Asymmetric supercapacitor based on cobalt hydroxide carbonate/GF composite and a carbonized conductive polymer grafted with iron (C-FP)

Highlights: • CHC/GF composites with different masses of GF are prepared by hydrothermal method. • CHC/GF₁50 mg composite displayed the best physical and electrochemical results. • CHC/GF₁50 mg//C-FP device gave energy density of 28 Wh kg⁻¹ at 0.5 Ag^-1. Cobalt hydroxide carbonate has a good electrochemical capability coupled with its, environmentally friendly nature and low cost which makes it a potential high performance material for electrochemical applications when combined with graphene foam (GF) as nanostructured composites. In this report, cobalt hydroxide carbonate/graphene foam (GF) with different mass contents of GF was synthesized by hydrothermal method. An asymmetric supercapacitor device was designed using the highest performance cobalt hydroxide carbonate/GF composite as a positive electrode and carbonized conductive polyaniline grafted with Iron (C-FP) as the negative electrode. The hybrid device exhibited a high specific capacity of about 69 mA h g⁻¹ with the maximum energy density of 28 Wh kg⁻¹ and power density of 554 W kg⁻¹ at a current density of 0.5 A g⁻¹ in the operation voltage range of 0–1.5 V. These impressive results enable the possible adoption of such cobalt hydroxide carbonate/GF//C-FP devices in high performance energy storage applications.