期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2021
卷号：118
期号：38
DOI：10.1073/pnas.2111549118
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance
Rechargeable Mg batteries constitute safe and sustainable high-energy density electrochemical energy storage devices. However, due to an extremely high charge density of Mg
2+ ions, “real” Mg
2+-intercalation chemistry has been rarely realized, and significantly decelerated Mg
2+-diffusion kinetics is always encountered, especially in metal-oxide systems. Herein, we demonstrate a generic strategy to overcome the hitherto insurmountable challenge of developing rechargeable metal-oxide electrode materials for Mg batteries, with genuine Mg
2+ storage, record fast diffusion kinetics, and excellent cycling performance.
Rechargeable magnesium batteries represent a viable alternative to lithium-ion technology that can potentially overcome its safety, cost, and energy density limitations. Nevertheless, the development of a competitive room temperature magnesium battery has been hindered by the sluggish dissociation of electrolyte complexes and the low mobility of Mg
2+ ions in solids, especially in metal oxides that are generally used in lithium-ion batteries. Herein, we introduce a generic proton-assisted method for the dissociation of the strong Mg–Cl bond to enable genuine Mg
2+ intercalation into an oxide host lattice; meanwhile, the anisotropic Smoluchowski effect produced by titanium oxide lattices results in unusually fast Mg
2+ diffusion kinetics along the atomic trough direction with a record high ion conductivity of 1.8 × 10
−4 S ⋅ cm
−1 on the same order as polymer electrolyte. The realization of genuine Mg
2+ storage and fast diffusion kinetics enabled a rare high-power Mg-intercalation battery with inorganic oxides. The success of this work provides important information on engineering surface and interlayer chemistries of layered materials to tackle the sluggish intercalation kinetics of multivalent ions.
