Polyethylene Powder Composition for Heat-Resistant Separator Membranes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyethylene powders used for microporous membranes in secondary battery separators lack sufficient heat resistance, membrane homogeneity, and dimensional stability, failing to meet the increasing demands for enhanced physical properties.
Innovation Solution
A polyethylene powder with a viscosity-average molecular weight between 100,000 and 4,000,000, and a crystal thickness parameter of 5° C. to 9° C., along with specific z-average shrinkage factor and peak top temperature, is developed to enhance heat resistance, membrane homogeneity, and dimensional stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyethylene powders are used for microporous membranes, then production cost and ease of manufacture are maintained, but heat resistance, membrane homogeneity, and dimensional stability are insufficient
Solution Approach 1:
The invention changes the molecular weight parameters of polyethylene to a specific range (viscosity-average molecular weight: 100,000-4,000,000, weight-average molecular weight: 1,000,000-10,000,000) to simultaneously achieve improved heat resistance, membrane homogeneity, and dimensional stability while maintaining ease of manufacture. This parameter optimization resolves the contradiction by finding the optimal molecular weight window that satisfies both performance and manufacturing requirements.
2Strength
If polyethylene with higher molecular weight is used to improve mechanical strength and heat resistance, then reliability improves, but processing difficulty and manufacturing complexity increase
Solution Approach 1:
The invention optimizes the molecular weight parameters within a specific range rather than simply increasing molecular weight indefinitely. By setting the viscosity-average molecular weight between 100,000-4,000,000 and weight-average molecular weight between 1,000,000-10,000,000, the invention achieves enhanced mechanical strength and heat resistance while keeping processing difficulty manageable. This resolves the contradiction by identifying the optimal molecular weight window that balances performance improvement with processing feasibility.
Data Source
AI summary
A polyethylene powderhaving a viscosity-average molecular weight of 100,000 or larger and 4,000,000 or smaller, andhaving a crystal thickness parameter of 5° C. or higher and 9° C. or lower obtained from measurement using a differential scanning calorimeter (DSC).