Incorporation of heteroatoms into reticulated vitreous carbon foams derived from sucrose to improve its energy storage performance

Herein, a binder-free 3D reticulated carbon doped with N, F, and B is proposed as an excellent choice to be used as an electrode in volumetric supercapacitors for stationary devices. The carbonaceous electrode was obtained by pyrolysis (N₂ atmosphere) of sucrose resin modified with precursors of heteroatoms doping, impregnated on the polyurethane foam used as a template. Different techniques such as SEM, Raman, XPS, and FTIR were employed to characterize the properties of RVC. Cyclic Voltammetry, Galvanostatic charge and discharge curves, and EIS were used to evaluate the energy storage performance of the foams. The electrochemical evaluation in acidic medium shows that the composition and chemical state of doping elements in the RVC determine their capacitance. RVC-N electrode exhibits the best performance among the foams here synthetized registering volumetric capacitances of 3.57, 3.20, 2.25, 1.45, and 0.63 F cm⁻³ at 5, 10, 20, 40, and 80 mV s⁻¹, respectively. Further, a symmetric supercapacitor was assembled by using RVC-N as a positive and negative electrode. The device shows volumetric capacitances of 3.82, 1.4, 0.57, 0.47, 0.37, 0.24, and 0.15 F cm⁻³ at 0.5, 1, 2, 4, 6, 18 y 35 mA cm⁻³ inside a voltage window of 1.4 V. Moreover, the device retained the 80% of its initial capacitance after 10 000 cycles.