LIN-CHI CHENChen, L.-CL.-CChenHuang, Y.-HY.-HHuangTseng, K.-SK.-STsengHo, K.-C.K.-C.Ho2019-08-142019-08-142002https://scholars.lib.ntu.edu.tw/handle/123456789/416475Upon considering the fact that the WO3/HxWO3 has a much more negative formal potential than that of the Berlin green (BG)/Prussian blue (PB) redox system, a novel thin-film electrochromic battery (ECB) based on PB and WO3, designated as PWECB, was proposed and investigated. By using the KCl-saturated poly-2-acrylamido-2-methylpropane sulfonic acid (K-PAMPS) electrolyte that accommodates the conduction of both K+ and H+, a PWECB can be charged/discharged reversibly between 0.80 V and 1.80 V and has a theoretical voltage of 1.35 V, which is almost twice the voltage of non-lithium PB-based batteries reported in literature. In addition, the PWECB showed green (charged state)-to-blue (discharged state) electrochromism; therefore, its state of charge (SOC) can be visualized. Visualization of the SOC, by the naked eye, can help people to judge a cell's charging condition. Moreover, it was demonstrated that the ECB with an energy capacity of 37.8 mW-s/cm2 could drive an 8-digit electronic calculator for several hours. By combining the ECB with a photovoltaic cell (PV), it is possible to realize the all-solar-driven electronic device. Consequently, the combinative PV-ECB power system offers an opportunity to reduce the use of primary button cells, which are disadvantageous to the environment. In addition to these superior applications, the dynamic and at-rest stabilities of the PWECB are discussed in this paper.All-solar-driven; Electrochromic battery (ECB); KCl-saturated poly-2-acrylamido-2-methylpropane sulfonic acid (K-PAMPS); Prussian blue (PB); Tungsten oxide (WO3)[SDGs]SDG7journal article2-s2.0-0344096698