KU has Developed a Positive Electrode Material
Enabling Seamless Adsorption and Conversion for High-Performance Lithium-Sulfur Batteries

▲ (From left) Professor Moon Jun-hyuk (corresponding author), Lee Hae-li (first author, student in integrated master-doctoral degree programs) and Nam Hyun-suk (participating author, student in integrated master’s-doctoral degree programs).

KU (President Kim Dong-one) has developed a lithium-sulfur battery with significantly improved energy capacity and charge/discharge stability.

The study which achieved this result was conducted by Professor Moon Jun-hyuk’s group at the Department of Chemical and Biological Engineering at KU (also the School of Smart Mobility), and the results were published on June 10 (Mon) in Energy Storage Materials (IF:20.4), an internationally renowned journal in the field of energy materials.
* Title of article: Seamless Integration of Nanoscale Crystalline-Amorphous MoO3 Domains for High-Performance Lithium-Sulfur Batteries
* Article DOI link: https://doi.org/10.1016/j.ensm.2024.103551

Lithium-sulfur batteries can achieve energy density that is 2 to 3 times higher than that of lithium-ion batteries. In addition, lithium-sulfur batteries are attracting attention as a next-generation secondary battery solution due to the abundance and low price of sulfur, which is used as a positive electrode material. However, the relatively low charge/discharge stability of lithium-sulfur batteries due to the slow conversion of polysulfide (an intermediate substance formed during charge/discharge) has required improvement.

To solve this problem, Professor Moon’s research group employed a crystalline-amorphous mixed molybdenum oxide that was prepared by partially amorphizing the crystalline molybdenum oxide. The research group found that polysulfide that was strongly adsorbed in the amorphous region quickly moved to the surrounding crystalline region, enabling prompt charge and discharge reactions.

The lithium-sulfur battery developed in this study exhibited charge/discharge stability in over 500 cycles and had an energy density of 330 Wh/kg, which was higher than that of lithium-ion batteries.

Professor Moon, the corresponding author of the article, said “We developed a seamless positive electrode material that enables dissolved polysulfide to be quickly adsorbed and to participate in charging and discharging, and confirmed that the material significantly improved the performance of lithium-sulfur batteries.”

This study was supported by the Midcareer Researcher Program of the Ministry of Science and ICT.

 * Professor Moon’s official website: http://moonlab.korea.ac.kr

<Figure 1> 

[Description of Figure 1] Atomic structure model of a crystalline-amorphous mixed molybdenum oxide; and illustration of the adsorption and conversion continuously occurring on the surface of the oxide.

<Figure 2> 

[Description of Figure 2] Operation of the LED device powered by the lithium-sulfur battery developed by the research group.