Battery Separator Substrate Structure for High-Pressure Lamination
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Solution Overview
Problem
Existing battery separators deform under high-pressure lamination conditions, leading to thickness reduction, pore damage, and reduced breakdown voltage, resulting in Hi-pot failure and low voltage failure.
Innovation Solution
A separator substrate with a polymer material containing polyolefin resin, featuring fibrils with a diameter of 50 nm to 250 nm and porosity of 30 vol % to 65 vol %, and a thickness of 5 μm to 50 μm, designed to maintain low thickness strain and high dielectric breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high pressure is applied during lamination to increase adhesion, then adhesion strength is improved, but separator deformation and pore damage occur
Solution Approach 1:
The patent applies parameter changes by controlling the molecular weight distribution (PDI) of polyethylene resin within 1.0 to 12.0 and using fibrillar structures with specific diameter ranges (50-250 nm). These parameter optimizations enable the separator to maintain dimensional stability and resist deformation under high-pressure lamination conditions while preserving pore structure integrity
Solution Approach 2:
The patent employs composite material strategies by creating a fibrillar network structure within the polyolefin matrix. The fibrils with controlled dimensions (50-250 nm diameter) distributed throughout the separator substrate provide structural reinforcement that resists compression deformation during lamination while maintaining the required porosity (30-65 vol %) for ion transport
2Quantity of substance
If separator thickness is reduced to improve energy density, then energy density is improved, but breakdown voltage decreases
Solution Approach 1:
The patent applies parameter changes by optimizing the PDI of polyethylene resin (1.0-12.0) and controlling fibril diameter (50-250 nm) to achieve a separator structure that maintains high dielectric breakdown voltage even at reduced thickness (5-50 μm). The controlled molecular weight distribution ensures uniform fibril formation that preserves electrical insulation properties while enabling thinner design
Solution Approach 2:
The patent utilizes porous material structures with controlled porosity (30-65 vol %) achieved through fibrillar networks. The specific pore structure formed by fibrils of 50-250 nm diameter provides both mechanical integrity for voltage resistance and optimized ion transport pathways, allowing thinner separators to maintain breakdown voltage requirements
3Reliability
If polyethylene content is increased to improve shutdown function, then shutdown characteristic is improved, but thermal shrinkage resistance decreases
Solution Approach 1:
The patent applies parameter changes by controlling the molecular weight distribution (PDI of 1.0-12.0) and using fibrillar structures with specific dimensions (50-250 nm diameter). These parameter optimizations enable polyethylene-based separators to achieve both shutdown function and thermal shrinkage resistance by creating a structured fibrillar network that maintains shape stability at elevated temperatures while preserving the shutdown mechanism
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 substrate exhibits high shape stability and dielectric breakdown voltage, reducing deformation and enhancing battery performance under high-pressure conditions.
Implementation Method 1
a sheet-shaped porous membrane having a plurality of pores and comprising a polymer material
Data Source
AI summary
A separator substrate for an electrochemical device. The separator substrate has pores that are small and uniform in size, good physical strength and durability, and high dielectric breakdown voltage. Therefore, with the use of the separator substrate, the probability of short circuiting is low.