Boosting the charge transfer efficiency of metal oxides/carbon nanotubes composites through interfaces control

Abstract Metal oxide/carbon materials composites (MOx/C) are broadly used as electrodes in energy storage devices. However, their capacity under high rates is limited due to the sluggish ion/electron transportation during faradaic reactions. In this work, carbon nanotube carpets (CC)/Fe2O3 nanoparticles covered with bud-liked carbon layer (CC/Fe2O3@b-C) is developed as an electrode by interfaces design. It is found that the bud-liked carbon wrapper enlarges interface area and provides an accelerated conducting network between CC and Fe2O3 nanoparticles through “seamless” connection. With boosted charge transfer efficiency, this composite demonstrates an excellent rate capability. The CC/Fe2O3@b-C electrode shows a high capacity of 246.15 mC cm−2 under 5 mV s−1 and can maintain ~95% when the scan rate is increased to 100 mV s−1. Moreover, the hybrid device paired with carbon fiber cloth (CFC)/Co(OH) 2 cathode exhibits simultaneous high energy density and power density, showing good potential application in high-power devices.