Reasonable reorganization of electrolyte structure helps to improve the performance of lithium-sulfur batteries

In the field of lithium battery research, scientists are committed to solving the dissolution and shuttle effects of lithium polysulfide (LiPS) and lithium selenide (LiPSe) intermediates in lithium-sulfur batteries. Recently , to address the trade‐off between energy and cycle life, Assistant Researcher Juan Zhang, Researcher Yuguo Guo, and Researcher Sen Xin from the Institute of Chemistry of the Chinese Academy of Sciences reasonably reorganized the electrolyte structure and reported a new electrolyte, which reconciles the merits of liquid and polymer electrolytes while resolving each of their inferiorities.

Researhers develop an in situ interfacial polymerization strategy to create a liquid/polymer hybrid electrolyte between a LiPF6‐coated separator and the cathode.

A polymer‐gel electrolyte in situ formed on the separator shows high Li+ transfer number to serve as a chemical barrier against the shuttle effect. Between the gel electrolyte and the cathode surface is a thin gradient solidification layer that enables transformation from gel to liquid so that the liquid electrolyte is maintained inside the cathode for rapid Li+ transport and high utilization of active materials.

By addressing the dilemma between the shuttle chemistry and incomplete discharge of S/Se, the new electrolyte configuration demonstrates its feasibility to trigger higher capacity retention of the cathodes. At the same time, the lithium sulfur oxygen battery achieves high capacity, stable circulation and good rate performance.

The reasonable configuration of the battery electrolyte helps to balance the chemical activity and stability of the cathode of the lithium-sulfur-oxygen battery, and provides a new perspective for the optimal design of the electrolyte configuration of the next-generation high-energy rechargeable lithium battery.

References: Wen-Peng Wang, et al, A Rational Reconfiguration of Electrolyte for High-Energy and Long-Life Lithium–Chalcogen Batteries [J]. Adv. Mater. DOI: 10.1002 / adma.202000302