Engraving Copper Foil to Give Large‐Scale Binder‐Free Porous CuO Arrays for a High‐Performance Sodium‐Ion Battery Anode

Abstract

Arrays of aligned porous CuO nanorods are obtained by a facile and scalable method of engraving Cu foil in situ. Direct use of the arrays as a flexible and binder-free sodium-ion battery anode — without adding auxiliary materials — results in superior electrochemical performance, including cycle stability and rate capability, even at room temperature. This can be attributed to the unique array structure and the lack of binder in the electrode.