无机材料学报 ›› 2021, Vol. 36 ›› Issue (2): 161-167.DOI: 10.15541/jim20200376

所属专题: 电致变色材料与器件 功能材料论文精选(2021) 电致变色专栏2021

• 专栏: 电致变色材料与器件(特邀编辑:刁训刚, 王金敏) • 上一篇    下一篇

基于高电导率的疏水气相SiO2复合凝胶电解质的高性能电致变色器件

赵起1(), 乔科1, 姚勇吉1, 陈长1, 陈东初2(), 高彦峰1()   

  1. 1.上海大学 材料科学与工程学院, 上海 200444
    2.佛山大学 材料科学与能源工程学院, 佛山 528000
  • 收稿日期:2020-07-06 修回日期:2020-10-29 出版日期:2021-02-20 网络出版日期:2020-11-05
  • 通讯作者: 高彦峰, 教授. E-mail: yfgao@shu.edu.cn;
  • 作者简介:赵起(1995–), 男, 博士研究生. E-mail: zq0911@shu.edu.cn

High-conductivity Hydrophobic Fumed-SiO2 Composite Gel Electrolyte for High Performance Electrochromic Devices

ZHAO Qi1(), QIAO Ke1, YAO Yongji1, CHEN Zhang1, CHEN Dongchu2(), GAO Yanfeng1()   

  1. 1. School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
    2. School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, China
  • Received:2020-07-06 Revised:2020-10-29 Published:2021-02-20 Online:2020-11-05
  • Contact: GAO Yanfeng, professor. E-mail: yfgao@shu.edu.cn;
  • About author:ZHAO Qi(1995–), male, PhD candidate. E-mail: zq0911@shu.edu.cn
  • Supported by:
    Foundation item: Ministry of Science and Technology of China(2016YFB0303901-05);Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-09-E00020);Science and Technology Commission of Shanghai Municipality(18JC1412800);Cheung Kong Scholars Programme of China(T2015136)

摘要:

凝胶电解质具有化学稳定、难燃和易于封装等特点, 其低离子电导率(10-4~10-5S?cm-1)阻碍了电致变色器件(ECDs)凝胶电解质的进一步发展。本研究制备了一种高电导率的疏水SiO2/PMMA/PC/LiClO4凝胶聚合物电解质(H-SiO2 GPEs), 并用电化学阻抗谱(EIS)、循环伏安法(CV)和计时电流法(CA)分析了ECDs的电化学行为。实验结果表明, 仅引入0.5wt%的疏水性气相SiO2, 即可使H-SiO2 GPEs的离子电导率达到5.14 mS?cm-1(25 ℃时)。离子电导率的增加归因于SiO2添加物和有机电解质之间良好的相容性和疏水-疏水吸引力促进了高氯酸锂的离解。同时, 不同气相二氧化硅含量的GPEs的粘度与剪切速率的关系表现出剪切稀化行为, 这表明研究体系形成了三维网状结构。该结构为离子提供了传输通道, 进而提高了基于H-SiO2 GPEs电致变色器件的响应速度(tbleaching= 4 vs 8 s和tcoloring = 14 vs 16 s)。同样, 通过探究添加疏水性气相SiO2对液态电解液的影响表明:复合疏水性气相SiO2使得LiClO4/PC液态电解液的离子电导率由原来的6.94 mS?cm-1增大到7.58 mS?cm-1。疏水性气相SiO2作为填料对电解质的离子电导率具有一定的积极作用, H-SiO2 GPEs的研究为解决ECDs高离子电导率和易泄漏之间的矛盾提供了新思路。

关键词: 凝胶电解质, 电致变色, 疏水性, SiO2

Abstract:

Gel electrolytes are chemically stable, nonflammable and easy to encapsulate, however, their moderate ionic conductivity (10-4-10-5S?cm-1) hinders their further development for the usage in electrochromic devices (ECDs). Here, we developed a highly conductive hydrophobic SiO2/PMMA/PC/LiClO4 gel polymer electrolyte (H-SiO2 GPE). Electrochemical behaviors of ECDs were characterized by electrochemical impedance spectroscope (EIS), cyclic voltammetry (CV) and chronoamperometry (CA). Systematic analyses show that the ionic conductivity of the H-SiO2 GPE can reach 5.14 mS?cm-1 (at 25 ℃) by introducing only 0.5wt% hydrophobic fumed SiO2. This increase is due to the good compatibility and hydrophobic-hydrophobic attractions between SiO2 additive and organic electrolyte, which promotes the dissociation of lithium perchlorate. Additionally, the viscosity as a function of shear rate for GPE with various fumed silica contents shows the behavior of shear thinning, which indicates the formation of a three-dimensional network structure. This structure provides ion transport channels, leading to a clearly improved switching speed for ECDs assembled with hydrophobic SiO2 GPEs (tbleaching=4 vs 8 s and tcoloring=14 vs 16 s). Similarly, the investigation of hydrophobic fumed SiO2 in liquid electrolyte is demonstrated that the ionic conductivity of LiClO4/PC liquid electrolyte without and with hydrophobic fumed SiO2 increases from 6.94 to 7.58 mS?cm-1, respectively. Therefore, hydrophobic fumed SiO2 as a filler has a positive effect on electrolytes, and the proposal of the H-SiO2 GPE provides a new idea for offsetting the trade-off between a high ionic conductivity and easy leakage when applied in ECDs.

Key words: gel electrolyte, electrochromic, hydrophobic, SiO2

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