Publication Date

2024

Document Type

Dissertation/Thesis

First Advisor

Brown, Dennis E.

Degree Name

Ph.D. (Doctor of Philosophy)

Legacy Department

Department of Physics

Abstract

Sodium-ion batteries are an attractive alternative to traditional lithium-ion batteries due to their low cost and eco-friendly components. The Fe3+/Fe4+ redox reaction provides similar operating voltages and specific energy densities to that of lithium-ion batteries. Mössbauer spectroscopy is a useful x-ray technique for measuring the chemical environment inside of the metal enclosure of batteries. In particular, it can measure the relative concentration of Fe3+/Fe4+ ions as a function of the battery’s voltage. In this dissertation ex-situ and in-situ Mössbauer spectroscopy were used to map out the effect of various electrolytes on the performance of NaFe(1−x)(Ni0.5Mn0.5)xO2 batteries. This was done by observing the time dependence of the isomer shifts and quadrupole splittings as a function of state of charge (SOC). A unique hermetically sealed Mössbauer battery cell was constructed for the in-situ measurements. This cell was used to successfully achieved more than 40% relative concentration of Fe4+.

Anode free Na metal batteries are promising for future energy storage because they provide the highest energy densities and also eliminate the need of handling hazardous Na metals during manufacturing. The high performance includes consistently higher than 99.8% Faradaic efficiencies, much more stable interfacial resistance, and negligible formation of mossy Na after 500 cycles. Anode-free Na metal batteries equipped with high-capacity sodium vanadium phosphate cathodes and pure Cu current collector exhibited at least ≈ 70% capacity retention for 100 cycles

Extent

173 pages

Language

en

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

Included in

Physics Commons

Share

COinS