Energy storage with bulk liquid redox materials

Project Information

LiquidS

Grant agreement ID: 101069247

DOI

10.3030/101069247

Project closed

EC signature date 24 March 2022

Start date 1 May 2022

End date 31 October 2023

Funded under

• European Research Council (ERC)

Total cost

No data

EU contribution

€ 150 000,00

Coordinated by

INSTITUTE OF SCIENCE AND TECHNOLOGY AUSTRIA
Austria

Periodic Reporting for period 1 - LiquidS (Energy storage with bulk liquid redox materials)

Reporting period: 2022-05-01 to 2023-10-31

Summary of the context and overall objectives of the project

Electrifying transport and storing electricity from intermittent renewable sources is essential for a carbon neutral society. Best-in-class energy density helped Lithium ion batteries (LIB) to now widespread use, giving a first taste of the full promise of electrochemical energy storage (EES). LIB, however, rely on scarce elements, with their production associated with major cost and energy input. The required giant scale deployment therefore makes no sense ecologically nor economically. Alternative EES devices – supercapacitors and redox flow batteries – each alleviate some of the weaknesses of LIB, such as power, elements used, and safety, but remain critically weak in energy per unit weight and mass. Overall, a carbon neutral society critically demands environmentally benign EES, combining the most promising features of these technologies.
Both the successes and difficulties of LIBs stem from the transition metal compounds used (e.g. based on Cobalt). Being solid and dense, they allow for high energy, but processes are slow in solids, restricting power. Furthermore, transition metals are scarce, expensive, sometimes toxic, and energy hungry in production and recycling.
Therefore, the ideal redox material is based on main group elements, liquid, and has a solid-like redox density. We discovered such classes of materials in the connected ERC project. The overall objective of this project is to evaluate the technical, commercial and industrial potential of these materials classes as an active material in batteries.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Starting from a very limited scope of materials of the materials classes we widely expanded the pool of candidate molecules. Electrochemical and spectroscopic characterization revealed prerequisites for molecules that allow for stable and reversible battery cycling both as anode and cathode material. These are currently undergoing IPR protection.
Bulk liquid redox materials have distinctly different physico-chemical properties to traditional electroactive materials (solid charge storage materials or redox flow electrolytes). These include their phase diagram, viscosity, electron transfer rate, charge mobility. We developed a workflow and methods to efficiently evaluate the properties and particularly the electrochemistry of these materials. This includes also the development of a redox flow setup particularly suited for rather high viscosity fluids.
Expanding the scope required enumerating a large potential scope and narrowing it down to a manageable range of molecules to be synthesized. We developed new efficient synthesis procedures from bulk feedstocks in high yields and absence of problematic and dangerous chemicals or synthesis conditions, which will be considered on their own right for IPR protection and then to be published.
In view of the translation into innovation, the competing market has been researched, costs estimated for the active materials, and contact to stakeholders in the battery value chain established.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We have established two previously not considered classes of organic materials as active battery materials. Particularly building on their liquid property and low molecular weight, which makes them competitive or even superior to common inorganic intercalation compounds in KPIs (e.g. energy/power density, cost, LCA parameters). IPR protection has had priority over further dissemination. Future works will need (i) further research into the basic physico-chemical properties, (ii) upscaling of synthesis, (iii) demonstration on higher TRL level, and (iv) funding acquisition for translational activities.