Efficient Electrochromic Electrode Materials Based on WO3/Ni(OH)2 with Dual Ion Implantation Modulability and Energy Level Matching

Abstract

Electrochromic materials have received a lot of attention due to dramatic growth of the smart window market and the demand in various emerging fields. In this study, WO₃/Ni(OH)₂ composite high efficient electrochromic electrode materials are prepared by hydrothermal-annealing and electrodeposition methods. It is observed by experimental characterization that the deposition of Ni(OH)₂ on WO₃ rods effectively increased the Li⁺ diffusion rate of WO₃ films (2.069 × 10⁻¹⁰ cm² s⁻¹), which is ≈1.5 times higher than that of pure WO₃ (1.413 × 10⁻¹⁰ cm² s⁻¹). Meanwhile, WO₃ and Ni(OH)₂ have relatively matched energy level structures, showing high overall optical modulation performance. In addition, density functional theory (DFT) calculations combined with electrochemical studies reveal that the injection of double ions can improve the reaction efficiency of the electrodes and promote the redox reaction, which makes the electrochemical reaction more efficient. This paper provides a practical method for designing multi-component electrochromic devices with excellent performance.