Restructured rimous copper foam as robust lithium host

Uncontrollable growth of lithium (Li) dendrites and infinite volume change during cycling limit the practical implementation of Li metal anode in batteries. Three-dimensional (3D) porous materials with interconnected conductive skeleton are expected as ideal hosts to boost uniform Li deposition by reducing the local current density and Li nucleation barrier. However, surface modifications for the 3D conductive frameworks are complicated and costly, and most of these host materials can only afford shallow cycling at smaller current densities. Herein, a new strategy is proposed to fabricate rimous Cu foam (RCF) with ant-nest-like porous skeleton via a novel polysulfide-assisted reconstruction approach. The interconnected conducting Cu network with a larger and lithiophilic surface enables uniform and deep Li deposition into the interior space of RCF. The unique ant-nest-like interior channel not only endows a high intake capacity for Li, but also abstains volume fluctuation of Li anode during cycling. Therefore, the RCF-modified Li anode delivers excellent cycling stability with high Coulombic efficiency of 99% after 660 cycles at 1 ​mA ​cm−2 and small overpotential of 30 ​mV over 200 ​h under a high plating/stripping rate of 3 ​mA ​cm−2. More importantly, full cells paired with practical-level LiFePO4 cathode exhibit exceptional performance under high current densities.