Electrochemical Investigations on Graphene and Lithium Phthalocyanine as Catalysts for Reversible Oxygen Reduction Reaction in Li-O2 Cells.

摘要

The theoretical energy density of Li-air battery is close to that of gasoline. One hurdle to implementation is electrochemistry of oxygen in non-aqueous electrolytes, including development of a suitable catalyst for reversible oxygen electrode for long cycle-life. Several reduced graphene oxide (RGO) preparations were tested in both aqueous and non-aqueous electrolytes using cyclic voltammetry and rotating disk electrode techniques. Studies were carried out using silver nano-particles (Ag-RGO), as well as gold (Au-RGO), palladium (Pd-RGO), iridium (Ir- RGO) and polypyrrole (PPY-RGO). Prototype cells were assembled and tested in charge and discharge at several current densities. Initial cycling shows a decrease in capacity, stabilizing after approximately 30 charge-discharge cycles. The results indicate that RGO based catalysts are appropriate for deriving high discharge capacity from rechargeable Li-O2 cells.