Investigation on Pesudocapacitance Mechanism of Magnéli Oxide Ti4O7in Aqueous Electrolyte
Journal
Electrochemistry
Journal Volume
92
Journal Issue
7
Start Page
70030
ISSN
1344-3542
2186-2451
Date Issued
2024-07-01
Author(s)
DOI
10.5796/electrochemistry.24-70030
Abstract
Possessing high electronic conductivity and the nature of chemical inertness, the Magnéli phase titanium oxide Ti4O7 is a promising material for various electrochemical applications. Herein, the Ti4O7 electrode in aqueous Li2SO4 electrolyte is characterized for its supercapacitor applications. The oxide electrode exhibits pseudocapacitive behavior over a wide potential range of +1.0 V (vs. Ag/AgCl), showing a specific capacitance of 105 F g-1, equivalent to 85 μF cm-2-oxide, along with outstanding high-rate performance and cycle stability (96% capacitance retention after 5000 cycles). In situ X-ray absorption near-edge spectroscopy analysis on the Ti K-edge absorption reveals that the pseudocapacitance does not involve the redox reaction of the oxide electrode material. A pseudocapacitance mechanism attributed to the reversible redox reactions of the hydrogen and oxygen atoms adsorbed on the oxide surface is proposed.
Subjects
In Situ X-ray Absorption Near-edge Spectroscopy
Pseudocapacitance Mechanism
Supercapacitor
Ti4O7
Publisher
The Electrochemical Society of Japan
Type
journal article