A Targeted Functional Design for Highly Efficient and Stable Cathodes for Rechargeable Li-Ion Batteries

Despite the great success of Li-ion batteries (LIBs) up to now, higher demand has been raised with the emergence of the new generation electrics, such as portable devices and electrical vehicles. Even with the improvement on anodes, the cathodes with high capacity and long-lastingness still remain a challenge. New 3D NiCo2O4@V2O5 core-shell arrays (CSAs) on carbon cloth as cathodes in LIBs have been reported in this work. The nanodesigned materials realize the theoretical specific capacity of V2O5 with high power rate based on the total mass of the framework and amount of active materials. The electrodes achieve superb cycling stability, among the most stable cathodes for LIBs ever reported. From both in situ transmission electron microscopy and quantum level calculations, the 3D NiCo2O4 nanosheet frameworks provide high electron conductivity and the skeleton of the robust CSAs without participating in the lithiation/delithiation; the thickness of the layered V2O5 plays a key role for Li diffusivity and the capacity contribution of electrodes. The structures herein point to new design concepts for high-performance nanoarchitectures for LIB cathodes.