High performance Li–O2 battery using γ-MnOOH nanorods as a catalyst in an ionic-liquid based electrolyte

Li–O2 batteries using the ionic-liquid based electrolyte consisting of 1-ethyl-3-methylimidazolium tetrafluoroborate and lithium bis((trifluoromethyl)sulfonyl)imide were investigated with carbon catalyst (Super P), α-MnO2 nanorods/carbon composite catalyst (Super P + α-MnO2) and γ-MnOOH nanorods/carbon composite catalyst (Super P + γ-MnOOH). It is demonstrated that γ-MnOOH nanorods display higher electrocatalytic performance for O2 reduction in ionic-liquid based electrolyte, compared with that of Super P and α-MnO2 nanorods. The Li–O2 battery using γ-MnOOH nanorods/carbon composite as catalyst displays a high discharge capacity of 9400 mAh/g at a low current density of 50 mA/g and can be stably cycled 100 times with a current density of 200 mA/g.

► Introduce a Li-O2 battery using γ-MnOOH nanorods as catalyst in ionic-liquid based electrolyte. ► Electrocatalytic performance of γ-MnOOH is higher than that of Super P and α-MnO2. ► The Li-O2 battery using γ-MnOOH as catalyst displays a high discharge capacity of 9400 mAh/g. ► The Li-O2 battery using γ-MnOOH as catalyst can be cycled 100 times.