Design of Polymer Electrolytes with Superionic Ion Transport

ChE Seminar Series Presents:

Rachel A. Segalman, PhD.

Department Chair, Chemical Engineering, University of California, Santa Barbara

Abstract:

Progress toward durable, high-energy density lithium-ion batteries has been hindered by instabilities at electrolyte-electrode interfaces leading to poor cycling stability, and by safety concerns associated with energy-dense lithium metal anodes. Solid polymeric electrolytes (SPEs) can help mitigate these issues, however SPE conductivity is limited by sluggish polymer segmental dynamics. Transport through the free volume of ordered, superionically conductive domains results in decoupling of ion motion and polymer segmental dynamics. Although crystalline domains are conventionally detrimental to ion conduction in SPEs, we demonstrate that semicrystalline polymer electrolytes with labile ion-ion interactions and tailored ion sizes exhibit excellent lithium conductivity (1.6 mS/cm) and selectivity (t+~0.6-0.8). This allows for simultaneous optimization of typically orthogonal properties including conductivity, Li-selectivity, mechanics, and processability.

Bio:

Rachel A. Segalman received her B.S. from the University of Texas at Austin and Ph.D from the University of California, Santa Barbara. She was a postdoctoral fellow at the Université Louis Pasteur before joining the faculty of UC Berkeley and Lawrence Berkeley National Laboratories from 2004-2014.  During a portion of this time she also served as the Materials Science Division Director at Lawrence Berkeley National Laboratories. In 2014, she moved to UC Santa Barbara to be the Kramer Professor of Chemical Engineering and Materials and became Department Chair of Chemical Engineering in 2015. In 2018 she also became the Schlinger Distinguished Chair of Chemical Engineering and the Associate Director of the UT/UCSB/LBL EFRC: Center for Materials for Water and Energy Systems.  She is the co-editor of the Annual Reviews of Chemical and Biomolecular Engineering and an associate editor of ACS Macro Letters.  Segalman’s group works on controlling the structure and thermodynamics of functional polymers for energy applications including polymeric ionic liquids and semiconducting and bioinspired polymers.  Among other awards, Segalman received the Journal of Polymer Science Innovation Award, the Dillon Medal from the American Physical Society, the Presidential Early Career Award in Science and Engineering, is an Alfred P. Sloan Fellow and a Camille Dreyfus Teacher Scholar. She is also a Fellow of the American Physical Society and was elected to the American Academy of Arts and Sciences and the National Academy of Engineering.

Please contact a.ramsey@northeastern.edu for the remote link.