Materials and Composite Structures Unit (UMEC), Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), 4000-014 Porto, Portugal.
LAETA-Associated Laboratory of Energy, Transports and Aeronautics, 4200-265 Porto, Portugal.
Int J Mol Sci. 2023 Jun 27;24(13):10703. doi: 10.3390/ijms241310703.
To effectively use (Li) lithium metal anodes, it is becoming increasingly necessary to create membranes with high lithium conductivity, electrochemical and thermal stabilities, as well as adequate mechanical properties. Composite gel polymer electrolytes (CGPE) have emerged as a promising strategy, offering improved ionic conductivity and structural performance compared to polymer electrolytes. In this study, a simple and scalable approach was developed to fabricate a crosslinked polyethylene oxide (PEO)-based membrane, comprising two different glass fiber reinforcements, in terms of morphology and thickness. The incorporation of a solvated ionic liquid into the developed membrane enhances the ionic conductivity and reduces flammability in the resulting CGPE. Galvanostatic cycling experiments demonstrate favorable performance of the composite membrane in symmetric Li cells. Furthermore, the CGPE demonstrated electrochemical stability, enabling the cell to cycle continuously for more than 700 h at a temperature of 40 °C without short circuits. When applied in a half-cell configuration with lithium iron phosphate (LFP) cathodes, the composite membrane enabled cycling at different current densities, achieving a discharge capacity of 144 mAh·g. Overall, the findings obtained in this work highlight the potential of crosslinked PEO-based composite membranes for high-performance Li metal anodes, with enhanced near room temperature conductivity, electrochemical stability, and cycling capability.
为了有效地使用（锂）金属阳极，越来越有必要创造出具有高锂离子电导率、电化学和热稳定性以及适当机械性能的膜。复合凝胶聚合物电解质（CGPE）作为一种很有前途的策略已经出现，与聚合物电解质相比，它提供了改进的离子电导率和结构性能。在这项研究中，开发了一种简单且可扩展的方法来制备交联聚环氧乙烷（PEO）基膜，该膜由两种不同的玻璃纤维增强体组成，在形态和厚度方面都有所不同。将溶剂化离子液体掺入所开发的膜中，提高了离子电导率并降低了所得 CGPE 的可燃性。恒电流循环实验表明，复合膜在对称 Li 电池中具有良好的性能。此外，CGPE 表现出电化学稳定性，使电池能够在 40°C 的温度下连续循环超过 700 小时而不会发生短路。当应用于具有磷酸铁锂（LFP）阴极的半电池配置时，复合膜能够在不同的电流密度下循环，实现了 144 mAh·g 的放电容量。总的来说，这项工作的结果突出了交联 PEO 基复合膜在高性能 Li 金属阳极中的潜力，其具有增强的室温附近电导率、电化学稳定性和循环能力。
