中国科学院化学研究所郭玉国团队研究软陶瓷氧化物电解质中桥连粒子间Li+导电性能。 相关研究成果于2021年4月12日发表于国际顶尖学术期刊《美国化学会杂志》。

石榴石结构的Li7La3Zr2O12等锂离子导电陶瓷氧化物电解质被认为是实现高能量密度下一代固态锂金属电池的理想材料。实际上，在高温下烧结的陶瓷颗粒通常具有高刚度低断裂韧性，使得它们对于制造薄膜电解质和涉及应变的固态电池操作来说太脆。虽然陶瓷粉末具有延展性，但由于陶瓷颗粒边界处的离子导电性差，因此不能获得令人满意的高Li+导电性。

该文中，研究人员通过固态核磁共振表明，在陶瓷氧化物颗粒表面形成的均匀共轭聚合物纳米涂层为未烧结陶瓷中相邻颗粒之间的Li+传导建立了通路。由聚合物包覆的陶瓷颗粒制备的流延薄膜电解质（厚度<10μm）具有足够的离子导电性、高的锂离子迁移数和宽的电化学窗口，使对称锂/锂电池和全固态可充电锂金属电池能够稳定循环。

附：英文原文

Title: Bridging Interparticle Li+ Conduction in a Soft Ceramic Oxide Electrolyte

Author: Wan-Ping Chen, Hui Duan, Ji-Lei Shi, Yumin Qian, Jing Wan, Xu-Dong Zhang, Hang Sheng, Bo Guan, Rui Wen, Ya-Xia Yin, Sen Xin, Yu-Guo Guo, Li-Jun Wan

Issue&Volume: April 12, 2021

Abstract: Li+-conductive ceramic oxide electrolytes, such as garnet-structured Li7La3Zr2O12, have been considered as promising candidates for realizing the next-generation solid-state Li-metal batteries with high energy density. Practically, the ceramic pellets sintered at elevated temperatures are often provided with high stiffness yet low fracture toughness, making them too brittle for the manufacture of thin-film electrolytes and strain-involved operation of solid-state batteries. The ceramic powder, though provided with ductility, does not yield satisfactorily high Li+ conductivity due to poor ion conduction at the boundaries of ceramic particles. Here we show, with solid-state nuclear magnetic resonance, that a uniform conjugated polymer nanocoating formed on the surface of ceramic oxide particles builds pathways for Li+ conduction between adjacent particles in the unsintered ceramics. A tape-casted thin-film electrolyte (thickness: <10 μm), prepared from the polymer-coated ceramic particles, exhibits sufficient ionic conductivity, a high Li+ transference number, and a broad electrochemical window to enable stable cycling of symmetric Li/Li cells and all-solid-state rechargeable Li-metal cells.

DOI: 10.1021/jacs.0c12965

Source: https://pubs.acs.org/doi/10.1021/jacs.0c12965