Phytic acid as an eco-friendly phosphorus source in the synthesis of phosphorus-doped NiCo2O4 for supercapacitor electrodes

Abstract

This study explores the synthesis of nickel-cobalt bimetallic precursors using phytic acid (PA) as a phosphorus source and their application as supercapacitor electrodes. Through high-temperature annealing, these precursors were converted into phosphorus-doped nickel-cobalt bimetallic oxides (NCO) with certain defects. The morphologies and particle size of NCO can be easily adjusted by the amount of PA. Compared to the undoped nickel-cobalt bimetallic oxides, the phosphorus-doped materials exhibited significantly enhanced electrochemical activity and specific capacitance. The optimized electrode exhibits the highest specific capacitance of 1075 F·g−1 at a current density of 1 A·g−1. The asymmetric supercapacitor assembled together with activated carbon can deliver a relatively high energy density of 39.8 Wh·kg−1 at a power density of 696 W·kg−1. Additionally, this paper provides a detailed discussion on the impact of phosphorus doping on the performance of supercapacitor electrodes and the potential of PA as an eco-friendly phosphorus source in the synthesis of high-performance electrode materials.

Keywords

• NiCo2O4
• Supercapacitors
• Heteroatom doping
• Phytic acid
• Electrochemical performance