Preparation And Performance Investigation Of The Complementary Electrochromic Device Comprised Of Composite Electrodes

Under the cyclic applied voltage,the materials that undergo reversible optical properties are called electrochromic materials.Electrochromic devices composed of electrochromic materials,electrolyte and counter electrode,which have an important promise for smart windows,displays and antiglare mirrors.The electrochromic films are much desired in smart windows,which do not only increase the aesthetics of traditional windows but also save energy by adjusting the transmittance of the building interiors.The single EC materials always has obvious shortcoming,but hybrid electrochromic materials can combine the advantages of both components and weaken the disadvantages.Therefore,the hybrid electrochromic materials with new functionalities have become one of the most active research areas of electrochromic materials science.Moreover,compared with the single-active-layer structure ECDs,due to the charge balance between the two electrodes,the complementary ECDs exhibit good electrochromic performance than the singleactive-layer ECDs.Thus,the complementary ECDs show tremendous promise in energy-saving smart windows and displays.The main purpose of this paper is to improve the applied EC performance of complementary devices prepared by composite electrochromic materials.This paper main content as follows:?1?The frame-shaped WO₃?0.33H₂O film was grown on FTO-coated glass via the hydrothermal method by adding ethylene glycol as a directing agent.The WO₃?0.33H₂O film is composed of nanosheets and thus forming a porous structure.The porous structure could accelerate the interface electron kinetics between the film and electrolyte because its large electrochemical active area.The PEDOT:PSS solution was made of PEDOT:PSS and absolute ethyl alcohol with 1:2 by volumetric component.The WO₃?0.33H₂O/PEDOT:PSS films were synthesized by suitable solution of PEDOT: PSS was spin coated on the top of the as-prepared WO₃?0.33H₂O film.To study the electrochemical performance of the hybrid films and WO₃?0.33H₂O film,it can be seen that the anodic peak of WO₃?0.33H₂O/PEDOT:PSS films is 45% higher than that of the WO₃?0.33H₂O film,and the cathodic peak has risen by 16%.The WO₃?0.33H₂O/PEDOT:PSS films exhibits a faster iondiffusion process.To evaluate the EC propertiea,the as-prepared WO₃?0.33H₂O film and WO₃?0.33H₂O/PEDOT:PSS films were assembled into EC devices.The results show that the optical modulation range and coloration efficiency had an obvious improvement.?2?The vertically grown NiO hierarchical nano-structures were synthesized on FTOcoated glass using a crystal-seed-assisted hydrothermal technique by adding potassium persulfate as a directing agent.The film exhibited a porous architecture,which comprised of interconnected uniform microflakes.The specific nanostructure gives a rough surface morphology,making large electrochemical active area for reactions in electrochromic processes.The NiO/PB film obtained by the electrodeposition of PB on the NiO film.To evaluate the EC propertiea,the as-prepared NiO film and NiO/PB films were assembled into EC devices.The results show that the optical modulation range and coloration efficiency had an obvious improvement.?3?To investigate the EC performance of the hybrid EC films,the ECDs were assembled including glass/FTO/WO₃?0.33H₂O/PEDOT:PSS/LiClO₄-PC/PB/NiO/FTO/glass,glass/FTO/ WO₃?0.33H₂O/LiClO₄-PC/NiO/FTO/glass,and studied the EC properties of ECDs.The results show that the complementary ECDs composed by the hybrid EC films exhibit excellent electrochemical and electrochromic performance.the complementary ECD exhibits higher optical modulation?52% at 700 nm without background correction?,faster response times?tb = 7.5 s,tc = 6 s?and higher CE?121 cm2/C?.Thus,the complementary device made of the as-prepared hybrid electrochromic films shows tremendous promise in energy-saving smart windows and displays.