Boron-doped yeast-derived carbon heterostructure electrode for flexible symmetric solid-state supercapacitor application

The development of sustainable, eco-friendly, and affordable energy storage electrodes is essential for overcoming the current limitations of energy storage technology. In this work, boron-doped yeast-derived carbon (B-YDC) was developed as a high-performance electrode for supercapacitors. Direct pyrolysis treatment was used to prepare yeast-derived carbon (YDC) and B-YDC materials under an inert gas atmosphere at 800 °C. The developed electrode materials were evaluated using a variety of physicochemical methods, including SEM, TEM, EDS, XRD, Raman, XPS, and BET. Electrochemical measurements were performed to evaluate the specific capacitance of the fabricated YDC and B-YDC electrodes using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The study showed that the specific capacitance of the B-YDC electrode was approximately 294 F g −1 at 1 A g −1 compared to undoped YDC (263 F g −1 at 1 A g −1 ). In long-term cycling stability, the B-YDC electrode demonstrated a higher capacitive retention of 94% than that of the YDC (86%) for 5000 cycles. The prepared B-YDC||B-YDC symmetric device exhibited an energy density of 51 Wh kg −1 at 998 W kg −1 . The results validated that B-YDC derived from biomass can serve as a promising source of electrode material for sustainable energy devices.