Electrochromism is the reversible change in optical properties when a material is electrochemically oxidized or reduced[6] and can be simply represented by Equation (1), where M+ can be H+, Li+, Na+ or K+ , 0 < x < 1, and e- are denoting electrons.[2]
(transparent) WO3 + xM+ + xe- ↔ 2 MxWO3 (deep blue) ------------- Equation (1)
An electrochromic system consists of an ion-containing material (electrolyte) that is of close proximity to the electrochromic layer and the transparent layers for the setting up a distributed electric field. Ions are shuttled back and forth within the electrochromic layer when potential is applied. Typically, an electrochromic system is fabricated from five layers which comprises of two transparent conductors, an ion conductor or electrolyte, a counter electrode and an electrochromic layer as shown in Figure 1.[7] Figure 1: Five layers in an electrochromic system
2.1.2 Working Principle of Electrochromic System Figure 2: Movement of electrons and protons in electrochromic system
Figure 2 …show more content…
In a study done by S.E. Selkowitz et. al, electrochromic windows have lower annual energy performance than an opaque insulated wall. Primary energy benefits include ability to reduce electric lighting by managing daylight admittance and reduced cooling loads. In hot climates or season, electrochromic windows minimize solar heat gain with adequate daylight[10].
2.1.6 Advantages and Disadvantages of Electrochromic System
Electrochromic devices typically have an upper visible transmission of TV=70 to 50% and a fully coloured transmission of TV=25 to 10%. The range of shading coefficient (SC) is between 0.67 to 0.60 for bleached condition and between 0.30 to 0.18 for coloured condition.
Electrochromic windows require only a small switching voltage, usually between 1 to 5 volts and exhibits adjustable memory for 12 to 48
(transparent) WO3 + xM+ + xe- ↔ 2 MxWO3 (deep blue) ------------- Equation (1)
An electrochromic system consists of an ion-containing material (electrolyte) that is of close proximity to the electrochromic layer and the transparent layers for the setting up a distributed electric field. Ions are shuttled back and forth within the electrochromic layer when potential is applied. Typically, an electrochromic system is fabricated from five layers which comprises of two transparent conductors, an ion conductor or electrolyte, a counter electrode and an electrochromic layer as shown in Figure 1.[7] Figure 1: Five layers in an electrochromic system
2.1.2 Working Principle of Electrochromic System Figure 2: Movement of electrons and protons in electrochromic system
Figure 2 …show more content…
In a study done by S.E. Selkowitz et. al, electrochromic windows have lower annual energy performance than an opaque insulated wall. Primary energy benefits include ability to reduce electric lighting by managing daylight admittance and reduced cooling loads. In hot climates or season, electrochromic windows minimize solar heat gain with adequate daylight[10].
2.1.6 Advantages and Disadvantages of Electrochromic System
Electrochromic devices typically have an upper visible transmission of TV=70 to 50% and a fully coloured transmission of TV=25 to 10%. The range of shading coefficient (SC) is between 0.67 to 0.60 for bleached condition and between 0.30 to 0.18 for coloured condition.
Electrochromic windows require only a small switching voltage, usually between 1 to 5 volts and exhibits adjustable memory for 12 to 48