Lithiophilic nanowire guided Li deposition in Li metal batteries

Lithium (Li) metal batteries (LMBs) provide superior energy densities far  beyond current Li-ion batteries (LIBs) but practical applications are hindered  by uncontrolled dendrite formation and the build-up of dead Li in “hostless”  Li metal anodes. To circumvent these issues, we created a 3D framework of  a carbon paper (CP) substrate decorated with lithiophilic nanowires (silicon  (Si), germanium (Ge), and SiGe alloy NWs) that provides a robust host for  efficient stripping/plating of Li metal. The lithiophilic Li22Si5, Li22(Si0.5Ge0.5)5, and Li22Ge5 formed during rapid Li melt infiltration prevented the forma?tion of dead Li and dendrites. Li22Ge5/Li covered CP hosts delivered the best  performance, with the lowest overpotentials of 40 mV (three times lower  than pristine Li) when cycled at 1 mA cm−2 /1 mAh cm−2  for 1000 h and at  3 mA cm−2 /3 mAh cm−2  for 500 h. Ex situ analysis confirmed the ability of  the lithiophilic Li22Ge5 decorated samples to facilitate uniform Li deposi?tion. When paired with sulfur, LiFePO4, and NMC811 cathodes, the CP-LiGe/ Li anodes delivered 200 cycles with 82%, 93%, and 90% capacity retention,  respectively. The discovery of the highly stable, lithiophilic NW decorated CP  hosts is a promising route toward stable cycling LMBs and provides a new  design motif for hosted Li metal anodes.