What comes after lithium-ion batteries?

On the occasion of Battery Day on 18 February, Dr Peter Bieker, a researcher at MEET, gave an outlook on the battery systems of the future and explained why the goal does not always have to be "higher, faster, further".

Germany is home to some of the world's leading battery research centres, including the MEET Battery Research Centre at the Westfälische Wilhelms-Universität Münster and the Helmholtz Institute Münster. While the former is dedicated to the development of new and optimised battery types as a whole and has just launched a new collaborative project to research lithium-sulphur batteries, the latter focuses on the electrolyte for ion transport. On the occasion of Battery Day on 18 February, Dr Peter Bieker, a researcher at MEET, gave an outlook on the battery systems of the future and explained why the goal does not always have to be "higher, faster, further".

The researcher assumes that there will not be one battery technology in the future and that the market will become more differentiated. The currently dominant lithium-ion technology will still be with us for the next 10 to 15 years. However, since the requirements differ greatly, other systems will come along, for example, lighter batteries for aeroplanes or smaller ones for smartphones and watches. However, parameters such as environmental friendliness, availability and cost-effectiveness would come more into focus than battery efficiency and performance.

Lithium metal batteries with solid electrolytes are considered promising candidates for mass use. They have a high energy density, can keep up with lithium-ion batteries in terms of safety and are hopefuls for electromobility and aviation. Bieker expects to see this technology on the market before the end of this decade. Due to the current price increases and the dubious mining methods, lithium and cobalt-free batteries are also in focus. Currently, several technologies are being worked on, which should be particularly suitable for home applications such as alarm systems, thermostats or loudspeakers. Another cheap and resource-saving alternative could be sodium-ion batteries. Although these have a lower energy density, they offer advantages in fast charging and are therefore already being used in Japan as intermediate storage for power plants.

Research is also being conducted on dual-ion technologies. In this case, electrolyte anions are also involved in energy storage - in addition to the lithium ions. The electrolyte thus functions as an active material, which brings numerous optimisation approaches. Areas of application would be, for example, emergency power generators or other stationary applications. Organic polymer batteries, on the other hand, are particularly suitable for applications such as brake boosters in cars, buses or trains due to their high charge and discharge rates.

For each of these alternatives, however, different aspects about energy density, safety or cycle stability would still have to be researched further. The researchers are already thinking about the manufacturing process. The topic of sustainability plays "a very big role here in Europe", as Bieker explains. Therefore, the researchers must already take into account materials from renewable raw materials, environmentally friendly production processes or second uses and recycling of used batteries. "There is enormous ecological and economic potential in a circular economy of batteries," emphasises the battery expert.