Boron-based electrolytes for rechargeable magnesium batteries: From design principles to the optimization of Mg[B(hfip)4]2 via additives and solvation modulations
Kangjie Xu, Xiquan Qi, Xiangyu Zhao
Abstract
Rechargeable magnesium batteries (RMBs) have emerged as a highly promising next-generation energy storage technology, offering enhanced safety and cost-effectiveness. However, conventional chlorine-containing electrolytes for RMBs are limited by their corrosive nature and low oxidative stability. In contrast, boron-based electrolytes have attracted increasing attention owing to the structural tunability and superior stability of their anions. This review highlights three representative classes of boron-based electrolytes: borohydride-based, carborane-based, and borate-based systems. Among them, the borate-based electrolyte using the Mg[B(hfip) 4 ] 2 salt is emphasized as a cost-performance benchmark, achieving a favorable balance between electrochemical performance and synthetic scalability. Optimized synthetic strategies for this compound are summarized, and two key approaches—incorporation of functional additives and regulation of solvation structure—are proposed to further enhance its electrochemical performance. The pivotal role of theoretical simulations in elucidating the solvation and interfacial mechanisms is highlighted. Finally, the industrial application prospects of this electrolyte system are critically assessed, outlining future research directions for boron-based electrolytes. Overall, this work aims to provide critical insights into the rational design of high-performance boron-based electrolytes, offering a roadmap for the advancement of RMB technologies.