context: In this contribution, we propose the use of a small amount of metallic 1T MoS2 nanodots (NDs, 3 wt% of the electrode) as a robust catalyst for advanced LSBs. Electrochemical tests and synchrotron in situ X-ray diffraction (XRD) characterizations demonstrated the strong anchoring and catalytic capability of MoS2 NDs. When MoS2 NDs were integrated with a porous carbon/catholyte, the new cathodes exhibited remarkable battery performance, including a high rate capacity of 8.5 mA h cm−2 at 1C and an impressive capacity retention of 9.3 mA h cm−2 after 300 cycles under a high sulfur loading of 12.9 mg cm−2, an extremely low E/S ratio of 4.6 μL mg−1, and a remarkable sulfur content of 81 wt%. Such high-energy densities delivered under high sulfur loading and lean electrolyte conditions are among the best reported so far for LSBs. Based on DFT calculations, we found that the phase and edge sites were the key to governing the catalytic capability for MoS2. Li2S anchored preferentially at Mo-terminated edges of MoS2 and the electrochemical dissociation occurred toward the surface of the monolayer where Li ions could diffuse faster. Indeed, the metallic 1T MoS2 showed a stronger affinity to polysulfides and a lower activation energy for Li2S than 2H MoS2 at most of the adsorption sites. These findings suggest that the catalytic activity in MoS2 can be maximized by downsizing 2H MoS2 flakes to 1T MoS2 NDs.
answer: MoS2 NDs