Enhanced Surface Interactions Enable Fast Li + Conduction in Oxide/Polymer Composite Electrolyte
Enhanced Surface Interactions Enable Fast Li + Conduction in Oxide/Polymer Composite Electrolyte
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增强的表面相互作用可实现氧化物/聚合物复合电解质中的快速锂传导
DOI：
10.1002/ange.201914478
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发表时间：
2020
影响因子：
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通讯作者：
Yu, Guihua
中科院分区：
文献类型：
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作者：
Wu, Nan;Chien, Po‐Hsiu;Qian, Yumin;Li, Yutao;Xu, Henghui;Grundish, Nicholas S.;Xu, Biyi;Jin, Haibo;Hu, Yan‐Yan;Yu, Guihua
Li+-导电氧化物被认为是比Li+-绝缘氧化物更好的陶瓷填料，用于改善复合聚合物电解质中的Li+导电性，这是因为它们能够通过陶瓷氧化物以及穿过氧化物/聚合物界面传导Li+。在这里，我们使用两种具有高浓度氧空位的Li+绝缘氧化物（萤石Gd0.1Ce0.9O1.95和钙钛矿La0.8Sr0.2Ga0.8Mg0.2O2.55）来演示两种氧化物/聚环氧乙烷（PEO）基聚合物复合电解质，每种电解质在30 °C下的Li+电导率均高于10−4S cm− 1。Li固态NMR结果显示在复合电解质中占据更移动的A2环境的Li+离子（> 10%）增加。这种A2-位占据率的增加源于Li-盐阴离子的O2-与每种氧化物的表面氧空位之间的强相互作用，并有助于更容易的Li+传输。具有这些复合电解质的全固态锂金属电池在35 °C下表现出小的界面电阻和良好的循环性能。
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 Gd0.1Ce0.9O1.95and perovskite La0.8Sr0.2Ga0.8Mg0.2O2.55) 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 10−4S cm−1at 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 O2−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.