Ultrafast Charging High Capacity Asphalt–Lithium Metal Batteries

Li metal has been considered an outstanding candidate for anode materials in Li-ion batteries (LIBs) due to its exceedingly high specific capacity and extremely low electrochemical potential, but addressing the problem of Li dendrite formation has remained a challenge for its practical rechargeable applications. In this work, we used a porous carbon material made from asphalt (Asp), specifically untreated gilsonite, as an inexpensive host material for Li plating. The ultrahigh surface area of >3000 m2/g (by BET, N2) of the porous carbon ensures that Li was deposited on the surface of the Asp particles, as determined by scanning electron microscopy, to form Asp–Li. Graphene nanoribbons (GNRs) were added to enhance the conductivity of the host material at high current densities, to produce Asp–GNR–Li. Asp–GNR–Li has demonstrated remarkable rate performance from 5 A/gLi (1.3C) to 40 A/gLi (10.4C) with Coulombic efficiencies >96%. Stable cycling was achieved for more than 500 cycles at 5 A/gLi, and the areal capacity reached up to 9.4 mAh/cm2 at a highest discharging/charging rate of 20 mA/cm2 that was 10× faster than that of typical LIBs, suggesting use in ultrafast charging systems. Full batteries were also built combining the Asp–GNR–Li anodes with a sulfurized carbon cathode that possessed both high power density (1322 W/kg) and high energy density (943 Wh/kg).