Micro-Redoxcapacitor : A Hybrid Architecture Out of the Notorious Energy-Power Density Dilemma

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Original languageEnglish
Article number2111805
Journal / PublicationAdvanced Functional Materials
Issue number19
Online published17 Jan 2022
Publication statusPublished - 9 May 2022


Insufficient areal energy density along with unstable delivery, resulting from a linearly sloped time-voltage response rooting in redox-free/surface-redox operating mechanisms severely restricts the application scenarios of micro-supercapacitors. Herein, by coupling silver nanowires (AgNWs) between MXene interlayers with the help of bacterial cellulose (BC) as bio-dispersant toward MXene/AgNWs&BC hybrid cathode to pair with Zn anode, a novel Zn2+-Cl dual-ions micro-redox capacitor (MRC) employing polyacrylamide/ZnCl+ NH4Cl hydrogel electrolyte is first present. The introduced AgNWs nanopillars alleviate the MXene nanosheets restacking to facilitate Cl transfer kinetics, and concurrently strengthen the charge storage capacity and output stability benefiting from a flat discharge plateau stemming from the extra phase transition behavior (Ag⇔AgCl). Thus, an appealing dual energy storage mechanism, featuring i) expedited Cl diffusion involved de/intercalation and ii) reversible solid-to-solid conversion of Ag/AgCl redox couple confined between MXene interlayers, is established and revealed by in situ XRD/Raman analyses. Consequently, remarkably boosted areal energy density up to 227 μWh cm−2 along with significantly improved output stability and suppressed notorious self-discharge behavior, are achieved in the resultant MRC. This work provides a brand new strategy for designing innovative MXene-based MRC featuring a hybrid charge storage mechanism of ions-intercalation and phase conversion to simultaneously realize high and steady energy output.

Research Area(s)

  • high energy density, high output stability, micro-redoxcapacitors, MXene, redox peak, silver nanowires