Superconcentrated ELectrolytes For Interfacial Electrochemistry – SELFIE

How much energy can I store in a device? How fast can it be charged? These two questions are at the heart of the research on electricity storage. We will mainly focus on the emerging family of supercapacitors which accumulate electricity through reversible ion adsorption inside porous carbon electrode. The objective of this project is to propose a molecular-scale description of the interfacial adsorption and electron transfer mechanisms for superconcentrated electrolytes. This will be done by molecular simulations, and we will investigate the following key aspects:

i) We will determine whether it is possible to boost the capacitance of supercapacitors by adsorbing multivalent inorganic ions in ultra-narrow pores. Testing this hypothesis is to date difficult in experiments, while simulations are able to provide new guidelines for optimizing the electrolyte compositions. We will explore superconcentrated electrolytes consisting of mixtures of ionic liquids with organic solvents at various ratios.

ii) We will investigate electron transfer at the electrolyte/electrode interface. Despite its paramount importance in many electrochemical processes, this area of research has not been investigated up to now at the molecular scale. In the case of supercapacitors, emerging concepts propose increasing the energy density by including redox active species in the electrolyte. In nanopores, the modified solvation structures can strongly impact on electron transfer rates. It is thus necessary to quantify how fast such devices can be charged for practical applications.

Addressing these points would enhance our knowledge of supercapacitors, but also of the more fundamental issue of ions and redox reactions at electrochemical interfaces.