Multi-storey corridor structured host for a large area capacity and high rate metallic lithium anode

Abstract

Lithium metal is one of the most promising candidates for next-generation anode materials due to its high theoretical specific capacity and the lowest electrochemical potential. However, the dendrite formation and infinite volume change during the Li stripping and plating behaviors severely hinder its practical application. Here, a multi-storey corridor structured lithium hybrid was achieved via a repeated rolling and folding strategy. The multi-storey corridor structure was constructed by lamellarly ranged MXene–Ti3C2 nanosheets and vertically aligned lithium-boron nanofibers. The conductive Ti3C2 layers can prevent vertical growth of lithium dendrites and enhance the conductivity of the hybrid anode, thereby decreasing the local current density and homogenizing electric field. The lithophilicity Li7B6 nanofibers between MXene–Ti3C2 layers act as pillars to prevent the collapse of the multi-storey corridor structure during the depth discharge process and work as nucleating sites to induce uniform deposition of lithium. As a consequence, the obtained hybrid lithium anode delivers outstanding electrochemical performances in terms of dendrite free, low overpotential (24 mV at 1.0 mA cm−2) and long cycling stability (over 1000 h). Moreover, such a unique structure hybrid could enable the hybrid anode to operate under practical working conditions of high rate (20 mA cm−2) and large area capacity (10 mAh cm−2).