Electrolyte Transport Evolution Dynamics in Lithium–Sulfur Batteries

The liquid electrolyte is a critical component in the lithium-sulfur battery, which dissolves long-chain intermediate polysulfides, forms electrochemically active interface, and allows species and charge transport. The electrolyte transport dynamics is, however, intricately affected by the underlying evolution of chemical speciation. In this work, a comprehensive description is presented to identify the role of speciation and intra- and interspecies interactions on electrolyte-transport dynamics. The evolutionary presence of different polysulfide species alters the transport characteristics which in turn affects electrochemical complexations. Microstructural changes and electrolyte evolution are concurrently present, and their mutual coupling is discussed. The role of the sulfur to electrolyte ratio, which dictates speciation in the electrolyte phase, and ionic transport limitations are elucidated.