Visualization electrochromic-supercapacitor device based on porous Co doped NiO films

摘要

In this work, a smart electrochromic-supercapacitor device was designed and fabricated by employing a porous Co doped NiO film as positive electrode. The porous Co doped NiO film was obtained through a simple hydrothermal method. The areal specific capacitance of the prepared porous Co doped NiO film composites is 88.24 mF cm(-2) and the color of films change from brown (colored) to yellow (bleached). Large planer spacing, porosity and high surface area of Co doped NiO guarantee achievement of high electrochemical and electrochromic performance. The constructed device has a high specific capacitance (10.8 mF cm(-2)), high energy density (3.84 x 10(-3) mW h cm(-2)) and superior cycle stability (initial capacitance retention rate of 84.5% after 2000 charge discharge cycles). After charging, two devices could light up two LED. Furthermore, the energy storage state of could be monitored by the color change of the device thus an intelligent electrochromic supercapacitor can be realized (C) 2020 Elsevier B.V. All rights reserved.