High lithium storage performance of Ni0.5Fe0.5O1−xNx thin film with NiO-type crystal structure

The large voltage hysteresis of the NiO anode, which owes much to the intermediate product Li2NiO2, is one of the main obstacles to its practical application in lithium-ion batteries. In this work, we show that the incorporation of Fe- and N-ions in the NiO lattice can suppress the formation of intermediate product Li2NiO2 and thus greatly reduces the voltage hysteresis of the NiO anode from ∼1.2 to ∼0.9 V. In comparison with the pure NiO electrode, the Ni0.5Fe0.5O1−xNx anode exhibits significantly enhanced reversible specific capacity (959 mAh·g−1 at 0.3 A·g−1), cycling stability (capacity retention of 96.1