Electrolyte Chemistry Development for Sodium-Based Batteries: A Blueprint from Lithium or a Step Toward Originality?

Currently, electrolyte design for sodium-based batteries is largely inherited from their lithium-based counterparts, which often present critical challenges that hinder forging new perspectives and thus further improvements. This work delves into the key properties of representative sodium- and lithium-based electrolytes, encompassing prevailing salt anions. It aims to evaluate the impact of cation chemistry, including their nature and the degree of interactions with counter anions, thereby bridging the gap in effectively transferring the know-how accumulated in lithium batteries to sodium-based batteries. The results demonstrate that the unique impact of salt anions on the properties of metal-ion conducting electrolytes is tightly correlated with the nature of metal cations. By synchronizing the anionic structures with the critical features of sodium cations, the solvating dynamics and transport properties, chemical stability, aluminum corrosion behavior, and other key properties of the electrolytes could be finely tuned to fit the specific requirements of advanced sodium-based batteries. This work gives an in-depth insight into the chemical and physical features of sodium-based electrolytes, with a potential avenue to accelerate the deployment of high-performance sodium batteries and simultaneously inspire and guide the design of other electrolytes for emerging mono- and multivalent cation-based rechargeable batteries.