In the uncharged configuration, bound oxygen atoms may be included in the first electrode 310, the solid electrolyte 320, and the second electrode 330. During charging, however, some of the oxygen atoms may become unbound, such as due to the addition of electrons to the first electrode 310, where the oxygen atoms may become free ions, such as oxygen anions (O? or O2?). These oxygen anions may move from first electrode 310 into the solid electrolyte 320. Oxygen ions added to the solid electrolyte 320 may migrate through the solid electrolyte 320 and pass to the second electrode 330. In some circumstances, the oxygen anions added to the solid electrolyte 320 may become bound in the structure of the solid electrolyte 320 and a different oxygen atom may be released from the structure of the solid electrolyte 320 as an oxygen anion, creating an effective migration of the oxygen anion through the solid electrolyte. The oxygen ions that are added to the second electrode 330 may be incorporated into the structure of the second electrode 330. In some cases, in the uncharged configuration the amounts of oxygen in the first electrode 310 and the second electrode 330 are the same.