Domestic researchers have developed a technology that significantly improves the charging speed and performance of lithium-sulfur batteries. This research is expected to be an important stepping stone to overcome the drawbacks of lithium-sulfur batteries and enhance commercialization prospects.
Professor Yoo Jong-seong and research team from the Daegu Gyeongbuk Institute of Science and Technology (DGIST) noted on the 27th that they developed an anode material capable of greatly improving the charging speed of lithium-sulfur batteries. The research results were published last November in the international academic journal "ACS Nano."
Lithium-ion batteries are essential in eco-friendly technologies like electric vehicles. However, they have low energy storage capacity and high prices. In contrast, lithium-sulfur batteries are gaining attention as next-generation batteries due to their high energy density and the low cost of sulfur materials. However, their commercialization has been difficult because the effectiveness of sulfur decreases during fast charging, reducing the battery's capacity.
Another major drawback is that lithium polysulfide, generated from the decomposition of sulfur during the battery discharge process, roams within the battery and degrades its performance. Research is being conducted to address this by creating batteries that incorporate sulfur into porous carbon structures, but they still have not achieved performance levels suitable for commercialization.
To solve this problem, the research team has newly synthesized a porous carbon material that contains nitrogen. This carbon material was synthesized using a thermal reduction method involving magnesium applied to a metal-organic framework called ZIF-8. Magnesium reacts with the nitrogen of ZIF-8 at high temperatures, making the carbon structure more stable and robust while forming a more varied pore structure than before. This structure not only accommodates more sulfur but also facilitates contact between sulfur and the electrolyte, enhancing battery performance.
The lithium-sulfur battery applying the developed material recorded a high energy capacity even under fast charging conditions, achieving a full charge in just 12 minutes and demonstrating a 1.6 times improved performance compared to existing technologies. Additionally, nitrogen doped on the carbon surface effectively inhibited the movement of lithium polysulfide, maintaining 82% of its capacity even after 1,000 charge and discharge cycles, showcasing excellent stability.
Professor Yoo Jong-seong said, "This research focused on improving the charging speed of lithium-sulfur batteries using a simple synthesis method involving magnesium," adding, "I hope this study accelerates the commercialization of lithium-sulfur batteries."
Reference materials
ACS Nano (2024), DOI: https://doi.org/10.1021/acsnano.4c09892