Curly MnOx nanomembranes as cathode materials for rechargeable lithium–oxygen battery systems

• MnOx nanomembranes were used as the catalysts of Li–O2 batteries.
• We reported a novel method—rolled-up technology to prepare MnOx catalysts.
• The MnOx nanomembranes show higher capacity and stability than pure carbon black.
• Oxygen vacancies of the MnOx nanomembranes contribute to the high performance.

Two-dimensional MnOx nanomembranes prepared by electron beam evaporation are rolled up into three-dimensional hybrid micro/nano-tubes by strain release. The material is characterized with Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), cyclic voltammetry and used as the cathode catalysts for lithium–oxygen (Li–O2) batteries. The Li–O2 battery using such curly MnOx nanomembranes as the cathode delivers a specific discharge capacity of 4610 mAhgC−1 at a current density of 70 mAgC−1 which is higher than that of carbon black. Moreover, the MnOx nanomembrane electrode gains improved stability, being capable of cycling 112 times at a current density of 200 mAgC−1. The encouraging performance is ascribed to the unique superiorities of nanomembranes and those inner oxygen vacancies, indicating that nanomembranes are promising materials for Li–O2 batteries.