March 21
@
4:00 PM
–
5:00 PM
Rachel Segalman
Edward Noble Kramer Professor
Department Chair – NAE
University of California, Santa Barbara
Santa Barbara, CA
Prof. Segalman is CBE’s 2023 Bird Stewart Lightfoot Lecturer
Please join us for a reception from 3:30 – 4:00 pm in the Cheney Room prior to the lecture.
Charge-neutral Polymer Complexes as Battery Components
Polymeric components impart inherent mechanical durability of electrochemical devices and decreased flammability to electrochemical devices, but must have higher performance metrics in order to gain widespread use. This is a particular challenge as long-range Li-ion transport is generally directly related to matrix dynamics and is ultimately limited by the sluggish dynamics of polymers. In this talk, I will discuss superionic conductivity in which the ion motion is decoupled from matrix dynamics and instead occurs through free volume elements in the structure. Semi-crystalline zwitterionic polymers appear both to demonstrate superionic conductivity and also very high salt solubilities due to their polarizability. As a result, they have both high Lithium ion conductivities (10-3 S/cm) and cation transport numbers (t+=0.67) despite their modest glass transition temperatures (0-25°C). I will also discuss new coacervate-based battery binders that demonstrate both high ion and electron conductivities and their use to in composite electrodes compatible with polymer electrolytes.
