Preparation Of Environmentally Stable Ionogels Electrolytes And Their Applications In Flexible Electronic Devices

Flexible electronics are now widely used as biosensors（artificial skin）,supercapacitors,batteries,nanogenerators,actuators,touch screens and so on.Among them,flexible biosensors can effectively collect basic information of the human body for health diagnosis.Flexible wearable supercapacitors don’t only possess good mechanical and electrochemical properties,but also work normally under different deformation states,which effectively improves the electrochemical stability and durability of supercapacitors.However,these flexible electronic devices more or less have environmental stability problems,including freezing at low temperature and evaporation at high temperature,which greatly limit their normal use in extreme environmental conditions.To ensure the environmental stability of flexible electronic devices,the flexible electrolytes were modified by different strategies,including elastomer packaging,inorganic salt colligative properties,organic gels,ionic liquid gels and polyol components introduced into the electrolyte network.With the advantages of ionic liquid,such as low freezing point,low vapor pressure and high ion mobility,thereby we chose it as the dispersion solvent of gel network to on the purpose of environmental stability.Specifically,with the 1-ethyl-3-methylimidazolium bis（trifluoromethyl sulfonyl）imide（[C₂mim][NTf₂]）as ionic liquid,an environmentally stable ionic liquid gel with excellent mechanical properties was prepared by one-step polymerization.The experimental results show that the fracture elongation of as-prepared ionic liquid based with[C₂mim][NTf₂]is as high as 800%～1876%,the elastic modulus is 5KPa～250KPa,which also exhibiting an excellent mechanical property and self-healing ability compared with other flexible electrolytes up to now.The gel electrolyte exhibits good self-healing ability both electrically and mechanically,which promotes the material’s recycling ability and prolonging the service life of subsequent flexible electronic devices.In addition,the ionic liquid gel can still work normally in the temperature range of-15℃to 280℃,on which the flexible electronic devices based can work in diverse extreme environments,including high temperature（100℃）,low temperature（-15℃）,high humidity（RH=100%）and so on.Herein,the environmentally stable ionic liquid gel prepared based on ionic liquid（[C₂mim][NTf₂]）doesn’t only achieve a wide range of work temperature,but also breaks through the limitation of the application scenarios of flexible electronic devices.