Reconstruction of copper shell on metal oxides as enhanced nanoarrays electrodes for lithium ion batteries

Abstract

Transition metal oxides anodes of lithium ion batteries (LIBs) usually suffer from low reaction kinetics with slow charge/ions transfer resulting from severe volume variation. In this work, thin porous copper shell is homogeneously coated on the CoO nanowires forming CoO/Cu hetero-structured arrays. Cu shell not only acts as a conductive network, but also serves as a protective “armor” layer to keep electrode stable upon cycling. Meanwhile, 3D porous architecture with large surface area is well preserved in the CoO/Cu hetero-structured arrays. Due to enhanced electron/ion transfer characteristics and strengthened electrode structure, the as-prepared CoO/Cu hetero-structured arrays exhibit much higher electrochemical reactivity with lower polarization and better reversibility due to the introduction of thin Cu shell. Additionally, enhanced discharge capacity and large-rate performances are also demonstrated in the CoO/Cu hetero-structure arrays when compared with the pure CoO nanowires counterpart.