an organic linking group or an organic linking group forming an aromatic ring, the organic linking groups each having a main chain which has 4-5 atoms and is constituted of at least one member selected from carbon, oxygen, nitrogen, sulfur, and phosphorus and having one single-bond end and one double-bond end; R1 is an alkyl group having 1-6 carbon atoms or an alkyl group in which at least one of the hydrogen atoms has been replaced by a fluorine atom; and X? is a fluorine-containing anion.

Abstract: The object is to provide a nonaqueous-electrolyte battery having high charge/discharge efficiency and excellent high-rate performance. This subject is accomplished by using a nonaqueous electrolyte which comprises an organic solvent and a lithium salt dissolved therein and is characterized by containing at least one quaternary ammonium salt in an amount of 0.06 mol/L or larger and 0.5 mol/L or smaller. This effect is thought to be attributable to the following mechanism: in a relatively early stage (stage in which the negative-electrode potential is relatively noble) in a first charge step, a satisfactory protective coating film is formed on the negative electrode by the action of the quaternary ammonium salt and, hence, the organic solvent employed in the nonaqueous electrolyte is inhibited from decomposing.