Synergistic Nitrogen-Doping and Carbon-Coating in N-MoSe2/C Nanoflowers Enable Ultra-high Discharge Capacity for Li-CO2 Batteries

Abstract

The development of highly efficient cathode catalysts with multiple active sites is crucial for improving the performance of lithium-carbon dioxide (Li-CO2) batteries, which hold great promise for achieving carbon neutrality and advancing energy storage technologies. Herein, a nitrogen-doped and carbon-coated N-MoSe2/C nanoflower material is utilized to construct a cathode for the first time. Due to the excellent electrical conductivity of the carbon material, the N doping effect that reduces the interaction forces between nanosheets and effectively suppresses agglomeration, as well as the large number of catalytically active sites exposed by the hierarchical structure, the Li-CO2 battery based on the N-MoSe2/C cathode exhibits an exceptionally high initial discharge capacity of 37720 mAh g-1 at 100 mA g-1, surpassing many single-metal and dual-metal cathode catalysts recently reported in high-impact journals and maintaining a stable discharge plateau at 2.76 V with a low overpotential of 1.56 V during the first charge/discharge cycle. The catalytic advantages of nitrogen-doped MoSe2 are deeply understood through the combination of density functional theory (DFT) calculations and experiments. Robust metrics such as the d-band center are employed to gain deep insights into the underlying mechanisms, providing a comprehensive understanding of the enhanced catalytic performance. This work underscores the potential of transition metal selenide N-MoSe2/C as an efficient cathode catalyst for Li-CO2 batteries and offers novel insights into the investigation of adsorption active sites in doped materials.