A bi-functional device for self-powered electrochromic window and self-rechargeable transparent battery applications

• Main Authors: Wang, Jinmin, Zhang, Lei, Yu, Le, Jiao, Zhihui, Xie, Huaqing, Lou, Xiong Wen (David), Sun, Xiao Wei
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Article
• Language: English
• Published: 2016
• Subjects: Physical chemistry; Materials science
• Online Access: https://hdl.handle.net/10356/81811; http://hdl.handle.net/10220/40970
• Institution: Nanyang Technological University

Electrochromic smart windows are regarded as a good choice for green buildings. However, conventional devices need external biases to operate, which causes additional energy consumption. Here we report a self-powered electrochromic window, which can be used as a self-rechargeable battery. We use ​aluminium to reduce ​Prussian blue (​PB, blue in colour) to Prussian white (PW, colourless) in ​potassium chloride electrolyte, realizing a device capable of self-bleaching. Interestingly, the device can be self-recovered (gaining blue appearance again) by simply disconnecting the ​aluminium and ​PB electrodes, which is due to the spontaneous oxidation of PW to ​PB by the dissolved ​oxygen in aqueous solution. The self-operated bleaching and colouration suggest another important function of the device: a self-rechargeable transparent battery. Thus the PB/aluminium device we report here is bifunctional, that is, it is a self-powered electrochromic window as well as a self-rechargeable transparent battery.