高力学性能及高导电性的防冻有机水凝胶电解质

由于水凝胶电解质的力学性能差且水在低温下会结冰,限制了水凝胶电解质在储能器件和电子导体方面的应用。加入大豆分离蛋白,以丙烯酰胺和甲基丙稀酰乙基磺基甜菜碱为单体,在二甲基亚砜/H₂O的混合溶液和氯化锂的存在下,通过自由基聚合制备了高力学性能、高导电性的防冻有机水凝胶。其具有良好的电导率(最高37.5 mS/cm)、良好的力学性能(最大应力69 kPa,最大应变762.5%)、优良的韧性和抗疲劳性能,对应变和温度具有良好的响应性、宽的传感窗口及稳定性,具有应用于传感器领域的潜力。另外,所制备的超级电容器在20 ℃和-20 ℃均表现出良好的电化学性能,20 ℃时,0.2 A/g电流密度下,超级电容器的比电容为62.1 F/g,5 A/g 的高电流密度下,比电容仍有30 F/g;同时具有良好的抗冻性能和循环稳定性,-20 ℃时,0.5 A/g电流密度下,超级电容器循环10 000圈后仍能保持20 ℃下容量的92%。

Antifreezing organic hydrogel electrolyte with high mechanical strength and ionic conductivity

The poor mechanical properties of hydrogel electrolytes and the freezing of water at low temperatures affect their ionic conductivity, thereby hindering their application in energy storage devices and electronic conductors. In this study, a type of antifreezing organic hydrogel with high mechanical properties and conductivity is fabricated. The electrolyte was synthesized via free-radical polymerization by adding soy protein isolates and using acrylamide and methacrylic ethyl sulfobetaine as monomers in a mixed solution of dimethyl sulfoxide/H₂O in the presence of lithium chloride. The fabricated hydrogel electrolyte exhibits good ionic conductivity (maximum 37.5 mS/cm), good mechanical properties (maximum stress 69 kPa and maximum strain 762.5%), and high toughness and fatigue resistance. Furthermore, the fabricated electrolyte shows a good response under varying strain and temperature conditions with a wide sensing window and good stability. Additionally, supercapacitors based on this electrolyte show good electrochemical performance between 20 ℃ and -20 ℃. In other words, at 20 ℃, the capacitances of the supercapacitor are 62.1 and 30 F/g at current densities of 0.2 and 5 A/g respectively, while at -20 ℃, the capacitance can maintain 59% of the value obtained at 20 ℃. Moreover, the supercapacitor can maintain 92% of the capacitance after 10 000 cycles, showing good cyclic stability.