Date of Award

Spring 1-1-2016

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Civil, Environmental & Architectural Engineering

First Advisor

Kurt Maute

Abstract

The rapid development of new technologies in recent decades has caused an ever increasing demand for energy storage devices that are lightweight, durable, and maintain high life-cycle expectancies. Lithium-ion batteries have emerged as a universal solution due to their exceptional energy storage and high power delivery. Lithium-ion batteries based on organic electrolytes suffer from safety concerns; specifically flammability, low temperature thresholds, and coupled electrochemical-mechanical degradation. From a design perspective, introducing a new type of lithium-ion battery with enhanced storage capacity, safe and reliable performance is the most ongoing challenge in battery research communities.

This research focuses on the numerical modeling of electrochemical and mechanical interactions in all solid-state lithium-ion batteries. In particular, we present physical and numerical modeling frameworks to model and understand the electrochemical and mechanical performance of all solid-state lithium-ion batteries under the influence of some electrochemical and mechanical degradation phenomena. To this end, we developed finite element modeling frameworks based on multi-scale and full resolution modeling methods. These models facilitate detailed understandings and comprehensive studies of the behavior of lithium-ion batteries under the evolution of degradation phenomena. While our model is not limited to any particular battery system and failure mechanism, we focus on the evaluation of the electrochemical performance of both thin and bulk solid-state lithium-ion batteries, stress-diffusion-damage coupling effects in the electrode active materials and interfacial debonding effects in the battery cell. The involved coupled physical phenomena includes mechanical deformation, diffusion-migration processes, stress-diffusion-damage coupling, electrochemical surface reactions, and cohesive zone model. To provide a predictive numerical tool for optimizing the performance of battery cell, our finite element model is augmented with a parameter identification method. The parameter identification method provides unique opportunities for parametric study and identifying key design parameters in the life-time performance of all solid-state lithium-ion batteries.

The characteristics of the research are explored by presenting comprehensive numerical examples. The presented numerical examples illustrate the performance of the battery cell under the influence of different physical phenomena. We verified and calibrated the accuracy and stability of the developed framework by numerical and experimental examples. The parameter identification method is applied for parametric study and error minimization in the battery. The results revealed the great influence of material properties and geometric configuration on the electrochemical performance of the battery cell. The influence of damage evolution on the mechanical and electrochemical performance of the battery is explored by numerical examples. The results showed that diffusion-damage coupling has significant influences on the life-time performance of the battery cell. The results of cohesive zone modeling revealed the main contribution of the interface properties on the separation and the debonding phenomena at the interface of multi-phase material.

Available for download on Sunday, September 27, 2020

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