PANI/FeS2/HPBC composite with cladding structure for high specific capacitance electrode in supercapacitors

Abstract

The integration of carbon-based materials with pseudocapacitive components represents an effective strategy for developing high-performance composite electrode materials. In this study, Sunflower straw-derived carbon (HPBC) with a hollow porous structure is developed and used as a conductive substrate for composites. HPBC provides enough space for the growth of redox-active substances. Subsequently, the solution oxidation method is utilized to synthesize PANI/FeS₂/HPBC composite with a cladding structure. Electrochemical characterization reveals that the HPBC framework not only improves charge transport through enhanced conductivity but also stabilizes redox-active species, whereas the synergistic redox activity of FeS₂ and PANI delivers exceptional pseudocapacitance. Specifically, the PANI/FeS₂/HPBC composite demonstrates a superior specific capacitance of 2242.4 F g⁻¹ at 1 A g⁻¹, along with outstanding cycling stability evidenced by 85.3 % capacitance retention at 10 A g⁻¹ after 10,000 cycles. The assembled ASC displays an exceptional energy density of 32.44 Wh kg⁻¹ while delivering a power density of 800 W kg⁻¹. Moreover, the ASC has an impressive cycle life, sustaining 85 % capacity retention after 5000 cycles at 10 A g⁻¹. The developed PANI/FeS₂/HPBC composite demonstrates promising prospects for supercapacitor electrode materials, with the sunflower straw-derived hollow porous carbon (HPBC) serving as an excellent substrate for composite fabrication.