Computational Approaches of Electrochemistry: Insights into Electrical Double Layers of Concentrated Aqueous Electrolytes and Ionic Liquids

The electrical double layer (EDL) is a fundamental structure of oppositely charged layers formed at the interface of an electrolyte and electrode. It plays a crucial role in electrochemistry by dynamically changing its structure in response to applied voltages, thereby influencing charge and electron transfer processes crucial for both electrocatalysis and electrosynthesis. Moreover, the charge response of EDLs directly determines the energy storage capabilities of batteries and supercapacitors. This thesis focuses on exploring various aspects of EDLs for concentrated electrolytes employing computational methods. The overarching goal is to provide a comprehensive understanding of EDLs for concentrated electrolytes. It becomes apparent that the behavior of EDLs in confined systems, particularly for ionic liquids, diverges significantly from that in aqueous and organic solvents. We systematically evaluate the relation between electrostatic screening, and the structure and dynamics of ionic liquids in confined systems. This evaluation holds significant importance as it substantially enhances our fundamental understanding of electrochemical supercapacitors. Additionally, differential capacitance is a characteristic measurement to probe the structure of electrochemical interfaces in response to an external voltage. Nonetheless, developing a general understanding of EDLs capacitance behavior is challenging due to the diverse range of electrochemical interfaces encountered in modern applications and technologies. We present a comprehensive exploration of the capacitance behavior of concentrated aqueous electrolytes and ionic liquids by characterizing the capacitance profiles of different electrochemical interfaces. Furthermore, we propose and demonstrate a novel model that describes the capacitance profiles for concentrated aqueous electrolytes and ionic liquids. Through these explorations using molecular dynamics simulations, this thesis strides in enhancing our understanding of EDL behavior for concentrated aqueous electrolytes and ionic liquids.

Level thesis:degree_level

Doctoral

Department dc:contributor.department

Chemistry and Biochemistry

Grantor dc:publisher

Georgia Institute of Technology

Year dc:date.issued

2023

Author dc:creator

• Park, Suehyun

Advisor dc:contributor.advisor

• McDaniel, Jesse

Committee members dc:contributor.committeemember

• Sherrill, David
• Kretchmer, Joshua
• Cicerone, Marcus
• Gumbart, James C.

• Electrical double layer
• Aqueous solutions
• Ionic liquids
• Interface
• Interfacial property
• Capacitance
• Confinement effect
• Electrochemistry
• Molecular Dynamics Simulations
• Computational Chemistry

Handle dc:identifier.uri

https://hdl.handle.net/1853/75612

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/75612