Dealloying-derived TiC hierarchical porous frameworks as stable host for advanced Li metal electrode

Abstract

Metallic Li has been presented to be an attractive anode for next generation energy storage devices. Nevertheless, uncontrollable Li dendrites growth and great volume change seriously restrict its applicability. Herein, we designed a hierarchical porous TiC as Li host for the advanced Li metal anode through a one-step mild dealloying method. The Li nucleation overpotential was effectively reduced due to the lithiophilic TiC as nucleation sites. Furthermore, the multilayered hierarchical structure could homogenize the current distribution and provide enough space to restrict the volume change during the cycling. As a result, the half-cell assembled with as-dealloyed TiC exhibited a markedly enhanced Coulombic efficiency of 98.5% over 400 cycles at 1 mA cm−2. The TiC/Li electrode cycled for over 1000 h with an ultralow voltage hysteresis of 17.1 mV in a symmetrical cell at 1 mA cm−2 for 1 mAh cm−2, which showed a stable cycle capacity of 117.2 mAh g− 1 at 1 C after 700 cycles in a full cell with a LiFePO4 cathode. This work provided a facile strategy to design stable host and solve the problem with Li metal batteries.