HONG KONG UNIVERSITY OF SCIENCE AND TECHNOLOGY
PICTURE: AN ALL-IN-ONE SOLUTION FOR THE DESIGN STRATEGY OF MACROPOROUS HOST WITH DOUBLE BINDING SITES. Show more CREDIT: HKUST
A team led by Cheong Ying Chan, Professor of Engineering and Environment, Prof. ZHAO Tianshou, Chair of Mechanical Engineering and Aerospace Technology and Director of the HKUST Energy Institute, has developed a novel cathode design concept for lithium-sulfur (Li-S ) Batteries proposed will improve the performance of this type of promising next generation battery.
Li-S batteries are considered attractive alternatives to lithium-ion (Li-ion) batteries, which are commonly used in smartphones, electric vehicles, and drones. They are known for their high energy density, while their main component, sulfur, is abundant, light, cheap and environmentally friendly.
Li-S batteries can potentially offer an energy density of over 500 Wh / kg, which is significantly better than Li-ion batteries, which reach their limit at 300 Wh / kg. The higher energy density means that the range of an electric vehicle with Li-ion batteries can be significantly increased from around 400 km to 600 to 800 km when powered by Li-S batteries.
While researchers around the world have had exciting results with Li-S batteries, there is still a huge gap between laboratory research and commercializing the technology on an industrial scale. A major problem is the polysulfide shuttle effect of Li-S batteries, which causes progressive leakage of active material from the cathode and lithium corrosion, resulting in a short life cycle for the battery. Other challenges are reducing the amount of electrolyte in the battery while maintaining stable battery performance.
To address these issues, Prof. Zhao's team worked with international researchers to propose a cathode design concept that can achieve good Li-S battery performance.
The highly oriented macroporous host can absorb the sulfur uniformly while abundant active sites are embedded in the host to densely absorb the polysulfide, thereby eliminating the shuttle effect and lithium metal corrosion. By introducing a construction principle for sulfur cathodes in Li-S batteries, the joint team increased the energy density of the batteries and made a big step towards industrialization of batteries.
"We are still doing basic research in this area," said Prof. Zhao. "However, our innovative electrode design concept and the associated performance breakthrough are a big step towards the practical use of a next-generation battery that is even more powerful and has a longer service life than today's lithium-ion batteries."
Her research was recently published in Nature Nanotechnology under the title “A high-energy and long-cycle lithium-sulfur pouch cell over a macroporous catalytic cathode with double-ended binding sites”.
HKUST team members include Prof. Zhao and his current PhD students ZHAO Chen, ZHANG Leicheng and former PhD student REN Yuxun (2019 graduate). Other collaborators include researchers from Argonne National Laboratory and Stanford University in the USA, Xiamen University in mainland China and Imam Abdulrahman Bin Faisal University in Saudi Arabia.