Semester

Summer

Date of Graduation

2020

Document Type

Dissertation

Degree Type

PhD

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Xingbo Liu

Committee Member

Harry Finklea

Committee Member

Kostas Sierros

Committee Member

Terence Musho

Committee Member

Wenyuan Li

Abstract

Lithium-sulfur battery is considered to be one of the most promising contenders for the next generation high-energy storages due to their high theoretical energy density (~2600 W h kg-1). However, a series of issues, especially for the dissolution of lithium polysulfides (LiPSs) with their “shuttle effect” and dendrite formation on the lithium anode, greatly limit their widely commercial applications. Starting from a brief overview of conventional methods to solve these problems, the achievements spotlighted in this research work mainly focus on the structure design of cathode materials by employing “chemical anchors” to effectively suppress the diffusion of LiPSs, as well as the Li anode modification to suppress the dendrite formation, thus the electrochemical performance of Li-S batteries can be comprehensively improved. The synthetic methods, characterization techniques with electrochemical performance are presented. Further work plans and implications are proposed regarding optimize the structure of materials, preparation technology, and to better understand the role of these “chemical anchors” and the protection mechanism of Li anode. Proposing with some perspectives and future research efforts, this research is hoped to provide an in-depth understanding and offer avenues in the rational design of Li-S batteries with long cycle life and high energy/power density in the near future.

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