ELECTROLYTE SOLUTION FOR SECONDARY BATTERY, AND BATTERY AND FLEXIBLE BATTERY COMPRISING SAME

An electrolyte for a secondary battery is provided. The electrolyte for a secondary battery according to an embodiment of the present invention comprises: a non-aqueous organic solvent including propyl propionate (PP) and ethyl propionate (EP); a lithium salt; and an additive. The lithium salt is contained in a concentration of 0.6-1.6 M. Accordingly, when the electrolyte is applied to a battery and a flexible battery, excellent discharge performance can be exhibited in extremely low temperature and high temperature. In addition, the flexible battery of the present invention can prevent or minimize the deterioration of physical properties required as a battery even if repeated bending occurs. Such an electrolyte for a secondary battery of the present invention can be applied to various fields which require high discharge capacity at extremely low temperature and high temperature.