(3be) Polymer Electrolytes for Energy and Water Technologies | AIChE

(3be) Polymer Electrolytes for Energy and Water Technologies


Hallinan, D. T. Jr. - Presenter, University of California, Berkeley

Fundamental investigations on polymer electrolytes require understanding the electrochemical driving forces associated with ions in polymers. Electrode interfaces are an essential part of any electrochemical system. As such, interactions between polymers and electrodes (inorganics) are relevant. A key part of my faculty research will therefore focus on polymer-inorganic composites for energy technologies. For example, in battery electrodes a polymer electrolyte can serve multiple functions as not only the ion conductor but also the binder of the active inorganic material. It can mitigate otherwise detrimental volume changes of the active material and improve safety by removing the need for flammable solvents of liquid electrolyte. However, side-reactions between the polymer and inorganic components can degrade battery performance. In order to develop compatible polymer-inorganic systems, the interactions between the two must be better understood. Molecular scale techniques such as infrared and Raman spectroscopies, nanoscale techniques such as hard and soft x-ray scattering and electron imaging, and interface sensitive techniques such as reflection mode scattering and X-ray Photoelectron Spectroscopy will prove useful for studying polymer-inorganic interactions. My postdoctoral experience has provided access to several sophisticated x-ray techniques at Lawrence Berkeley National Laboratory.

In addition to interfacial effects in electrochemical systems, ion transport through the bulk polymer electrolyte can be important. The interplay among cations, anions, and polymer functional groups affects ionic conductivity and, thereby, device performance. In situ electrochemical techniques, for example with reflection infrared spectroscopy, are needed to probe both the thermodynamic interactions in polymer electrolytes and the ion transport, as well as polymer mobility. My extensive work with infrared spectroscopy during my PhD combined with development of in situ electrochemical techniques during my post doctoral fellowship, will provide a solid foundation for developing such techniques as a faculty member.

Ion transport in polymer electrolytes is also relevant for water desalination. As I have extensive experience studying water in polymers, I would like to develop a project for membrane purification and desalination of water. Access to clean, fresh water is an important human need that requires a low-energy solution. I expect research funding in this field to grow in the coming years.