A lithium secondary battery is intended to suppress deterioration upon storage at high temperature of 50° C. or higher without deteriorating the output characteristics at a room temperature. The battery includes a positive electrode capable of occluding and releasing lithium ions, a negative electrode capable of occluding and releasing lithium ions, a separator disposed between the positive electrode and the negative electrode, and an electrolyte. The electrolyte contains a compound having a double bond in the molecule and a compound having a plurality of polymerizable functional groups in the molecule, and the electrolyte contains a compound represented by formula (4): (in which Z1 and Z2 each represent any one of an allyl group, a methallyl group, a vinyl group, an acryl group, and a methacryl group).