Renewable biopolymer-derived carbon–nickel oxide nanocomposite as an emerging electrode material for energy storage applications

The high capacity electrode material design with rapid charging/discharging and long life capability has become a critical issue and main concern in recent years. Nickel oxide (NiO) has received much attention in the field of energy storage as a cathode electrode material owing to its layered structure with large spacing, crystal structure, and high specific surface area. In this study, the chitosan derived carbon–nickel oxide (CDC@NiO) nanocomposite was synthesized from a NiO nanoparticle precursor using a precipitation approach, and chitosan (a renewable biopolymer) was used as a carbon resource. The formation mechanism, structural behavior, and morphological properties were examined using various types of microscopic and spectroscopic characterization techniques. The design material was tested further as electrode material in an electrochemical half-cell and full cell symmetric assembly. In a three electrode system, the CDC@NiO nanocomposite exhibited satisfactory electrochemical performance with a high specific capacitance of around 1011.10 Fg−1 and better cyclic stability of 94.20% after 3000 cycles. In a two electrode symmetric supercapacitive system, the fabricated CDC@NiO delivered maximum Cs 88.30 Fg−1, stability with a higher power density of 7.84 Whkg−1 at an energy density of 133.05 Wkg−1. The fabricated CDC@NiO electrode material retains the cyclic stability of around 90% after 3500 consecutive charge/discharge cycles.