Anchoring 2D NiMoO4 nano-plates on flexible carbon cloth as a binder-free electrode for efficient energy storage devices

Abstract

The energy security and mounting environmental issues compel the scientific community to allocate greatly efficient and economical energy renovation and storage systems. Among the energy storage devices, supercapacitors have become the forefront in energy storing systems in recent decades. The efficiency of supercapacitors mainly depend on the electrode's material and they usually suffer from a quick reduction in specific capacitance at higher current densities. Herein, we combined the nano-plates like bimetallic oxides (NiMiO4) with mixed valence states on the surface of a conductive substrate (carbon cloth) without any binder and additives (denoted NMO@CC). The as-prepared electrode NMO@CC showed marvelous electrochemical properties in the aqueous basic electrolyte by achieving a high capacity of 1500 C g−1 at current density of 5 A g−1 with high degree of rate capability. More interestingly, the NMO@CC electrode demonstrated excellent cycling stability of 94.63% after 5000 cycles during charge-discharge process. Further, the charge storage mechanism of NMO@CC electrode is investigated by analyzing the surface capacitive and diffusion controlled processes and it shows high surface capacitive storage (71%). These admirable results are based on the highly open channels for efficient diffusion of electrolyte ions and electronic transmission through the NMO and backbone carbon cloth, respectively. Therefore, accurate morphology and surface manufacturing engineering are highly appreciated to enhance the active surface area and inherent conductivity of electrode materials.