A method to extend the life of eco-friendly organic electrode-based batteries has been developed. It is expected to advance the commercialization of organic electrode-based batteries and serve as a basis for related follow-up research.

UNIST (President Yong-Hoon Lee) announced on the 1st that Professor Won-Jin Kwak's research team in the Department of Energy and Chemical Engineering and Professor Jun-Myeong Choi's research team in the Department of Mechanical Engineering at Hanyang University have developed an electrolyte that can dramatically improve battery performance while maintaining the advantages of organic electrodes.

The developed electrolyte effectively suppressed the dissolution of organic electrode active materials into the electrolyte. It also extended the life of the battery by inducing stabilization of the interface between the electrode and the electrolyte.

Eco-friendly organic electrode materials are being studied as next-generation electrodes to replace transition metal-based inorganic electrode materials currently used in lithium-ion batteries. On the other hand, it has a fatal disadvantage in that the life of the battery is shortened due to dissolution that occurs within the electrolyte.

Professor Kwak Won-jin explained, “Previously, dissolution was suppressed by using polymerization of organic electrode materials, but there was a loss in capacity or output.” He continued, “This study is an approach that can be easily applied because, unlike polymerization, there is no loss in capacity because it is controlled through electrolytes.”

The developed electrolyte suppresses dissolution by adding a co-solvent. The co-solvent has the characteristic of being miscible with the electrolyte solvent but not with the salt. This characteristic is used to reduce the interaction between the solvent and the active material that causes dissolution. As a result, the dissolution of the organic electrode active material can be suppressed.

The research team verified through computational methods and experiments that the developed electrolyte effectively suppresses dissolution. They confirmed that more than 80% of the capacity was maintained even after 1,000 charge/discharge experiments. This is in contrast to the existing electrolyte, which showed less than 50% of its capacity after 20 charge and discharge cycles.

First author Hyunwook Lee, a doctoral candidate, said, “Research on electrodes and secondary batteries using organic materials as active materials is a very important research direction for overcoming resource depletion and rising material prices.”

Professor Kwak Won-jin added, “There are many issues that need to be resolved for the practical use of organic electrode-based secondary batteries,” and “We expect that this research, which improved reversibility without loss of output or capacity, will lead to meaningful follow-up results.”

This study was officially published on January 19 in Advanced Energy Materials, a world-renowned international academic journal in the field of materials science, and was conducted with the support of the Excellent New Researcher Program of the National Research Foundation of Korea, Ministry of Science and ICT.