Quantification of ion confinement and desolvation in nanoporous carbon supercapacitors with modelling and in situ X-ray scattering

Autor(en)

C. Prehal, C. Koczwara, N. Jaeckel, A. Schreiber, M. Burian, H. Amenitsch, M. A. Hartmann, V. Presser, O. Paris

Abstrakt

A detailed understanding of confinement and desolvation of ions in electrically charged carbon nanopores is the key to enable advanced electrochemical energy storage and water treatment technologies. Here, we present the synergistic combination of experimental data from in situ small-angle X-ray scattering with Monte Carlo simulations of length-scale-dependent ion arrangement. In our approach, the simulations are based on the actual carbon nanopore structure and the global ion concentrations in the electrodes, both obtained from experiments. A combination of measured and simulated scattering data provides compelling evidence of partial desolvation of Cs+ and Cl- ions in water even in mixed micro-mesoporous carbons with average pore size well above 1 nm. A tight attachment of the aqueous solvation shell effectively prevents complete desolvation in carbons with subnanometre average pore size. The tendency of counter-ions to change their local environment towards high confinement with increasing voltage determines conclusively the performance of supercapacitor electrodes.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Montanuniversität Leoben, Leibniz-Institut für Neue Materialien, Universität des Saarlandes, Technische Universität Graz

Journal

Nature Energy

Band

2

Anzahl der Seiten

8

ISSN

2058-7546

DOI

https://doi.org/10.1038/nenergy.2016.215

Publikationsdatum

03-2017

Peer-reviewed

Ja

ÖFOS 2012

104005 Elektrochemie, 103018 Materialphysik, 103029 Statistische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Energy Engineering and Power Technology, Fuel Technology, Renewable Energy, Sustainability and the Environment

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/992500bf-091e-497e-8878-b0a24c846052