Tailoring the Composition of Ternary NiCoFe Layered Double Hydroxide with Graphitic Carbon Nitride as a Positive Electrode Material for High‐Performance Hybrid Supercapacitors

This work reports a simple hydrothermal‐assisted method to prepare a high‐performance nickel cobalt iron layered double hydroxide/graphitic carbon nitride (NiCoFe LDH/g‐C3N4) composite for supercapacitor (SC) applications. Various spectral and analytical techniques were used to confirm the formation of NiCoFe LDH/g‐C3N4 composite. The NiCoFe LDH/g‐C3N4 composite demonstrates battery‐like SC behavior in the three‐electrode measurements. The NiCoFe LDH/g‐C3N4 composite has a maximum specific capacity (366 C g‐1 at 1 A g‐1) compared to the individual NiCoFe LDH and g‐C3N4 electrode materials. Further, the NiCoFe LDH/g‐C3N4 composite electrode shows 89% capacity retention even after 8000 galvanostatic charge‐discharge (GCD) cycles at 6 A g‐1. In addition, a hybrid supercapacitor (HSC) is fabricated by using NiCoFe LDH/g‐C3N4 composite as a positive electrode and activated carbon (AC) as a negative electrode. The as‐fabricated NiCoFe LDH/g‐C3N4//AC HSC demonstrates an impressive energy density of 76.44 Wh kg‐1 and a power density of 1279.9 W kg‐1, along with excellent long‐term cycle stability of 83% capacity retention even after 6000 GCD cycles at 6 A g‐1. Considering its simplicity of fabrication and exceptional energy storage capabilities, the as‐fabricated NiCoFe LDH/g‐C3N4//AC hybrid supercapacitor has significant promise for practical use in the near future.