The strategic collaboration between Ferroglobe and CETIM has made it possible to optimise the processes for obtaining silicon and biocarbons with excellent results for lithium-ion batteries, significantly improving both their capacity and useful life.

UMI VOLTA project came to an end last September, when a final event was held to present the excellent results of this strategic collaboration between Ferroglobe and CETIM. Both entities have implemented complementary approaches to develop more efficient and sustainable lithium-ion batteries for the electromobility sector.

The event also featured a presentation by Carmen Cotelo Queijo, Director of the Galician Innovation Agency, the body that has subsidised the project’s activities within the framework of the 2022 call for proposals for the Joint Research Units Programme.

Silicon and local products for sustainable batteries

Ferroglobe is leading cutting-edge research into the industrial implementation of silicon in lithium-ion batteries. At VOLTA, it has succeeded in precisely controlling the synthesis of silicon through grinding processes, achieving high homogeneity at the micro and nanometric scales. In addition, it has made surface modifications to optimise the reactivity and electrochemical performance of the material.

At CETIM, we have transformed local biomass into advanced bio-carbons for energy storage, creating a regional value chain that reduces dependence on imported materials. We have worked mainly with materials such as lignin, cellulose, sawdust and also invasive algae, with lignocellulosic materials demonstrating the best performance in both carbonisation and electrochemical behaviour. At the same time, at CETIM we have developed recyclability studies and a decentralised blockchain-based application that guarantees the traceability of materials and processes, facilitating their recycling and moving towards the concept of a green passport.

The results of the project are remarkable: the processes for obtaining silicon and biochar have been optimised with excellent results for lithium-ion batteries, achieving retention capacities of over 80% for more than 350 cycles. In fact, the combination of these materials has significantly improved both the capacity and the service life of the batteries. In addition, the optimisation of electrode manufacturing has allowed for the use of more environmentally friendly components, replacing toxic solvents with water. These advances have been validated through prototypes in high-amperage pouch cells subjected to demanding thermal conditions. These achievements consolidate the project as a benchmark in energy storage technologies for the electric mobility sector.

The actions carried out by the Unidad Mixta de Investigación “VOLTA” are subsidized by the Galician Innovation Agency (Xunta de Galicia) within the framework of the 2022 call for the Unidad Mixta de Investigación Program, co-financed by the European Union through the European Regional Development Fund (FEDER) – Galicia Operational Programme FEDER 2021-2027.