Halogen-Doped Counter Electrode Material for Reliable Electrochromics
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Solution Overview
Problem
Electrochromic devices face limitations in realizing their full commercial potential due to various problems, including high defectivity and inefficiencies in material composition and fabrication processes, which affect their reliability and performance.
Innovation Solution
The development of a novel electrochromic stack comprising a cathodically coloring layer and an anodically coloring layer with specific metal and additive compositions, including nickel tungsten oxide, and an integrated deposition system for controlled layer deposition, aiming to reduce defects and enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrochromic materials and fabrication processes are used, then device fabrication can be performed with standard materials, but high defectivity and poor reliability result
Solution Approach 1:
The patent applies parameter changes by modifying the composition parameters of the counter electrode material. Specifically, it uses a non-stoichiometric metal oxide with controlled oxygen content (deviating from ideal stoichiometry) and incorporates specific metal elements (Ni, Co, Mn, Fe, Cu, Zn) at controlled concentrations. These compositional parameter changes improve ion insertion/extraction performance and reduce defectivity, thereby enhancing device reliability while maintaining manufacturability.
Solution Approach 2:
The patent employs composite materials by creating a counter electrode that combines multiple metal elements (Ni, Co, Mn, Fe, Cu, Zn) with tungsten oxide in a non-stoichiometric structure. This composite approach leverages the synergistic effects of different metals to improve electrochromic performance, ion conductivity, and device reliability while reducing defects compared to conventional single-material electrodes.
2Productivity
If standard counter electrode materials are used, then material composition is simple, but ion insertion and extraction performance is poor
Solution Approach 1:
The patent improves ion insertion/extraction performance by changing the compositional parameters of the counter electrode. It uses a non-stoichiometric tungsten oxide structure with controlled oxygen deficiency and incorporates multiple metal elements at optimized concentrations. These parameter changes create more active sites and improve ion conductivity, enhancing productivity despite increased material complexity.
Solution Approach 2:
The patent applies local quality by creating regions with different metal compositions and oxygen contents within the counter electrode structure. Different metal elements are distributed to create localized areas with optimized properties for specific functions (ion insertion, electron transfer, structural stability), thereby improving overall ion insertion/extraction performance while managing material complexity through functional zonation.
3Reliability
If conventional electrochromic devices are manufactured, then fabrication processes are standard, but optical properties and transition efficiency are limited
Solution Approach 1:
The patent improves performance reliability by changing key fabrication parameters, particularly the composition parameters of the counter electrode. It specifies precise metal content ranges and oxygen stoichiometry deviations that optimize electrochromic performance. These parameter changes enhance transition efficiency and optical properties while maintaining compatibility with existing fabrication processes, balancing improved reliability with ease of manufacture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution improves the reliability and performance of electrochromic devices by reducing defectivity and optimizing material composition, leading to efficient and long-lasting electrochromic transitions with improved optical properties.
Implementation Method 1
Electrochromism is a phenomenon in which a material exhibits a reversible electrochemically-mediated change in an optical property when placed in a different electronic state, typically by being subjected to a voltage change
Implementation Method 2
Tungsten oxide is a cathodic electrochromic material in which a coloration transition, transparent to blue, occurs by electrochemical reduction
Data Source
AI summary
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.