Battery Electrode Insulation Layer for Water-Peelable Recycling

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Solution Overview

Problem

Existing lithium-ion battery recycling methods face challenges in efficiently removing insulation layers from current collectors due to the use of polyvinylidene fluoride (PVDF) binders, leading to reduced recycling rates and increased costs, along with environmental concerns from N-methylpyrrolidone (NMP) toxicity.

Innovation Solution

An electrode design featuring a water-based binder and inorganic material insulation layer that forms a mutually fitted structure with the active layer, allowing easy peeling through water immersion, ensuring high recycling rates and environmental sustainability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PVDF binder and NMP solvent are used in the insulation layer, then the insulation layer provides effective electrical insulation and structural stability, but the insulation layer becomes difficult to remove during recycling, reducing recycling rates and increasing costs

Engineering Contradiction:

Improveinsulation performanceVSAvoidrecycling rate

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical composition parameters of the insulation layer by replacing PVDF/NMP with water-based binder systems. This parameter change enables the insulation layer to maintain its insulating function while becoming water-soluble or water-swellable, allowing easy removal during recycling through water immersion without requiring additional trimming processes

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies the discarding and recovering principle by designing an insulation layer that can be easily discarded (removed) from the current collector during recycling. The water-based binder allows the insulation layer to be selectively removed while the current collector and active layer are recovered, improving the overall recycling rate and reducing waste

Inventive Principle:

Principle #34Discarding and recovering

2Stability of the object's composition

If PVDF binder and NMP solvent are used in the insulation layer, then the insulation layer maintains structural integrity, but NMP toxicity causes environmental pollution

Engineering Contradiction:

Improvestructural integrityVSAvoidenvironmental pollution

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent uses a water-based binder system that is environmentally benign and can be easily disposed of or degraded. The insulation layer is designed to be temporary and removable, using materials that do not persist in the environment like NMP, thereby reducing environmental pollution while maintaining functional integrity during battery operation

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent converts the potential harm of using binders that are easy to remove into a benefit by selecting water-based binders that are both easy to remove for recycling and environmentally friendly. The water solubility that enables easy removal also ensures environmental compatibility, transforming a potential disadvantage into an environmental advantage

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If additional edge trimming process is used to remove insulation layers during recycling, then insulation layers are effectively removed, but recycling costs increase and current collector recycling rate decreases

Engineering Contradiction:

Improveinsulation layer removalVSAvoidrecycling efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent extracts the harmful and difficult-to-remove PVDF/NMP-based insulation layer and replaces it with a water-based binder system. This extraction of the problematic binder system allows the insulation layer to be easily separated from the current collector through water immersion, eliminating the need for additional edge trimming processes and improving recycling efficiency

Inventive Principle:

Principle #2Taking out (Extraction)

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 design enables efficient recycling of current collectors with high peel strengths after water immersion, improving safety and reducing recycling costs while minimizing environmental impact.

Implementation Method 1

The insulation layer includes a water-based binder and an inorganic material, and a peel strength of the insulation layer after being immersed in water for 1 minute at a preset temperature is less than or equal to 7N/m

Methodology Applied

Scientific EffectHydrophilicity: Hydrophile

Data Source

PatentUS12573732B2Electrode and electrochemical apparatus

Publication Date: 2026.03.10 XIAMEN HITHIUM ENERGY STORAGE TECHNOLOGY CO LTD

AI summary

An electrode and an electrochemical apparatus are provided. The electrode includes a current collector, an active layer, and an insulation layer. The active layer is coated on at least one surface of the current collector. The insulation layer is coated on the at least one surface of the current collector and connected to a periphery of the active layer. The insulation layer includes a water-based binder and an inorganic material, and a peel strength of the insulation layer after being immersed in water for 1 minute at a preset temperature is less than or equal to 7N/m.