LOW-COST ELECTROCHROMIC GLASS MASS PRODUCTION TECHNOLOGY

Electrochromic glass market challenges

Existing technologies are quite expensive

  • Existing engineering solutions are only suitable for complete-cycle companies whose activities range from application of electrochromic layers to production of insulated glass units (IGU) and installation of facades
  • As the production technique is not flexible it is only very special-purpose equipment which can be used to manufacture a certain type of electrochromic glass
  • The production cost of glass is too high ranging between at $400 – 450 per sq. m.

Restricted consumer attributes

  • Limited light transmission range (the difference in transparency in colored and bleached states) not exceeding 45-50 percent
  • Slow switching rate between colored and bleached states (10 to 20 minutes)
  • A limited choice of colors (generally blue)
  • Difficult to combine an electrochromic glass of the same color with solutions involving several colors for facade-finishing works

Improved energy efficiency in buildings

  • Heating of buildings consumes from 50 to 80% of electricity in the service sector, and air conditioning up to 20%
  • High ventilation and air-conditioning requirements for new building designs

Solution

Electrochromic glass

An electrical potential once applied alters the transparency of the electrochromic glass in the visible optical range while also ensuring control of the amount of heat penetrating into a room. According to View Glass, this kind of glass reduces peak energy consumption for cooling and lighting by 20%.

Comberry has developed an electrochromic glass production technology based on durable materials for mass industrial application called TUNOX.

The TUNOX electrochromic materials offer an extended range of colors, including shades of blue, gray, black and more. The unique proprietary technologies used in the TUNOX material system addresses many of the challenges associated with production and operation of electrochromic glass substantially improving performance as well as the consumer appeal of darkened glass units and making production cheaper and «flexible».

The technology is ready to scale.

Applications

Architecture

  • Home construction (smart house): facades, partitions, windows, doors
  • Office space construction (smart office): facades, conference rooms, business, office partitions, job design
  • Commercial construction: display cases, fitting booths, display cabinets
  • Construction of sports facilities: glazing, interior space creation in sports and health institutions
  • Construction of health facilities: partitions for wards, operating rooms, offices


Vehicles

  • Car glazing (as a substitute for tinted glass)
  • Panoramic roofs
  • Partitions in limos and buses
  • Windows for air and sea transport
  • Train windows

Electrochromic glass operation description

In most instances, electrochromic glass consists of a darkened electrode (an electrochromic electrode) and a transparent electrode (a counter-electrode with an ion-conducting electrolyte located between the electrodes (fig. 1). The nature of the materials used and the manner in which they are applied on the glazing surface may vary. This choice is left to the producer and is determined by a number of economic and technological factors influencing the consumer attributes as well as the cost of the product. In any of the versions, electrochromic glass is a galvanic device (a kind of a rechargeable battery) based on optically transparent materials.

An electrical potential when applied causes ions (normally lithium) to move towards the working electrode. This makes the working electrode colored until the apparent light transmission ratio required by the consumer is reached. When the power supply is off, the coloring of the electrode does not disappear remaining exactly the same as it was before. This means that electrochromic glass does not consume electricity permanently, but only when the light transmission mode is being switched. Inverse voltage application ensures that lithium ions move from the working electrode to the counter-electrode with the working electrode becoming discolored. The electrochromic unit becomes transparent, a process similar to a battery charging and discharging process.

Despite its apparent simplicity, electrochromic glass is in fact a sophisticated product as it is comprised of a large number of additional materials and various transition layers which reduce internal resistance or affect other important electrochemical properties of the entire galvanic system. Besides, it is as labor-intensive to assemble an electrochromic device as, for example, to produce lithium ion batteries.

Comberry has developed the TUNOX technology and a prototype electrochromic device (system) based on a combination of inorganic and organic materials.

System specifications:

  • Quick transparency switch with low voltage applied
  • Wide range of transparency between colored and bleached states: 5% to 60%
  • Shades of blue, gray and black available for the glass
  • If required, it enables converting an electrochromic device to an almost opaque state (with a transparency of 0.3%) through a unique system of dopants and thicker electrode layers without significantly reducing the service life and speed of the device
  •  Working temperature range: -30 °C…+ 65 °C (an electrochromic device is integrated into the glass unit which makes its operation easier in any climatic zone)
  • A lifetime of up to 20 years
Fig. 1. A diagram demonstrating a set of layers for an electrochromic stack

A system comprised of two electrodes and a gel-polymer electrolyte located between them

Fig. 2. A system comprised of two electrodes
and a gel-polymer electrolyte between them

The technology consists of replacing the solid-state electrochromic stack with a semi-solid-state stack. The inorganic electrolyte is replaced by a gel-polymer or a polymer electrolyte offering adhesive properties and good conductivity.

Gel-polymeric electrolyte properties:

  • Ionic conductivity comparable to liquid electrolytes
  • Good adhesion to the surface of electrodes
  • High transparency (>98%)
  • UV resistance
  • Resistance to elevated temperatures
  • Wide volt-ampere window
  • Good conductivity at sub-zero temperatures

TUNOX technology and the advantages that it offers

  • Universal: suitable for float glass manufacturers, insulated glass unit manufacturers and complete-cycle companies
  • A manufacturer’s standard equipment can be used to roll out an electrochromic glass system which means that there is no need to purchase expensive special-purpose equipment
  • Expanded product range
  • Parts of the system can be manufactured and assembled across different production environments also relying on cooperation
  • Production cost per sq. m.: $100-150

Technology Developer

Comberry, LLC (based in Ulyanovsk, Russia) is a tech company and a combinatory platform. It ensures multiple acceleration of R&D in PVD application of thin-film coatings. The company was established in 2013 with the participation of nano-centers of Ulyanovsk, the Republic of Mordovia and Dubna and in cooperation with Intermolecular, Inc. (California, USA).

Technology Partners

Cooperation

The Comberry team is ready to adapt its technology to scale it up from production of small research batches to commercial production or to establish a joint electrochromic glass production company.

Contacts

+7 (8422) 37–01–01

Comberry, LLC 

9 44th Inzhenerny proyezd,

Ulyanovsk, Russia, 432072

info@comberry.ru