Many organic heterocyclic compounds undergo reversible one-electron electrochemical oxidation. However, in order to function effectively as redox shuttles in lithium batteries, such materials must display such behavior at potentials exceeding 4.2 V vs Li/Li⁺, and designing compounds that meet this requirement yet remain stable in the cation radical form represents a significant challenge. We have developed two families of organic heterocycles suitable for battery applications; namely appropriately substituted carbazoles and phenothiazine 5,5-dioxides.

We will describe the synthesis and characterization of these compounds, along with preliminary results of testing in lithium ion batteries and redox flow batteries.