Correlating Ion Dynamics with Structure: From Liquid to Hybrid Solid Electrolytes

Abstract

Rechargeable lithium (Li)-metal batteries (LMBs) stand out as a top contender for nextgeneration high-energy-density storage solutions, originating from the high theoretical specific capacity and low redox potential of metallic Li. However, developing LMBs is hindered by safety issues arising from dendrite growth as well as electrolyte decomposition reactions during Li plating/stripping. These dendrites can cause short-circuits that may start thermal runaway, greatly amplifying fire hazards. The rapid reaction between the electrolyte and Li-metal leads to the formation of the solid electrolyte interphase (SEI), whose structure and Li-ion conduction properties are crucial for the uniformity of Li deposition. This affects dendrite formation and cycling efficiency, which in turn influences battery life. Yet very little is known about the Li-ion kinetics through the SEI and how these correlate with the structure and composition of the SEI...