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 Li Si , Li (Si Ge ) and Li Ge formed during rapid Li melt infiltration prevented the formation of dead Li and dendrites. Li Ge /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 /1 mAh cm for 1000 h and at 3 mA cm /3 mAh cm for 500 h. Ex situ analysis confirmed the ability of the lithiophilic Li Ge decorated samples to facilitate uniform Li deposition. When paired with sulfur, LiFePO 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.