Laminated Battery Separator With Controlled Roughness and Heat Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laminated separators for nonaqueous electrolyte secondary batteries have limitations in rate characteristics and heat resistance.
Innovation Solution
A laminated separator comprising a polyolefin-based substrate with a heat-resistant layer on one or both surfaces, and a particle layer on at least one side, with controlled standard deviation of surface roughness to enhance uniformity and bonding with electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional separator structure is used, then the manufacturing process is simple, but the rate characteristic and heat resistance are insufficient
Solution Approach 1:
The patent employs a laminated separator structure combining a polyolefin-based substrate with a heat-resistant layer containing aromatic resin and inorganic particles. This composite material approach provides both excellent heat resistance (maintaining structural integrity at high temperatures) and improved rate characteristics, while the specific layer configuration manages the complexity through functional specialization of each layer.
Solution Approach 2:
The heat-resistant layer is applied selectively on one or both surfaces of the polyolefin substrate, providing localized heat resistance where it is most needed during battery operation. The inorganic particles are distributed within this layer to specifically enhance thermal stability at critical interface regions, rather than uniformly throughout the entire separator structure.
2Manufacturing precision
If the surface roughness is not controlled, then the manufacturing process is simpler, but the bonding with electrodes is uneven causing deformation
Solution Approach 1:
The patent specifies controlling the standard deviation of surface roughness to 0.06 μm or less on the particle layer surface. This precise parameter control ensures uniform bonding with electrodes during assembly, preventing localized stress concentrations that would cause uneven deformation during charge-discharge cycles, while maintaining practical manufacturability through defined tolerances.
3Stability of the object's composition
If the separator has poor heat resistance, then the structure is simpler, but the damage expands unevenly during battery operation
Solution Approach 1:
The patent incorporates a heat-resistant layer containing aromatic resin and inorganic particles that actively responds to thermal stress during battery operation. When heat is generated during charge-discharge cycles, this layer maintains its structural integrity and provides a stable framework that distributes thermal stress uniformly, converting the potential harmful effect of heat into a controlled condition that prevents uneven damage propagation.
Data Source
AI summary
A laminated separator for a nonaqueous electrolyte secondary battery is provided which makes it possible to obtain a battery having an excellent rate characteristic and which has excellent heat resistance. A laminated separator for a nonaqueous electrolyte secondary battery according to the present disclosure includes a polyolefin-based substrate and a heat-resistant layer that is provided on one surface or both surfaces of the polyolefin-based substrate, the laminated separator including a particle layer which is provided on at least one side of the laminated separator, a standard deviation of surface roughness on a surface of the laminated separator which surface is located on the at least one side on which the particle layer is provided being not more than 0.06.