High-capacity, high-rate, and dendrite-free lithium metal anodes based on a 3D mixed electronic-ionic conductive and lithiophilic scaffold

Abstract

Lithium metal anode possesses a high theoretical capacity and the lowest redox potential, while the severe growth of Li dendrite prevents its practical application. Herein, we prepared a structure of Li3P nanosheets and Ni nanoparticles decorated on Ni foam (NF) as a three-dimensional (3D) scaffold for dendrite-free Li metal anodes (Li-Li3P/Ni@Ni foam anodes, shortened as L-LPNNF) using a facile melting method. The Li3P nanosheets exhibit excellent Li-ion conductivity as well as superior lithiophilicity, and the 3D nickel scaffold provides sufficient electron conductivity and ensures structure stability. Therefore, symmetric cells assembled by L-LPNNF possess lowered voltage hysteresis and improved long cycle stability (a voltage hysteresis of 104.2 mV after 500 cycles at a high current density of 20 mA cm−2 with a high capacity of 10 mA h cm−2), compared with the cells assembled with Li foil or Li-NF anodes. Furthermore, the full cells with paired L-LPNNF anodes and commercial LiFePO4 cathodes suggest a specific capacity of 124.6 mA h g−1 and capacity retention of 90.8% after 180 cycles with the Coulombic efficiency (CE) of ∼100% at a current rate of 1 C. This work provides a potentially scalable option for preparing a mixed electronic-ionic conductive and lithiophilic scaffold for dendrite-free Li anodes at high current densities.