PVDF基复合凝胶聚合物电解质的制备及其性能研究

发布时间：2018-06-03 02:14

本文选题：聚合物锂离子电池 + 聚合物电解质　；参考：《江苏科技大学》2014年硕士论文

【摘要】：聚合物锂离子电池是目前锂电池研究的最高水平，它不仅具有液态锂离子电池的特点，而且还在形状设计、容量、充放电效率、循环寿命和环保性能等方面更具优势。此外，聚合物锂离子电池还不存在液态电解质电池所存在的漏液污染和燃烧爆炸等问题，从根本上解决安全隐患。本文重点研究了聚偏氟乙烯(PVDF)基体的复合多孔凝胶聚合物电解质，用不同方法设计制备了三种复合多孔凝胶聚合物电解质：(1)采用原位聚合和溶胶凝胶法制备出新型添加剂SiO2(Li+)，以浸没沉淀法制备出复合多孔凝胶聚合物电解质样品。通过SEM对其形貌进行表征，对样品进行电化学方面的交流阻抗、线性伏安扫描和电池性能进行了测试。研究结果表明，添加5%SiO2(Li+)的复合聚合物电解质形貌均匀，对应的凝胶聚合物电解质的室温离子电导率达4.6×10-3S/cm，电化学稳定窗口可达5.1V；(2)采用溶液聚合反应与中和反应合成一种新型离子聚合物：聚氨酯锂盐(PLS)，以热相分离法制备出混合多孔凝胶聚合物电解质。电化学性能测试表明，10%PLS共混的复合多孔凝胶聚合物电解质室温离子电导率可达2.5×10-3S/cm、离子迁移数达0.457、电化学稳定窗口可达4.95V以及充放电50次循环后的放电容量仍然可达到初始放电容量的89%；(3)采用原位聚合法与酸碱中和法制备出一种有机物包覆无机相的新型有机/无机纳米粒子(SiO2-PAALi)，以静电纺丝法制备出纳米复合凝胶聚合物电解质。机械性能测试表明，，掺杂SiO2-PAALi纳米颗粒制备出的静电纺膜，其拉伸强度和断裂伸长率分别可达48.8MPa和25.6%。电化学测试分析表明，添加SiO2-PAALi颗粒凝胶聚合物电解质的电化学性能得到了很大的提升。其室温离子电导率为3.5×10-3S/cm、离子电导率与温度的关系符合阿累尼乌斯关系式；电化学稳定窗口可达5.05V、及充放30次循环后的放电容量仍然可达到初始放电容量的96.99%，表现出良好的循环性能。
[Abstract]:Polymer lithium-ion battery is the highest research level at present. It not only has the characteristics of liquid lithium-ion battery, but also has more advantages in shape design, capacity, charge / discharge efficiency, cycle life and environmental protection performance. In addition, polymer lithium-ion batteries do not have the problems of liquid leakage pollution and combustion explosion in liquid electrolyte batteries, which fundamentally solve the potential safety problems. In this paper, the polyvinylidene fluoride (PVDF) matrix composite porous gel polymer electrolyte was studied. Three kinds of composite porous gel polymer electrolytes were designed and prepared by different methods. In situ polymerization and sol-gel method were used to prepare a new additive, SiO2(Li, and the composite porous gel polymer electrolyte samples were prepared by immersion precipitation method. The morphology was characterized by SEM, electrochemical impedance, linear voltammetry and battery performance were measured. The results show that the morphology of the composite polymer electrolyte with 5%SiO2(Li) is uniform. The ionic conductivity of the corresponding gel polymer electrolyte was 4.6 脳 10 ~ (-3) S / cm at room temperature, and the electrochemical stability window could reach 5.1 V ~ (2) A new ionic polymer, polyurethane lithium-ion salt, was synthesized by solution polymerization and neutralization reaction. The polymer was prepared by thermal phase separation method. Mixed porous gel polymer electrolyte. The electrochemical performance test shows that the ionic conductivity of composite porous gel polymer electrolyte mixed with 10PLS is 2.5 脳 10 ~ (-3) S / cm at room temperature, the ion mobility is 0.457, the electrochemical stability window can reach 4.95 V and the discharge capacity can still be obtained after 50 cycles of charge and discharge. A novel organic / inorganic nano-particle, SiO2-PAALiN, was prepared by in-situ polymerization and acid-base neutralization, and nano-composite gel polymer electrolyte was prepared by electrospinning. The mechanical properties show that the tensile strength and elongation at break of the electrospun films prepared by doped SiO2-PAALi nanoparticles can reach 48.8MPa and 25.6, respectively. Electrochemical analysis showed that the electrochemical properties of polymer electrolytes with SiO2-PAALi particles were greatly improved. The ionic conductivity at room temperature is 3.5 脳 10 ~ (-3) S / cm, and the relationship between ionic conductivity and temperature is in accordance with the Arrhenius relation. The electrochemical stability window can reach 5.05 V, and the discharge capacity after 30 cycles can still reach 96.99% of the initial discharge capacity, showing good cycling performance.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM912

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