Year

2020

Degree Name

Doctor of Philosophy

Department

Institute for Superconducting & Electronic Materials

Abstract

For the past few decades, lithium-based batteries have played a crucial role in facilitating more rapid growth of portable electric devices and electric vehicle markets, because of their fascinating higher energy density and operating voltage than those of previous secondary batteries. However, in recent years, the development of lithium-based batteries is beyond increasing demands for energy storage devices due to the difficulties in further progress with the current transition metal oxides-graphite system. To resolve this issue, the exploration of new advanced materials is required to achieve a major breakthrough as well as, to change to next generation lithium batteries.

From the point of view of anode materials, both silicon (Si) and lithium (Li)-metal are regarded as the two most promising alternatives to replace the graphite anode due to their substantially high theoretical capacities (3590 mAh g-1 for Si and 3860 mAh g-1 for Li-metal). Thus, many researchers have endeavoured to explore these two candidates for achieving “beyond graphite”. However, applying Si and Li-metal into their practical applications as anodes has still many hurdles to clear to each of them. Firstly, Si-based anodes suffer from poor cycling performance and dimensional instability induced by large volume changes during cycling. To resolve such problems, for example, nanostructured Si-based materials with delicately controlled microstructure and interfaces should be intensively investigated. Secondly, repeated Li plating/stripping during Li-metal anode cell operation forms dendritic Li and irreversible Li (dead-Li), leading to internal short-circuit and capacity fading. To resolve such problems, for example, strategically designed host structure for stable Li-metal storage should be suitably introduced.

FoR codes (2008)

0912 MATERIALS ENGINEERING, 0904 CHEMICAL ENGINEERING, 0303 MACROMOLECULAR AND MATERIALS CHEMISTRY, 1007 NANOTECHNOLOGY

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Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.