This SBIR Phase I project is proposed by SAGE Electrochromics, Inc. to evaluate the feasibility of using spray coating technology to produce solution-derived, ceramic lithium-ion conductor (IC) films for electrochromic windows. The worldwide development of electrochromic (EC) glazing technology has been severely impeded by the inability to identify and develop an electrolyte that satisfies the performance, durability and cost requirements demanded for architectural glass applications. SAGE believes it has uniquely achieved the performance and stability objectives with a patented solution-derived IC. Although used to some extent in commercial applications, dip coating is an expensive and impractical batch process when production throughput, handling and manufacturing costs are critical to the ultimate commercial potential. A technology well-developed by the automotive industry, spray coating has tremendous potential in the extremely demanding EC window application. A key challenge will be to adapt this continuous process technology to the difficult-to-process thin-film ceramic materials in a way that preserves the essential functionality and performance of SAGE's dip coating developed IC. Specific issues associated with this include microstructure, composition, thickness, ionic and electronic conductivity's and surface morphology. During Phase I, SAGE's principal objective is to demonstrate the feasibility of spray coating for lithium ion-conductor films by successfully making a functional small-area EC device. To achieve this goal, SAGE will 1) spray coat lithium IC films on glass substrates to evaluate uniformity, thickness, and composition, 2) fabricate partial device structures to establish compositional uniformity, ion conductivity, electronic resistance and functionality of the relevant interfaces, and 3) incorporate the spray coated IC into a complete EC device to demonstrate the performance of the integrated system. If successful, this research will raise production rates, improve safety and process reliability, and reduce manufacturing costs - resolving the one major technological barrier to cost-effective electrochromic glazing. These results are estimated to represent a 25% cost savings based on costs at full market penetration. Electrochromicglazing will have a large impact on the architectural glass industry since, for the first time, building occupants and owners will have the ability to electronically control the shading of their window glass - anywhere from clear to heavily darkened. EC glazing will find application in any window where solar control is an issue - benefiting the residential, commercial and government building sectors by providing substantial energy savings and enhanced comfort. In addition to architectural windows, EC glazing will be ideally suited for automobiles and other transportation vehicles, and also for numerous specialty applications - including large-area electronic displays, recreational products, and consumer appliances and gadgetry. Beyond its application in electrochromics, this proposed spray coating technology may find uses in other large-area thin-film applications that include rechargeable lithium batteries, sensors, and optical coatings.
