Morphology regulation of Li2O2 by flower-like ZnCo2S4 enabling high performance Li-O2 battery
The development of high-efficiency oxygen electrode with well structural and chemical stability is critical to boost the rapid development of lithium-oxygen (Li-O2) batteries. Which are reckoned as a potent contender for next-generation energy storage devices due to their ultra-high theoretical energy density. Here, a flower-like three-dimensional self-standing ZnCo2S4-based electrode without an addition of binders are fabricated and employing as positive electrode for Li-O2 batteries. The bifunctional catalytic activity of flower-like ZnCo2S4 is conducive to improving the hysteresis kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Representative ultrathin petal edge exposes adequate active sites and provides a sufficient contact interface between Li2O2 and positive electrode, which are essential for reducing the charge overpotential during OER. Compared with the control electrodes, the flower-like ZnCo2S4@Ni-based Li-O2 battery shows decreased overpotential (0.78 V) and improved cycle stability (over 500 cycles).