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Electrochromic capacitive windows based on all conjugated polymers for a dual function smart window


A highly transparent electrochromic capacitive (ECC) window was explored by combining a high contrast electrochromic polymer (ECP) and a transparent capacitive polymer. A blue and red color ECP, poly(3,3-bis(bromomethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) (PR-Br) and poly(3,4-di(2-ethylhexyloxy)thiophene-co-3,4-di(methoxy)thiophene) (Th-OR), respectively, were introduced in an ECC window having a thin polyaniline (PANI) film as a capacitive layer. As prepared ECC window showed high transparency (> 72 % for PR-Br), large color contrast, and long capacitive stability over 10,000 cycles, by combining non-aqueous acidic electrolyte and precise control of each electrode’s working potential using in-situ potential matching. Upon introducing the dielectric poly(methylmethacrylate) (PMMA)layer, the blue ECC window made of PR-Br and PANI showed bistable ECC properties, along with high energy density of 9.7 and 13.5 Wh/kg with a power density of 75.3 and 58.8 kW/kg, respectively, for bleaching and coloring, respectively. The red ECC window made of Th-OR and PANI showed also high energy density (10.5 Wh/kg). The energy stored in an ECC window could be transferred to another, like a battery, to switch the color or to light a LED when the ECC windows connected in series. Thus ECC window in this study function as a color switching smart window and rechargeable battery, to provide a new path to achieve energy saving EC windows with multi-color tunability. The working principle of these ECC windows can be widely applied in various electrochemical devices for multiple functions in one device.

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Publication details

The article was received on 09 Jan 2018, accepted on 10 May 2018 and first published on 11 May 2018

Article type: Paper
DOI: 10.1039/C8EE00080H
Citation: Energy Environ. Sci., 2018, Accepted Manuscript
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    Electrochromic capacitive windows based on all conjugated polymers for a dual function smart window

    Y. Kim, M. Han, J. Kim and E. Kim, Energy Environ. Sci., 2018, Accepted Manuscript , DOI: 10.1039/C8EE00080H

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