Interfacial Reactions in Li–S and Li–O2 Batteries

Lithium-sulfur (Li–S) and Lithium-oxygen (Li–O2) are new technologies that could theoretically deliver the transformation in performance required in the long term. The reactions at the cathode (positive electrode) in Li-air and Li–S cells involve the reversible reduction of elemental S and O2 gas, respectively, and are fundamentally different from those in Li-ion cells. Neither of these technologies is an established commercial product yet.