Reviewed by Lexie CornerJan 7 2025
A research team led by Professor Jong-sung Yu from the DGIST Department of Energy Science and Engineering has developed a novel method to significantly enhance the charging speed of lithium-sulfur batteries. The findings were published in ACS Nano.
Lithium-ion batteries are widely used in technologies like electric vehicles due to their reliability, but they face limitations such as low energy storage capacity and high costs. In contrast, lithium-sulfur batteries have gained attention as next-generation energy storage systems due to their high energy density and the low cost of sulfur. However, commercialization has been hindered by challenges such as low sulfur utilization during rapid charging and capacity losses caused by lithium polysulfides, which form during discharge and degrade performance.
To address these issues, the research team developed a nitrogen-doped, highly graphitic, multiporous carbon material integrated into the cathode of lithium-sulfur batteries. This approach enabled the batteries to maintain high energy capacity even under rapid charging conditions.
The novel carbon material was synthesized using a magnesium-assisted thermal reduction process involving ZIF-8, a metal-organic framework. At high temperatures, magnesium reacts with nitrogen in ZIF-8 to create a stable and robust carbon structure with a diverse pore network. This structure enhances sulfur loading and increases the interface between sulfur and the electrolyte, leading to improved battery performance.
The lithium-sulfur battery designed in this study used the multifunctional carbon material as a sulfur host. It achieved a high capacity of 705 mAh g⁻1, a 1.6-fold improvement over conventional batteries, with a full charge time of just 12 minutes. Additionally, nitrogen doping on the carbon surface effectively suppressed lithium polysulfide migration, allowing the battery to retain 82 % of its capacity after 1,000 charge-discharge cycles, demonstrating excellent stability.
Advanced microscopic analyses, led by Dr. Khalil Amine of Argonne National Laboratory, confirmed the formation of lithium sulfide (Li2S) in a specific orientation within the layered structures of the carbon material. These findings highlighted that nitrogen doping and the porous carbon framework enhanced sulfur loading, while the graphitic nature of the material facilitated sulfur reactions, enabling faster charging.
This research focused on improving the charging speed of lithium–sulfur batteries using a simple synthesis method involving magnesium. We hope this study will accelerate the commercialization of lithium–sulfur batteries.
Jong-sung Yu, Professor, Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology
This study was funded by the National Research Foundation of Korea's Mid-Career Researcher Support Program. It was carried out in partnership with Argonne National Laboratory, and the first authors were Jung-hoon Yu, Integrated Master-Ph.D. Student, and Byung-jun Lee, Ph.D.
Journal Reference:
Yu, J.-H., et. al. (2024) Tailoring-Orientated Deposition of Li2S for Extreme Fast-Charging Lithium–Sulfur Batteries. ACS Nano. doi.org/10.1021/acsnano.4c09892