Document Type

Restricted

Advisor

Stanton Ching

Publication Date

2020

Comments

This paper may only be accessed on the Connecticut College campus.

Abstract

The need for better energy storage system has been a crucial challenge in fully utilizing renewable energy. Supercapacitors are energy storage devices that have been gaining attention due to their ability to charge and discharge at faster rates than batteries. Nonetheless, improving the specific capacitance of supercapacitors is an important key for commercial use. Manganese oxides are inexpensive and non-toxic materials that have shown considerable promise as supercapacitor electrodes. Microporous/mesoporous manganese oxide nanoparticles were synthesized with a self-assembly mechanism under the presence of butyric acid to control the particle size and morphology. Electrode was fabricated from nanoparticles, and examined through cyclic voltammetery. High quality manganese oxide thin films were synthesized through sol-gel route by reducing tetraethylammonium permanganate in methanol and spin coating onto stainless steel foil. Layered birnessite-type structures formed after calcination. Different metal ions were doped into the thin films to examine their effect on capacitive behavior of the films. The electrochemical performance of the thin films was examined through cyclic voltammetry and chronopotentiometry charge-discharge experimentsMaterial characterization of the films both before and after long-term electrochemical scans were conducted using scanning electron microscopy to determine changes in morphology. X-ray photoelectron spectroscopy was conducted on selected films for oxidation state characterization.

Hollow microporous/mesoporous manganese oxide nanoparticle showed promising results for application on supercapacitor electrodes among the synthesized manganese oxide nanoparticles. Sol-gel manganese oxide thin films exhibited specific capacitance between 60-100 Fg-1, with 0.25 Fe3+ doped MnOx thin film showing the best capacitance, with electrochemical stability.

Available for download on Friday, May 15, 2020

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The views expressed in this paper are solely those of the author.