Thiourea formaldehyde resin has been condensation‐polymerized in the polypyrrole hollow spheres suspension to obtain TF/PPy. Then, TF/PPy has been carbonized at 750 °C to acquire CTF/PPy composites. Scanning electron microscope and transmission electron microscope images were used to observe the morphology of the samples, TGA, XRD, Raman, XPS, and BET were used to analyze the structure of the materials. The results show PPy was blended with the TF resin, and the obtained CTF/PPy exhibited improved supercapacitive performances compared with CTF. The specific capacitance of CTF/PPy is 226.8 F g−1 at the current density of 1 A g−1 according to GCD curves, much higher than that of CTF. More interestingly, the cycling retention of CTF/PPy electrode at the current density of 10 A g−1 is up to 120.2% after 10 000 cycles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47816.

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Synthesis of porous carbon electrodes with high volumetric capacitance and excellent rate capability, especially for a higher mass loading of 10 mg cm–2, remains a challenge and is important for wide applications of the new generation supercapacitors. We report unprecedented volumetric capacitance of 942.9 F cm–3 in 2 M H2SO4 for partially graphitized carbon microspheres co‐doped with N and O prepared by simple hydrothermal route followed by direct cobalt catalytic pyrolysis, which is comparable to the expensive metal oxide and MnO2‐based pseudo‐capacitors. The resulted carbon also shows excellent rate capability (65.4% and 52.2% capacitance retention as the current density increases from 1 to 20 A g–1 in 2 M H2SO4 and 6 M KOH, respectively) and cyclic stability with a higher mass loading of 9.84 mg cm–2 in acidic/basic electrolytes. More importantly, the high volumetric energy density (22.39 Wh L–1) of the assembled symmetrical supercapacitors in 6 M KOH makes it possible to compete with even some Ni metal hydride batteries. This work offers a way to develop advanced porous carbon materials with ultrahigh volumetric capacitance/mass loadings and fast charge rates for supercapacitors.