We discovered an organic weak acid, 3,4,9,10-perylene tetracarboxylic acid (PTCA), confined on the electrode surface, revealing a reversible and ultrafast protonation/deprotonation non-Faradaic process but exhibiting analogous voltammetric peaks (capacitive peaks). A further synthesized PTCA-graphene supra molecular nanocomplex discloses a wide voltage window (1.2 V) and ultrahigh specific capacitance up to 143 F g(-1) at an ultrafast charge-discharge density of 1000 A g(-1) (at least 1 order of magnitude faster than present speeds). The capacitance retention maintained at 73% after 5000 cycles. This unique capacitive, voltammetric behavior suggests a new type of charge-storage modes, which-may offer a way for overcoming the present difficulties of supercapacitors.
Gan, S., Zhong, L., Gao, L., Han, D., & Niu, L. (2016). Electrochemically Driven Surface-Confined Acid/Base Reaction for an Ultrafast H+ Supercapacitor. Journal of the American Chemical Society, 138(5), 1490-1493. https://doi.org/10.1021/jacs.5b12272