The lithium-sulfur (Li-S) battery with a high theoretical specific energy of 2600 Wh/kg and a high reversible capacity of 1675 mAh/g is evaluated to have great potential as a next-generation battery. Unfortunately, the energy density of a practical Li-S battery is far from theoretical values due to the following factors, such as the electrical insulating characteristics of sulfur and Li2S/Li2S2, and migration of soluble intermediate lithium polysulfide (shuttle effect). Although various approaches have been reported to solve the above problems, the fabrication process of these reported materials is complicated and expensive.
We are interested in using conductive carbon-based materials and polymers to resolve the aforementioned issues. Highly conductive materials can reduce charge transfer resistance and improve electrochemical properties in the battery. We are also trying to suppress the shuttle effect by using functional groups in the polymer materials. In addition, the effect of shape is also being studied by forming the aforementioned conductive material into a nanometer-thick large-area film or 3D structure using solution-shearing technique or 3D printing.