Electron Transfer in Self-Assembled Micelles Built by Conductive Polyoxometalate-Surfactants Showing Battery-Like Behavior

An ideal material for the storage of electrical energy is characterized by high specific energy and high specific power at the same time, which is a task of enormous difficulty. The so-called redox flow battery is a highly promising approach. This new energy storage technology is based on two half-cells containing dissolved electrochemically active species. Compared to conventional, static accumulators it is not only engineered in a unique way but also needs a tailor-made basis of chemical materials. Therefore, many different redox-active materials are being investigated. However, research is focused mainly on the redox properties, not taking possible synergistic effects arising from self-assembled structures into account. Here, a novel surfactant is presented containing an electroactive polyoxometalate (POM) head connected to anthraquinone (AQ) as the relevant electron reservoir via a pi-conjugated chain. When organized into micelles, electrons put on the POM corona "slide" into their depot inside the micellar core until needed. Cyclic voltammetry proves the high reversibility and stability of this system, which therefore can be regarded as micellar energy storage.