Utilizing a photocatalysis process to achieve a cathode with low charging overpotential and high cycling durability for a Li-O2 battery.

The practical applications of non-aqueous lithium-oxygen batteries are impeded by large overpotentials and unsatisfactory cycling durability. Reported here is that commonly encountered fatal problems can be efficiently solved by using a carbon- and binder-free electrode of titanium coated with TiO(2)nanotube arrays (TNAs) and gold nanoparticles (AuNPs). Ultraviolet irradiation of the TNAs generates positively charged holes, which efficiently decompose Li(2)O(2)and Li(2)CO(3)during recharging, thereby reducing the overpotential to one that is near the equilibrium potential for Li(2)O(2)formation. The AuNPs promote Li(2)O(2)formation, resulting in a large discharge capacity. The electrode exhibits excellent stability with about 100 % coulombic efficiency during continuous cycling of up to 200 cycles, which is due to the carbon- and binder-free composition. This work reveals a new strategy towards the development of highly efficient oxygen electrode materials for lithium-oxygen batteries.