Vertically Oriented MXene Bridging the Frequency Response and Capacity Density Gap for AC‐Filtering Pseudocapacitors. (7th March 2022)

• Record Type: Journal Article
• Authors: Wen, Yeye; Chen, Hongwu; Wu, Mingmao; Li, Chun
• Is Part Of: Advanced functional materials. Volume 32:Number 21(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-07
• Subjects: alternate current filtering -- high rate -- MXene -- pseudocapacitance -- vertical structures; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202111613
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Electrochemical capacitors (ECs) with high‐rate characteristics demonstrate great promise for replacing bulky aluminum electrolytic capacitors with alternate current (AC)‐filtering functions. Currently, the performance of AC‐line filtering ECs is limited by the vast gap between the ionic transport kinetics and capacity density of electrode materials. Herein, vertically oriented MXene and reduced graphene oxide composite (VMG) electrodes are prepared by electrochemical co‐deposition to bridge the performance gap for AC‐line filtering ECs. Benefiting from the unique pseudocapacitive characteristic and vertically interconnected microstructure, the VMG‐based EC exhibits an outstanding areal capacitance of 1.14 mF cm −2 with a phase angle of −80° at 120 Hz. Moreover, by utilizing the advantages of MXene at negative potential, an asymmetric pseudocapacitor is constructed with an energy density up to 805 µF V 2 cm −2 at 120 Hz, which can be further incorporated in portable and wearable devices with excellent environmental ripple filtering capability in diverse scenarios. Abstract : A MXene‐based electrode with a vertically oriented structure and pseudocapacitive characteristics is rationally designed to realize the synergistic improvement of the frequency response and capacity density of electrochemical capacitors, which demonstrate the capability of effectively filtering the alternate current signal to direct current signal.