To provide a storage battery including a carbon-based material. To provide a graphene compound film having desired ion conductivity and mechanical strength while preventing direct contact between electrodes in a storage battery. To achieve long-term reliability. A lithium-ion storage battery includes a positive electrode, a negative electrode, an exterior body, and a separator between the positive electrode and the negative electrode. In the lithium-ion storage battery, one of the positive electrode and the negative electrode is wrapped in a first film, and the positive electrode, the negative electrode, and the separator are stored in the exterior body. The first film may include a first region in which the first film includes a first functional group. The first film may further include a second region in which the first film includes a second functional group different from the first functional group. The first film may be a graphene compound film.