Electrochemical mechanisms in nano-structured graphitic and redox-active polymeric architectures

Hui, Jingshu

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https://hdl.handle.net/2142/99451 Copy

Description

Title

Electrochemical mechanisms in nano-structured graphitic and redox-active polymeric architectures

Author(s)

Hui, Jingshu

Issue Date

2017-08-14

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

Rodríguez-López, Joaquín

Doctoral Committee Chair(s)

Dillon, Shen J.

Committee Member(s)

• Braun, Paul V.
• Cheng, Jianjun

Department of Study

Materials Science & Engineerng

Discipline

Materials Science & Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Electrochemistry
• Energy storage materials
• Graphene
• Redox-active polymers
• Scanning electrochemical microscopy

Abstract

One of the greatest challenges for our modern society is developing efficient and low-cost electrochemical energy storage and conversion systems for stationary and transportation applications. Understanding the detailed electrochemical mechanisms in energy-related materials with new designs and modification methods will help us break the ceiling of current existing systems. The goal of my Ph.D. is to combine the power of versatile electrochemistry techniques and materials with diversified architecture, and explore various mechanisms of different nano-structured energy storage and conversion materials. The first part of this dissertation explores the application of ultra-thin graphene as an electronically transparent and physically impermeable interface. Outer-sphere reactions on metal substrate-modulated graphene prove the electronic transparency of the graphene interface. Inner-sphere oxygen reduction reaction activity changes demonstrate the electronic coupling between metal substrates and molecular adlayers above graphene. This work provides new strategies for systematically tuning the electrocatalytic reactivity using hybridized electrocatalyst structures. The second part of this dissertation utilizes few layer graphene as an ultra-thin bulk material that can reversibly intercalate alkali ions. The finite thickness of graphene leads to layer number-controlled Li-ion intercalation behavior. Passivating the few layer graphene surface can selectively facilitate stable K-ion intercalation while suppressing the K plating reaction. The last part of this dissertation introduces redox-active polymers and advanced redox-active colloids as electrochemical energy storage carriers, which have shown facile charge transfer kinetics and good charge storage ability. Combining these macromolecular electrolytes with size-exclusion porous membranes provides a potential solution to current ionic conductivity restriction in non-aqueous redox flow batteries.

Graduation Semester

2017-12

Type of Resource

text

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Copyright and License Information

Copyright 2017 Jingshu Hui

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