An organic electrolytic solution includes: a lithium salt; an organic solvent; a disultone-based compound represented by Formula 1; and a silicon-based compound represented by Formula 2: wherein in Formulae 1 and 2, A1, A2, A3, and A4 are each independently selected from a substituted or unsubstituted C1 to C5 alkyl group; a carbonyl group; or a sulfinyl group, n1 to n4 each are independently an integer from 1 to 3, when each of n1 to n4 is 2 or more, a plurality of A1, A2, A3, or A4 are identical or different, X is N or O, and n is 0 or 1, when X is O, n is 0, Y is a covalent bond, a carbonyl group, or —N═C(Rf)—, and Ra, Rb, Rc, Rd, and Re are the same as described in the detailed description.