Waste-derived carbon-enhanced iron sulfide microflowers for high-performance energy storage applications

This work presents an environmentally friendly form of activated carbon (AC) made from pea peels using a microwave and zinc chloride. Iron sulfide (FeS₂-FeS) microflowers were also efficiently synthesized via a simple hydrothermal technique over various times. The AC/(FeS₂-FeS) composite was developed using a simple hydrothermal technique with a variable AC ratio. A 20-mg AC/(FeS₂-FeS) achieved a superior electrochemical energy storage behavior because of its unique structure and high conductivity, allowing efficient pathways for the movement of ions/electrons. When it is employed as an electrode material for supercapacitors, the as-prepared 20-mg AC/(FeS₂-FeS) electrode produces an excellent capacity of 433.4C g⁻¹ at a current density of 1 A g⁻¹. Exceeding the performance of other composites, the 20-mg AC/(FeS₂-FeS) demonstrates remarkable stability, maintaining 82 % of its capacity after 3000 cycles. A 20-mg AC/(FeS₂-FeS)//AC hybrid device is developed for practical applications. This configuration has a high specific energy of 14.4 Wh kg⁻¹ and a specific power of 517.97 W kg⁻¹. Interestingly, even after 5000 cycles, the hybrid device maintained 72.7 % of its specific capacity and achieved 100 % coulombic efficiency. These findings emphasize the stability and exceptional performance of the 20-mg AC/(FeS₂-FeS)//AC device.