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题目：Sodium vs. Lithium Batteries. Towards an All Solid-State Sodium Ion Battery
演讲人：Richard M. Laine教授，外籍千人专家，密歇根大学 材料科学与工程系
时间：2018年4月20日（本周五）13：30-
地点：化学楼B楼410室
邀请人：杨 军 教授

报告摘要
β’’-Al2O3 is used commercially as a Na+ conducting ceramic electrolyte for its high ionic conductivity (0.2-0.3 S cm-1 at 300°C) and low materials’ costs. However, for batteries using β'’-Al2O3, about half of the cell resistance arises from the electrolyte itself because traditionally processed electrolyte materials are 1-2 mm thick. One can anticipate dramatic drops in cell resistance at thicknesses <100 µm. However, the traditional high sintering temperatures of 1600 °C/0-4 h cause rapid and excessive Na2O loss driving formation of β- rather than β'’-Al2O3 lowering ionic conductivities limiting final properties.

In line with our latest success using flame made nanopowders (NPs) to minimize the external energy input for sintering Li7La3Zr2O12, the Li+ conducting ceramic electrolyte known for its difficulty in sintering, we show that the same approach can be used to process Na+ β’’-Al2O3. In this study, β’’-Al2O3, TiO2 and ZrO2 NPs were produced by liquid-feed flame spray pyrolysis (LF-FSP). As expected, superior densification of β'’-Al2O3 films occurs with increasing TiO2 wt. %. Near full densities are reached at ≥ 1360 °C/2 h. Further efforts were explored to perturb grain reorientation during liquid phase sintering, and also pin grain boundaries to reduce grain growth that also reduced Na2O loss rate by reducing surface exposure of β’’-Al2O3. These efforts will be described as well as methods to sinter β'’-Al2O3 at 1320 °C, the lowest ever reported providing superionic sodium ion conductivities at room temperature. Symmetrical Na/ β’’-Al2O3/Na cells offer room temperature performance pointing the way to all solid state, thin-film Na batteries.

报告人简历
Richard M. Laine is currently a full Professor in the Dept. of Materials Science and Engineering (MSE) and Professor and Director Emeritus of the Macromolecular Science and Engineering Center.  Dr. Laine received a Ph.D. in Chemistry from the University of Southern California in 1973 (Prof. Robert Bau).  Following three years of postdoctoral study (R.F. Heck, Delaware; P.C. Ford, UCSB), Dr. Laine worked at SRI International for 11 years, last as Associate Director of Inorganic and Organometallic Chemistry Programs. A change in interests led to the positions of Full Research Professor in the Dept. of MSE at the University of Washington and Director of the Polymeric Materials Laboratory in the Washington Technology Center. Dr. Laine joined UM in 1990 as Associate Professor. He is a 2013 recipient of the International Fellow Award of Society of Polymer Science of Japan. He became an ACC fellow in 2015.

Major research areas for the Laine group include the synthesis and processing of inorganic and organometallic hybrid polymers and nanooxide powders for their catalytic (energy conversion in particular) and photonic applications. Research in the nanooxide powder area emphasizes the direct synthesis of single and mixed-metal oxide nanopowders by flame spray pyrolysis of mixed-metal alkoxides. The Laine group has over 265 published papers, 47 patents and 8 books.