The development of a high-efficiency, small-life energy storage device is expected to improve the energy density and lifespan of secondary batteries and supercapacitors, which are energy sources that use the device.

The Korea Institute of Materials Science (KIMS, President Lee Jung-hwan), a government-funded research institute under the Ministry of Science and ICT, announced on the 7th that the research team of Dr. Lee Ji-hoon of the Green Hydrogen Materials Laboratory, together with the research teams of Professor Choi In-seok of Seoul National University and Professor Shin Jung-ho of Kangwon National University, developed a three-dimensional porous carbon-based current collector material and developed a technology to simultaneously improve energy density and lifespan characteristics by applying it to secondary batteries and supercapacitors.

The current collector is an important element in the production of thin film electrodes. On the other hand, it occupies a significant portion of the electrode weight and volume, which limits the improvement of energy density and the weight reduction of energy storage devices. This is especially noticeable in fields where medium and large electrochemical energy storage devices such as electric vehicles are applied. The same applies to repeated charging and discharging. The corrosion problem of existing metal current collectors due to separation of active materials or inflow of moisture and air into the battery is the cause of shortening the battery life.

The research team applied the floating catalytic chemical vapor deposition method to carbon, which is stable even in various environments, and produced a carbon-based current collector with a three-dimensional porous structure. Afterwards, considering the mass production process, we succeeded in making an electrode by applying the active material coating method used in the secondary battery industry. This is a groundbreaking overcoming of the existing constraints that required changing and applying the current collector material according to environmental changes such as electrolyte and operating voltage.

Additionally, the porous structure facilitates the movement of lithium ions, leading to faster charging and discharging, improved energy density, and increased capacity through wide pores. Compared to the existing metal foils, which have a two-dimensional planar structure and thus have a limited interfacial contact area with the active material, the developed three-dimensional carbon-based current collector plays a key role in maximizing the area, forming a stable interface, and improving the lifespan of the device.

Senior Researcher Lee Ji-hoon, the principal investigator of the study, said, “By solving problems originating from the essential parts of the material, we are expected to lower the barriers to commercialization of carbon-based current collectors and increase the utility of current collectors that can cover everything from small to medium- to large-sized energy storage devices.” He added, “This is an important study that redefines the role of current collectors, which have been limited to being auxiliary materials for electrode formation. We will continue to conduct follow-up research to develop eco-friendly and highly technologically economical energy conversion technologies.”

This research was carried out with the support of the Ministry of Science and ICT through the National Research Council for Science and Technology's 'Creative Convergence Research Project', the National Research Foundation of Korea's 'Nano and Materials Technology Development Project, Basic Research Project in Science and Engineering', and Seoul National University's 'Creative Leading New Researcher Support Project' and 'Local Government-University Cooperation-Based Regional Innovation Project (RIS)'.

In addition, the research results were selected and published as a cover paper in the May 18 issue of 'ACS Applied Materials & Interfaces (IF=10.383 / First author: Jeon Jong-han, PhD candidate),' a renowned international academic journal in the field of materials.