Xue Shida, Chen Shiming, Fu Yanda, Zhu Hengyao, Ji Yuchen, Song Yongli, Pan Feng, Yang Luyi
School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.
School of Energy and Power Engineering, Jiangsu University, Zhenjiang, 212013, China.
Small. 2023 Nov;19(46):e2305326. doi: 10.1002/smll.202305326. Epub 2023 Jul 27.
Composite solid electrolytes (CSEs) consisting of polyethylene oxide (PEO) matrix and active inorganic fillers have shown great potential for practical applications. However, mechanisms of how different active fillers enhance ion transport in CSEs still remain inconclusive. In this work, the component dependencies of ionic conductivity of PEO-based CSEs are investigated by comparing two widely investigated active fillers: NASICON-type (LATP) and garnet-type (LLZTO). In terms of ionic conductivity, the optimum ratios are strikingly different for LLZTO (10 wt%) and LATP (50 wt%). Through experimental and computational studies, it is demonstrated that the high affinity between LATP and PEO facilitates unhindered interfacial Li transfer so that LATP functions as a bulk-active filler to provide additional inorganic ion pathways. By contrast, Li transfer between LLZTO and PEO is found to be sluggish. Instead, LLZTO mainly improves ionic conductivity by dissociating lithium salt, making it a surface-active filler. Through categorizing active fillers based on their Li conductive mechanisms, this work provides new understanding and guidelines for componential design and optimization of solid composite electrolytes.
由聚环氧乙烷（PEO）基体和活性无机填料组成的复合固体电解质（CSE）在实际应用中显示出巨大潜力。然而，不同活性填料如何增强CSE中离子传输的机制仍尚无定论。在这项工作中，通过比较两种广泛研究的活性填料：NASICON型（LATP）和石榴石型（LLZTO），研究了基于PEO的CSE的离子电导率与成分的相关性。就离子电导率而言，LLZTO（10 wt%）和LATP（50 wt%）的最佳比例显著不同。通过实验和计算研究表明，LATP与PEO之间的高亲和力促进了无障碍的界面Li转移，因此LATP作为本体活性填料发挥作用，提供额外的无机离子传导途径。相比之下，发现LLZTO与PEO之间的Li转移较为缓慢。相反，LLZTO主要通过离解锂盐来提高离子电导率，使其成为表面活性填料。通过根据活性填料的Li传导机制对其进行分类，这项工作为固体复合电解质的成分设计和优化提供了新的认识和指导方针。
