Spherical porous carbon framework derived from yeast cell wall for high rate performance supercapacitors

Abstract

The growing demand for efficient energy storage systems drives research into advanced electrode materials for supercapacitors. In this paper, a spherical porous carbon framework (YCW-H-3) is synthesized through hydrothermal treatment combined with one-step carbonization and activation, using yeast cell walls as the precursor. The specific surface area of YCW-H-3 is 1598.0 m² g⁻¹, and the hierarchical porous structure, along with abundant N and O surface functional groups, significantly enhances the transport efficiency of electrolyte ions. YCW-H-3 demonstrates remarkable electrochemical performance, achieving a specific capacitance of 302.5 F g⁻¹ at a current density of 0.5 A g⁻¹ in three-electrode system. The rate performance of YCW-H-3 ranging from 0.5 A g⁻¹ to 70 A g⁻¹ achieves 71.0 %, reflecting excellent rate capability. The symmetric supercapacitor constructed with YCW-H-3 as electrode and 6 M KOH solution as electrolyte exhibits excellent energy storage capability, achieving an energy density of 8.57 Wh kg⁻¹ at a power density of 100 W kg⁻¹. Furthermore, after 50,000 charge-discharge cycles, the capacitance retention remains impressive at 99.45 %.