According to one embodiment, a tungsten oxide material containing potassium is provided. The tungsten oxide material has a shape of particles including a central section and a peripheral section adjacent to the central section, and having an average particle size of 100 nm or less. A periodicity of a crystal varies between the central section and the peripheral section. In addition, a tungsten oxide powder mass for an electrochromic device including 80% by mass to 100% by mass of the tungsten oxide material is provided. Moreover, a slurry for producing an electrochromic device containing the above tungsten oxide material is provided.

An object of the present invention is to provide a novel electrochromic device (ECD). Disclosed is an electrochromic device (ECD) comprising two metal-complex-based electrochromic thin films individually acting as a working electrode and a counter electrode; (i) one of the two metal-complex-based electrochromic thin films being a film of a cathodically coloring metallo-supramolecular polymer comprising at least one organic ligand having a plurality of metal coordination positions and a metal ion of at least one transition metal and/or lanthanoid metal with the at least one organic ligand and the metal ion being arranged alternately, and the other of the two metal-complex-based electrochromic thin films being a film of an anodically coloring metal hexacyanoferrate (MHCF) represented by the formula: M(II).sub.3[Fe(III)CN.sub.6].sub.2 (where M=Fe, Ni or Zn), and (ii) the electrochromic device having a first conducting substrate; the film of the cathodically coloring metallo-supramolecular polymer; an electrolyte; the film of the anodically coloring metal hexacyanoferrate (MHCF); and a second conducting substrate being arranged in this order.

An object of the present invention is to provide a novel electrochromic device (ECD). Disclosed is an electrochromic device (ECD) comprising two metal-complex-based electrochromic thin films individually acting as a working electrode and a counter electrode; (i) one of the two metal-complex-based electrochromic thin films being a film of a cathodically coloring metallo-supramolecular polymer comprising at least one organic ligand having a plurality of metal coordination positions and a metal ion of at least one transition metal and/or lanthanoid metal with the at least one organic ligand and the metal ion being arranged alternately, and the other of the two metal-complex-based electrochromic thin films being a film of an anodically coloring metal hexacyanoferrate (MHCF) represented by the formula: M(II).sub.3[Fe(III)CN.sub.6].sub.2 (where M=Fe, Ni or Zn), and (ii) the electrochromic device having a first conducting substrate; the film of the cathodically coloring metallo-supramolecular polymer; an electrolyte; the film of the anodically coloring metal hexacyanoferrate (MHCF); and a second conducting substrate being arranged in this order.

Methods are provided for fabricating electrochromic devices that mitigate formation of short circuits under a top bus bar without predetermining where top bus bars will be applied on the device. Devices fabricated using such methods may be deactivated under the top bus bar, or may include active material under the top bus bar. Methods of fabricating devices with active material under a top bus bar include depositing a modified top bus bar, fabricating self-healing layers in the electrochromic device, and modifying a top transparent conductive layer of the device prior to applying bus bars.

Methods are provided for fabricating electrochromic devices that mitigate formation of short circuits under a top bus bar without predetermining where top bus bars will be applied on the device. Devices fabricated using such methods may be deactivated under the top bus bar, or may include active material under the top bus bar. Methods of fabricating devices with active material under a top bus bar include depositing a modified top bus bar, fabricating self-healing layers in the electrochromic device, and modifying a top transparent conductive layer of the device prior to applying bus bars.

An electrochromic device composed of a pattern forming layer, an optical coating layer, an electrochromic component, and an opaque white layer arranged is revealed. The pattern forming layer has at least one pattern-shaded hollow hole for exposure of the optical coating layer. The optical coating layer which includes at least two layers of high and low refractive index material stacked alternately is the main layer to render colors. When transmittance of the electrochromic component which generates color changes is lower than 50%, a difference in the transmittance at 500 nm, 600 nm, and 700 nm is no more than 10%. Under such colored state, the color of light reflected by the optical coating layer is enhanced. The opaque white layer is for a sharper color contrast of the reflected light. Thereby light reflected by the optical coating layer show colors different from those of the electrochromic component in bleached and colored states.

An electrochromic device composed of a pattern forming layer, an optical coating layer, an electrochromic component, and an opaque white layer arranged is revealed. The pattern forming layer has at least one pattern-shaded hollow hole for exposure of the optical coating layer. The optical coating layer which includes at least two layers of high and low refractive index material stacked alternately is the main layer to render colors. When transmittance of the electrochromic component which generates color changes is lower than 50%, a difference in the transmittance at 500 nm, 600 nm, and 700 nm is no more than 10%. Under such colored state, the color of light reflected by the optical coating layer is enhanced. The opaque white layer is for a sharper color contrast of the reflected light. Thereby light reflected by the optical coating layer show colors different from those of the electrochromic component in bleached and colored states.

An electrochromic device comprising a substrate, a set of electrodes disposed on or within the substrate, and a layer comprising ε-WO.sub.3 disposed in electrical communication with the set of electrodes, wherein the layer of ε-WO.sub.3 exhibits polarization switching are described. Methods of making and using the electrochromic devices are also described. The electrochromic devices are used for detecting acetone in a fluid. The observed change in color of the ε-WO.sub.3 layer can be correlated with a subject's medical condition, such as diabetes.

An electrochromic device comprising a substrate, a set of electrodes disposed on or within the substrate, and a layer comprising ε-WO.sub.3 disposed in electrical communication with the set of electrodes, wherein the layer of ε-WO.sub.3 exhibits polarization switching are described. Methods of making and using the electrochromic devices are also described. The electrochromic devices are used for detecting acetone in a fluid. The observed change in color of the ε-WO.sub.3 layer can be correlated with a subject's medical condition, such as diabetes.

Methods are provided for fabricating electrochromic devices that mitigate formation of short circuits under a top bus bar without predetermining where top bus bars will be applied on the device. Devices fabricated using such methods may be deactivated under the top bus bar, or may include active material under the top bus bar. Methods of fabricating devices with active material under a top bus bar include depositing a modified top bus bar, fabricating self-healing layers in the electrochromic device, and modifying a top transparent conductive layer of the device prior to applying bus bars.