讲座报告主题：Heteroatom (P, O, and N)-doped Hollow Carbon/Graphene Nanocomposites as Efficient Hosts for sulfur cathodes in Lithium-sulfur Batteries
专家姓名：Jeongyeon Jaden Lee
主讲概况：Jeongyeon (Jaden) Lee是香港理工大学应用生物与化工系博士后高级研究人员，2013年获韩国仁荷大学材料科学学士学位，2019年2月获韩国国立首尔大学纳米科学博士学位。主要研究方向是基于锂金属的二次电池，特别是锂硫电池。在国际学术期刊上发表19篇学术论文，其中15篇是第一编辑。多篇论文被选为学术期刊封面或封底论文，取得了较大关注。他的文章被SCI引用超过270次。他在合成纳米复合材料、电化学表征和锂基电池组装测试方面有丰富的经验和技术。研究专长：基于锂金属的二次电池，特别是锂硫电池。
主讲内容：Lithium-sulfur batteries with their high theoretical capacity and energy density are one of the most promising candidates as an alternative devices for conventional lithium-ion batteries. However, there are several challenges for commercialization of Li-S batteries, such as the low electrical conductivity of sulfur, the excess dissolution of lithium polysulfides, and the volume expansion during the cycling, resulting in low coulombic efficiency, the capacity fading, and poor cycle life. In this work, P, O, and N heteroatoms-doped hollow carbons on graphene (PONHC/G) from nano-sized LiFePO4 (LFP) as a hard template are shown to be a very efficient sulfur host for lithium-sulfur batteries. The PONHC/G made from LFP nanoparticles as hard materials provides sufficient voids with various pore sizes for sulfur storage and doping of the carbon structures with various heteroatoms minimized dissolution/diffusion of the polysulfides. The obtained PONHC/G can store sulfur and mitigate diffusion of the dissolved polysulfide owing to the well-organized host structure and the strong chemical affinity for polysulfides due to the polarization effect of the heteroatom dopants. As a cathode, S@PONHC/G shows excellent cycle stability and rate capability.