New lithium-sulfur battery achieves rapid charging, lasting stability.

In a breakthrough that could reshape battery technology, researchers at the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in Korea have developed a groundbreaking lithium-sulfur battery that can fully charge in just 12 minutes, leveraging a specially engineered carbon material to achieve rapid charging, higher energy capacity, and exceptional long-term durability.

Considered a promising alternative to lithium-ion technology, lithium-sulfur batteries combine the high energy density of lithium with the affordability and abundance of sulfur.

While their potential to store more energy at a lower cost makes them attractive for applications such as electric vehicles and grid storage – slow charging speeds, limited cycle life, and performance degradation caused by sulfur instability have prevented their widespread adoption.

During use, lithium-sulfur batteries produce compounds called lithium polysulfides, which form when sulfur reacts during the charge and discharge process, that move within the battery and cause structural damage.

Although researchers have tried using porous carbon materials to hold the sulfur in place, these efforts have not yet resulted in a stable or efficient solution. However, scientists at DGIST have made significant breakthroughs in addressing these limitations, achieving advancements in charging speed and long-term stability.

To accomplish this, the DGIST team created an innovative new material that strengthens the battery's structure, allowing it to charge faster and last longer.

More specifically, they modified a carbon base by forming tiny, interconnected pores that enhance sulfur storage and reduce degradation, directly addressing the instability that has hindered lithium-sulfur battery development.

This discovery is hinged on the method used to create the new material, a process involving magnesium and a compound known as ZIF-8 that transforms the carbon structure for improved battery performance.

Made up of tiny metal pieces and organic building blocks, Zeolitic Imidazolate Framework 8 (ZIF-8) – a metal-organic blueprint formed by the coordination of metal ions and organic ligands – forms a strong structure that can handle high heat and tough chemicals.

Its unique, porous design allows it to trap other materials inside, making ZIF-8 useful for tasks like filtering gases or storing chemicals.

At high temperatures, magnesium reacts with the nitrogen in ZIF-8, making the carbon structure more stable and robust while creating a diverse pore structure. This structure not only allows for higher sulfur loading but also improves the contact between sulfur and the electrolyte, significantly enhancing battery performance.

To confirm the effectiveness of the new material, the research team collaborated with experts at Argonne National Laboratory in the United States, which performed advanced microscopic analyses. These analyses revealed that the sulfur within the battery formed in specific orientations, improving the reaction rates and overall battery efficiency.

As a result, even under rapid charging conditions with a full charge time of just 12 minutes, the lithium-sulfur battery demonstrated a capacity about 1.6 times higher than conventional batteries. The nitrogen infusion in the carbon material also helped prevent the harmful movement of compounds, allowing the battery to retain 82% of its capacity after 1,000 charge cycles, showcasing its long-term stability.

This validation showed that the nitrogen infusion in the carbon material helped improve sulfur storage and prevent the harmful movement of compounds, which is crucial for enhancing both long-term stability and charging speed.

With these improvements, lithium-sulfur batteries are now closer to becoming a viable option for EVs, grid-scale electrical storage, and other applications that require rapid charging and high energy capacity.

"This research focused on improving the charging speed of lithium-sulfur batteries using a simple synthesis method involving magnesium," said Jong-sung, research lead at DGIST. "We hope this study will accelerate the commercialization of lithium-sulfur batteries."