The breakthrough material could lead to cheaper potassium batteries

The growing global demand for portable electronics and electric vehicles has increased the need for affordable and environmentally friendly battery solutions. Potassium-ion batteries have become a powerful alternative to traditional lithium-ion systems due to the abundant and widely available potassium resources around the world.

This latest breakthrough makes potassium-ion batteries a viable alternative to lithium-ion systems, thanks to their high potassium content and favorable properties, including fast charging.

Reduction of costs for renewable energy storage

Experts expect these batteries to eventually become more affordable and easier to manufacture than lithium-ion batteries, potentially enabling broader applications such as storing electricity from renewable energy sources.

Li-ion batteries, now widely used in devices ranging from smartphones to electric cars, offer excellent performance, according to Oleksii Ganin, lead author and head of the Glasgow ElectroChemistry on Solids (GECOS) group at the University of Glasgow’s School of Chemistry. However, lithium’s relative scarcity makes it a strategically important and limited resource.

“Potassium is a much more common material, and potassium-ion batteries have great potential as an alternative method of storing and delivering large amounts of electricity. The use of potassium-ion batteries for stationary storage can help free up lithium resources for use in more energy-intensive mobile applications in the future,” Ganin explained.

Many of the most efficient potassium ion battery designs currently use cathodes made of Berlin White. However, for optimal performance, Berlin White must be mixed with carbon to increase its conductivity, adding to the complexity of the design.

A new chromium selenide cathode achieves near-maximum battery capacity

Researchers demonstrated that their naturally conductive chromium selenide cathode achieves high performance with less than 10% carbon. Their prototype has a capacity of 125 mAh/g, which is close to its theoretical maximum of 127 mAh/g.

The multilayer structure of the material allows potassium ions to move smoothly between layers during charging and discharging, allowing the battery to retain 85% of its capacity even at high charging rates in laboratory tests. The team’s next step is to find an electrolyte that could further improve battery efficiency in future designs.

Ganin noted that while the results are promising, battery performance could be further improved with an optimized electrolyte. Unlike lithium-ion batteries that use readily available specialized electrolytes, potassium-ion batteries require additional research to develop highly efficient electrolyte options.

“Designer electrolytes for lithium-ion batteries are available off the shelf, but further work is needed to improve the performance of electrolytes for potassium-ion batteries. We look forward to working with robotics experts who can help us screen thousands of potential chemical combinations to find the best candidate for use in our battery.” Ganin added.

The scientists also emphasized that this research advances efficient and sustainable energy storage solutions. This shows that the study of TMC-based cathodes for potassium-ion batteries can significantly help to find alternatives to lithium-ion batteries, contributing to more sustainable energy storage technologies.