Long-term electrochemical behaviors of manganese oxide aqueous electrochemical capacitor under reducing potentials

Autor:	Nae-Lih Wu, Kuang-Tsin Lee, Fatemeh Ataherian
Rok vydání:	2010
Předmět:	Electrolytic capacitor Chemistry General Chemical Engineering Analytical chemistry Oxide Electrolyte Electrochemistry Chloride Capacitance Dielectric spectroscopy chemistry.chemical_compound Electrode medicine medicine.drug
Zdroj:	Electrochimica Acta. 55:7429-7435
ISSN:	0013-4686
DOI:	10.1016/j.electacta.2010.01.102
Popis:	Long-term electrochemical behaviors of hydrated MnO 2 electrochemical capacitor (EC) electrode in alkali chloride (KCl (aq) ) electrolyte have been studied by using potential cycling for thousands of cycles within different potential windows spanning from 0.8 V (versus Ag/AgCl (aq) ) to varied lower-end potentials below the open-circuit potential. Three potential ranges resulting in different cycling behaviors of the oxide EC have been identified. Range I: cycling above 0.2 V results in no change in either microstructure or surface chemistry of the oxide electrode, and no capacitance reduction has been observed. Range II: cycling down to 0.0 V leads to extensive morphological reconstruction and limited reduction of surface Mn ions, while the electrode capacitance remains stable. Range III: cycling with lower-potential end below 0.0 V results in obvious capacitance reduction, along with different morphological reconstruction and Mn reduction from those in Range II. For each selected lower-end potential in Range III, the capacitance descends to a plateau within first thousand cycles, and the extent of the capacitance reduction increases as the lower-end potential decreases.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7b1ed52437eff889e0513985479dbe6d https://doi.org/10.1016/j.electacta.2010.01.102 Zobrazit plný text záznamu Full Text from ScienceDirect