Direct Observation of Ion Dynamics in Supercapacitors

• Applicant: Dr. Henry Reynolds Nana Benyin Enninful
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: from 2022 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 514614917

Electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, complement or replace batteries for electrical energy storage and harvesting applications. They are electrochemical energy storage devices having energy densities higher than plate capacitors but lower than batteries. On the other hand, ECs possess power densities substantially higher than batteries. To optimize energy and power performance of ECs, the influence of electrode and/or electrolyte properties need to be understood from its fundamentals. The main objective of this work is to provide in-depth understanding of ion dynamics for supercapacitor applications. It seeks to unravel suitable conditions for precise control over power and energy densities. To meet this objective, direct observation of the behavior of charge transport and molecular diffusion under an applied voltage in various pore environments will be probed. This will help reveal the mechanisms responsible for charging and discharging in the various supercapacitor systems and inform further tuning and optimization for efficient devices. Particularly, the project seeks to(i) Understand the impact of particle size on ion dynamics in supercapacitors.(ii) Investigate the influence of pore heterogeneity on charge dynamics.From these objectives, more light will be shed on the limiting step to efficient ion storage and charging and discharging in the various electrode confinements.

• DFG Programme: WBP Position