The present disclosure relates to a sodium-ion storage material and an electrode material for a sodium-ion battery, an electrode material for a seawater battery, an electrode for a sodium-ion battery, an electrode for a seawater battery, a sodium-ion battery, and a seawater battery, which include the sodium-ion storage material. Specifically, the sodium-ion storage material may include one or more materials selected from the group consisting of CuxS, FeS, FeS2, Ni3S, NbS2, SbOx, SbSx, SnS and SnS2, wherein 0