All-Solid Electrochromic Bilayer for Infrared Control

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Solution Overview

Problem

Current electrochromic devices for infrared applications face challenges such as fragile interfaces, degradation at high temperatures, and poor resistance to UV radiation, making them unsuitable for space conditions and requiring complex designs with infrared-transparent electrodes.

Innovation Solution

An all-solid electrochromic device with a bilayer electrode structure, comprising a substrate, a first electrochromic proton storage material, a proton-conducting and electronic-insulating electrolyte, a sub-stoichiometric tungsten oxide layer, and a second electrochromic material with variable proton intercalation, which eliminates the need for infrared-transparent electrodes and simplifies the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If flexible all-organic electrochromic devices are used, then the device can be made flexible and lightweight, but the device has fragile interfaces and poor resistance to high temperatures and UV radiation

Engineering Contradiction:
Improvedevice weightVSAvoidresistance to high temperatures and UV radiation
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent changes the material state from organic/flexible to inorganic/all-solid, transforming the device into a rigid structure with superior thermal and UV stability. The all-solid inorganic layers (tungsten oxide, electrolyte, insertion material) replace organic components, eliminating fragility and enhancing resistance to extreme conditions while maintaining electrochromic functionality.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If all-solid electrochromic devices with classic design are used, then the device has good thermal and UV resistance, but the device requires infrared-transparent electrodes such as gold grids which complicates the design

Engineering Contradiction:
Improveresistance to high temperatures and UV radiationVSAvoidelectrode structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the complex infrared-transparent electrode structure (gold grids) by extracting this unnecessary component. The invention achieves infrared modulation through the electrochromic active material itself, eliminating the need for separate transparent electrode layers and simplifying the overall device architecture.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The electrochromic active material performs multiple functions: it provides the electrochromic effect for visual modulation and simultaneously serves as the infrared-modulating element. This multi-functionality eliminates the need for dedicated infrared-transparent electrodes, reducing device complexity while maintaining all required functionalities.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If all-solid electrochromic devices are used, then the device has good resistance to high temperatures and UV radiation, but the manufacturing process is complex requiring precise deposition of multiple inorganic layers

Engineering Contradiction:
Improveresistance to high temperatures and UV radiationVSAvoidmanufacturing process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple functional layers (electrochromic active material, electrolyte, insertion material, conductive layers) into an integrated all-solid stack structure. This merging of functions into a unified device architecture simplifies manufacturing by eliminating the need for separate assembly steps and reducing the number of components that require precise alignment and integration.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If flexible electrochromic devices with gel electrolytes are used, then the device can be made flexible, but the gel electrolytes pose problems when used under vacuum

Engineering Contradiction:
ImproveflexibilityVSAvoidperformance under vacuum
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the electrolyte state from gel (flexible) to solid (rigid), transforming the device into an all-solid structure. This parameter change eliminates vacuum compatibility issues while sacrificing flexibility. The solid inorganic electrolyte layers provide stable performance under vacuum and extreme conditions, prioritizing reliability over adaptability.

Inventive Principle:
Principle #35Parameter changes

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 device provides adjustable infrared reflection or emission, is robust and resistant to high temperatures and UV radiation, and can be manufactured using a simplified process, making it suitable for space applications without the need for gold grids or complex encapsulation.

Implementation Method 1

an all-solid electrochromic device with controlled infrared reflection or emission

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

a second electrochromic material with variable proton intercalation rate

Methodology Applied
Scientific EffectProton intercalation:

Implementation Method 3

a layer of a proton-conducting and electronic-insulating electrolyte

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentEP2652548B1All solid-state electrochromic device, electrochromic bilayer for said device, and method for producing said device
Publication Date: 2018.07.11 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2652548B1 patent drawingFigure 1~2
  • EP2652548B1 patent drawingFigure 3~4
  • EP2652548B1 patent drawingFigure 5~6

AI summary

The invention relates to a completely solid electrochromic device having controlled infrared reflection or emission, in particular an electrically controllable one, including a stack that sequentially includes, from a rear surface (3) to a front surface (1) exposed to infrared rays (2): a substrate (4) made of an electronically conductive material, or a substrate made of an electronically non-conductive material coated with a layer of an electronically conductive material, forming a first electrode; a layer made of a first electrochromic material (5) for storing protons; a layer consisting of a proton-conducting electrolyte and an electronic insulator (6); a bilayer including a substoichiometric tungsten-oxide (WO3-y) layer forming a second electrode; said WO3-y layer being arranged beneath a layer having variable reflection in the infrared range, a second electrochromic material having a variable proton intercalation rate, which is selected from crystallized tungsten oxide (HxWO3. nH2O- c) and hydrated crystallized tungsten oxide (HxWO3. nH2O - c); and a protective layer (10) transparent to infrared radiation. The invention also relates to a bilayer for said device and to a method for producing said device.