Lithiophilic NiO Nanoarrays-Modified Ni Skeletons with Vertical Channels for High-Loading Li Metal Batteries

Abstract

Li metal has been a promising anode material for high-energy-density batteries because of its ultrahigh theoretical capacity, but its practical application is hindered by serious dendrite growth and volume change. Herein, NiO nanoarrays are grown on a porous Ni skeleton derived from phase inversion method for stabilizing Li metal. The lithiophilic NiO nanoarrays decrease Li nucleation barrier and local current density, and provide abundant sites for nucleation. The Ni skeleton with vertical channels and interconnected small pores, not only provides Li storage space and ion channels, but also alleviates top-surface deposition and improved uniformity of Li distribution. As a result, the half cells comprising the NiO nanoarrays-modified Ni skeletons demonstrate a high Coulombic efficiency of 98.8% under 4 mAh cm−2 over 210 cycles (>1700 h), and the symmetric cells show much reduced voltage hysteresis and prolonged lifespan (>2000 h) under a capacity of 5 mAh cm−2 and a current density of 2 mA cm−2. Full cells with LiFePO4 as cathodes delivered a capacity retention of 79.4% after 500 cycles at 2 C and excellent rate capability at 10 C, shedding a fresh light on an effective strategy for the practical application of Li metal batteries.