A high-performance potassium-ion capacitor based on a porous carbon cathode originated from the Aldol reaction product

Potassium-ion capacitors (KICs) emerge as a promising substitute for the well-developed lithium-ion capacitors (LICs), however, the energy density of KICs is below expectations because of lacking a suitable electrical double-layer positive electrode. Using chemical activation of the Aldol reaction product of acetone with KOH, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 2947 m(2)/g and a narrow pore size distribution ranging from 1 nm to 3 nm. Half-cell (versus potassium metal) test demonstrates that this porous carbon has high capacitive performance in K+ based organic electrolytes. Furthermore, a novel KIC fabricated by this porous carbon as the cathode, yields high values of energy density and power density. The processes used to make this porous carbon are readily low-cost to fabricate metal-ion capacitors. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.