Capacity Enhancement in Quasi-Solid-State Lithium–Oxygen Batteries via Self-Constructing Li+ Transport Channels

Abstract

Lithium–oxygen batteries (LOBs) attract widespread attention due to their high energy density and safety. The morphology of the solid discharge product bears a close correlation with the battery capacity. In this work, the capacity of LOBs surprisingly increases from 790 mAh g^–1 under the liquid electrolyte to 2395 mAh g^–1 by using a quasi-solid-state electrolyte (QSSE). The thin film and spherical Li₂O₂ under the QSSE system construct new Li⁺ transport channels, which help to extend the solid-phase Li⁺ transport boundary to the entire electrode to enhance the spatial utilization efficiency of the electrode. Furthermore, a novel mechanism for the growth of Li₂O₂ is proposed, which is determined by the coupling of the conductivity of Li⁺ and electrons within the products and the electrode. The result innovatively reveals a new mechanism for the growth of discharge products and a new model of Li⁺ conduction in LOBs under QSSE systems.