Li Yutao, Xu Henghui, Chien Po-Hsiu, Wu Nan, Xin Sen, Xue Leigang, Park Kyusung, Hu Yan-Yan, Goodenough John B
Materials Science and Engineering Program and Texas Materials Institute, University of Texas at Austin, Austin, TX, 78712, USA.
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32310, USA.
Angew Chem Int Ed Engl. 2018 Jul 9;57(28):8587-8591. doi: 10.1002/anie.201804114. Epub 2018 Jun 7.
Solid-oxide Li electrolytes of a rechargeable cell are generally sensitive to moisture in the air as H exchanges for the mobile Li of the electrolyte and forms insulating surface phases at the electrolyte interfaces and in the grain boundaries of a polycrystalline membrane. These surface phases dominate the total interfacial resistance of a conventional rechargeable cell with a solid-electrolyte separator. We report a new perovskite Li solid electrolyte, Li Sr Ta Hf O F , with a lithium-ion conductivity of σ =4.8×10 S cm at 25 °C that does not react with water having 3≤pH≤14. The solid electrolyte with a thin Li -conducting polymer on its surface to prevent reduction of Ta is wet by metallic lithium and provides low-impedance dendrite-free plating/stripping of a lithium anode. It is also stable upon contact with a composite polymer cathode. With this solid electrolyte, we demonstrate excellent cycling performance of an all-solid-state Li/LiFePO cell, a Li-S cell with a polymer-gel cathode, and a supercapacitor.
可充电电池的固态氧化物锂电解质通常对空气中的水分敏感，因为氢会与电解质中的可移动锂发生交换，并在电解质界面以及多晶膜的晶界处形成绝缘表面相。这些表面相主导了具有固体电解质隔膜的传统可充电电池的总界面电阻。我们报道了一种新型钙钛矿型锂固体电解质LiSrTaHfOF，在25°C时锂离子电导率σ = 4.8×10⁻³ S·cm⁻¹，它不与pH值在3≤pH≤14的水发生反应。在其表面带有一层薄的锂导电聚合物以防止钽还原的这种固体电解质会被金属锂润湿，并能实现锂阳极的低阻抗无枝晶电镀/脱镀。它与复合聚合物阴极接触时也很稳定。使用这种固体电解质，我们展示了全固态Li/LiFePO₄电池、具有聚合物凝胶阴极的Li-S电池以及超级电容器的优异循环性能。
