Dual-Coated Battery Separator for Low-Temperature Cell Adhesion
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Solution Overview
Problem
Conventional battery separators face challenges in achieving high safety, cycling performance, and low-temperature dynamic performance while maintaining cost-effectiveness.
Innovation Solution
A battery separator with a substrate and two coating layers, where the first coating layer consists of first polymer particles and inorganic particles, and the second coating layer consists of second polymer particles, optimized with specific particle size ratios to enhance adhesion and heat shrinkage resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional battery separator structure is used, then the manufacturing process is simple, but the adhesion to electrode plates is insufficient and low-temperature dynamic performance is poor
Solution Approach 1:
The separator is divided into multiple functional layers: a base layer providing structural support and shutdown function, and a coating layer containing polymer particles and inorganic particles for enhanced adhesion. This segmentation allows each layer to perform its specific function optimally, resolving the contradiction between adhesion performance and structural simplicity.
Solution Approach 2:
The coating layer uses a composite material system combining polymer particles (for adhesion and flexibility) with inorganic particles (for thermal stability and surface roughness). This composite structure enhances adhesion to electrode plates while maintaining the separator's overall simplicity and manufacturability.
2Ease of manufacture
If the separator structure is simplified for industrial production, then manufacturing cost is reduced, but safety performance may be compromised
Solution Approach 1:
The invention optimizes particle size parameters (Dv10, Dv50, Dv90) of both polymer and inorganic particles to achieve the desired balance. By controlling these parameters within specific ranges, the coating layer provides excellent adhesion and safety performance while maintaining a simple two-layer structure suitable for industrial manufacturing.
Solution Approach 2:
The coating layer is applied only on one side of the base layer, creating local quality enhancement where adhesion is most needed (at the electrode plate interface) while keeping the rest of the separator structure simple and cost-effective for mass production.
3Reliability
If particle size ratio of polymer to inorganic particles is not optimized, then manufacturing is easier, but heat shrinkage resistance and adhesion are insufficient
Solution Approach 1:
Specific particle size ranges are defined for both polymer particles (Dv10, Dv50, Dv90) and inorganic particles (Dv90), with explicit ratio constraints (0.2≤A/C≤5 and 1≤B/C≤40). These parameter specifications ensure optimal heat shrinkage resistance and adhesion while providing clear manufacturing guidelines to achieve consistent quality.
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 battery separator provides excellent adhesion to electrode plates, improving low-temperature dynamic performance, safety, and cycling performance of the battery, while simplifying the separator's structure for industrial applicability.
Implementation Method 1
the first coating layer includes first polymer particles and inorganic particles
Implementation Method 2
the second coating layer includes second polymer particles; the second polymer particles coated with the second coating layer can ensure the adhesion of the battery separator to an electrode plate
Implementation Method 3
the first coating layer includes first polymer particles and inorganic particles; ensures heat shrinkage resistance of the battery separator
Data Source
AI summary
Disclosed are a battery separator and a battery. The battery separator includes a substrate, a first coating layer and a second coating layer, and the first coating layer and the second coating layer are arranged opposite to one another on two sides of the substrate; the first coating layer includes first polymer particles and inorganic particles; and the second coating layer includes second polymer particles; Dv10 of the first polymer particles is denoted as A, and Dv50 of the first polymer particles is denoted as B; Dv90 of the inorganic particles is denoted as C; and 0.2≤A/C≤5; and 1≤B/C≤40. The battery separator of the present disclosure adheres well to an electrode plate in a battery cell, giving the battery cell excellent low-temperature dynamic performance. Meanwhile, the battery containing the battery has excellent safety performance and cycling performance.