A multi-site strategy for boosting Li-CO2 batteries performance

Herein, we develop a multi-site strategy to boost Li-CO₂ battery performance using Co nanoparticles (NPs) loaded nitrogen-doped holey carbon nanotubes (Co@N-hCNT) as high-efficiency cathode catalyst. The Co@N-hCNT possesses high-efficiency multiple active sites of defects, nitrogen sites and Co NPs for reversible conversion of insulating Li₂CO₃ as well as rapid charge and ion transport provided by the nitrogen-doped holey CNTs. Benefiting from these excellent properties, the as-assembled Li-CO₂ battery with Co@N-hCNT cathode shows outstanding electrochemical performance with a low overpotential of 1.03 V at 0.05 A g⁻¹ and a high full discharge capacity of 27952 mA h g⁻¹ at 0.2 A g⁻¹. More importantly, the Li-CO₂ battery with Co@N-hCNT exhibits a long-term durability over 220 cycles even at a high current density of 0.5 A g⁻¹. This work opens a new venture for the development of high-efficiency cathode catalysts for Li-CO₂ batteries and beyond via a multi-site strategy.