Boosting the Cycle Life of Aprotic Li-O-2 Batteries via a Photo-Assisted Hybrid Li2O2-Scavenging Strategy

The development of the nonaqueous Li-O-2 battery, a promising candidate for high-gravimetric-energy-storage techniques, is seriously restrained by the high charge overpotential during electrochemical decomposition of insulating Li2O2. Benefiting from the photovoltage, photo-assisted charging is revealed as a feasible method to reduce the charge potential. However, a long period of illumination will inevitably aggravate the degradation of the electrolyte. Herein, composed of contact-ion-pairs (CIPs), a newly introduced superconcentrated electrolyte presents superior stability against parasitic photocatalytic decomposition. More significantly, the conventional and photo-assisted charging processes are rationally integrated as a unique hybrid strategy, in which the highly polarized charging stage is replaced by the photo-assisted Li2O2-scavenging process. By tuning the photocatalysis and Li2O2 electrochemical oxidization, the hybrid Li2O2-scavenging strategy not only boosts the cycle life of rechargeable Li-O-2 batteries but also opens possibilities in designing photocatalysis-involved rechargeable energy-storage battery systems.