Zhang Lun, Feng Junrun, Zhu Guanghan, Yan Jay, Bartlett Stuart, Wang Zhipeng, Hao Zhangxiang, Gao Zhonghui, Wang Ryan
Materials and Catalysis Laboratory, Department of Chemical Engineering, University College London, London WC1E 7JE, United Kingdom.
School of Science, School of Chip Industry, Hubei University of Technology, Wuhan, Hubei 430068, China.
ACS Appl Mater Interfaces. 2024 Mar 20;16(11):13786-13794. doi: 10.1021/acsami.3c19519. Epub 2024 Mar 6.
PEO-LiX solid polymer electrolyte (SPE) with the addition of LiLaZrTaO (LLZTO) fillers is considered as a promising solid-state electrolyte for solid-state Li-ion batteries. However, the developments of the SPE have caused additional challenges, such as poor contact interface and SPE/Li interface stability during cycling, which always lead to potentially catastrophic battery failure. The main problem is that the real impact of LLZTO fillers on the interfacial properties between SPE and Li metal is still unclear. Herein, we combined the electrochemical measurement and in situ synchrotron-based X-ray absorption near-edge structure (XANES) imaging technology to study the role of LLZTO fillers in directing SPE/Li interface electrochemical performance. In situ XRF-XANES mapping during cycling showed that addition of an appropriate amount of LLZTO fillers (50 wt %) can improve the interfacial contact and stability between SPE and Li metal without reacting with the PEO and Li salts. Additionally, it also demonstrated the beneficial effect of LLZTO particles for suppressing the interface reactions between the Li metal and PEO-LiTFSI SPE and further inhibiting Li-metal dendrite growth. The Li|LiFePO batteries deliver long cycling for over 700 cycles with a low-capacity fade rate of 0.08% per cycle at a rate of 0.3C, revealing tremendous potential in promoting the large-scale application of future solid-state Li-ion batteries.
添加了LiLaZrTaO（LLZTO）填料的聚环氧乙烷-锂盐（PEO-LiX）固态聚合物电解质（SPE）被认为是一种很有前景的固态锂离子电池固态电解质。然而，SPE的发展带来了额外的挑战，例如循环过程中接触界面不佳以及SPE/锂界面稳定性差，这总是会导致潜在的灾难性电池故障。主要问题在于LLZTO填料对SPE与锂金属之间界面性质的实际影响仍不清楚。在此，我们结合电化学测量和基于同步加速器的原位X射线吸收近边结构（XANES）成像技术，研究LLZTO填料在指导SPE/锂界面电化学性能方面的作用。循环过程中的原位XRF-XANES映射表明，添加适量的LLZTO填料（50重量%）可以改善SPE与锂金属之间的界面接触和稳定性，而不会与PEO和锂盐发生反应。此外，它还证明了LLZTO颗粒在抑制锂金属与PEO-LiTFSI SPE之间界面反应以及进一步抑制锂金属枝晶生长方面的有益作用。锂|磷酸铁锂电池在0.3C倍率下可实现超过700次的长循环，容量衰减率低至每循环0.08%，在推动未来固态锂离子电池大规模应用方面显示出巨大潜力。
