A solid-state lithium-oxygen battery operating at ambient temperature and full charge-discharge

Solid-state Li-O 2 batteries (SSLOBs) have been denoted as the holy grail in next-generation Li metal batteries for their high theoretical energy density , manipulation of ambient air to energy storage as well as high safety. However, the solid rigid interfaces both at the cathode and anode side introduce ultra-high resistances in the battery system and impede its operation under ambient temperature. Moreover, the high-reductive Li anode and semi-open cathode would cause severe side reactions during cycling which further degrade battery performance. To manage the above-mentioned issues, a rationally designed SSLOBs based on plastic crystal electrolyte is proposed in this study to enable SSLOBs operation at ambient temperature and in full charge-discharge mode. The brand-new Li-O 2 battery has been improved mainly from two aspects. First, we propose a polyacrylonitrile (PAN) modified succinonitrile (SN) electrolyte (PAN-SN) to retard the polymerization of SN and meanwhile suppress the degradation of Li ionic conductivity. Second, we propose an alternative mixed electron/ion complex conductor (MEIC) cathode to coordinate with plastic crystal electrolyte with an expanded Li-O 2 reactive zone and improved interfacial charge transfer during the charge-discharge process. The fabricated flexible SSLOBs based on PAN-SN electrolyte and MEIC cathode could be successfully fully charged-discharged (cutoff 2.0–4.5 V) for tens of cycles at ambient temperature under simulated air condition (20 vol% oxygen), with high-capacity retention of around 85 %.