KERI’s new approach tackles lithium-sulfur battery’s commercialization hurdles

A research team at the Korea Electrotechnology Research Institute (KERI) has reported progress in addressing longstanding challenges that have hindered the commercialization of lithium-sulfur batteries. Dr. Park Jun-woo led the team, which focused on the “shuttle effect,” lithium polysulfides formed during charging and discharging migrate between the electrodes. This phenomenon has often resulted in performance declines and shortened battery life.

Dr. Park Jun-woo’s team at KERI (fourth from the left) overcame the limitations of next-generation lithium-sulfur batteries by combining carbon nanotubes and oxygen functional groups.

The group introduced single-walled carbon nanotubes (SWCNTs) treated with oxygen functional groups to control the shuttle effect. SWCNTs⁽¹⁾ combine high strength with electrical conductivity, while the oxygen functional groups⁽²⁾ improve the material’s dispersion. This setup helps stabilize electrodes that expand during repeated charging and discharging, reducing the loss of sulfur and preventing polysulfide diffusion.

By applying this method, the team developed a uniform, flexible, thick electrode⁽³⁾ measuring 50 × 60 mm and built a 1,000  mAh pouch-type lithium-sulfur battery prototype⁽⁴⁾. After 100 charge-discharge cycles, the prototype retained over 85% of its initial capacity. According to KERI, the approach could open avenues for practical uses of lightweight and cost-effective lithium-sulfur batteries, especially in urban air mobility (UAM), aerospace, and electric vehicles (EVs).

The study was published in Advanced Science, and KERI has applied for a domestic patent covering the technology. The institute hopes its findings will appeal to companies looking for next-generation energy solutions.

(1) Carbon Nanomaterials are characterized by nanoscale conductivity and a hexagonal carbon structure. They include graphene, often called a “dream material,” and carbon nanotubes (CNTs), essentially graphene layers rolled into tubes. Single-walled CNTs are thinner, more transparent, and exhibit higher conductivity than multi-walled types.
(2) Functional Group: A group of atoms (or a single atom) with specific chemical and physical properties influencing how a molecule interacts with its environment.
(3) Thick Electrode: A design that increases a battery’s energy density by packing more active material into the electrode.
(4) mAh (milliampere-hour): A unit of electric charge. One mAh corresponds to the amount of current (in milliamperes) that can be drawn for one hour. One thousand mAh equals 1 Ah.