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 37 720 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.