Inhibition of Lithium Dendrite Formation in Lithium Metal Batteries via Regulated Cation Transport through Ultrathin Sub-Nanometer Porous Carbon Nanomembranes

Suppressing Li dendrite growth has gained research interest due to the high theoretical capacity of Li metal anodes. Traditional Celgard membranes which are currently used in Li metal batteries fall short in achieving uniform Li flux at the electrode/electrolyte interface due to their inherent irregular pore sizes. Here, the use of an ultrathin (approximate to 1.2 nm) carbon nanomembrane (CNM) which contains sub-nanometer sized pores as an interlayer to regulate the mass transport of Li-ions is demonstrated. Symmetrical cell analysis reveals that the cell with CNM interlayer cycles over 2x longer than the control experiment without the formation of Li dendrites. Further investigation on the Li plating morphology on Cu foil reveals highly dense deposits of Li metal using a standard carbonate electrolyte. A smoothed-particle hydrodynamics simulation of the mass transport at the anode-electrolyte interface elucidates the effect of the CNM in promoting the formation of highly dense Li deposits and inhibiting the formation of dendrites. A lithium metal battery fabricated using the LiFePO4 cathode exhibits a stable, flat voltage profile with low polarization for over 300 cycles indicating the effect of regulated mass transport.

Automated summary

This study demonstrates the use of ultrathin carbon nanomembrane as an interlayer to regulate Li-ion transport and suppress dendrite growth in lithium metal batteries. Analysis on symmetrical cells and Li plating on Cu foil reveals highly dense deposits of Li metal. The experimental results suggest that this approach can improve the cycling performance, stability, and voltage characteristics of the battery.