Wang Tao, Ock Jiyoung, Chen X Chelsea, Wang Fan, Li Meijia, Chambers Matthew S, Veith Gabriel M, Shepard Lauren B, Sinnott Susan B, Borisevich Albina, Chi Miaofang, Bhattacharya Amit, Clément Raphaële J, Sokolov Alexei P, Dai Sheng
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Department of Chemistry, Institute for Advanced Materials and Manufacturing, University of Tennessee, Knoxville, TN, 37996, USA.
Adv Sci (Weinh). 2025 Jan;12(3):e2408805. doi: 10.1002/advs.202408805. Epub 2024 Nov 25.
Inorganic fillers play an important role in improving the ionic conductivity of solid composite electrolytes (SCEs) for Li-ion batteries. Among inorganic fillers, perovskite-type lithium lanthanum titanate (LLTO) stands out for its high bulk Li conductivity on the order of 10 S cm at room temperature. According to a literature survey, the optimal LLTO filler should possess the following characteristics: i) a single-crystal structure to minimize grain boundaries; ii) a small particle size to increase the filler/polymer interface area; iii) a 1D morphology for efficient interface channels; and iv) cubic symmetry to facilitate rapid bulk Li diffusion within the filler. However, the synthesis of single crystal, 1D LLTO nanomaterials with cubic symmetry is challenging. Herein, a flux strategy is developed to synthesize LaMTiO (LMTO, M═Li, Na, and K) single-crystal nanorods with an A-site-disordered, cubic perovskite phase. The flux media promotes the oriented growth of nanorods, prevents nanorods from sintering, and provides multiple alkali metal ion doping at M sites to stabilize the cubic phase. SCEs compositing the Li-conducting LMTO nanorods as fillers and poly[vinylene carbonate-co-lithium sulfonyl(trifluoromethane sulfonyl)imide methacrylate] matrix exhibit more than twice the conductivity of the neat polymer electrolyte (30.6 vs 14.0 µS cm at 303 K).
无机填料在提高锂离子电池固体复合电解质（SCE）的离子电导率方面起着重要作用。在无机填料中，钙钛矿型钛酸锂镧（LLTO）因其在室温下高达10 S cm数量级的高本体锂电导率而脱颖而出。根据文献调查，最佳的LLTO填料应具备以下特性：i）单晶结构以最小化晶界；ii）小粒径以增加填料/聚合物界面面积；iii）一维形态以形成高效的界面通道；iv）立方对称性以促进锂在填料内的快速本体扩散。然而，合成具有立方对称性的单晶、一维LLTO纳米材料具有挑战性。在此，开发了一种助熔剂策略来合成具有A位无序立方钙钛矿相的LaMTiO（LMTO，M = Li、Na和K）单晶纳米棒。助熔剂介质促进纳米棒的定向生长，防止纳米棒烧结，并在M位提供多种碱金属离子掺杂以稳定立方相。以锂导电的LMTO纳米棒作为填料和聚[碳酸亚乙烯酯 - 甲基丙烯酸锂磺酰基（三氟甲烷磺酰基）亚胺酯]基体复合而成的SCE，在303 K时的电导率是纯聚合物电解质的两倍多（30.6对14.0 µS cm）。
