Silica‐assisted urea‐formaldehyde‐based carbon microspheres with enhanced supercapacitor performances as electrode

Abstract

Novel silica (SiO2)‐assisted urea‐formaldehyde‐based microspheres (SUFMs) have been successfully prepared by condensation polymerization with SiO2 nanoparticles as template. The support effect of SiO2 and the improved thermal stability of SUFM have been investigated. The SUFM is pyrolyzed at high temperature under Ar atmosphere to achieve its carbonized product (SUFCM), which retains its spherical morphology by alkali etching after carbonization. The SiO2 acts as a stabilizer that limits the flowing domain of the melt resin around the SiO2. When used as the electrode material for supercapacitors, the SUFCM exhibits excellent electrochemical performance with a high specific capacitance of 218 F g−1 at 1 A g−1 in 2 M H2SO4 aqueous electrolyte and a good rate capability of 138 F g−1 (63% capacitance retention) at 10 A g−1. More importantly, the SUFCM electrode demonstrates a robust long‐term stability without capacitance fading after 10,000 cycles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48388.