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/cm 2 at the power density of 2.4 mW/cm 2 ) 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.