Ambipolar molecules for non-aqueous redox flow batteries

Summary

Implementation of intermittent renewable energy sources in the energy grid will require the use of large-scale energy storage to mitigate the discrepancies between energy production and demand. Non-aqueous organic redox flow batteries from abundant all-carbon based materials can provide a sustainable solution. Flow batteries decouple storage capacity from power output, allowing for independently scalable, cheap and massive energy storage. However, current technology has not reached a mature enough level and many scientific questions still need to be answered. Specifically, new active materials need to be developed that simultaneously deliver high cell voltages and energy density in combination with good cyclability and stability. Here the development of a new class of molecules is proposed that is expected to meet these requirements, advancing the state-of-the-art of this technology. This will be achieved by a unique interdisciplinary approach, combining organic synthesis, electrochemistry, device engineering and device physics.

The use of ambipolar redox active materials comprised of electron rich and electron poor groups (donor-acceptor strategy) is proposed to generate molecules with tuneable redox potentials. This allows their implementation on both the positive as negative half-cell of the battery, avoiding capacity loss by crossover. An iterative design strategy will be used to build a library of compounds that will be screened for reversible redox chemistry and stability. New membranes separating the half cells will be developed and matched with redox materials that passed the first screening, testing for compatibility and crossover rates. Finally, all components will be combined and studied in prototype flow batteries. Results from these studies will be used as input for computational modelling in order to predict a new generation of redox compounds and improved membrane design. This ultimately leads to a detailed understanding on their structure-property relations and development of materials that can be used for large-scale energy storage.

Details

Project number

722.017.004

Main applicant

Dr. K.H. Hendriks

Affiliated with

University of Michigan

Duration

01/01/2018 to 31/12/2020