There is disclosed a battery in which a metal ion dissolved in an electrolyte is oxidized and reduced to charge or discharge the battery. The battery may include a first liquid electrode in which a first half reaction occurs; a second electrode in which a second half reaction occurs; a frame forming a first electrode reservoir that is a space in which the first liquid electrode is stored and a second electrode reservoir that is a space in which the second liquid electrode is stored; a separator bonded to the frame to be disposed between the first electrode reservoir and the second reservoir; and an injection hole in fluidic communication with the first electrode reservoir and the second electrode reservoir to inject a liquid electrode from the outside therethrough.