UC researchers develop silica-polymer composite aerogels for new solid batteries

A research team from the Faculty of Sciences and Technology of the University of Coimbra (FCTUC) has developed silica-polymer composite aerogels for the production of lithium-free electric batteries (solid-state batteries).

The project "Silica-Polymer Composite Aerogels as Solid Sodium Electrolytes (AeroNaLyte)", one of the winners of the 4th edition of the University of Coimbra's Seed Projects for Interdisciplinary Research Awards, aimed to find materials that can help develop a new generation of batteries and improve the safety (more stable and non-flammable) and durability of future post-lithium batteries.

"The problem with today's batteries is that they are made from lithium, a finite resource that the European Union considers to be a critical raw material that is unevenly distributed worldwide. Some countries benefit from the exploitation of lithium, while others are at the mercy of its exploitation. João Vareda, a researcher at the Department of Chemical Engineering (DEQ) and coordinator of the project, explains that "there is a global effort to reduce this dependency, but also to reduce the use of certain materials, such as cobalt, a metal whose exploitation is linked to human rights violations".

"Sodium batteries could be the solution to replace lithium, as they are globally available and very affordable," says João Vareda. "Moreover, sodium batteries would already allow us to replace some of the problematic metals," he adds.

To take another step towards a greener future, the "AeroNaLyte" project focused on creating silica-polymer composite aerogels using biocompatible materials and green solvents as solid electrolytes for a possible new generation of batteries, as well as testing the functionality of this approach and its application. The results are very positive and promising, but more work is needed to achieve the full potential of this strategy.

"The safety concerns associated with current lithium batteries, due to their flammability, and the difficulty or near impossibility of recycling them, were among the reasons the young researcher considered using aerogels in batteries. João Vareda also highlighted the problems caused by the extraction of metals, particularly in terms of environmental and social impact.

For the chemical engineer, the development of this new generation of batteries could "provide access to electricity in areas where it's not currently available. They may not have a grid like ours, but the ability to store electricity in batteries will be crucial to democratising access to electricity worldwide," he explains.

The researcher emphasises the critical importance of batteries: "Providing global access to an electricity grid will undoubtedly have a profound social, environmental and economic impact.