Herein, solid-state electrochemical reactions are collectively viewed and studied as the formation and dissolution of a solid phase under non-equilibrium. We first consider an ideal reaction pathway where a solid phase grows and shrinks along the same reaction path. Next, the realistic situation is studied based on the voltammetry of solids to reveal how a solid phase is formed and dissolved in contact with either a liquid or another solid phase. Finally, the reaction asymmetry between phase formation and dissolution, hysteresis, and the memory effect are studied and discussed in detail.