The innovation engine for new materials

Kareem Asham

Kareem Asham

Major: 

Chemistry and Biochemistry

University: 

California State University, Long Beach

Mentor(s): 

Gordon Pace

Faculty Sponsor(s): 

Rachel Segalman

Faculty Sponsor's Department(s): 

Chemical Engineering

Project Title: 

Design and Analysis of Mixed Ion and Electron Conducting Polymers

Project Description: 

Polymeric battery binders are an integral part of cathodes’ composition but currently only serve as a glue between active material, conductive additive, and current collector while inadvertently adding a resistive barrier, straining the performance of the battery. A recently developed class of materials, mixed ion and electron conducting (MIEC) polymers, serve to address this issue by providing the necessary adhesive properties, while simultaneously removing the resistive barrier. In this study, we examine two model MIEC polymers with the goal of elucidating two distinct ion transport mechanisms. Electrochemical impedance spectroscopy (EIS) was deployed to measure the conductivity of both ions and electrons in the polymers as a function of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) addition, which was chosen due to its relevance to Li ion batteries . Preliminary data show that polythiophenes with charged side chains, such as P3HT Im+ , exhibit higher conductivity than that of the alkyl and glycol substituted equivalents,  P3HT and P3MEEMT. This shows that side chain chemistry is an effective tuning point for functionalized battery binders.