Significant Achievement in Cathode Composition Unveiled, Paving Way for Commercial Use of Lithium-Sulfur Batteries

In a groundbreaking development, a team of chemical engineers at Drexel University has found a way to introduce sulfur into lithium-ion batteries, potentially revolutionising the electric vehicle (EV) industry.

Over the past year, the sulfur cathode has undergone more than 100 tests and performed remarkably well, without causing shuttling – a common issue that affects battery performance. This breakthrough could make sulfur batteries commercially viable, offering a sustainable and abundant alternative to traditional battery materials.

Sulfur, a waste product of petroleum production, is found in vast quantities worldwide, and in particular, in the United States. The human and environmental impact of extracting raw materials for batteries has been a topic of concern, making the use of a readily available and abundant resource like sulfur an attractive prospect.

The new sulfur cathode would alleviate the need for sourcing cobalt, nickel, and manganese, which have seen surging prices in 2021. These materials are often sourced from countries like Congo and China, making their availability and price volatile. The use of sulfur would not only reduce the reliance on these materials but also contribute to a more sustainable and equitable supply chain.

One of the challenges in introducing sulfur into lithium batteries has been the use of a commercially friendly carbonate electrolyte. However, the Drexel University team has managed to overcome this hurdle, with the sulfur cathode functioning effectively in a carbonate electrolyte. This opens up opportunities for researchers to examine replacements for the lithium anode.

The capacity of the Li-S battery is more than three-fold that of a Li-ion battery, and it has demonstrated extraordinary performance after more than a year of testing. The sulfur cathode has not degraded in 4,000 charge-discharge cycles, which is equivalent to 10 years of regular use. Moreover, the monoclinic gamma-phase sulfur, created in a cathode undergoing thousands of charge-discharge cycles, has remained stable for over a year without diminished performance.

The team is still working to understand the exact mechanism behind the creation of this stable monoclinic sulfur at room temperature. However, the development of a viable Li-S battery could open pathways to replacing materials like lithium and sodium in battery technology, offering even more potential for sustainable and efficient energy storage solutions.

With global sales of electric vehicles more than doubling in 2021, the need for advanced and sustainable battery technology has never been greater. The introduction of the sulfur cathode into lithium-ion batteries could be a significant step forward in meeting this demand and ensuring the continued growth of the electric vehicle industry.