MoC nanoclusters anchored Ni@N-doped carbon nanotubes coated on carbon fiber as three-dimensional and multifunctional electrodes for flexible supercapacitor and self-heating device

Abstract

With the rapid development of different kinds of wearable electronic devices, flexible and high-capacity power sources have attracted increasing attention. In this study, a facile strategy to fabricate Ni nanoparticles embedded in N-doped carbon nanotubes (CNTs) (Ni@NCNTs) homogeneously coated on the surface of carbon fiber with a multistructural component of molybdenum carbide (MoC/Ni@NCNTs/CC) was synthesized. There are two forms of MoC in MoC/Ni@NCNTs/CC, including the MoC nanoclusters in a size of 2 to 4 nm anchored on Ni@N-doped CNTs and the MoC nanoparticles as an interface between MoC/Ni@NCNTs and carbon cloth (CC). Multifunctional MoC/Ni@NCNTs/CC served as both positive and negative electrode and a heater in flexible supercapacitors and in wearable devices, which exhibited excellent electrochemical and heating performance. Besides, an all-solid-state supercapacitor consists of two pieces of MoC/Ni@NCNTs/CC that exhibited extraordinary energy storage performance with high-energy density (78.7 µWh/cm2 at the power density of 2.4 mW/cm2) and excellent cycling stability (≈91% capacity retention after 8000 cycles). Furthermore, all-solid-state flexible supercapacitors were incorporated with an MoC/Ni@NCNTs/CC electrode into self-heating flexible devices for keeping the human body warm. Thus, MoC/Ni@NCNTs/CC is a promising electrode material for flexible and wearable storage systems and heating electronic application.