High-Energy Density Li metal Dual-Ion Battery with a Lithium Nitrate-Modified Carbonate-Based Electrolyte

Lithium (Li) metal is a favorable anode for most energy storage equipment, thanks to its higher theoretical specific capacity. However, nonuniform Li nucleation/growth results in large-sized and irregular dendrites generated from the Li anode, which causes rapid capacity fade and serious safety hazard, hindering its widespread practical applications. In this paper, with the aid of a lithium nitrate (LiNO₃) additive in a carbonate-based electrolyte, the Li anode shows low hysteresis for in excess of 1000 h at a current density of 0.5 mA cm^-2. At the same time, a Li-graphite dual-ion battery exhibits an outstanding cycling stability at 5C; after 1000 cycles, 81% of the capacity is retained. After calculation, the Li-graphite dual-ion battery shows a competitive specific energy density of 243 Wh kg^-1 at a power density of 234 W kg^-1. Moreover, the linear sweep voltammetry test was first performed to analyze the Li nucleation/growth mechanism and explain the effect of the LiNO₃ additive. The superior electrochemical properties of the Li-graphite dual-ion battery are ascribed to the formation of smooth Li composed of Li nanoparticles and a steady solid electrolyte interface film.