Access Type

Open Access Embargo

Date of Award

January 2016

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Mechanical Engineering

First Advisor

leela Arava

Abstract

With massive commercial success of lithium ion batteries, the ability to operate at

and above 70 °C still a crucial issue and a safety concern to combat ever-increasing

global warming and to extend applications beyond portable electronics. Among various

components of battery, anode and electrolyte and the passivation layer formed between

them is crucial towards the development of Li-ion batteries for extendable temperature

range. In this regard, room temperature ionic liquids (RTILs) have the capability to

tackle thermal stability issues of lithium ion batteries but their poor compatibility with

traditional graphite anodes limits their practical application. Towards addressing this

issue, we explore the feasibility of engineered three-dimensional Si (3D Si) anodes inconjunction

with modified RTIL as an electrolyte and their electrochemical performance

up to 150 °C. Detailed electrochemical studies such as electrochemical stability, ionic

conductivity, specific capacity, rate capability, and coulombic efficiency reveal that 3D

Si anode and RTIL combinations are thermally stable for high temperature rechargeable

battery applications. Further, silicon electrode in full cell configuration has been demonstrated in associated with LiFePO4/C cathode to develop next generation Li-ion

batteries with enhanced safety and thermal stability. Interaction between electrode and

electrolyte has been evaluated by conducting X-ray photoelectron spectroscopy and

electron microscopy studies at various electrochemical conditions.

Available for download on Thursday, December 14, 2017

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