High-frequency supercapacitors based on carbonized melamine foam as energy storage devices for triboelectric nanogenerators

摘要

Triboelectric nanogenerators (TENG) are mechanical energy harvesting devices with pulsed output at frequencies ranging from a few to hundreds of hertz. Supercapacitors (SCs) are ideal energy storage devices for TENGs because of their high specific capacitance and excellent cycling performance, except that the poor high-frequency response of conventional supercapacitors limits their capability for storing pulsed energy at high frequencies. In this work, via a simple high-temperature carbonization process, we have fabricated carbonized melamine foams as electrode materials for high-frequency supercapacitors (HF-SCs). The resulting HF-SCs with a phase angle of - 80.1 degrees and a specific areal capacitance of 132 mu F cm(-2) at 120 Hz were successfully employed as alternating current (ac) line filter for smoothing ripple current. When charged with a rotating TENG (R-TENG), the HF-SCs exhibited an energy utilization efficiency that is 20.3% higher than conventional activated carbon-based SCs, demonstrating the advantage of HF-SCs for storing pulsed energy generated by TENGs.