Lithium–oxygen
batteries (LOBs) have attracted
worldwide
attention due to their high specific energy. However, the poor rechargeability
and cycling stability of LOBs hinders their practical use in applications.
Here, we explore the incomplete charging behavior of redox-mediated
LOBs operated at a feasible capacity for a practical level (3.25 mAh
cm–2) and resolve it using a sustainable lithium
protection strategy. The incomplete charging behavior, promoted by
self-discharge of redox mediators (RMs), hampers the reversible cycling
of LOBs, which was investigated through multiangle in situ and ex situ analyses. Meanwhile, the proposed lithium
protection strategy, introducing an inorganic/organic hybrid artificial
composite layer with a preformed stable interface between the lithium
metal and the composite layer, enhances the stability of the lithium
metal anode during the prolonged cycling by preventing the chemical/electrochemical
interactions of RMs on the lithium metal surface, thus improving the
overall rechargeability of LOBs. This work provides guidelines for
the effective use of RMs with an adequate lithium protection strategy
to achieve sustainable cycling of LOBs, creating a feasible approach
for the practical use of LOBs with high areal capacity