MasterNanosciences, nanotechnologies

Ionic liquids (ILs) are pure salts that are liquid under room temperature-pressure conditions. These electrolytes exhibit exceptional stability (low volatility, nonflammability, wide electrochemical windows, etc.), which makes them very promising systems for a range of applications, including energy storage (batteries, supercapacitors). In such a device, an electrolyte is put into contact with nanoporous electrodes, and is therefore confined at the nanometric scale between charged surfaces. That is why the behaviour of ionic liquids in nanoconfinement has been the focus of intense study during the last decade.

Nanoporous electrodes are generally used in order to maximize the energy density that can be stored; however, this can also be detrimental to the power density that can be delivered. To optimize these energy storage devices, it is thus important to understand not only the electrostatic interactions, but also the hydrodynamic flows in nanoconfined ionic liquids. This is particularly challenging, as common theoretical descriptions, i.e. Poisson-Boltzmann theory and classical hydrodynamics equations, cannot a priori be applied to such highly concentrated electrolytes.

In this seminar, I will show how these questions can be answered experimentally, with a Surface Force Apparatus. This instrument is indeed a tool of choice to measure the interactions across nanoconfined ionic liquids, and to disentangle the equilibrium and dynamic contributions to these interactions.