△ Professors Kang June, Choi Jae-hyuk and Lee Won-ju

Professors at Korea Maritime and Ocean University (KMOU) have developed new ways to utilize soot, which is a fine dust generating material emitted from ships, as an energy source.

 Professors Choi Jae-hyuk, Lee Won-ju, and Kang June jointly carried out a convergent study covering main research interests of each other. Their study which used soot carbon generated from a ship as electrode materials for lithium-ion battery has been recently published in a Nature Sister Journal of Scientific Reports.

 The paper is titled as "Recycling Waste Soot from Merchant Ships to Produce Anode Materials for Rechargeable Lithium-Ion Batteries".

 A 5,300 TEU container ship generates about 1 ton of waste soot annually. Most shipping companies collect waste soot for being treated at waste processors with their own expenditure. At processors, the waste material is thermally decomposed, but this process often generates a significant amount of fine dust.

Utilizing the waste material as a new energy source, this study has attracted attention by finding a new way of soot disposal which is beneficial both for energy production and the environment.

Lithium-ion batteries can be easily found in our daily life usages like cell phones and electric cars. Electrode materials for these lithium-ion batteries consist of the graphite, which is divided into two types, natural and artificial graphite. The artificial graphite refers to the synthetic graphite which is formed by mixing with filler (like coke) and binder (like pitch), carbonizing the mixture, and then artificially crystallizing the resulting material at a high temperature of 2,500°C. This artificial graphite has a higher purity than the natural one, but with a shortcoming of being expensive.

The research team tried an attempt to produce the artificial graphite by using soot, which is an inevitable waste material from ships to overcome the shortcoming of the artificial graphite. The soot, having being graphitized, has developed a structure of carbon nanoonion, which is a spherical carbon structure. The team tested it with a lithium-ion battery electrode material and found that the soot has a discharging capacity of about 270 mAg /g, proving the potential use as an electrode active material for a lithium-ion battery. It has also been demonstrated that soot can be used not only as an active material but also as a conductive material. The research team has secured intellectual property rights for this achievement.

 While the production of artificial graphite requires processes of carbonization and graphitization in addition to raw materials, the soot, already in a carbonized state, only requires graphitization giving it much higher price competitiveness than the artificial graphite.

The study was conducted through active support from the SM group. After signing an MOU with KLCSM Co., Ltd.(CEO Park Chan-min), the nation’s leading ship management company in charge of comprehensive management of ships operated by SM Group shipping companies (Korea Line Corporation, SM Line, and Korea Shipping Corporation), the research team collected waste soot generated from ships managed by KLCSM for their study. After the publication of their paper, the team tried a field test at SM Bexel, a battery manufacturer under the SM group and confirmed that their development could be used as a negative electrode material for lithium-ion batteries.