"Novel Silicon Anodes for Improved Lithium Ion Battery" by Amir Hegazy

Date of Award

Spring 2025

Language

English

Embargo Period

5-11-2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College/School/Department

Department of Nanoscale Science and Engineering

Program

Nanoscale Engineering

First Advisor

Harry Efstathiadis

Committee Members

Harry Efstathiadis (Chair), Mengbing Huang, Seiichiro Higashiya, and Devendra Sadana

Keywords

Lithium Ion battery, silicon anode, nanoscale engineering, PECVD Deposition

Subject Categories

Nanoscience and Nanotechnology

Abstract

Li-ion battery (LIB) have been dominating the development of electronics shaping our daily life owing to their good specific and volumetric energy densities. However, the technological advancement calls for higher energy, safer, lower cost, and large-scale manufacturing batteries.

Silicon is considered an excellent candidate for anode material for higher energy LIB. This thesis examines the potential of silicon as an anode in high-capacity LIBs where the role of silicon is studied at the frontside (FS) and the backside (BS) of the anode. At the frontside, the effect of deposition of silicon on graphite on the battery performance was studied. Graphite acts as a buffer to limit silicon expansion and provide a conductive matrix, while silicon increases the specific capacity. It is concluded that the battery performance depends mainly on deposition thickness, deposition temperature, and silicon phase. Data shows the correlation of these factors for optimal battery performance with capacity gain of 20%.

At the backside of the anode, we introduce a novel method to fabricate silicon-based anodes, in particular, nickel silicide anode. Nickel silicide offers high specific capacity, and higher conductivity compared to graphite anode. This novel method compromises of series of wet and dry cleaning of nickel substrate prior to reaction with silicon. This study demonstrates the success of the reaction forming nickel silicide with strong adhesion to the surface. The electrochemical performance showed improvement in comparison to graphite anodes. The novel anode shows that higher capacity gain depends on the phase of the nickel silicide, with nickel di-silicide showing the highest capacity performance and lowest fade.

License

This work is licensed under the University at Albany Standard Author Agreement.

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