基于非离子水性聚氨酯的固态电解质的制备与性能

发布时间：2018-06-19 02:29

本文选题：非离子型水性聚氨酯 + LiClO_4含量　；参考：《安徽大学》2016年硕士论文

【摘要】：自新兴产业迅速发展以来,锂离子电池因具有工作电压高、放电平稳、循环寿命长、能量密度大、绿色环保等优点在电源应用领域受到了广泛的广阔。在锂离子电池中,与传统的液态电解质相比,固态聚合物电解质(SPE)具有质轻、易成膜、黏弹性好、使用安全等特点,不仅解决了锂电池在工作中漏液、热分解问题,而且具有优良的热稳定性和机械性能,因此,它成为了锂电池电解质的重点发展对象。水性聚氨酯(WPU)是一种绿色环保、结构可调且在水中分散性好的大分子材料,尤其是非离子型WPU (NPU)因具有生物相容性好、耐电解质等特点而被广泛应用。聚氧化乙烯(PEO)与锂盐的“络合-解离”作用实现了Li+在PEO基聚合物电解质中的迁移,增加SPE的离子电导率。但是目前PEO基SPE存在低温结晶度高,电导率低和力学强度小等问题。将PEO通过共价键引入到NPU中,不仅可以提高SPE的低温离子传导性,而且力学强度也得到了改善。本文将EO链段引入到NPU中,并以NPU为聚合物基体,制备了不同系列固态电解质,并探讨了锂盐含量和聚氨酯结构对固态电解质性能的影响。本文主要分为四个章节：(1)不同LiClO4含量对固态电解质性能的影响本章首先以异佛尔酮二异氰酸酯(IPDI)、聚环氧丙烷二元醇(N 220)、三羟甲基丙烷聚乙二醇单甲醚(Ymer N-120)、1,4-丁二醇(BDO)为原料,合成了非离子型水性聚氨酯乳液,并以此为聚合物基体,添加LiClO4制备了固态聚合物电解质。采用傅里叶转变红外光谱(FT-IR)、动态热力学分析(DMA)、热重分析(TGA)、力学性能分析、电化学工作站等测试方法,通过改变LiClO4含量,探讨了其对固态电解质性能的影响。结果表明,随着LiClO4含量的增加,固态电解质膜的耐热性能有所降低；电解质胶膜的拉伸强度逐渐增大,而断裂伸长率则降低,当LiClO4含量为18%时,电解质膜的拉伸强度达到18.2 MPa；固态电解质的离子电导率随着温度升高逐渐升高,并符合Arrhenius方程。相同温度下,电解质的离子电导率随着LiCO4含量增加呈现先增加后减小的趋势,当LiCO4含量为15%时,电解质的离子电导率达到最大,值为9.55×10-6S/cm。(2)不同聚氨酯硬段含量对固态电解质性能的影响本章首先以异佛尔酮二异氰酸酯(IPDI)、聚环氧丙烷二元醇(N 220)、三羟甲基丙烷聚乙二醇单甲醚(Ymer N-120)、1,4-丁二醇(BDO)为原料,合成了非离子型水性聚氨酯乳液,并以此为聚合物基体,制备了固态聚合物电解质。采用傅里叶转变红外光谱(FT-IR)、动态热力学分析(DMA)、热重分析(TGA)、力学性能分析、电化学工作站等测试方法,通过改变聚氨酯的硬段含量,探讨了其对固态电解质性能的影响。结果表明,随着聚氨酯硬段含量的升高,固态电解质的耐热性能逐渐下降；电解质胶膜的拉伸强度逐渐增大,而断裂伸长率则降低,当硬段含量为44.81% 时,电解质膜的拉伸强度达到18.6MPa；该系列固态电解质的离子电导率随着温度升高逐渐升高,并符合Arrhenius方程,相同温度下,电解质的离子电导率随着聚氨酯硬段含量的增加呈现先增加后减小的趋势；当硬段含量为38.28%时,电解质的离子电导率达到最大,值为1.55×10-5S/cm。(3)不同Ymer N-120含量对固态电解质性能的影响本章首先以异佛尔酮二异氰酸酯(IPDI)、聚环氧丙烷二元醇(N 220)、三羟甲基丙烷聚乙二醇单甲醚(Ymer N-120)、1,4-丁二醇(BDO)为原料,合成了非离子型水性聚氨酯乳液,并以此为聚合物基体,添加LiC104制备了固态聚合物电解质。采用傅里叶转变红外光谱(FT-IR)、示差扫描量热法(DSC)、热重分析(TGA)、力学性能分析、电化学工作站等测试方法,通过改变Ymer N-120含量,探讨了其对固态电解质性能的影响。结果表明,随着Ymer N-120含量的增加,电解质的玻璃化转变温度有所降低；膜的拉伸强度减小,而断裂伸长率升高。红外分峰结果显示,室温下,Li+主要以Li+ClO4-离子对的形式存在,自由锂离子占有比例较少；随着Ymer N-120含量的增加,与Li+络合的C—O—C数量先增加后减小,当Ymer N-120含量为24.88%时,自由的Li+最多,占总离子数的24.35%,并且Li+与C—O—C络合的峰面积最大,为92.07%。该固态电解质离子电导率随着温度的升高逐渐升高,并符合Arrhenius方程。相同温度下,电解质的离子电导率随着Ymer N-120含量增加呈现先增加后减小的趋势,当Ymer N-120含量为24.88%时,电解质离子电导率达到最大值(2.44×10-5S/cm)。(4)锂离子电池的组装工艺和电化学性能研究本章选取前三章中离子电导率最高的三种固态电解质(SPE5、SPE9、SPE15),分别以Li/电解质/不锈钢片和Li/电解质/Li体系组装了扣式模型电池,综述了电池的装配流程并研究对比了三种固态电解质的电化学稳定性和离子迁移数。结果发现,SPE15的电化学稳定性(分解电压为4.7 V)优于SPE9(分解电压为4.5 V)、SPE5(分解电压为4.2 V),而且SPE15的离子迁移数为0.40,均大于SPE9 (0.34)、SPE5 (0.30)。
[Abstract]:Since the rapid development of new industry, lithium ion batteries have been widely used in power applications because of their high working voltage, smooth discharge, long cycle life, high energy density, green environmental protection and so on. In lithium ion batteries, the solid polymer electrolyte (SPE) is light, easy to film and sticky compared with the traditional liquid electrolyte. With good elasticity and safety, it not only solves the problem of leakage and thermal decomposition in the work of lithium battery, but also has excellent thermal stability and mechanical properties. Therefore, it has become the key development object of lithium battery electrolyte. WPU is a kind of large molecular material with green ring protection, adjustable structure and good dispersion in water. The non ionic WPU (NPU) is widely used because of its good biocompatibility and electrolyte resistance. The "complexing dissociation" effect of polyoxyethylene (PEO) and lithium salts has realized the migration of Li+ in PEO based polymer electrolytes and increased the ionic conductivity of SPE. However, there are high cryogenic crystallinity, low conductivity and Mechanical properties of PEO based SPE before the eyes. The introduction of PEO through covalent bond into NPU can not only improve the conductivity of the low temperature ion of SPE, but also improve the mechanical strength. In this paper, the EO chain is introduced into NPU, and the different series of solid electrolytes are prepared with NPU as the polymer matrix, and the content of lithium salt and the structure of the polyurethane structure to the solid electrolyte are also discussed. The influence of the performance is divided into four chapters: (1) the effects of different LiClO4 content on the properties of solid electrolytes in this chapter are first synthesized by isophorone diisocyanate (IPDI), polyepoxide propane diol (N 220), three hydroxymethylpropane propane polyethylene glycol monomethyl ether (Ymer N-120) and 1,4- butanediol (BDO) as raw materials. Ester emulsion was used as the polymer matrix and the solid polymer electrolyte was prepared by adding LiClO4. Fourier transform infrared spectroscopy (FT-IR), dynamic thermodynamic analysis (DMA), thermogravimetric analysis (TGA), mechanical properties analysis, electrochemical workstation and other testing methods were used. The effect of LiClO4 content on the properties of solid electrolyte was discussed. The results showed that with the increase of LiClO4 content, the heat resistance of the solid electrolyte membrane decreased, the tensile strength of the electrolyte film increased gradually and the elongation at break decreased. When the content of LiClO4 was 18%, the tensile strength of the electrolyte membrane reached 18.2 MPa, and the ionic conductivity of the solid electrolyte increased gradually with the increase of temperature, and was consistent with the temperature. Arrhenius equation. At the same temperature, the ionic conductivity of electrolyte increases first and then decreases with the increase of LiCO4 content. When the content of LiCO4 is 15%, the ionic conductivity of the electrolyte reaches the maximum. The value of the electrolyte is 9.55 x 10-6S/cm. (2) and the content of different polyurethane hard segments has an effect on the solid state electrosolution properties. This chapter is first with isophorone two. Cyanate (IPDI), polyepoxide propane diol (N 220), three hydroxymethyl propane polyethylene glycol monomethyl ether (Ymer N-120) and 1,4- butanediol (BDO) were used as raw materials to synthesize a nonionic waterborne polyurethane emulsion, which was used as a polymer matrix to prepare solid polymer electrosolution. Fourier transform infrared spectroscopy (FT-IR) and dynamic thermodynamic analysis (DMA) were used. The results show that the heat resistance of the solid electrolyte decreases with the increase of the content of the hard segment of the polyurethane, and the tensile strength of the electrolyte film increases gradually, and the tensile strength of the electrolyte film is gradually increased with the increase of the hard segment content of the polyurethane, and the results show that the strength of the solid electrolyte decreases gradually with the increase of the hard segment content of the polyurethane. The elongation at break decreased, when the hard segment content was 44.81%, the tensile strength of the electrolyte membrane reached 18.6MPa, and the ionic conductivity of this series of solid electrolyte increased gradually with the increase of temperature, and conformed to the Arrhenius equation. At the same temperature, the ionic conductivity of the electrolyte increased first and then decreased with the increase of the content of the hard segment of the polyurethane. When the content of the hard segment is 38.28%, the ionic conductivity of the electrolyte reaches the maximum, the value is 1.55 x 10-5S/cm. (3) different Ymer N-120 content to the solid electrolyte performance. This chapter first is isophorone diisocyanate (IPDI), polyepoxide propane diol (N 220), three hydroxymethyl propane polyethylene glycol monomethyl ether (Ymer N-120), 1,4- butyl The non ionic waterborne polyurethane emulsion was synthesized from BDO as the raw material. The polymer electrolyte was prepared by using LiC104 as the polymer matrix, and the solid polymer electrolyte was prepared by adding the Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), force performance analysis, electrochemical workstation and other testing methods, by changing Ymer N-120. The results showed that the glass transition temperature of the electrolyte decreased with the increase of Ymer N-120 content, the tensile strength of the membrane decreased and the elongation at break increased. The result of infrared peaks showed that at room temperature, Li+ was mainly in the form of Li+ClO4- ion pair, free lithium ion occupied. As the content of Ymer N-120 increases, the number of C - O - C complex with Li+ increases first and then decreases. When the content of Ymer N-120 is 24.88%, the free Li+ is the most, accounting for 24.35% of the total number of ions, and the peak area of the complex of Li+ and C O is the largest, and the electrical conductivity of the solid electrolysis increases gradually with the increase of temperature. In accordance with the Arrhenius equation, the ionic conductivity of electrolyte increases first and then decreases with the increase of Ymer N-120 content. When the content of Ymer N-120 is 24.88%, the electrolyte ionic conductivity reaches the maximum value (2.44 x 10-5S/cm). (4) the assembly process and electrochemical properties of lithium ion batteries are selected in the first three chapters. Three kinds of solid electrolytes with the highest electrical conductivity (SPE5, SPE9, SPE15) were assembled with Li/ electrolyte / stainless steel sheet and Li/ electrolyte /Li system respectively. The assembly process of the batteries was reviewed and the electrochemical stability and the migration number of the three kinds of solid electrolytes were compared and compared. The results showed that the electrochemical stability of SPE15 was found. The solution voltage is 4.7 V) is superior to SPE9 (decomposition voltage 4.5 V), SPE5 (decomposition voltage is 4.2 V), and SPE15 ion migration number is 0.40, which is greater than SPE9 (0.34) and SPE5 (0.30).
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM912;TQ317

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