Interfacial engineering in hollow NiS2/FeS2-NSGA heterostructures with efficient catalytic activity for advanced Li-CO2 battery

Abstract

Lowering the charge barrier is of central importance to develop the advanced lithium-carbon dioxide (Li-CO2) battery with high energy efficiency, yet great challenges remain owing to the sluggish decomposition kinetics of lithium carbonate (Li2CO3) discharge products. Herein, we demonstrate a latent cathode catalyst by strategically constructing the heterointerfaces in hollow NiS2/FeS2 nanostructures dispersed on N, S co-doped graphene aerogel (NiS2/FeS2-NSGA), which displays an exceptional capability to enhance the Li2CO3 decomposition rate, thereby remarkably improving the Li-CO2 battery performance. It has been revealed that the functional heterointerfaces can effectively facilitate the electron transfer and tailor the electronic structure of cathode catalyst, and the hierarchical porous architecture provided by NSGA component favors the mass and electrolyte transportation. Consequently, associated with these synergistic merits, the Li-CO2 battery with NiS2/FeS2-NSGA cathode catalyst delivers a significantly reduced discharge–charge overpotential of 1.10 V at a current density of 0.1 A g−1. Moreover, such battery can be stably cycled over 127 cycles at an increased current density of 1 A g−1 and simultaneously exhibits a superb rate capability. These results highlight the significant role of heterointerface active sites in considerably promoting the Li2CO3 decomposition, opening a new avenue to advance the promising Li-CO2 battery technique.