Indiana University-Purdue University Indianapolis (IUPUI) / Recent innovations in portable electronics, electric vehicles and power generation
by wind and solar have expanded the need for effcient battery storage. Lithium-ion
batteries have been the frontline contender of battery storage yet are not able to
match current demands. Alternatively, lithium-sulfur batteries are a promising technology
to match the consumer demands. Elemental sulfur cathodes incur a variety
of problems during cycling including the dissolution of intermediate lithium polysul-
fides, an undesirable volume change (~ 80%) when completely reduced and a high
dependence on liquid electrolyte, which quickly degrades the cell's available energy
density. Due to these problems, the high theoretical capacity and energy density of
lithium sulfur cells are unattainable. In this work, A new class of phenyl polysul-
fides, C6H5SxC6H5(4 < x <6), are developed as liquid sulfur containing cathode
materials. This technology was taken a step further to fulfill and emerging need
for
exible electronics in technology. Phenyl tetrasulfide (C6H5S4C6H5) was polymerized
to form a high energy density battery with acute mobility. Lithium half-cell
testing shows that phenyl hexasulfide (C6H5S6C6H5) can provide a specific capacity of
650mAh/g and capacity retention of 80% through 500 cycles at 1C rate along with
superlative performance up to 10C. Furthermore, 1, 302W h/ kg and 1, 720W h/L
are achievable at a low electrolyte/active material ratio. Electrochemical testing of
polymer phenyl tetrasulfide reveals high specific capacities of 634mAh /g at 1C,
while reaching 600mAh /g upon mechanical strain testing. This work introduces
novel cathode materials for lithium-sulfur batteries and provides a new direction for
the development of alternative high-capacity
flexible cathode materials.
| Identifer | oai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/15954 |
| Date | 05 1900 |
| Creators | Bell, Michaela Elaine |
| Contributors | Fu, Yongzhu |
| Source Sets | Indiana University-Purdue University Indianapolis |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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