Yu Jianming, Wang Chao, Li Shiheng, Liu Nian, Zhu Jia, Lu Zhenda
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing, 210093, P. R. China.
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Small. 2019 Oct;15(44):e1902729. doi: 10.1002/smll.201902729. Epub 2019 Sep 9.
Solid-state electrolytes have recently attracted significant attention toward safe and high-energy lithium chemistries. In particular, polyethylene oxide (PEO)-based composite polymer electrolytes (CPEs) have shown outstanding mechanical flexibility and manufacturing feasibility. However, their limited ionic conductivity, poor electrochemical stability, and insufficient mechanical strength are yet to be addressed. In this work, a novel CPE supported by Li -containing SiO nanofibers is developed. The nanofibers are obtained via sol-gel electrospinning, during which lithium sulfate is in situ introduced into the nanofibers. The uniform doping of Li SO in SiO nanofibers increases the Li conductivity of SiO , generates mesopores on the surface of SiO nanofibers, and improves the wettability between SiO and PEO. As a result, the obtained SiO /Li SO /PEO CPE yields high Li conductivity (1.3 × 10 S cm at 60 °C, ≈4.9 times the Li SO -free CPE) and electrochemical stability. Furthermore, the all-solid-state LiFePO -Li full cell demonstrates stable cycling with high capacities (over 80 mAh g , 50 cycles at C/2 at 60 °C). The Li -containing mesoporous SiO nanofibers show great potential as the filler for CPEs. Similar methods can be used to incorporate Li salts into other filler materials for CPEs.
固态电解质最近在安全和高能量锂化学领域引起了广泛关注。特别是，基于聚环氧乙烷（PEO）的复合聚合物电解质（CPE）表现出出色的机械柔韧性和制造可行性。然而，它们有限的离子电导率、较差的电化学稳定性和不足的机械强度仍有待解决。在这项工作中，开发了一种由含锂SiO纳米纤维支撑的新型CPE。通过溶胶 - 凝胶静电纺丝获得纳米纤维，在此过程中硫酸锂原位引入到纳米纤维中。Li₂SO₄在SiO₂纳米纤维中的均匀掺杂提高了SiO₂的锂电导率，在SiO₂纳米纤维表面产生中孔，并改善了SiO₂与PEO之间的润湿性。结果，所获得的SiO₂/Li₂SO₄/PEO CPE具有高的锂电导率（60°C时为1.3×10⁻⁴ S cm⁻¹，约为不含Li₂SO₄的CPE的4.9倍）和电化学稳定性。此外，全固态LiFePO₄-Li全电池在高容量下（超过80 mAh g⁻¹，60°C时在C/2下循环50次）表现出稳定的循环性能。含锂介孔SiO₂纳米纤维作为CPE的填料显示出巨大潜力。类似的方法可用于将锂盐掺入其他CPE的填料材料中。
