ELECTROLYTE SOLUTION FOR ELECTRICAL ENERGY STORAGE DEVICES, AND ELECTRICAL ENERGY STORAGE DEVICES INCLUDING THIS ELECTROLYTE SOLUTION

To provide an electrolyte solution for storage battery devices, which is free from corroding electrodes and free from impairing battery performance such as electrical conductivity and which is provided with nonflammability and practically sufficient conductivity, and a battery using such an electrolyte solution. An electrolyte solution for storage battery devices, which comprises a lithium salt represented by the following formula (1) (wherein at least one fluorine atom may be substituted by a perfluoroalkyl group having at most 4 carbon atoms, and n is an integer of from 1 to 5), a hydrofluoroether and a high-permittivity solvent, as the main components: