Yan Shuo, Al-Salih Hilal, Yim Chae-Ho, Merati Ali, Baranova Elena A, Weck Arnaud, Abu-Lebdeh Yaser
Department of Chemical and Biological Engineering, Centre for Catalysis Research and Innovation (CCRI), University of Ottawa, Ottawa, ON, Canada.
National Research Council of Canada, Ottawa, ON, Canada.
Front Chem. 2022 Aug 10;10:966274. doi: 10.3389/fchem.2022.966274. eCollection 2022.
Perovskite LaLiTiO (LLTO) materials are promising solid-state electrolytes for lithium metal batteries (LMBs) due to their intrinsic fire-resistance, high bulk ionic conductivity, and wide electrochemical window. However, their commercialization is hampered by high interfacial resistance, dendrite formation, and instability against Li metal. To address these challenges, we first prepared highly dense LLTO pellets with enhanced microstructure and high bulk ionic conductivity of S cm at room temperature. Then, the LLTO pellets were coated with three polymer-based interfacial layers, including pure (polyethylene oxide) (PEO), dry polymer electrolyte of PEO-LITFSI (lithium bis (trifluoromethanesulfonyl) imide) (PL), and gel PEO-LiTFSI-SN (succinonitrile) (PLS). It is found that each layer has impacted the interface differently; the soft PLS gel layer significantly reduced the total resistance of LLTO to a low value of 84.88 Ω cm. Interestingly, PLS layer has shown excellent ionic conductivity but performs inferior in symmetric Li cells. On the other hand, the PL layer significantly reduces lithium nucleation overpotential and shows a stable voltage profile after 20 cycles without any sign of Li dendrite formation. This work demonstrates that LLTO electrolytes with denser microstructure could reduce the interfacial resistance and when combined with polymeric interfaces show improved chemical stability against Li metal.
钙钛矿型LaLiTiO（LLTO）材料因其固有的耐火性、高体相离子电导率和宽电化学窗口，有望成为锂金属电池（LMBs）的固态电解质。然而，其商业化受到高界面电阻、枝晶形成以及对锂金属不稳定的阻碍。为应对这些挑战，我们首先制备了具有增强微观结构且室温下体相离子电导率为 S cm的高密度LLTO颗粒。然后，在LLTO颗粒上涂覆了三层聚合物基界面层，包括纯（聚环氧乙烷）（PEO）、PEO-LITFSI（双（三氟甲烷磺酰）亚胺锂）的干聚合物电解质（PL）以及凝胶状PEO-LiTFSI-丁二腈（PLS）。结果发现，每层对界面的影响各不相同；柔软的PLS凝胶层将LLTO的总电阻显著降低至84.88 Ω cm的低值。有趣的是，PLS层显示出优异的离子电导率，但在对称锂电池中的表现较差。另一方面，PL层显著降低了锂成核过电位，并在20次循环后显示出稳定的电压曲线，没有任何锂枝晶形成的迹象。这项工作表明，具有更致密微观结构的LLTO电解质可以降低界面电阻，并且与聚合物界面结合时，对锂金属表现出更好的化学稳定性。
