Date of Award

Fall 2025

Document Type

Open Access Thesis

Department

Chemical Engineering

First Advisor

William E. Mustain

Abstract

The rising global demand for high-performance and sustainable energy storage solutions has placed lithium-ion batteries (LIBs) at the forefront of technological progress. However, the energy density limits of traditional graphite anodes require the investigation of alternative materials. Silicon (Si), with its high theoretical capacity, is a promising anode material. Still, its practical use faces major challenges such as volumetric expansion, unstable solid electrolyte interphase (SEI) formation, and low conductivity. This thesis examines the electrochemical behavior and limitations of Si-based electrodes using coin cells and ex-situ three-electrode cells. A comparison of electrochemical testing methods – i.e., Galvanostatic Intermittent Titration Technique (GITT) and Intermittent Current Interruption (ICI) – was performed to assess lithium-ion diffusion kinetics within Si anodes. The ICI method showed a significant time-saving advantage while providing diffusion coefficient estimates that aligned with GITT results in trend. Moreover, differential capacity (dQ/dV) analysis revealed similar oxidation-redox patterns across coin and three-electrode systems, suggesting that the impedance mostly comes from the electrode material rather than other factors such as the lithium metal counter electrode, etc. Additionally, poly (methacrylic acid) (PMAA) was studied as a binder for its surface adhesion, self-healing, and conductive properties. This work offers insights into the performance-limiting factors and Li+ diffusion coefficient determination techniques for Si-based anodes, supporting the development of optimized electrode designs and characterization strategies for next-generation LIBs.

Rights

© 2025, Najmaddin Bashirzada

Download

Share

COinS