MOF@rGO-based cathodes for Li-S Batteries (MOGLiS)

The increasing market of electric vehicles and the growing importance of renewable energy sources calls for next-generation high-efficiency batteries. Li-ion batteries, which dominate the current market, are limited by capacity due to the use of graphite as electrodes. Alternatively, Lithium-sulfur batteries (Li-S) are studied to be promising next-generation substitutes for lightweight energy storage systems thanks to their theoretical capacity, which is about five times more than lithium-ion batteries. However, the availability of suitable cathode materials that can immobilize large amounts of sulfur and have high conductivity while simultaneously not compromising on flexibility in terms of mechanical property is the main challenge in the implementation and industrialization of Li-S batteries. The MOGLiS (MOF@rGO-based cathodes for Li-S Batteries) project uses techniques of nanotechnology and thin film fabrication to overcome the challenge of Li-S batteries. The project employs a unique nanomaterial design methodology to fabricate new functional materials that will be used as cathodes in Li-S batteries. The functional materials comprise Metal Organic Frameworks (MOFs) grafted over 2-dimensional reduced Graphene Oxide (rGO) nanosheets. Suitable MOFs have been screened, and two selected MOFs have been synthesized and deposited at GO sheets. These MOF@rGO cathodes have been made into coin cells and tested, showing very stable and high-rate capability at high current density (cycle number >3500), outperforming most Li-S batteries reported in the literature, demonstrating the potential of the developed cathode material for flexible and foldable batteries with very high capacity and advantageous over existing batteries in terms of size, safety, and efficiency.

Lithium-sulfur (Li-S) batteries are attractive next generation energy storage devices in sectors like transportation due to their higher theoretical capacity and energy density. The lack of high-performance cathodes that can overcome the decay in cell capacity with cycling hinders the current market realization of Li-S batteries. The MOGLiS project aims at fabricating high performance cathode materials using novel MOF@rGO architectures. These new nanostructures will be synthesized and upscaled by the Norwegian partners in this project with the aim of engineering high performance cathodes sourced from carefully crafted chemistry and tailored nano-architectures. The resulting cathodes will be characterized with superior electrical and mechanical properties with efficient immobilization of sulfur compared to state-of-the-art Li-S cathodes. Upscaling of the developed functional materials using novel flow reactor technology in the view of securing commercialization interests is also planned in MoGLiS. These next generation flexible Li-S cathodes will be designed and demonstrated at TRL 4 for a high initial capacity >1300 mAh.g-1 and a reversible capacity, after 20 cycles, superior to 1200 mAh.g-1, but also a high cyclability with demonstrations >100 cycles with a capacity loss of less than 0.010% per cycle, for a sulfur loading in the cathode superior to 75%.