Tailoring the Growth and Morphology of Lithium Peroxide: Nickel Sulfide/Nickel Phosphate Nanotubes with Optimized Electronic Structure for Lithium–Oxygen Batteries

Abstract

AbstractHeterogeneous crystalline‐amorphous structures, with tunable electronic structures and morphology, hold immense promise as catalysts for lithium‐oxygen batteries (LOBs). Herein, a nanotube network constructed by crystalline nickel sulfide/amorphous nickel phosphate (NiS/NiPO) heterostructure is prepared on Ni foam through the sulfurization of the precursor generated hydrothermally. Used as cathodes, the NiS/NiPO nanotubes with optimized electronic structure can induce the deposition of the highly porous and interconnected structure of Li2O2 with rich Li2O2–electrolyte interfaces. Abundant active sites can be created on NiS/NiPO through the charge redistribution for the uniform nucleation and growth of Li2O2. Moreover, nanotube networks endow cathodes with efficient transport channels and sufficient space for the accommodation of Li2O2. A high discharge capacity of 27 003.6 mAh g−1 and a low charge overpotential of 0.58 V at 1000 mAh g−1 can be achieved at 200 mA g−1. This work provides valuable insight into the unique role of the electronic structure and morphology of catalysts in the formation mechanisms of Li2O2 and the performances of LOBs.