An Asymmetric Supercapacitor–Diode (CAPode) for Unidirectional Energy Storage. (5th August 2019)

• Record Type: Journal Article
• Authors: Zhang, En; Fulik, Natalia; Hao, Guang‐Ping; Zhang, Han‐Yue; Kaneko, Katsumi; Borchardt, Lars; Brunner, Eike; Kaskel, Stefan
• Is Part Of: Angewandte Chemie. Volume 131:Number 37(2019)
• Page Start: 13194
• Page End: 13199
• Publication Date: 2019-08-05
• Subjects: Elektroadsorption -- Ionensieben -- Ionentronik -- Nanoporöser Kohlenstoff -- Superkondensatoren; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201904888
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: A new asymmetric capacitor concept is proposed providing high energy storage capacity for only one charging direction. Size‐selective microporous carbons ( w <0.9 nm) with narrow pore size distribution are demonstrated to exclusively electrosorb small anions (BF4 − ) but size‐exclude larger cations (TBA + or TPA + ), while the counter electrode, an ordered mesoporous carbon ( w >2 nm), gives access to both ions. This architecture exclusively charges in one direction with high rectification ratios (RR=12), representing a novel capacitive analogue of semiconductor‐based diodes ("CAPode"). By precise pore size control of microporous carbons (0.6 nm, 0.8 nm and 1.0 nm) combined with an ordered mesoporous counter electrode (CMK‐3, 4.8 nm) electrolyte cation sieving and unidirectional charging is demonstrated by analyzing the device charge‐discharge response and monitoring individual electrodes of the device via in situ NMR spectroscopy. Abstract : Die Größe macht's : Durch Kopplung einer Kohlenstoff‐Molekülsieb‐Elektrode mit geordnetem mesoporösen Kohlenstoff (CMK‐3) wurde eine neue Art Kondensator mit Gleichrichterfunktion und hoher Kapazität entwickelt. In‐situ‐NMR‐Spektroskopie bestätigt den Größenausschluss und unidirektionalen Auflademechanismus.