Generic Synthesis of Carbon Nanotube Branches on Metal Oxide Arrays Exhibiting Stable High‐Rate and Long‐Cycle Sodium‐Ion Storage

Abstract

A new and generic strategy to construct interwoven carbon nanotube (CNT) branches on various metal oxide nanostructure arrays (exemplified by V 2 O 3 nanoflakes, Co 3 O 4 nanowires, Co 3 O 4 –CoTiO 3 composite nanotubes, and ZnO microrods), in order to enhance their electrochemical performance, is demonstrated for the first time. In the second part, the V 2 O 3 /CNTs core/branch composite arrays as the host for Na + storage are investigated in detail. This V 2 O 3 /CNTs hybrid electrode achieves a reversible charge storage capacity of 612 mAh g −1 at 0.1 A g −1 and outstanding high‐rate cycling stability (a capacity retention of 100% after 6000 cycles at 2 A g −1 , and 70% after 10 000 cycles at 10 A g −1 ). Kinetics analysis reveals that the Na + storage is a pseudocapacitive dominating process and the CNTs improve the levels of pseudocapacitive energy by providing a conductive network.