Capacitance of thin films containing polymerized ionic liquids

Kumar, Rajeev; Mahalik, Jyoti P.; Silmore, Kevin S.; Wojnarowska, Zaneta; Erwin, Andrew J.; Ankner, John Francis; Sokolov, Alexei P.; Sumpter, Bobby; Bocharova, Vera

doi:10.1126/sciadv.aba7952

DOE OSTI · 1649210

Capacitance of thin films containing polymerized ionic liquids

Kumar, Rajeev·Mahalik, Jyoti P.·Silmore, Kevin S.·Wojnarowska, Zaneta·Erwin, Andrew J.·Ankner, John Francis·Sokolov, Alexei P.·Sumpter, Bobby·Bocharova, Vera

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Abstract

Electrode-polymer interfaces dictate many of the properties of thin films such as capacitance, the electric field experienced by polymers, and charge transport. However, structure and dynamics of charged polymers near electrodes remain poorly understood, especially in the high concentration limit representative of the melts. To develop an understanding of electric field–induced transformations of electrode-polymer interfaces, we have studied electrified interfaces of an imidazolium-based polymerized ionic liquid (PolyIL) using combinations of broadband dielectric spectroscopy, specular neutron reflectivity, and simulations based on the Rayleigh’s dissipation function formalism. Overall, we obtained the camel-shaped dependence of the capacitance on applied voltage, which originated from the responses of an adsorbed polymer layer to applied voltages. This work provides additional insights related to the effects of molecular weight in affecting structure and properties of electrode-polymer interfaces, which are essential for designing next-generation energy storage and harvesting devices.

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Kumar, Rajeev, Mahalik, Jyoti P., Silmore, Kevin S., Wojnarowska, Zaneta, Erwin, Andrew J., Ankner, John Francis, Sokolov, Alexei P., Sumpter, Bobby, Bocharova, Vera. 2020-06-26. Capacitance of thin films containing polymerized ionic liquids. https://doi.org/10.1126/sciadv.aba7952

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