后处理工艺对POSS-PMMA8改性凝胶聚合物电解质性能的影响

摘要

To improve the ion conductivity and tensile strength of gel polymer electrolyte (GPE), a novel star-shaped polyhedral oligomericsilsesquioxane-polymethyl methacrylate (POSS-PMMA8) was successfully synthetized and introduced to the polymethyl methacrylate/polyacrylonitrile/polyvinylidene fluoride (PMMA-PAN-PVDF) matrix to obtain fibrous membrane M1 (POSS-PMMA8/PMMA-PAN-PVDF) by electrospinning.Membrane M1 was annealed at 120 oC to get membrane M2, or processed by hotpressing and pre-oxidizing to get membrane M3.Then the corresponding activated GPEs were prepared by soaking M1, M2 and M3 in liquid electrolyte.The morphologies, porosity, electrolyte uptake, and mechanical properties of these membranes (M1, M2 and M3), as well as the ion conductivity and electrochemical stability of their corresponding GPEs were fully investigated.The results show that, compared to M1, the tensile strength of M2 and ion conductivity of its GPE increase by 9.2% and 181.1%, respectively, and the electrochemical window of M2 and its GPE increases to 5.3 V;besides, the tensile strength of M3 and ion conductivity of its GPE increase by 193.7% and 20.2%, respectively, and the electrochemical window of M3 and its GPE increases to 5.5 V.%为解决凝胶聚合物电解质(GPE)的离子电导率低、 力学性能差等问题, 通过静电纺丝制备星型笼型低聚倍半硅氧烷-聚甲基丙烯酸甲酯(POSS-PMMA8)改性聚甲基丙烯酸甲酯-聚丙烯腈-聚偏氟乙烯(PMMA-PAN-PVDF)得到聚合物纺丝薄膜(POSS-PMMA8/PMMA-PAN-PVDF)M1, 将聚合物纺丝薄膜M1在120℃热处理得到聚合物纺丝薄膜M2, 或热压并预氧化处理得到聚合物纺丝薄膜M3, 将其浸泡于电解液中活化得到POSS-PMMA8/PMMA-PAN-PVDF的GPE.对不同状态聚合物纺丝薄膜M1、 M2、 M3的形貌、 孔隙率、 吸液率、 力学性能及其GPE的电导率和电化学稳定窗口进行测试.结果发现, 相比于M1, M2的拉伸强度及GPE的电导率分别提高9.2%及181.1%, 电化学窗口增至5.3 V;而M3的拉伸强度和GPE电导率分别较M1增加193.7%、 20.2%, 电化学窗口增至5.5 V.