EVA/E/X-Y Copolymer Encapsulant for PID Resistance

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Solution Overview

Problem

Photovoltaic modules are susceptible to potential-induced degradation (PID) due to ion and water migration, which affects their efficiency and lifetime, and existing encapsulants do not adequately prevent this issue.

Innovation Solution

An encapsulant composition comprising a copolymer of ethylene and vinyl acetate combined with an enhancing ANTI-PID copolymer, specifically an E/X or E/X/Y copolymer where E is ethylene, X is a half-ester of maleic anhydride, and Y is an alkyl acrylate, which reduces ion permeability and mitigates PID.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional EVA-based encapsulants are used, then the encapsulant provides basic protection and adhesion, but the module suffers from potential-induced degradation due to ion and water migration

Engineering Contradiction:
Improveresistance to potential-induced degradationVSAvoidion and water migration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses a composite encapsulant material consisting of EVA copolymer blended with E/X/Y copolymer (where E is ethylene, X is half-ester of maleic anhydride, and Y is alkyl acrylate). This composite structure combines the adhesive properties of EVA with the low ion permeability of the E/X/Y copolymer, creating a material that simultaneously provides protection and resists ion/water migration that causes PID

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the encapsulant's chemical composition by incorporating specific copolymers with controlled monomer ratios. The E/X/Y copolymer contains 5-50 mol% X (half-ester of maleic anhydride) and 5-50 mol% Y (alkyl acrylate), which changes the material's ion permeability parameter while maintaining adequate adhesion properties

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the encapsulant composition is modified to reduce ion permeability, then PID resistance improves, but adhesion to solar cells and glass may be compromised

Engineering Contradiction:
ImprovePID resistanceVSAvoidadhesion strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent merges two different copolymer materials (EVA and E/X/Y) in a blended composition. The EVA component provides strong adhesion to solar cells and glass, while the E/X/Y copolymer component provides low ion permeability. By combining these materials, the encapsulant achieves both strong adhesion and high PID resistance simultaneously

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The encapsulant composition is designed with different functional components distributed throughout the material matrix. The EVA regions provide adhesion functionality while the E/X/Y copolymer regions provide ion barrier functionality, allowing different parts of the encapsulant to perform different functions locally

Inventive Principle:
Principle #3Local quality

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 encapsulant composition significantly reduces PID, maintaining high power retention and module stability under various voltage and humidity conditions, outperforming conventional EVA-based encapsulants by retaining over 95% of initial power output.

Implementation Method 1

an encapsulant composition comprising a copolymer of ethylene and vinyl acetate and an enhancing ANTI-PID copolymer... which reduces ion permeability and mitigates PID

Methodology Applied
Scientific EffectIon permeability reduction: Permeation

Data Source

PatentEP3762973B1Photovoltaic module and encapsulant composition having improved resistance to potential induced degradation
Publication Date: 2023.03.29 DOW GLOBAL TECHNOLOGIES LLC

AI summary

Provided herein is an encapsulant composition and photovoltaic modules having Anti-PID ability.