报告题目：Probing Li-ion transport in sulfide-based solid state batteries by 7Li solid state NMR
报告人：余创博士
时间：2017年4月17日（星期一）9:30
地点：材料馆A325
报告摘要：
Current flammable liquid organic electrolyte can cause serious problems due to leakage and can cause gas evolution when operating at elevated temperatures and at higher voltages. Unlike the liquid electrolyte, a solid electrolyte does not suffer from these drawbacks and in addition, improves the thermal and mechanical stability of the battery while providing the possibility to work in a higher voltage window under extreme conditions. The halogen doped Li6PS5X (X=Cl, Br, I) evolved from the argyroditie Li7PS6 solid-electrolyte exhibiting a promising Li-ion conductivity of the order of 10-3~10-2 S/cm, approaching the conductivity of liquid electrolyte.Here, we propose an optimized intermediate mechanical milling route for Li6PS5X (X=Cl and Br) precursor. 7Li NMR solid-state NMR measurements including line shape analysis and spin lattice relaxation (SLR) measurements give us lithium hopping rates and bulk diffusion coefficients. These are compared with and discussed in relation to Li-ion diffusion rates and possible diffusion pathways which have been determined using First-principle Molecular Dynamics (MD) simulations and Neutron diffractions. Finally, the performance of this material in a solid-state Li-S cell with different sizes of Li2S particles as the cathode and an In foil anode was studied and an optimum charge/discharge voltage window was determined. The kinetics process of this solid-state cell during cycling process was also investigated by EIS. The Li-ion exchanges between the cathode and the solid electrolyte were investigated by 1D and 2D 7Li-7Li solid-state NMR exchange experiments.
个人简介：
余创博士，毕业于荷兰代尔夫特理工大学(TU Delft)，现为该大学博士后。主要从事固态锂／钠离子电解质的合成及其在全固态锂／钠电池中的应用的研究。研究方法主要采用交流阻抗，DFT模拟和固态核磁共振测试(line shape analysis和Spin-lattice relaxation measurements)揭示锂／钠固态电解质中的离子传导相关机理以及指导其离子传导性能的改善。利用电化学阻抗谱(EIS)以及7Li固态核磁共振离子交换测试技术(1D and 2D 7Li-7Li exchange NMR)探测全固态电池中关键材之间的离子交换动力学，如电极材料和固态电解质之间的固体离子交换，寻找限制两者之间发生快速离子交换的因素，指导改善全固态电池性能的研究，从而获得具有优异电化学性能的全固态电池。参与“欧洲研究委员会European research council（erc）”等重要研究课题，目前已经在JACS，JMCA，PCCP, Electrochimica Acta，Scripta Materialia，Journal of Alloys and Compounds上发表sci学术论文13篇，发表英文专著一章(Chapter 6 Heterogeneous Nanostructured Electrode Materials for Lithium-Ion Batteries – Recent Trends and Developments)。Google学术搜索被引用325次(H因子10，H10因子10)。
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