Solar Cell Module Disassembly via Thermoplastic Interlayer

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Solution Overview

Problem

Conventional silicon solar cell modules are difficult to disassemble for recycling due to the use of thermosetting polymers, which require time-consuming and labor-intensive methods that cause secondary pollution, preventing the reuse of glass and cells without damage.

Innovation Solution

A solar cell module design incorporating a thermoplastic resin layer between the cell unit and thermosetting resin layers, allowing for easy disassembly through thermal or chemical dissociation methods without damaging the components, while maintaining high light transmittance and insulation properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If thermosetting polymers (EVA or PO) are used as packaging materials to encapsulate and fix solar cells, then the service life and structural stability of solar modules are extended, but the modules become difficult to disassemble for recycling, requiring time-consuming and labor-intensive methods that cause secondary pollution

Engineering Contradiction:
Improveservice life of solar moduleVSAvoidease of disassembly for recycling
Core Design Contradiction:
Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The packaging structure is segmented into multiple functional layers: a thermosetting polymer layer (EVA or PO) for structural stability and a thermoplastic resin layer for easy disassembly. This segmentation allows each layer to perform its specific function - the thermosetting layer provides long-term durability while the thermoplastic layer enables recycling by melting at elevated temperatures to release glass and cells intact.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If thermosetting plastic material is removed by heating at 300°C to 550°C or decomposition in acid/organic solvent, then the glass and cells can be separated from the module, but the process is time-consuming, labor-intensive, and causes secondary pollution

Engineering Contradiction:
Improveremoval of thermosetting plasticVSAvoiddisassembly time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

A thermoplastic resin layer is introduced as an intermediary between the cell unit and the thermosetting polymer layer. This intermediary layer facilitates easy separation by melting at relatively low temperatures (above its melting point but below 300°C), allowing the thermosetting plastic to be removed without requiring high-temperature combustion or chemical decomposition, thereby reducing disassembly time and avoiding secondary pollution.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If conventional disassembly methods are used to separate glass from cell modules, then the packaging film is degraded, but the glass and cells cannot be obtained intact for reuse

Engineering Contradiction:
Improvedegradation of packaging filmVSAvoidintegrity of glass and cell panel
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The disassembly process utilizes parameter changes in the thermoplastic resin layer by controlling temperature to above its melting point (but below 300°C). This parameter change causes the thermoplastic layer to transition from a solid encapsulating state to a molten state, enabling easy separation of glass and cells while maintaining their structural integrity and allowing them to be reused without damage.

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

Enables efficient disassembly and recycling of solar cell modules with minimal fragmentation, maintaining high light transmittance and insulation, and improving light utilization and power gain, while meeting IEC61215 electrical verification specifications.

Implementation Method 1

a first thermoplastic resin layer disposed between the cell unit and the first thermosetting resin layer; a second thermoplastic resin layer disposed between the cell unit and the second thermosetting resin layer

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

Once a cross-linking network occurs among molecules of the thermosetting polymers, neither the glass nor the solar cell panel can be separated by heating and melting the packaging film

Methodology Applied
Scientific EffectCross-linking: Chemical Bonding

Data Source

PatentEP3846227B1Solar cell modules
Publication Date: 2022.05.04 IND TECH RES INST
  • EP3846227B1 patent drawingFigure 1
  • EP3846227B1 patent drawingFigure 2A~2C
  • EP3846227B1 patent drawingFigure 2D~2F

AI summary

A solar cell module is provided. The solar cell module includes a first substrate, a second substrate opposite the first substrate, a cell unit disposed between the first and second substrates, a first thermosetting resin layer disposed between the cell unit and the first substrate, a first thermoplastic resin layer disposed between the cell unit and the first thermosetting resin layer, a second thermosetting resin layer disposed between the cell unit and the second substrate, and a second thermoplastic resin layer disposed between the cell unit and the second thermosetting resin layer.