| Electrochromic technology is a new electrochemical control method that can adjust the light absorption/transmission/reflection properties of materials by applying an electric field.In recent years,the cross-fertilization of electrochromic technology with other fields has given rise to a variety of emerging smart devices and technologies.By combining with supercapacitors,smart energy storage devices and smart windows have been generated.However,there are still a lot of problems in this field,such as low capacitance,low electrochromic contrast,poor accuracy of energy state recognition,and difficulty of large area preparation of high-performance electrode materials.To address these problems,this paper focuses on the optimized design of thin-film electrodes and device structures for electrochromic supercapacitors based on conducting polymers.A method for the synthesis of conducting polymer films by interfacial liquid-phase chemical oxidation was developed to realize the preparation of polypyrrole(PPy)and polyaniline(PANI)films on the surface of different substrate materials in a large area.Further,CNTs/Au/PPy composite thin film electrode materials were constructed by covering carbon nanotubes(CNTs)layer and nanogold(Au)layer,and the feasibility of their construction as smart supercapacitors with electrochromic function was conceptually verified.Then,the mathematical relationship between electrochromic color contrast and internal voltage of supercapacitor was established by using CIE-Lab color coordinates,and the quantitative determination of energy storage state of supercapacitor was realized by measuring electrochromic color contrast.The highprecision quantified monitoring method of charge state based on color contrast measurement has the advantages of simple method,high accuracy,and no damage to materials,which is expected to promote the miniaturization and lightweight development of electronic systems.To address the challenge of simultaneous realization of high energy density and high electrochromic performance in single smart supercapacitor,the concept of smart collector is proposed for the first time in this paper.The smart function of real-time visual monitoring of the energy state inside the supercapacitor is realized by functionalizing the current collector with the electrochromic design.At the device level,it breaks through the limitation of existing transmissive smart supercapacitors in terms of energy storage material loading,and increases the energy density of smart supercapacitors by 1～2 orders of magnitude while maintaining significantly higher electrochromic performance,which bridging the performance gap between smart supercapacitors and conventional energy storage supercapacitors.The design and preparation of this smart current collector is expected to promote the development of smart wearable supercapacitors with both high electrochromic performance and high energy density.For the demand of low-cost,large-area preparation and high energy storage capacity of electrode materials for smart windows in the field of energy-saving buildings,this paper combines the interfacial liquid-phase chemical oxidation method and ultrasonic atomization spraying method to successfully design and construct a large-area PANI/CNTs/PANI composite structure electrode.The enhancement of the electrical conductivity,electrochemical activity and stability of PANI thin films by CNTs as "nano-rebar" was investigated.Further,a zinc ion(Zn-ion)smart window with a dual positive structure was constructed using PANI/CNTs/PANI composite film,and its electrochromic and electrochemical energy storage performance was evaluated.In addition,its ability to modulate the radiative power of simulated daylight was also verified,which provides a new option for energy storage smart window materials for energy-efficient buildings. |
PDF Full Text Request