Chalcocarbogels as High-Capacity and Cycle-Stable Electrode Materials for Lithium and Sodium Ion Batteries

Abstract

The low capacities of commercial Li ion batteries and cycle instabilities of amorphous metal sulfide based batteries impose constraints on their utilization for large-scale energy storage. We report here the acid-free, room-temperature (RT), and solution-based synthesis of a chalcogenide–carbonaceous hybrid aerogel, termed as “chalcocarbogel”, comprising molybdenum sulfide (MoSx) and graphene oxide (GO). The chalcocarbogel is a nanoparticle-aggregated, porous, amorphous gel consisting of Mo3S13 and Mo2S12-like structures as determined by synchrotron X-ray PDF, XANES, and EXAFS. The MoSx-GO chalcocarbogel demonstrates high specific capacities of ∼1215 and ∼807 mAh g–1 for Li/MoSx-GO and Na/MoSx-GO cells, respectively, for a 50 mAg–1 discharge rate during the first cycle. After the activation cycles, the MoSx-GO chalcocarbogel stabilizes, maintaining high specific capacities of approximately ∼700 mAh g–1 for Li/MoSx-GO and ∼473 mAh g–1 for Na/MoSx-GO cells, while continuously cycling. The MoSx-GO aerogel reported here serves as a promising platform to develop chalcocarbogels for applications spanning both Li and Na ion batteries.