Abstract A composite solid electrolyte based on Al-doped Li7-3xAlxLa3Zr2O12 (LALZO) was synthesized by the sol-gel method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) were used to characterize Li7La3Zr2O12 (LLZO) precursors with different Al doping concentrations. The results show that LLZO precursor doped with 0.4 mol% Al (LALZO-4) has high stability and good crystallinity. Further, this composite solid electrolyte was co-coated with carbon to optimize the LiFePO4 battery. Electrochemical performance tests show that the LiFePO4/C battery with 5% LALZO-4 precursor (LFP-5) exists in the form of uniformly dispersed spherical particles, and exhibits excellent cycling stability and high rate performance. In addition, the LALZO-4 coating layer can increase the diffusion rate by reducing the charge transfer resistance.

中文翻译：

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通过Al掺杂Li7La3Zr2O12和碳共涂层表面改性提高LiFePO4正极材料的电化学性能

摘要 采用溶胶-凝胶法合成了一种基于Al掺杂Li7-3xAlxLa3Zr2O12（LALZO）的复合固体电解质。X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和能量色散谱 (EDS) 用于表征具有不同 Al 掺杂浓度的 Li7La3Zr2O12 (LLZO) 前驱体。结果表明，掺杂 0.4 mol% Al 的 LLZO 前驱体（LALZO-4）具有较高的稳定性和良好的结晶度。此外，该复合固体电解质与碳共涂层以优化 LiFePO4 电池。电化学性能测试表明，含有 5% LALZO-4 前驱体（LFP-5）的 LiFePO4/C 电池以均匀分散的球形颗粒形式存在，表现出优异的循环稳定性和高倍率性能。此外，