Figure 10.

Sketch of the first room temperature sodium–oxygen cell and its discharge and charge potentials during the first ten cycles (left), Figure adapted with permission from [101], copyright 2012 Elsevier B.V. The voltage profile can be classified as Type 2C. Voltage profile of a sodium–oxygen cell with graphene nanosheets as cathode and NaPF₆ in DME as electrolyte (Type 2C) (right). The discharge product was identified as sodium peroxide. Figure adapted with permission from [103], copyright 2013 The Royal Society of Chemistry.