LAUSR

We use sorghum core-derived carbon sheets (SCDCS) as electrodes for a lithium-ion capacitor due to their large specific surface area (1122 m2 g−1) and sheet-like structure. A lithium-ion capacitor with high energy density is fabricated using SCDCS as both the negative and positive electrodes, in which the potential of the electrode is adjusted to obtain equal capacity in both the negative and positive electrodes. The lithium-ion capacitor demonstrates a high energy density of 124.8 W h kg−1 at a power density of 107 W kg−1, and maintains 59.5 W h kg−1 at a high power density of 10 508 W kg−1. The capacity retention ratio is 66% for the fabricated lithium-ion capacitor after 5000 cycles at a current of 10 A g−1, indicating that this lithium-ion capacitor is promising for fast energy storage.