Breakthrough material could lead to cheaper potassium batteries

Growing global demand for portable electronics and electric vehicles has increased the need for affordable and environmentally friendly battery solutions. Potassium-ion batteries have emerged as a strong 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 practical alternative to lithium-ion systems due to the abundance of potassium and its beneficial properties, including fast charging.

Reducing renewable energy storage costs

Experts expect these batteries could eventually become more affordable and easier to produce than lithium-ion batteries, potentially allowing them to be used more widely, such as for storing electricity from renewable energy sources.

According to Alexey Ganin, lead author and leader of the Glasgow Group on Electrochemistry of Solids (GECOS) at the University of Glasgow’s School of Chemistry, lithium-ion batteries, which are now common in devices ranging from smartphones to electric vehicles, provide superior performance. However, the relative scarcity of lithium makes it a strategically important and limited resource.

“Potassium is a much more abundant material, and potassium-ion batteries have great potential as an alternative method for storing and delivering large amounts of electricity. Using potassium-ion batteries for stationary storage purposes could 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 from Prussian white. However, to achieve optimal performance, Prussian white must be mixed with carbon to increase its conductivity, which adds complexity to the design.

New chromium selenide cathode reaches near maximum battery capacity

The researchers demonstrated that their naturally conducting chromium selenide cathode provides high performance at less than 10% carbon content. Their prototype has a capacity of 125 mAh/g, almost reaching the theoretical maximum of 127 mAh/g.

The layered structure of the material allows potassium ions to move smoothly between the 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 performance in future designs.

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

“Designer electrolytes for lithium-ion batteries can be purchased off-the-shelf, but further work is required to improve the performance of electrolytes for potassium-ion batteries. We are eager to collaborate with robotics experts who can help us test thousands of potential chemical combinations to find the best candidate for use in our battery.” – added Ganin.

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