fig1

Figure 1. (A) Clarkes number and melting point of representative alkaline-earth and alkali metals; (B) Gravimetric and volumetric capacities of alkaline-earth and alkali metals with the redox potentials; (C) Schematic diagram of ionic liquid electrolyte-based Ca-O₂ battery; (D) The details of two-electron and four-electron pathways; (E) The control factors of the reaction mechanism for Li-O₂ battery; (F) The possible logic diagram for the change from a four-electron to two-electron pathway; (G) The applications of flexible Ca-O₂ batteries on wearable fields.