Optimized Hydroxyapatite–Carbon Nanotube Composite Electrodes for Enhanced Supercapacitor Performance

Abstract Advanced research into electrode materials for supercapacitors exists because of increasing consumer demand for effective, sustainable energy storage systems. The current work examines the production and analytical investigation of hydroxyapatite–carbon nanotube (HAp–CNT) composite electrodes for superior supercapacitor applications. A chemical precipitation method produced the HAp–CNT composite material, and its structural, morphological, and electrochemical properties were systematically scrutinized. The HAp–CNT composite's specific capacitance value of 133.012 F/g measured at 10 mV/s through electrochemical tests showed superior results compared to pure HAp's value of 31.125 F/g. The composite showed an outstanding energy density of 32.32 Wh/kg coupled with a suitable power density of 701.04 kW/kg as well as low charge transfer resistance at 11.27 Ω and equivalent series resistance at 16.96 Ω. The best‐performing electrode was used for the fabrication of a prototype supercapacitor and check its viability for energy storage. The HAp–CNT prototype supercapacitor maintained above 100% capacitance retention following 3000 charge–discharge cycles while delivering improved energy density up to 198.31 Wh/kg and power density up to 3250.54 kW/kg when compared to pre‐cycling results. The combined use of HAp and CNTs creates an effective performance enhancement that provides the HAp–CNT composite with exciting potential for emerging energy storage technologies.