Systematic Evaluation of Carbon Hosts for High-Energy Rechargeable Lithium-Metal Batteries

Rechargeable lithium (Li)-metal batteries have great potential for high energy and low cost, but poor Li anode stability remains a challenge. Carbon host structures have been widely studied; however, our understanding of the key factors determining the performance of such materials is poor, and these limitations have significantly affected the progress of this important field. Here we systematically evaluate the electrochemical properties of representative carbon host materials and chemically functionalized carbon materials for Li anodes in different electrolytes. We demonstrate that the interaction between the electrolyte and the carbon material plays a dominant role compared to other factors such as the host structure types and surface chemistries. Poor Coulombic efficiency is observed with different materials unless a compatible electrolyte is used. Hard carbon shows high-efficiency deposition and good cycle life with the compatible electrolyte using experimental conditions required for >300 Wh kg–1 cells.