Electrochromic/Electrofluorochromic Supercapacitor Based on a Network Polysiloxane Bearing Oligoaniline and Cyanophenethylene Groups
Yingchao Zhang, Erik B. Berda, Xiaoteng Jia, Zan Lu, Meihua Zhu, Danming Chao
Abstract
Electrochromic supercapacitors capable of indicating their energy levels by color changes have emerged as promising materials for use in a variety of next-generation devices and applications. However, a reflective indicating mode is less adventitious in applications and conditions with low ambient light, which inspires the exploration of emissive indicators. In this paper, we synthesized a network polysiloxane bearing fluorescence emissive cyanophenethylene groups and electroactive oligoaniline groups (PSZT) via an electrochemistry-assisted hydrolytic cross-linking reaction. The resulting PSZT exhibited high-performance electrochromic/electrofluorochromic behavior with a high optical contrast ratio (ΔT % of 52.5% varying from 71.0% to 18.5% at 700 nm), a marked fluorescence quenching ratio of 85%, and good switching durability. This PSZT was then incorporated into a smart symmetrical supercapacitor device integrating energy storage with the electrochromism/electrofluorochromism functions. Here, the energy status can be simultaneously indicated via tunable colors from transmissive green-yellow to dark green, along with a fluorescence on/off switch. This electrochromic/electrofluorochromic supercapacitor represents a direction toward smart energy storage systems.