A water-activated power bank structure, comprising: a bottle body with a top opening and a bottom opening, wherein the bottle body is configured to accommodate a first electrode structure and a second electrode structure. The water-activated power bank structure further comprises: a top cap configured to mate with the top opening of the bottle body; a first bottom cap configured to mate with the bottom opening of the bottle body; a second bottom cap configured to mate with the first bottom cap; and a power output module disposed in the second bottom cap; wherein the first electrode structure has a cylindrical shape and the second electrode structure has a mesh shape, and wherein the power output module is electrically connected to the first electrode structure and the second electrode structure.