Stretchable and Transparent Ionogels with High Thermoelectric Properties
Stretchable and Transparent Ionogels with High Thermoelectric Properties
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DOI：
10.1002/adfm.202004699
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发表时间：
2020-09-18
影响因子：
19
通讯作者：
Ouyang, Jianyong
中科院分区：
文献类型：
--
作者：
Fang, Yuanlai;Cheng, Hanlin;Ouyang, Jianyong
可拉伸电子材料和器件在包括可穿戴电子和生物电子的柔性电子系统中具有重要应用。灵活的电子系统需要方便的发电，如热电转换。因此，开发具有高机械拉伸性的高性能热电材料将是非常期望的。在这里，展示了具有高热电性能的可拉伸和透明的离子凝胶。以弹性体水性聚氨酯和离子液体1-乙基-3-甲基咪唑二氰胺（EMIM：DCA）为原料，采用溶液法制备了离子凝胶。其力学和电学性能取决于EMIM：DCA的负载量。具有40wt%EMIM：DCA的离子凝胶可以具有高达156%的高机械拉伸性、0.6MPa的低拉伸强度和0.6MPa的低杨氏模量。它们还表现出34.5 mV K-1的高离子热电压、8.4 mS cm（-1）的高离子电导率和0.23 W m（-1）K（-1）的低热导率（在90%的相对湿度下）。因此，它可以具有1.3 +/-0.2的高离子品质因数（ZT（i））。可拉伸热电材料的热电压和ZT（i）值都是最高的。它们可用于离子热电电容器，将热量转化为电能。
Stretchable electronic materials and devices have important applications in flexible electronic systems including wearable electronics and bioelectronics. Convenient electricity generation such as thermoelectric conversion is required for the flexible electronic systems. Hence, it is development of high-performance thermoelectric materials with high mechanical stretchability would be highly desirable. Here, stretchable and transparent ionogels with high thermoelectric properties are demonstrated. The ionogels made of elastomeric waterborne polyurethane and 1-ethyl-3-methylimidazolium dicyanamide (EMIM:DCA, an ionic liquid) are prepared by solution processing. Their mechanical and electrical properties depend on the loading of EMIM:DCA. The ionogels with 40 wt% EMIM:DCA can have a high mechanical stretchability of up to 156%, low tensile strength of 0.6 MPa, and low Young's modulus of 0.6 MPa. They also exhibit a high ionic thermovoltage of 34.5 mV K-1, high ionic conductivity of 8.4 mS cm(-1)and low thermal conductivity of 0.23 W m(-1)K(-1)at a relative humidity of 90%. As a result, it can have a high ionic figure of merit (ZT(i)) of 1.3 +/- 0.2. Both the thermovoltage and the ZT(i)value are the highest for stretchable thermoelectric materials. They can be used in ionic thermoelectric capacitors to convert heat into electricity.