In a world that is increasingly moving towards renewable energies and electromobility, we are facing an exciting challenge: how can we make batteries not only more powerful, but also more environmentally friendly? This is where a new joint project dedicated to precisely this question comes into play. Coordinated by the University of Würzburg and supported by funding from the Federal Ministry of Education and Research to the tune of a good two million euros, this project aims to take sodium-ion batteries to the next level.

Why sodium?

Sodium-ion batteries are like the little siblings of lithium-ion batteries, but with one crucial difference: instead of the rare and expensive lithium, they rely on sodium, an element that is available in virtually unlimited quantities on earth. Yes, you read that right – we’re talking about the same sodium that’s in our table salt. This availability makes sodium an exciting candidate for the battery technology of the future, especially because it allows us to dispense with rare metals such as cobalt and copper, which are indispensable in lithium-ion batteries.

The challenges

But of course there is no progress without challenges. Sodium-ion batteries currently have a lower energy density than their lithium counterparts, which means that they need to be larger and heavier to store the same amount of energy. This is a particular disadvantage for applications where compactness and lightness are important. But the project team is optimistic: sodium-ion batteries could soon be a viable solution for stationary energy storage or as buffer storage to compensate for fluctuations in the power grid, as well as for smaller cars that are only driven for short distances.

The NaKlaR project

Under the leadership of Dr. Guinevere Giffin and Professor Maik Finze from the University of Würzburg, the NaKlaR project aims to improve the performance and sustainability of sodium batteries. A particular focus here is on optimizing the production process and the recyclability of the batteries. The project brings together experts from the Karlsruhe Institute of Technology, the Helmholtz Institute Ulm and the Fraunhofer Institute for Silicate Research ISC Würzburg and is supported by an industrial advisory board that promotes a regular exchange between science and industry.

A look into the future

With a duration of three years, the project team has ambitious goals: To develop a sodium battery that is not only powerful and sustainable, but also sets new standards in terms of recycling. The vision is a battery that works with protected cathode materials, aqueous production of the electrodes and hydrolysis-resistant electrolytes and delivers a performance that comes close to today’s reference cells.

The journey to more sustainable batteries is undoubtedly fraught with challenges, but projects like NaKlaR show that we are on the right track. With sodium-ion batteries, we could soon have a technology in our hands that is not only more environmentally friendly, but also practical for a wide range of applications. The future looks green – and pretty salty!