Differential electrochemically active humidity sensor and its use as energy storage or energy collection device

摘要

The electromechanically and mechanoelectrically active three-layer laminate composed out of Nation membrane, carbide-derived carbon-based electrodes, and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid electrolyte responds to the change in ambient humidity over the electrodes and can therefore be used as a humidity sensor or an energy harvesting element. The hydrophilic nature of all constituents of the laminate promotes fast sorption and diffusion of water across the membrane, which causes volumetric effects. Diffusion of water and formation of hydration shell around the ionic groups induces reorientation and dislocation of ionic liquid ions, which in turn induces an electric charge across the electrodes exposed to different ambient humidity. The generated charge can be registered as voltage or electric current between the electrodes. Furthermore, the supercapacitor like properties of the laminate allows the storage of charge in the same laminate, where it was generated.