Electrode/Electrolyte Interface Control for Multivalent-Ion Batteries with High Stability and Reversibility

Rechargeable multivalent-ion batteries (RMBs) are attractive as a “beyond lithium-ion battery” because of their multi-electron transfer and high abundance (eg. Zn²⁺and Mg²⁺), which principally provides higher volumetric capacity and better affordability. The development of highly reversible and stable RMBs is correlated to the multivalent feature of these ions, which poses great challenges to the design of functional electrode/electrolyte interfaces.<br/>This presentation will include discussion of key obstacles for these interfaces, followed by tailored strategies to foster good performance. The main topics will cover two different approaches to stabilize the electrode/electrolyte interface by preventing interfacial side reactions in nonaqueous magnesium batteries with an operating potential of over 3.5 V. This includes<b> a)</b> a low-cost inorganic surface membrane that protects against the decomposition of an organoborate-based electrolyte to yield an ultra-stable Mg anode for high-power magnesium batteries; <b>b)</b> eliminating passivation on the Mg anode by tailoring commercially available electrolytes to achieve over 2500-hour Mg plating/stripping at 2 mA cm^-2 and 2 mAh cm^-2. Brief highlights of interfacial optimization in aqueous zinc batteries will be also presented. Characterization of these designed and highly functional interfaces using depth-profiling high-resolution XPS, TEM and cryogenic-EM will be described.