Compatibility of Molybdenum Disulfide and Magnesium Fluorinated Alkoxyaluminate Electrolytes in Rechargeable Mg Batteries

• Published in: Batteries and Supercaps
• Main Author: Falyouna O.; Faizul Idham M.; Eljamal O.; Mandai T.
• Format: Article
• Language: English
• Published: John Wiley and Sons Inc 2024
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85197663270&doi=10.1002%2fbatt.202400231&partnerID=40&md5=9f15ee7049ad3576afd95cb6966452d9

Molybdenum disulfide (MoS2)-based cathodes have exhibited good electrochemical reactions in all phenyl complex (APC) electrolytes. However, APC electrolytes are highly corrosive and susceptible to oxidation. Alternatively, magnesium fluorinated alkoxyaluminate electrolyte (Mg[Al(HFIP)4]2) is a pioneering chloride-free electrolyte with remarkable electrochemical activity in rechargeable Mg batteries (RMBs). This study aims to investigate the compatibility of various MoS2 nanomaterials with Mg[Al(HFIP)4]2 in RMBs. Seven MoS2 nanomaterials were synthesized under different hydro/solvothermal conditions and evaluated as cathode materials in RMBs. The results revealed that the electrochemical activity of the as-synthesized MoS2 in RMBs significantly varied and MoS2 with high content of 1T-phase (M5) exhibited the best specific capacity of ca. 35 mAh g−1. Heteroatom doping, graphene oxide (GO) incorporation, and dual-salt electrolytes were employed to enhance the electrochemical performance of M5. The electrochemical tests showed that all doped-MoS2 and GO-MoS2 delivered poor specific capacities (<20 mAh g−1), properly due to the disorder of the cathode material and the entrapment of Mg2+ ions. In contrast, dual-salt electrolytes (0.3 M Mg[Al(HFIP)4]2/0.3 M LiCl) improved the initial specific capacity by 242 %. This is attributed to the preferential intercalation of Li+ ions that reduces the diffusion energy barrier and facilitates the intercalation of Mg+2 ions. © 2024 The Authors. Batteries & Supercaps published by Wiley-VCH GmbH.