A binder-free, flexible cathode for rechargeable Na-O2 batteries

Rechargeable Na-O2 batteries have attracted significant attention as energy storage devices owing to their theoretically high energy storage capacity and the natural abundance of sodium. However, practical applications of this type of battery still suffer from low specific capability, poor cycle stability, instable electrolytes, and unstable polymer binders. Herein, we report a facile method of synthesizing binder free and flexible cathodes with Co3O4 nanowire arrays vertically grown onto carbon textiles. When employed as a cathode for Na-O2 batteries, this cathode exhibits superior performance, including a reduction of charge overpotential, high specific capacity (4687 mAh/g), and cycle stability up to 62 cycles. These enhanced performance can be attributed to the synergistic effect of the porosity and catalytic activity of the Co3O4 nanowire catalyst.

Graphical AbstractCo3O4 NWs grow on the carbon textiles via hydrothermal and thermal treatment processes, which can be used as flexible and binder free cathodes for Na–O2 batteries. The discharge products consist of NaO2 and Na2O2.Figure optionsDownload full-size imageDownload as PowerPoint slide