Fast kinetics of multivalent intercalation chemistry enabled by solvated magnesium-ions into self-established metallic layered materials

• Published in: Nature communications 2018-11, Vol.9 (1), p.5115-13, Article 5115
• Main Authors: Li, Zhenyou, Mu, Xiaoke, Zhao-Karger, Zhirong, Diemant, Thomas, Behm, R. Jürgen, Kübel, Christian, Fichtner, Maximilian
• Format: Article
• Language: English
• Subjects: 140/146; 147/135; 147/137; 147/143; 639/4077/4079/891; 639/638/161/891; Batteries; Cathodes; Cations; Charge density; Electrolytes; Humanities and Social Sciences; Intercalation; Interfaces; Ion diffusion; Ions; Kinetics; Layered materials; Lithium; Magnesium; Molybdenum; Molybdenum disulfide; multidisciplinary; Organic chemistry; Rechargeable batteries; Science; Science (multidisciplinary); Solvation; Strong interactions (field theory)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-07484-4

Rechargeable magnesium batteries are one of the most promising candidates for next-generation battery technologies. Despite recent significant progress in the development of efficient electrolytes, an on-going challenge for realization of rechargeable magnesium batteries remains to overcome the sluggish kinetics caused by the strong interaction between double charged magnesium-ions and the intercalation host. Herein, we report that a magnesium battery chemistry with fast intercalation kinetics in the layered molybdenum disulfide structures can be enabled by using solvated magnesium-ions ([Mg(DME) x ] 2+ ). Our study demonstrates that the high charge density of magnesium-ion may be mitigated through dimethoxyethane solvation, which avoids the sluggish desolvation process at the cathode-electrolyte interfaces and reduces the trapping force of the cathode lattice to the cations, facilitating magnesium-ion diffusion. The concept of using solvation effect could be a general and effective route to tackle the sluggish intercalation kinetics of magnesium-ions, which can potentially be extended to other host structures. While magnesium rechargeable batteries could combine high energy density with low cost and good safety, the extremely sluggish reaction kinetics remains to be overcome. Here, the authors show that by using solvated Mg 2+ intercalation, the high charge density of bare Mg 2+ may be effectively mitigated.