Electrochromic Window Substrate Coating Sequence

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Solution Overview

Problem

Current electrochromic windows face challenges with limited color variation, slow switching times, high operational costs, and compatibility issues with high-volume manufacturing due to the need for tempered glass, which affects thickness variation and process control, leading to inefficiencies in energy management and durability.

Innovation Solution

Incorporating novel electrochromic materials such as optically doped cathodes and anodes, lithium phosphorus oxynitride electrolytes, and improved transparent current collectors, along with laminated/bonded glass substrates and high-throughput deposition sources, to enhance visible transmission, solar heat gain control, and reliability, while eliminating the need for tempered glass in the fabrication process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lithium-based inorganic EC materials are used, then durability and low voltage operation are improved, but switching time increases (5-10 minutes)

Engineering Contradiction:
ImprovedurabilityVSAvoidswitching time
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent changes the material composition parameters by incorporating nanoscale tungsten oxide particles (5-50 nm) into the EC layer, altering the physical and chemical properties to achieve faster lithium ion diffusion rates while maintaining durability and low voltage operation characteristics

Inventive Principle:
Principle #35Parameter changes

2Reliability

If current EC device fabrication processes are used, then device functionality is achieved, but compatibility with high-volume manufacturing is reduced due to tempered glass requirements

Engineering Contradiction:
Improvedevice functionalityVSAvoidmanufacturing compatibility
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies EC coatings to glass substrates before tempering operations, performing the coating action in advance when the glass is still in a more manufacturable state, allowing subsequent cutting and tempering to proceed without damaging the delicate EC layers

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the manufacturing process into distinct stages: glass substrate preparation, EC coating deposition, cutting to size, and tempering, allowing each operation to be optimized independently and enabling high-volume manufacturing compatibility

Inventive Principle:
Principle #1Segmentation

3Strength

If tempered glass is used in EC fabrication, then strength is improved, but thickness variation increases affecting process control

Engineering Contradiction:
Improveglass strengthVSAvoidthickness control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent performs EC coating deposition on glass substrates before tempering operations, capturing the coating process when thickness control is more precise, and then proceeds with tempering to achieve the desired strength without compromising the already-deposited EC layers

Inventive Principle:
Principle #10Preliminary action

4Loss of energy

If static low-E coatings are used, then U-value is reduced improving energy efficiency, but dynamic control capability is lost

Engineering Contradiction:
Improveenergy efficiencyVSAvoiddynamic control
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent transforms the static low-E coating into a dynamic electrochromic system by incorporating lithium ion conductive layers and tungsten oxide that can reversibly change optical properties in response to applied voltage, enabling real-time adjustment of solar heat gain while maintaining thermal efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a composite structure combining traditional low-E coating materials with electrochromic tungsten oxide and lithium ion conductive electrolytes, integrating the thermal efficiency benefits of low-E with the dynamic control capabilities of electrochromism in a single multi-layer system

Inventive Principle:
Principle #40Composite materials

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

This approach results in electrochromic windows with faster switching speeds, improved appearance, increased durability, and reduced costs, enabling more efficient energy management and broader architectural applications, while being compatible with high-volume manufacturing processes.

Implementation Method 1

Fundamentally, the electrochromic device dynamically changes optical absorptivity, with the movement (intercalation and de-intercalation) of the Li into and out of the cathode

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

A plurality of EC device layers are sputtering-deposited, directly or indirectly, on the first substrate

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP2470954B1Method of making electrochromic windows
Publication Date: 2018.12.05 GUARDIAN GLASS LLC
  • EP2470954B1 patent drawingFigure 1(a)~1(b)
  • EP2470954B1 patent drawingFigure 2~5
  • EP2470954B1 patent drawingFigure 6(a)~6(b)

AI summary

Certain example embodiments of this invention relate to electrochromic (EC) devices, assemblies incorporating electrochromic devices, and/or methods of making the same. More particularly, certain example embodiments of this invention relate to improved EC materials, EC device stacks, high- volume manufacturing (HVM) compatible process integration schemes, and electrochromic window assemblies (600a) comprising a first glass substrate (402), which is not thermally tempered and supports a stack (400) of electrochromic layers, a second glass substrate (602), made of thermally tempered glass and a laminated to the first substrate, and a third glass substrate (604).