Laminated Battery Separator Particle Layer for Voltage and Ion Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nonaqueous electrolyte secondary battery separators with heat-resistant layers have limitations in both voltage resistance and ion permeability, particularly in larger cells where safety improvements are needed.
Innovation Solution
A nonaqueous electrolyte secondary battery laminated separator is developed with a heat-resistant layer on a polyolefin-based base material, featuring a particle layer with particles of 3 μm to 10 μm in diameter and a weight per unit area of 0.1 g/m² to 1.0 g/m², enhancing both voltage resistance and ion permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional heat-resistant layer is used on a separator, then heat resistance is improved, but voltage resistance remains insufficient
Solution Approach 1:
The invention uses a composite structure consisting of a polyolefin base material layer and a heat-resistant layer containing inorganic particles and heat-resistant resin. This composite material approach allows the separator to simultaneously achieve both heat resistance (through the heat-resistant layer) and voltage resistance (through the synergistic combination with the base material), resolving the technical contradiction between these two properties.
2Reliability
If a heat-resistant layer is added to improve safety, then heat resistance is improved, but ion permeability deteriorates
Solution Approach 1:
The heat-resistant layer is designed with a porous structure containing inorganic particles distributed within a heat-resistant resin matrix. This porous structure allows ion transport through the layer while the heat-resistant resin provides thermal stability. The inorganic particles serve as spacers to maintain pore structure, enabling the layer to simultaneously provide safety through heat resistance and maintain ion permeability for battery operation.
3Ease of manufacture
If the separator structure is simplified, then manufacturing is easier, but both voltage resistance and ion permeability are insufficient
Solution Approach 1:
The separator is segmented into distinct functional layers: a polyolefin base material layer providing voltage resistance and a separate heat-resistant layer with inorganic particles providing thermal stability and ion permeability. This segmentation allows each layer to be optimized for its specific function while maintaining relatively simple manufacturing processes for each individual layer, which are then combined through lamination.
Data Source
AI summary
Provided is a nonaqueous electrolyte secondary battery laminated separator which achieves both of voltage resistance and ion permeability. A nonaqueous electrolyte secondary battery laminated separator (4a) having a heat-resistant layer (2a, 2b) on one surface or both surfaces of a polyolefin-based base material (1) includes a particle layer (3a, 3b) on at least one side of the laminated separator, the particle layer containing particles having an average particle diameter of 3 μm to 10 μm, and the particle layer having a weight per unit area per layer of 0.1 g/m2 to 1.0 g/m2.