The Library
Investigating the effects of mechanical events on electrochemical properties of Li-ion batteries
Tools
Khah, Nasrin Shahed (2018) Investigating the effects of mechanical events on electrochemical properties of Li-ion batteries. PhD thesis, University of Warwick.
|
PDF
WRAP_Theses_Khan_2018.pdf - Submitted Version - Requires a PDF viewer. Download (105Mb) | Preview |
Official URL: http://webcat.warwick.ac.uk/record=b3228230~S15
Abstract
This study explored the effects of mechanical loads on Li-ion pouch cells by considering their operation under laboratory conditions. The focus of the research conducted was exploratory in nature with the aim of developing advanced experimental methods and techniques to answer a specific research question motivating this work: \Do mechanical events influence the electrochemical performance of Li-ion batteries?". In order to address this research question, the following goals were targeted: 1) study the effects of high g impacts on the cell performance and investigate the extent of cell damage under such an event, 2) examine the influence of mechanical bending loads on cells and ageing effects introduced on the cell performance.
In the context of studying the effects of high g pulses and mechanical bending load on the electrochemical performance of Li-ion batteries, a comprehensive analysis of the internal impedance and capacity measurements was undertaken. Throughout the entire study, none of the analyses established any signs of statistically significant relationships between the specified electrochemical parameters. This study therefore finds that high g pulses and external mechanical bending load have no adverse influences on the electrochemical characteristics of Li-ion batteries in use, within the bounds of the investigation, as no evidence of electrochemical performance degradation by the effects of such events were substantiated.
The study examined the influence of charge/discharge cycles on the load relaxation characteristics of a cell retained under bending deformation, by quantifying its structural evolution prior to and post electrochemical cycling using X-ray CT. It was ascertained that a cell subjected to a constant bending deformation during electrochemical cycling experienced a healing effect, owing to its viscoelastic properties and volume expansion of the electrodes during charging and discharging.
The work shows tantalising evidence that external mechanical load on a cell may provide possibilities to improve its electrochemical characteristics. It is recommended that this phenomena is investigated further.
Item Type: | Thesis (PhD) | ||||
---|---|---|---|---|---|
Subjects: | T Technology > TK Electrical engineering. Electronics Nuclear engineering | ||||
Library of Congress Subject Headings (LCSH): | Lithium ion batteries, Electrochemical analysis, Lithium cells, Viscoelasticity | ||||
Official Date: | 15 June 2018 | ||||
Dates: |
|
||||
Institution: | University of Warwick | ||||
Theses Department: | Warwick Manufacturing Group | ||||
Thesis Type: | PhD | ||||
Publication Status: | Unpublished | ||||
Supervisor(s)/Advisor: | Dashwood, R. J. ; Offer, Greg, 1978- | ||||
Sponsors: | Jaguar Land Rover (Firm) | ||||
Extent: | xvii, 158 leaves : illustrations, charts | ||||
Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year