Combining electroanalysis and nanoscale characterization to understand battery electrolytes
Abstract/Contents
- Abstract
- Development of batteries with higher energy density than conventional Li-ion batteries can facilitate electrification of passenger vehicles, aeronautics, and long-range transportation. Metallic lithium is the ideal anode for maximizing energy density, but insufficient rechargeability limits its widespread adoption. The reactivity of Li with electrolytes and growth of filamentary "dendritic" Li morphologies during charging underly its poor rechargeability. Electrolyte engineering can simply and effectively mitigate these problems; however, the mechanistic basis for the dependence of Li passivation and morphology on electrolyte chemistry remains poorly understood. In this dissertation, I discuss how it is now possible to understand the complex multiscale relationship between electrolyte chemistry and rechargeability by using the complementary strengths of electroanalysis and cryogenic transmission electron microscopy. First, I discuss the electrochemical and structural evolution of a passivation film on Li called the solid electrolyte interphase (SEI) in select electrolytes. The results refine our understanding of SEI structure and growth and suggest control of electroplated Li morphology is key to prevent corrosion of Li during calendar aging. Next, I will discuss the current and electrolyte dependence of Li plating pathways and kinetics to reveal the main factors controlling Li morphology. The results first show that fracture of the SEI and exposure of fresh Li-electrolyte interfaces -- as opposed to mass transport limitations alone -- are responsible for dendritic Li plating during fast charging. I then discuss a new electroanalytical method using ultramicroelectrodes that can probe the charge-transfer kinetics at fresh Li-electrolyte interfaces after SEI fracture. The kinetics deviate from classical Butler-Volmer models and provide insight into how solvation and interfacial structure tune reaction rates in batteries. Correlating the kinetics in many electrolytes to rechargeability suggests that the equilibrium potential of Li/Li+ redox and surface energy -- thermodynamic factors modulated by the strength of Li+ solvation -- underly trends of Li morphology across distinct classes of electrolyte.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Boyle, David Thomas |
|---|---|
| Degree supervisor | Cui, Yi, 1976- |
| Thesis advisor | Cui, Yi, 1976- |
| Thesis advisor | Chidsey, Christopher E. D. (Christopher Elisha Dunn) |
| Thesis advisor | Kanan, Matthew William, 1978- |
| Degree committee member | Chidsey, Christopher E. D. (Christopher Elisha Dunn) |
| Degree committee member | Kanan, Matthew William, 1978- |
| Associated with | Stanford University, Department of Chemistry |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | David Boyle. |
|---|---|
| Note | Submitted to the Department of Chemistry. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/wd719vj4331 |
Access conditions
- Copyright
- © 2022 by David Thomas Boyle
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...