Wu Nan, Chien Po-Hsiu, Qian Yumin, Li Yutao, Xu Henghui, Grundish Nicholas S, Xu Biyi, Jin Haibo, Hu Yan-Yan, Yu Guihua, Goodenough John B
Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China.
Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Angew Chem Int Ed Engl. 2020 Mar 2;59(10):4131-4137. doi: 10.1002/anie.201914478. Epub 2020 Jan 23.
Li -conducting oxides are considered better ceramic fillers than Li -insulating oxides for improving Li conductivity in composite polymer electrolytes owing to their ability to conduct Li through the ceramic oxide as well as across the oxide/polymer interface. Here we use two Li -insulating oxides (fluorite Gd Ce O and perovskite La Sr Ga Mg O ) with a high concentration of oxygen vacancies to demonstrate two oxide/poly(ethylene oxide) (PEO)-based polymer composite electrolytes, each with a Li conductivity above 10 S cm at 30 °C. Li solid-state NMR results show an increase in Li ions (>10 %) occupying the more mobile A2 environment in the composite electrolytes. This increase in A2-site occupancy originates from the strong interaction between the O of Li-salt anion and the surface oxygen vacancies of each oxide and contributes to the more facile Li transport. All-solid-state Li-metal cells with these composite electrolytes demonstrate a small interfacial resistance with good cycling performance at 35 °C.
由于锂导电氧化物能够通过陶瓷氧化物以及跨越氧化物/聚合物界面传导锂，因此在改善复合聚合物电解质的锂电导率方面，它们被认为是比锂绝缘氧化物更好的陶瓷填料。在此，我们使用两种具有高氧空位浓度的锂绝缘氧化物（萤石型GdCeO和钙钛矿型LaSrGaMgO）来展示两种基于氧化物/聚环氧乙烷（PEO）的聚合物复合电解质，在30°C时每种电解质的锂电导率均高于10 S cm。锂固态核磁共振结果表明，复合电解质中占据迁移性更强的A2环境的锂离子增加（>10%）。A2位点占有率的这种增加源于锂盐阴离子的O与每种氧化物的表面氧空位之间的强相互作用，并有助于锂的更易传输。具有这些复合电解质的全固态锂金属电池在35°C时表现出较小的界面电阻和良好的循环性能。
