Vertically aligned MnO2 nanosheets on carbon fiber cloth as lithiophilic host enables dendrite-free lithium metal anode

The main challenges limiting the practical application of lithium metal anodes are dramatical volume effect and uncontrolled lithium dendrite growth during the repeated plating and stripping, which inevitably causes the rapid capacity decay, poor coulombic efficiency and potential safety concerns. Herein, vertically aligned manganese dioxide (MnO2) nanosheets on carbon fibers cloth (MnO2@CFC) is successfully fabricated through one-pot solution approach and further treated with molten Li to prepare three-dimensional composite lithium metal anode (Li-Mn@CFC). The experiment result and theoretical analysis show that MnO2 can significantly ameliorate the reaction activity between MnO2@CFC and Li, and regulate uniform Li distribution during infusion process. Furthermore, the well-defined nanochannel assembled by vertical-aligned MnO2 nanosheets endow abundant spaces to expedite the transfer kinetics of charge carriers and eliminate volume variation of the electrode during cycling. As a result, Li-Mn@CFC-based symmetric cells exhibit highly stable Li plating/stripping with small hysteresis over long cycles. When coupling with high-loading LiCoO2 cathodes (11.66 mg•cm−2), the assembled full cells also deliver superior cycling stability and rate capability.