A Li/CO₂–O₂ (2 : 1, volume ratio) battery and a Li/CO₂ battery with discharging specific capacities of 1808 mA h g⁻¹ and 1032 mA h g⁻¹, respectively, are reported. Li₂CO₃ is the main discharge product in the Li/CO₂–O₂ (2 : 1) battery and can be decomposed during charging. In the Li/CO₂ battery, the main discharge products could be Li₂CO₃ and carbon. Both batteries can be cycled reversibly at room temperature.

The inhomogeneous multi-layered structure, thickness, Young's modulus and coverage of the SEI on silicon anodes during cycling are visualized three-dimensionally by a scanning force curve method.