Carbon nanofiber frameworks for Li metal batteries: the synergistic effect of conductivity and lithiophilic-sites

The utilization of carbon framework to guide the growth of the Li dendrites is an important theme for Li metal batteries. The conductivity and electronegative sites of carbon materials will greatly affect the nucleation of Li metal. However, how much these two contributing factors affect the Li plating/stripping stability should be considered. This work presents N, O doped carbon nanofiber framework (CNF) membrane as the interlayer for protecting the Li anode. The amounts of N and O elements and their ratios, the conductivity, the thickness of CNF membrane and their effects on the Li plating/stripping process have been fully analyzed. The voltage profile and the stability of Li plating/stripping process are evaluated by symmetric and asymmetrical coin cells. The lithiophilic heteroatom doped surface mainly works as an excellent guide during the Li plating process, whereas the conductivity and mechanical stability of CNF equalize the current density and confine the volume change in during cycling. With the optimized CNF membrane as the interlayer, both Li metal and Li-S full cells exhibit good capacity properties and cyclic stability.

Automated summary

This study investigates the use of N, O doped carbon nanofiber (CNF) membrane as an interlayer for protecting the Li anode in Li metal batteries. The results show that the lithiophilic heteroatom doped surface acts as an excellent guide during the Li plating process, while the conductivity and mechanical stability of CNF help equalize current density and confine volume change.