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

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

Hui, Jingshu

关键词: Electrochemistry;    Energy storage materials;    Graphene;    Redox-active polymers;    Scanning electrochemical microscopy;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/99451/HUI-DISSERTATION-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

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.