Aston University researchers will explore the use of gel electrolyte materials to make lithium-ion batteries safer and less environmentally damaging. The University has received a grant of £443,058 from the Engineering and Physical Sciences Research Council to develop safe, reliable, sustainable and commercially relevant gel electrolyte materials.

Currently batteries and other energy storage devices are assembled via multiple processing steps and typically use flammable solvents and fossil fuel-derived materials with poor thermal and chemical stability. The researchers will develop renewable ionogels which conduct electrically charged ions.

The gel electrolyte materials could replace current harmful, flammable components and could help prevent batteries from leaking.

The Aston University team is led by Dr Matt Derry, a lecturer in chemistry, who is based in the University’s College of Engineering and Physical Sciences.

In addition to the research grant to start on 1 March 2024, Dr Derry and his team have just had a paper published in Chemical Science, the Royal Society of Chemistry’s flagship open access journal, which showcases the generation of ionogels via their new approach.

We report for the first time a reversible addition–fragmentation chain transfer polymerisation-induced self-assembly (RAFT-PISA) formulation in ionic liquid (IL) that yields worm gels. A series of poly(2-hydroxyethyl methacrylate)-b-poly(benzyl methacrylate) (PHEMA-b-PBzMA) block copolymer nanoparticles were synthesised via RAFT dispersion polymerisation of benzyl methacrylate in the hydrophilic IL 1-ethyl-3-methyl imidazolium dicyanamide, [EMIM][DCA].

This RAFT-PISA formulation can be controlled to afford spherical, worm-like and vesicular nano-objects, with free-standing gels being obtained over a broad range of PBzMA core-forming degrees of polymerisation (DPs). … Nanoparticle morphologies were identified using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM), and further detailed characterisation was conducted to monitor rheological, electrochemical and thermal characteristics of the nanoparticle dispersions to assess their potential in future electronic applications. Most importantly, this new PISA formulation in IL facilitates the in situ formation of worm ionogel electrolyte materials at copolymer concentrations >4% w/w via efficient and convenient synthesis routes without the need for organic co-solvents or post-polymerisation processing/purification.

Moreover, we demonstrate that the worm ionogels developed in this work exhibit comparable electrochemical properties and thermal stability to that of the IL alone, showcasing their potential as gel electrolytes.

—Maitland et al.

The research project will end in February 2027.

Resources

• Maitland, Georgia & Liu, Mingyu & Neal, Thomas & Hammerton, James & Han, Yisong & Worrall, Stephen & Topham, Paul & Derry, Matthew. (2024). “Block copolymer synthesis in ionic liquid via polymerisation-induced self-assembly: A convenient route to gel electrolytes.” Chemical Science doi: 10.1039/D3SC06717C.