Construction of porous interface on CNTs@NiCo-LDH core-shell nanotube arrays for supercapacitor applications

Abstract Carbon-based materials have always been a research hotspot in the field of supercapacitors due to their unique stability under a wide range of potential. However, most of carbon-based materials used in supercapacitors cannot maximize the intrinsic capacitance performance due to the limited internal mass transfer. Herein, hierarchical well-aligned nanotube arrays with porous diffusive interfaces are in-situ fabricated by the self-templated effect of ZnO nanorod and ZIF-8 nano-shell. In this unique architecture, the well-aligned carbon nanotubes (CNTs) growing firmly on carbon fibers (CFs) can not only improve the mass transfer of ions onto the NiCo-LDHs surfaces, but also used as good backbones for the subsequent loading of NiCoLDHs nanosheets with high capacity. The optimized core-shell electrode displays an excellent capacity of 176.33 mAh g−1 at 1 A g−1. The as-prepared CNTs@NiCo-LDH//ZIF-8 derived carbon asymmetric supercapacitor (ASC) exhibits a high energy density of 37.38 Wh kg−1 at 800 W kg−1 and an outstanding cycling stability (90.22% retention after 5200 cycles), which offers a new synthesis strategy for design of carbon-based materials in superior electrochemical energy storage applications.