聚环氧乙烷（PEO）聚合物电解质的电性能研究

发布时间：2018-05-26 08:31

  本文选题：聚环氧乙烷 + 全固态聚合物电解质　； 参考：《沈阳工业大学》2017年硕士论文

【摘要】：固态聚合物电解质用来制备全固态高能密度的可充电式锂离子电池,因其具有质量轻、柔顺度好、弹性好、易成膜以及有较好的导电性等特点。固态的聚合物电解质的电导率虽然没有液态电解质的电导率高,但具备易成膜,寿命长,适合各种各样的形状等优点,所以固态聚合物电解质膜成为最近锂离子电池工业化应用研究的热点。在过去的30年里,人们虽然一直在研究固态聚合物电解质,并且聚环氧乙烷(PEO)是研究最早最多的,被认为是比较理想的聚合物电解质,但电导率低,仍然是未解决的问题。液晶离聚物(LCI),既有液晶的性能又有离子的性能,采用原位界面聚合方法制备出LCI/PEO固态聚合物电解质,研究聚合物电解质各组分的含量以及反应条件对产量产率的影响,通过IR、透射电镜、交流阻抗对电解质结构、形貌和导电性进行表征。结果表明,PEO含量增大使LCI/PEO固态聚合物电解质的产率下降,电导率随PEO含量的增加先增加后降低,在PEO与液晶离聚物质量比为0.8时,电解质的电导率达到最大值,为2.65×10-6S/cm;对于锂盐含量的改变对LCI/PEO固态聚合物电解质的产率无明显影响,电解质的电导率随锂盐含量的增加而减少,在其含量为5%时,电解质的电导率达到最大值,为2.65×10-6S/cm,而后因离子间库仑力作用增强,抑制离子的移动,电解质的电导率下降。制备液晶离聚物/蒙脱土(LCI/MMT)杂化材料,研究以PEO和聚甲基丙烯酸甲酯(PMMA)为基体,添加LCI/MMT杂化材料作为增容剂来制备聚合物电解质膜,得出成膜工艺的最佳条件:PEO:PMMA的质量比为7:3,LiClO4的添加量为0.004g/mL,转速搅拌为700rmp,时间4h,刮膜后50℃烘干2h。通过扫描电镜(SEM)、热重分析(DSC/TGA)、交流阻抗(AC)等研究表明LCI/MMT杂化材料的加入提高了聚合物电解质膜的相容性和电导率,在LCI/MMT纳米杂化材料含量1.01%时电导率最高为9.86×10-6 S/cm,由于LCI/MMT杂化材料的加入,使PEO相的结晶度降低,电导率升高,热性能增加,在0到300之间热稳定性良好,没有发生分解。
[Abstract]:Solid polymer electrolytes are used to prepare rechargeable lithium-ion batteries with all-solid-state high energy density due to their advantages of light weight, good flexibility, good elasticity, easy film formation and good electrical conductivity. Although the conductivity of solid polymer electrolyte is not as high as that of liquid electrolyte, it has the advantages of easy film formation, long life, suitable for various shapes, etc. Therefore, solid polymer electrolyte membrane has become a hot spot in the industrial application of lithium ion batteries. In the past 30 years, people have been studying solid polymer electrolyte, and PEO is the earliest and ideal polymer electrolyte, but the conductivity is low, it is still an unsolved problem. LCI/PEO solid polymer electrolytes were prepared by in situ interfacial polymerization with liquid crystal ionomer and ionic properties. The effects of the content of polymer electrolyte components and reaction conditions on the yield were studied. The structure, morphology and conductivity of the electrolyte were characterized by IR, TEM and AC impedance. The results show that the yield of LCI/PEO solid polymer electrolyte decreases with the increase of PEO content, and the conductivity increases first and then decreases with the increase of PEO content. When the mass ratio of PEO to liquid crystal ionomer is 0. 8, the conductivity of the electrolyte reaches the maximum. The conductivity of LCI/PEO solid polymer electrolyte decreased with the increase of lithium salt content, and the conductivity reached the maximum when the content of lithium salt was 5%, and the content of lithium salt was 2.65 脳 10 ~ (-6) s / cm, and there was no significant effect on the yield of solid polymer electrolyte with the change of lithium salt content, and the conductivity of electrolyte decreased with the increase of lithium salt content. It is 2.65 脳 10 ~ (-6) S / cm, but the ionic conductivity decreases due to the enhancement of the interaction between ions and the inhibition of ion movement. Liquid crystal ionomer / montmorillonite LCI / MMT hybrid materials were prepared. Polymer electrolyte membranes were prepared using PEO and PMMA as matrix and LCI/MMT hybrid materials as compatibilizer. The optimum conditions of the film forming process were obtained: the mass ratio of 1: PEO: PMMA was 7: 3, the addition of LiClO4 was 0.004g / mL, the stirring speed was 700rmpand the time was 4h, and the film was dried at 50 鈩，

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