Graphene Based Materials for Lithium Sulfur Batteries
Beijing Institute of Technology
Abstract: Lithium sulfur batteries attract great attention due to their advantages in high theoretical energy density. However, the practical applications of Li-S batteries are still hindered by the insulating nature of sulfur, the volumetric fluctuation during cycles, and also the dissolution/shuttle of polysulfides. In this presentation, the rational design of cathode and separator materials based on graphene materials for Li-S batteries will be dicussed.
To tackle the problems in the sulfur cathode towards the full utilization of active sulfur materials, a series of hierarchical nanocarbon hosts were developed to accommodate sulfur materials. Further introduction of heteroatom doping and other additives like TiC, etc. realized the chemisorption of polysulfide, and the propelling of kinetics in polysulfide redox reactions. These concepts also enabled the fabrication of highly efficient sulfur cathode with high areal loading towards practical applications.
Despite great effort devoted to solving the polysulfide shuttle between the cathodes, it remains as a serious challenge to build high-stable lithium sulfur battery, which related to the inevitable diffusion and reaction between polysulfides and the lithium metal. We proposed ion selective membrane to improve the stability and coulombic efficiency of lithium sulfur battery. With the permselective membrane, the polysulfide anions can be confined in the cathode side, which would favor the cyclic stability and lower self-discharge performance. Moreover, multifunctional separators with conductive layer was also introduced in lithium sulfur batteries to facilitate the reactivation and electrochemical conversion of sulfur-containing species.
Biography: Dr. Jia-Qi Huang received his bachelor and Ph.D. degree in Department of Chemical Engineering from Tsinghua University in 2007 and 2012, respectively. Currently, he is a professor in Advanced Research Institute for Multidisciplinary Science at Beijing Institute of Technology. His research interests covers the synthesis approaches and application of nanomaterials for rechargeable batteries, especially lithium sulphur batteries. He has published over 100 peer-reviewed SCI papers in scientific journals of Adv. Mater., ACS Nano, Energy Environ. Sci., etc. These papers have been cited for over 5500 times, with a H-index of 42. Over twenty papers out of these publications are Essential Science Indicators Highly Cited Paper.