NonAqueous, Metal-Free, and Hybrid Electrolyte Li-Ion O2 Battery with a Single-Ion-Conducting Separator.

The rechargeable lithium-oxygen (Li-O2) batteries suffer from not only the low practical capacity and high overpotential at the oxygen cathode but also the low lithium utilization and dendrite growth of the Li metal. In this work, by coupling the dual mediator catholyte and the carbonate-based anolyte for the high specific capacity Si anode, we propose a hybrid electrolyte design for the fabrication of Li-ion O2 batteries. A single-ion-conducting lithiated Nafion membrane is introduced to bridge the two electrolyte systems. Benefiting from the restraint of mediator shuttling and the uniform solid electrolyte interface film of silicon anode, the hybrid electrolyte Li-ion O2 battery exhibits high reversible capacity, low overpotential, and improved cycling stability. Beyond the Li-ion O2 battery, the hybrid electrolyte design shows great potential for the development of stable battery systems with high energy efficiency.