Multifunctional devices integrated with electrochromism and energy storage or energy production functions are attractive because these devices can be used as an effective approach to address the energy crisis and environmental pollution in society today. In this review, we explain the operation principles of electrochromic energy storage devices including electrochromic supercapacitors,electrochromic batteries, and the photoelectrochromic devices. Furthermore, the material candidates and structure types of these multifunctional devices are discussed in detail. The major challenges of these devices along with a further outlook are highlighted at the end.
Zhongqiu TongYanlong TianHongming ZhangXingang LiJunyi JiHuiying QuNa LiJiupeng ZhaoYao Li
Electroactive conducting copolymers of aniline （ANI） and diphenylamine （DPA） are prepared on indium tin oxide （ITO） surface from 1 mol/L H2SO4 aqueous solution with different feed ratios of ANI to DPA by using a potentiostatic method. FTIR spectra and SEM measurements are used to confirm the formation of copolymers. Due to the combination of the N,N＇-diphenyl benzidine and aniline units in the molecular chain, the copolymer films exhibit improved electrochemical and electrochromic properties, compared to PANI and PDPA. The copolymer [marked as P（ANI9-co-DPA1）] film prepared at a ratio of 9：1 （ANI/DPA） exhibits novel transmittance modulation both in visible and near-infrared （NIR） region between -0.8 V and 0.8 V （52% and 67% respectively） and fast response time （3.6 s for coloration and 2.3 s for bleaching at 600 nm）. An electrochromic device （ECD） based on P（ANI9-co-DPA1） and PEDOT：PSS is also fabricated and shows a multicolor electrochromic performance, with a good optical contrast （29% in visible region and 40% in NIR region）, acceptable response time （8.3 s for coloration and 7.5 s for bleaching at 600 nm） and long-term stability. Clear color changes from transparent （-0.8 V）, bright green （0 V）, seagreen （0.4 V） to dark slate gray （0.8 V） are demonstrated.
