In situ investigation of electrochemical surface stress development in rechargeable batteries

Seo, Yeong-Hui

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https://hdl.handle.net/2142/102503 Copy

Description

Title

In situ investigation of electrochemical surface stress development in rechargeable batteries

Author(s)

Seo, Yeong-Hui

Issue Date

2018-12-10

Director of Research (if dissertation) or Advisor (if thesis)

Gewirth, Andrew A.

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• rechargeable batteries
• lithium
• sodium
• electrochemical surface stress

Abstract

Rechargeable batteries are everywhere these days such as portable electric devices and electric vehicles. The global annual sales of electric vehicles are increasing, showing the rechargeable battery market is obviously getting bigger. Li-ion batteries are operated by an intercalation mechanism. Lithium ions shuttle reversibly between the cathode and anode during charging and discharging. Typically, intercalation cathodes deliver around one hundred to two hundred in specific capacity. The operating voltage is around three to five vs. lithium. The current inorganic-compound cathodes have several challenges such as limited reserves and harmfulness to the environment due to the toxic materials released from current inorganic complexes. In contrast to the harmful current cathodes, organic cathode materials enable access to metal-free, environmentally benign rechargeable energy systems. Poly (1,4-anthraquinone) (PAQ) was chosen as the cathode material for this research based on its high capacity and superstable cycle life. The reduction occurs as two reversible, continuous single-electron steps. PAQ was applied to the cathode vs. lithium and sodium. There are two types of stress evolutions arising from lithiation/sodiation and delithiation/desodiation. Accommodating metal ion process makes compressive stress whereas stripping metal ion process makes tensile stress. These two types of stress evolution was measured by employing in situ electrochemical stress measurement. Through the measurement, electrochemical property was analyzed thoroughly parallel with the change of stress and stress derivative. Obviously different behaviors of PAQ-composite cathode depend on lithium and sodium were analyzed.

Graduation Semester

2018-12

Type of Resource

text

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http://hdl.handle.net/2142/102503

Copyright and License Information

Copyright 2018 Yeong-Hui Seo

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