In the electrochromic device according to an embodiment of the present application, when the first voltage is applied to the electrochromic device in a state that the electrochromic element has the first state, the electrochromic device becomes the second state, and when the first voltage is applied to the electrochromic element in a state that the electrochromic element has the fourth state, the electrochromic element becomes the third state.

A method for preparing an electrochromic device. In the method the device is prepared by inserting monovalent cations into a reducing electrochromic layer in advance, for instance, through a dry process. In particular, the method involves inserting monovalent cations into an electrochromic layer which includes a reducing electrochromic material. Then, subsequently and sequentially, placing an electrolyte layer and an ion storage layer on the electrochromic layer. In this way, it is possible to improve driving durability of the electrochromic device.

The embodiments herein relate to electrochromic stacks, electrochromic devices, and methods and apparatus for making such stacks and devices. In various embodiments, an anodically coloring layer in an electrochromic stack or device is fabricated to include nickel-tungsten-tin-oxide (NiWSnO). This material is particularly beneficial in that it is very transparent in its clear state.

The embodiments herein relate to electrochromic stacks, electrochromic devices, and methods and apparatus for making such stacks and devices. In various embodiments, an anodically coloring layer in an electrochromic stack or device is fabricated to include nickel-tungsten-tin-oxide (NiWSnO). This material is particularly beneficial in that it is very transparent in its clear state.

Window units, for example insulating glass units (IGU's), that have at least two panes, each pane having an electrochromic device thereon, are described. Two optical state devices on each pane of a dual-pane window unit provide window units having four optical states. Window units described allow the end user a greater choice of how much light is transmitted through the electrochromic window. Also, by using two or more window panes, each with its own electrochromic device, registered in a window unit, visual defects in any of the individual devices are negated by virtue of the extremely small likelihood that any of the visual defects will align perfectly and thus be observable to the user.

An electrochromic device can include a substrate, a transparent conductive oxide layer over the substrate, and a bus bar over the substrate. The bus bar can include silver and has a resistivity of at most 6.7×10.sup.−6 Ω*cm, an average adhesion strength to SiO.sub.2 of at least 3N based on 20 measurements, as determined by Method A of ASTM B905-00 (Reapproved 2010), or a classification of at least 4, as determined by Method B of ASTM B905-00 (Reapproved 2010). In another aspect a process of forming an electrochromic device can include forming a transparent conductive oxide layer over a substrate; forming a bus bar precursor over the substrate, wherein the precursor includes silver; and firing the precursor to form a bus bar. Firing can be performed such that the first bus bar is at a temperature of at least 390° C.

Electrochromic devices and methods may employ the addition of a defect-mitigating insulating layer which prevents electronically conducting layers and/or electrochromically active layers from contacting layers of the opposite polarity and creating a short circuit in regions where defects form. In some embodiments, an encapsulating layer is provided to encapsulate particles and prevent them from ejecting from the device stack and risking a short circuit when subsequent layers are deposited. The insulating layer may have an electronic resistivity of between about 1 and 10.sup.8 Ohm-cm. In some embodiments, the insulating layer contains one or more of the following metal oxides: aluminum oxide, zinc oxide, tin oxide, silicon aluminum oxide, cerium oxide, tungsten oxide, nickel tungsten oxide, and oxidized indium tin oxide. Carbides, nitrides, oxynitrides, and oxycarbides may also be used.

Electrochromic devices and methods may employ the addition of a defect-mitigating insulating layer which prevents electronically conducting layers and/or electrochromically active layers from contacting layers of the opposite polarity and creating a short circuit in regions where defects form. In some embodiments, an encapsulating layer is provided to encapsulate particles and prevent them from ejecting from the device stack and risking a short circuit when subsequent layers are deposited. The insulating layer may have an electronic resistivity of between about 1 and 10.sup.8 Ohm-cm. In some embodiments, the insulating layer contains one or more of the following metal oxides: aluminum oxide, zinc oxide, tin oxide, silicon aluminum oxide, cerium oxide, tungsten oxide, nickel tungsten oxide, and oxidized indium tin oxide. Carbides, nitrides, oxynitrides, and oxycarbides may also be used.

An electrochromic (EC) device and method, the EC device including: an optically transparent first substrate; a working electrode disposed on the first substrate and including electrochromic nanoparticles and a flux material having a melting point ranging from about 25° C. to about 500° C.; and an electrolyte disposed on the working electrode. The flux material is configured to prevent or reduce sintering of the nanoparticles at a temperature of up to about 700° C.

Provided is an electrochromic element including: a first electrode; a second electrode apart from and opposite to the first electrode; an electrolyte layer between the first electrode and the second electrode, containing an oxidizable substance or a reducible substance, or both; and at least one of an oxidizable electrochromic layer between the first electrode and the electrolyte layer, containing an oxidizable electrochromic compound, and a reducible electrochromic layer between the second electrode and the electrolyte layer, containing a reducible electrochromic compound, wherein an oxidation potential of the oxidizable substance is nobler than an oxidation potential of the oxidizable electrochromic compound, a reduction potential of the reducible substance is baser than a reduction potential of the reducible electrochromic compound, an oxidation reaction of the oxidizable substance is irreversible, and a reduction reaction of the reducible substance is irreversible.