Understanding the Mechanism of High Capacitance in Nickel Hexaaminobenzene-Based Conductive Metal-Organic Frameworks in Aqueous Electrolytes.
ACS Nano
; 14(11): 15919-15925, 2020 Nov 24.
Article
em En
| MEDLINE
| ID: mdl-33166110
ABSTRACT
Recently, intrinsically conductive metal-organic frameworks (MOFs) have demonstrated promising performance in fast-charging energy storage applications and may outperform some current electrode materials (e.g., porous carbons) for supercapacitors in terms of both gravimetric and volumetric capacitance. In this report, we examine the mechanism of high capacitance in a nickel hexaaminobenzene-based MOF (NiHAB). Using a combination of in situ Raman and X-ray absorption spectroscopies, as well as detailed electrochemical studies in a series of aqueous electrolytes, we demonstrate that the charge storage mechanism is, in fact, a pH-dependent surface pseudocapacitance, and unlike typical inorganic systems, where transition metals change oxidation state during charge/discharge cycles, NiHAB redox activity is ligand-centered.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article