The present disclosure relates to electrochromic elements (10) and devices (110) comprising an electrochromic material layer (114), an insulating layer (116), and a bulk heterojunction layer (118), having one or more optical properties that may be changed upon application of an electric potential. Upon provision of an electric potential above a threshold, electrons and holes may be injected into the electrochromic layer (114) and bulk heterojunction layer (118), and blocked by the insulating layer (116), resulting in an accumulation of the electrons and holes in their respective electrochromic material resulting in a change to the one or more optical properties of the electrochromic materials (114; 118). An opposite electric potential may be provided to reverse the change in the one or more optical properties.

A heat treated electrochromic device comprising an anodic complementary counter electrode layer comprised of a mixed tungsten-nickel oxide and lithium, which provides a high transmission in the fully intercalated state and which is capable of long term stability, is disclosed. Methods of making an electrochromic device comprising an anodic complementary counter electrode comprised of a mixed tungsten-nickel oxide are also disclosed.

The present disclosure relates to electrochromic devices including an insulating layer and at least one electrochromic material having one or more optical properties that may be changed upon application of an electric potential. The device may include a conductive nanoparticle layer and/or a buffer layer. Upon provision of an electric potential above a threshold, electrons and holes may be injected into the electrochromic material and blocked by the insulating layer, resulting in an accumulation of the electrons and holes in their respective electrochromic material resulting in a change to the one or more optical properties of the electrochromic material. An opposite electric potential may be provided to reverse the change in the one or more optical properties.

When transitioning an electrochromic (EC) device between two tint levels, a control unit may repeatedly adjust an applied voltage based on a stack voltage of the EC device. The stack voltage of the EC device may be measured and compared to a reference or target stack voltage. The stack voltage may be measured in any of various methods, such as by measuring it directly, via a measured equivalent series resistance, or via an open circuit voltage measurement. The applied voltage may then be changed or adjusted based on the measured stack voltage and the comparison of the stack voltage to the reference value. This process may be repeated multiple times and may essentially be performed continually until the stack voltage attains the desired level or at least attains a level within a predetermine threshold of the desired level.

A method of making an electrochromic device, includes: providing an electrochromic layer comprising a p-type electrochromic material; providing an ion-storage layer comprising an n-type metal oxide; and tuning the ion-storage layer, the electrochromic layer, or both the ion-storage layer and the electrochromic layer, so that when the electrochromic device is operating, the ion-storage layer operates in a minimally color changing mode.

Various embodiments herein relate to electrochromic devices, methods of fabricating electrochromic devices, and apparatus for fabricating electrochromic devices. In a number of cases, the electrochromic device may be fabricated to include a particular counter electrode material. The counter electrode material may include a base anodically coloring material. The counter electrode material may further include one or more halogens. The counter electrode material may also include one or more additives.

A overcharge-aware electrochromic device driver for preventing overcharge of an electrochromic device is described. One driver applies a constant supply current to an electrochromic device from a power supply. The driver determines an amount of charge as a function of time and current supplied to the electrochromic device. The driver determines whether the amount of charge reaches an overcharge limit before a sense voltage reaches a first sense voltage limit. Responsive to the amount of charge reaching the overcharge limit, the driver sets the sense voltage as a second sense voltage limit that is lower than the first sense voltage limit, ceases the constant supply current, and applies one of a variable voltage or a variable current to the electrochromic device from the power supply to maintain the sense voltage at the second sense voltage limit.

An electrochromic device and an electrochromic method therefor are disclosed. The electrochromic device comprises a first substrate, a first transparent conductive layer, a first electrochromic layer, an electrolyte layer, a second electrochromic layer, a second transparent conductive layer, and a second substrate which are sequentially stacked. Both the first electrochromic layer and the second electrochromic layer are made of a cathode electrochromic material or made of an anodic electrochromic material. The electrochromic method for the electrochromic device comprises: circularly applying a voltage having a direction opposite to and same as that of a first voltage to a pretreated electrochromic device. Because a structure in which two layers of electrochromic layers are made of the anodic electrochromic material or the cathode electrochromic material is used, and a specific electrochromic method is combined, the switching between different colors can be performed, and a selection range of the electrochromic materials can be expanded.

The present disclosure relates to an electrochromic material having a relatively high response speed and a reversible discoloration even by a relatively low driving voltage and an electrochromic particle, a transmittance variable panel and a transmittance variable display device including the electrochromic material.

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 tantalum oxide (NiWTaO). This material is particularly beneficial in that it is very transparent in its clear state.