Agricultural waste-derived activated carbon for high performance lithium-ion capacitors

Abstract

Activated carbon (AC) derived from the most common agricultural waste, corncob, has been synthesized through a simple chemical activation process. Furthermore, high energy density lithium-ion capacitors (LICs) were fabricated using corncob-derived AC as the cathode and commercially available Li₄Ti₅O₁₂ as the anode. The optimized LIC achieves a maximum energy density of 79.6 W h kg⁻¹ and is also capable of delivering high power density of 4 kW kg⁻¹, which is much higher than that of similar constructions employing commercial AC as the cathode. In addition, the corncob-based LIC exhibits great cycle performance with 85.2% retention of the initial capacitance value after 2000 cycles. The present research offers a new approach for the development of high performance LICs employing carbonaceous electrodes of biomass precursors. These results make the corncob-derived activated carbon the most promising candidate for future energy storage applications.