Cuevas Ignacio, Elbouazzaoui Kenza, Valvo Mario, Mindemark Jonas, Brandell Daniel, Edström Kristina
Department of Chemistry - Ångström Laboratory, Uppsala University, Box 538, SE-751 21, Uppsala, Sweden.
ChemSusChem. 2025 Feb 1;18(3):e202401304. doi: 10.1002/cssc.202401304. Epub 2024 Nov 1.
Despite being promoted as a superior Li-ion conductor, lithium lanthanum zirconium oxide (LLZO) still suffers from a number of shortcomings when employed as an active ceramic filler in composite polymer-ceramic solid electrolytes for rechargeable all-solid-state lithium metal batteries. One of the main limitations is the detrimental presence of LiCO on the surface of LLZO particles, restricting Li-ion transport at the polymer-ceramic interfaces. In this work, a facile way to improve this interface is presented, by purposely engineering the LLZO particle surfaces for a better compatibility with a PEO:LiTFSI solid polymer electrolyte matrix. It is shown that a surface treatment based on immersing LLZO particles in a boric acid solution can improve the LLZO surface chemistry, resulting in an enhancement in the ionic conductivity and cation transference number of the CPE with 20 wt % of boron-treated LLZO particles compared to the analogous CPE with non-treated LLZO. Ultimately, an improved cycling performance and stability in Li//LiFePO cells was also demonstrated for the modified material.
尽管锂镧锆氧化物（LLZO）被宣传为一种优异的锂离子导体，但在用作可充电全固态锂金属电池的复合聚合物-陶瓷固体电解质中的活性陶瓷填料时，它仍然存在许多缺点。主要限制之一是LLZO颗粒表面存在有害的LiCO，这限制了聚合物-陶瓷界面处的锂离子传输。在这项工作中，提出了一种改善这种界面的简便方法，即通过有目的地设计LLZO颗粒表面，使其与PEO:LiTFSI固体聚合物电解质基体具有更好的相容性。结果表明，将LLZO颗粒浸入硼酸溶液中的表面处理可以改善LLZO的表面化学性质，与含有未处理LLZO的类似复合聚合物电解质相比，含有20 wt%经硼处理的LLZO颗粒的复合聚合物电解质的离子电导率和阳离子迁移数有所提高。最终，改性材料在Li//LiFePO电池中也表现出了改善的循环性能和稳定性。
