A new study from Khalifa University demonstrates how covalent organic frameworks can significantly improve the stability and efficiency of lithium-sulfur batteries听
Unpack the science behind Li-S innovation – Listen Now!
Lithium-sulfur (Li-S) batteries are often considered the next big leap in energy storage due to their higher energy density and lower cost compared to traditional lithium-ion batteries. However, their widespread use has been limited by one major problem: the polysulfide shuttle effect 鈥� a phenomenon where lithium polysulfides (LiPSs) dissolve and migrate within the battery, leading to capacity loss, poor efficiency, and short cycle life.听听
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A team of researchers from Khalifa University, including Dr. Dinesh Shetty, Dr. Kayaramkodath Chandran Ranjeesh and Safa Gaber, has collaborated with researchers from CSIR-National Chemical Laboratory, India, and Technische Universitat Dresden, Germany, to develop a solution. The research team developed a novel sulfur-hosting material based on covalent organic frameworks (COFs). These materials offer strong chemical and physical confinement of LiPSs, preventing their migration and stabilizing battery performance over hundreds of cycles.听听
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The team published their work in .听听
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鈥淭he rapid evolution of modern electronics and electric vehicles has motivated the development of safer rechargeable batteries with greater capacity and lower costs,鈥� Dr. Shetty said. 鈥淩echargeable lithium-sulfur batteries are a promising candidate but despite extensive research, their performance remains significantly below theoretical potential. We used molecular-level material design to unravel the structure and property relationship in enhancing the performance of sulfur-hosting cathodes for Li-S batteries.鈥澨�
鈥�The rapid evolution of modern electronics and electric vehicles has motivated the development of safer rechargeable batteries with greater capacity and lower costs. Molecularly engineered covalent organic frameworks can unlock the true potential of lithium-sulfur batteries for next-generation energy storage.鈥�
Dr. Dinesh Shetty, Associate Professor, Khalifa University.
Covalent organic frameworks are a class of materials that form two- or three-dimensional structures through reactions between their organic components, resulting in strong, covalent bonds that create porous, crystalline materials. The research team designed chalcone-linked nanographene COFs that serve as advanced sulfur hosts. These COFs provide dual confinement for LiPSs through physical trapping, as the microporous structure prevents them from escaping, and chemical anchoring. The chalcone and pyridine groups in the COFs form strong bonds with the lithium polysulfides, keeping them in place. These molecular interactions suppress the shuttle effect and allow for more efficient and stable sulfur utilization.听听
In the team鈥檚 experiments, the batteries retained 80 percent of their original capacity, even after 500 cycles, while enhanced redox kinetics improved charge and discharge rates. With further optimization, this technology could soon power anything from electric vehicles to grid-scale renewable energy storage, bringing us closer to a cleaner, more sustainable future.听听
Jade Sterling
Science Writer
