Tang Wenhao, Deng Yirui, Xing Zhiwei, Zhang Xin, Zhou Taotao, Hou Lianlong, Zhao Dalei, Liu Ruiping
School of Chemical & Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, P. R. China.
Hebei Provincial Key Laboratory of Flexible Functional Materials, Hebei University of Science and Technology, Shijiazhuang, 050091, P. R. China.
Small Methods. 2025 Jul;9(7):e2401606. doi: 10.1002/smtd.202401606. Epub 2024 Nov 22.
Lithium metal battery with high specific energy and high safety is crucial for the next-generation energy storage technologies. However, the poor thermal stability, lower mechanical performance, and poor electrochemical performance of the commercially available polyethylene (PE) separator hinders the development of high-specific lithium metal batteries. Herein, a functional PE separator is prepared by innovative coating the TiNbO microspheres with oxygen vacancies on the surface of PE (denoted as TNO-PE). The porosity, contact angle, electrolyte uptake rate, thermal shrinkage rate, mechanical properties, conductivity as well as lithium ions transference number of the TNO modified PE separator are all improved. The favorable TNO is beneficial for facilitating fast Li migration and impeding anions transfer, guiding the uniform distribution of lithium-ion flux. Consequently, the lithium symmetric cells with TNO-PE separator can be stably cycled more than 1600 h at 1 mA cm, and the initial capacity of the LFP/Li cells with TNO-PE separator is as high as 139.8 mAh g, and after 500 cycles, the capacity retention rate is still 99.5%. This work may provide a new idea to construct a multi-functional separator with high safety and superior electrochemical performance and promote the development of LMBs.
具有高比能量和高安全性的锂金属电池对于下一代储能技术至关重要。然而，市售聚乙烯（PE）隔膜较差的热稳定性、较低的机械性能和不良的电化学性能阻碍了高比能锂金属电池的发展。在此，通过在PE表面创新性地涂覆具有氧空位的TiNbO微球制备了一种功能性PE隔膜（表示为TNO-PE）。TNO改性PE隔膜的孔隙率、接触角、电解液吸收率、热收缩率、机械性能、电导率以及锂离子迁移数均得到改善。良好的TNO有利于促进Li快速迁移并阻碍阴离子传输，引导锂离子通量均匀分布。因此，采用TNO-PE隔膜的锂对称电池在1 mA cm下可稳定循环超过1600 h，采用TNO-PE隔膜的LFP/Li电池的初始容量高达139.8 mAh g，500次循环后容量保持率仍为99.5%。这项工作可能为构建具有高安全性和优异电化学性能的多功能隔膜提供新思路，并推动锂金属电池的发展。
