Interconnected mesoporous carbon sheet for supercapacitors from low-cost resources

•Both CaCO3 and CTAB are used to synthesize mesoporous carbon nanosheet (MCS).•The capacitance of MCS is 90.7 μF cm−2 at 0.05 A g−1 in ionic liquid electrolyte.•The energy density of MCS capacitor remains at 22.19 Wh kg−1 at 4267 W kg−1.•All the MCS electrodes show good cycle stability in the ionic liquid electrolyte.

Interconnected mesoporous carbon sheets (MCSs) were prepared from cheap coal tar pitch with low-cost CaCO3 nanoparticles and cetyltrimethyl ammonium bromide (CTAB) as porogens for supercapacitors. The results show that the surface area of MCSs can be tuned in the range of 87–167 m2 g−1. The interconnected MCS2–1–1 made at 2:1:1 of CaCO3/coal tar pitch/CTAB mass ratio retains a capacitance of 87 F g−1 at 0.1 A g−1 after 100 cycles in ionic liquid electrolyte with high retention of 93.1%, showing excellent cycle stability. The energy density of MCS2–1–1 capacitor only drops from 64.18 Wh kg−1 to 22.19 Wh kg−1 with the average power density increasing from 115 W kg−1 to 4267 W kg−1, demonstrating good rate performance. This work suggests a low-cost way to synthesize high performance MCS for energy storage materials.

Graphical abstractInterconnected mesoporous carbon nanosheets are prepared from cheap coal tar pitch with low-cost CaCO3 nanoparticles and cetyltrimethyl ammonium bromide (CTAB) as porogens and exhibit a high energy density for supercapacitor.Figure optionsDownload full-size imageDownload as PowerPoint slide