Dr. Joon-Woo Park’s team at the Korea Electrotechnology Research Institute (KERI) has successfully suppressed the elution of “lithium polysulfide” by combining carbon nanotubes and oxygen functional groups. This breakthrough has enabled the development of high-capacity and large-area pouch-type flexible batteries with a capacity of 1000mAh. This research has been published in a prestigious international journal.
KERI announced on the 20th that Dr. Joon-Woo Park’s Next-Generation Battery Research Center team overcame key challenges that hindered the commercialization of next-generation lithium-sulfur batteries and succeeded in creating large-area, high-capacity prototypes.
Lithium-sulfur batteries, with a cathode of sulfur and an anode of lithium metal, have theoretical energy densities more than eight times that of lithium-ion batteries. Due to the use of sulfur, which is cheaper and more environmentally friendly than costly rare earth materials, lithium-sulfur batteries are noted for being lightweight, long-lasting, and an essential technology for the upcoming era of urban air mobility (UAM).
However, lithium-sulfur batteries face a significant hurdle during charging and discharging cycles, where the intermediate material “lithium polysulfide” is produced, causing unnecessary chemical reactions as it moves between the cathode and anode, thus degrading the battery’s lifespan and performance.
In response, Dr. Park’s team proposed a new technology combining single-walled carbon nanotubes (SWCNT) with oxygen functional groups. SWCNTs are a future material with strength surpassing steel and electrical conductivity comparable to copper. The oxygen functional groups help in dispersing SWCNTs well with other materials in the battery. This combination can effectively control the elution and diffusion of lithium polysulfide and significantly reduce the loss of sulfur.
The high flexibility of SWCNTs and the hydrophilicity of the oxygen functional groups allow for a uniform and smooth surface during the electrode manufacturing process, enabling large-area and high-capacity battery designs. As a result, the research team produced flexible thick electrodes of 50x60mm and successfully manufactured a 1000mAh pouch-type lithium-sulfur battery prototype. This prototype maintained over 85% of its capacity even after 100 charge and discharge cycles.
Dr. Joon-Woo Park stated, “Our technology not only overcomes the biggest challenge in lithium-sulfur batteries through the combination of SWCNTs and oxygen functional groups, but also achieves the design and prototype production of large-area, high-capacity flexible electrodes.” He emphasized that this development lays the groundwork for practical commercialization of next-generation lithium-sulfur batteries.
The research has been recognized for its excellence and published in ‘Advanced Science,’ a leading journal in the field of materials science. The paper’s “Impact Factor” is 14.3, placing it in the top 7.18%. The research has also led to domestic patent applications, and KERI plans to seek industrial partners for technology transfer in industries needing next-generation lithium-sulfur batteries, such as urban air mobility, aerospace, energy storage systems, and electric vehicles.
KERI is a government-funded research institute under the National Research Council of Science & Technology, supported by the Ministry of Science and ICT. This research was conducted as part of the “Global Top Strategy Research Group” project and KERI’s basic research projects on lithium-sulfur batteries.