Thin Inorganic-Coated Separator for High-Voltage Battery Stability
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Solution Overview
Problem
The challenge is to develop a separator for electrochemical devices that maintains high capacity/high output characteristics and excellent withstand voltage characteristics while being thinned, and also ensures improved dimensional stability at high temperatures, as existing separators face issues with dielectric breakdown voltage and heat stability.
Innovation Solution
A separator is designed with a porous substrate and an inorganic particle layer, where the inorganic particle layer has a specific particle size distribution and is bonded using a condensation-suppressed hydrolytic condensate of a silane compound, applied under a weakly acidic atmosphere, to enhance packing density and dielectric breakdown voltage, and the substrate is treated with corona or plasma discharge to introduce polar functional groups for improved adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the separator thickness is reduced to achieve high capacity/high output characteristics, then the energy density and output characteristics are improved, but the dielectric breakdown voltage decreases deteriorating withstand voltage characteristics
Solution Approach 1:
The patent applies composite materials by forming an inorganic particle layer on the porous substrate. This composite structure combines the advantages of the porous substrate (providing basic separation function) with inorganic particles (providing enhanced dielectric breakdown voltage and thermal stability), thereby achieving both high energy density through thinning and excellent withstand voltage characteristics.
Solution Approach 2:
The patent utilizes porous materials by controlling the porosity of the porous substrate and the inorganic particle layer. The porous structure allows for ion transport while maintaining mechanical integrity and electrical insulation, enabling the separator to achieve high capacity through optimized pore structure while maintaining adequate withstand voltage performance.
2Productivity
If the separator thickness is reduced to achieve high capacity/high output characteristics, then the energy density is improved, but the battery stability deteriorates
Solution Approach 1:
The composite structure of porous substrate plus inorganic particle layer provides enhanced battery stability. The inorganic particles contribute to thermal stability and structural integrity, preventing separator failure under various operating conditions while maintaining the thin profile needed for high energy density.
Solution Approach 2:
The patent applies parameter changes by optimizing various parameters including the thickness of the porous substrate, the particle size distribution of inorganic particles, the porosity of the substrate, and the packing density of the inorganic particle layer. These parameter optimizations enable the separator to achieve high energy density while maintaining adequate battery stability.
3Stability of the object's composition
If an inorganic particle layer is stacked on a porous substrate to improve dimensional stability at high temperature, then the thermal stability is improved, but the overall thickness increases which is disadvantageous to high capacity/high output characteristics
Solution Approach 1:
The patent utilizes porous materials with optimized porosity to achieve high dimensional stability at high temperature while maintaining thin overall thickness. The porous structure provides thermal stability through the inorganic particle layer while the controlled porosity ensures adequate ion transport, allowing the separator to remain thin for high capacity applications.
Solution Approach 2:
The patent applies parameter changes by optimizing the porosity of the porous substrate and the packing density of the inorganic particle layer. By carefully controlling these parameters, the separator achieves high dimensional stability at elevated temperatures while maintaining a thin overall thickness suitable for high capacity and output characteristics.
4Reliability
If the inorganic particle layer packing density is increased to improve dielectric breakdown voltage, then the withstand voltage characteristics are improved, but the ion transport resistance may increase
Solution Approach 1:
The patent applies parameter changes by optimizing the packing density of the inorganic particle layer within a specific range (1.0-2.5 g/(m2·μm)). This optimized packing density achieves high dielectric breakdown voltage and withstand voltage characteristics while maintaining adequate porosity and pore connectivity for efficient ion transport, thereby balancing reliability and productivity.
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 solution significantly improves dielectric breakdown voltage, thermal stability, and withstand voltage characteristics, allowing the separator to maintain performance even at high temperatures with a thin configuration, thus ensuring high capacity and output while ensuring user safety.
Implementation Method 1
the substrate is treated with corona or plasma discharge to introduce polar functional groups for improved adhesion
Implementation Method 2
the substrate is treated with corona or plasma discharge to introduce polar functional groups for improved adhesion
Implementation Method 3
the inorganic particle layer is bonded using a condensation-suppressed hydrolytic condensate of a silane compound, applied under a weakly acidic atmosphere
Implementation Method 4
the dielectric breakdown voltage of the separator is decreased to deteriorate withstand voltage characteristics
Data Source
AI summary
Provided are a separator, a method of manufacturing the separator, and an electrochemical device including the separator. According to an embodiment of the present disclosure, a separator including: a porous substrate and an inorganic particle layer provided on at least one surface of the porous substrate may be provided, wherein a value of the following Formula (1) is 0.135 or more: (1) BDV/t, wherein BDV is a voltage (kV) when a leakage current value is 5 mA, and t is an overall average thickness (μm) of the separator.