Derivatives of the aromatic molecule phenothiazine have been used in batteries due to their ability to form the corresponding radical with minimal degradation, allowing them to redirect excess energy and prevent overcharge.  This project aimed to find more efficient molecules for use as overcharge protectors in batteries.  Specifically, oxidation potential, determined via cyclic voltammetry, was used to identify derivatives that could be used for higher end-of-charge potential cathodes, and the reversibility of the oxidation was examined.  Derivatives of phenothiazine were synthesized in which alternate groups were substituted for the hydrogen molecules at junctions two and seven, as were molecules with 2,7-cyano groups but alternate base compounds.  More broadly, the x-ray crystal structure was determined for each molecule to determine relative planarity in the hopes of discovering a relationship between planarity and efficiency.  This experiment provides a basis for determining the accuracy of planarity as an indicator of a compound's effectiveness as an overcharge protector; results may also suggest the most efficient base molecules to serve as said additives.

Fused aromatic heterocycles for overcharge protection in lithium-ion batteries

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.