Carbon supported TiN nanoparticles: an efficient bifunctional catalyst for non-aqueous Li-O-2 batteries

A Li-O-2 battery with TiN nanoparticles supported on Vulcan XC-72, n-TiN/VC, as the cathode catalyst presented an onset potential for the oxygen evolution reaction (OER) at 2.9 V, contrasting with a mixture of micro-sized TiN and VC (m-TiN/VC), and VC, both at similar to 3.1 V. The discharge-recharge voltage gap of n-TiN/VC was estimated to be 1.05 V, which is 390 and 450 mV smaller than that of m-TiN/VC and VC, respectively, at 50 mA g(carbon)(-1). These indicate that n-TiN/VC can function as both an active ORR catalyst during discharge and an efficient OER catalyst during recharge.