Coated Battery Separator for Uniform Adhesion and Ion Transport
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Solution Overview
Problem
Lithium-ion batteries face issues with quick cycling attenuation and poor low-temperature performance, necessitating improved cycling performance and safety.
Innovation Solution
A separator with an inorganic coating and adhesive layer, featuring specific particle size ratios and distributions, enhances adhesion and electrolyte transport uniformity, facilitating fast lithium ion transport and improving cycling performance and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional separator is used, then the structure is simple, but the adhesion uniformity and electrolyte transport uniformity are poor
Solution Approach 1:
The separator is divided into multiple functional layers: a substrate layer providing mechanical support, an inorganic coating layer on one surface for enhanced adhesion and safety, and an adhesive layer on the other surface for electrode bonding. This segmentation allows each layer to optimize its specific function, resolving the contradiction between structural complexity and performance uniformity.
Solution Approach 2:
The separator employs composite material structure combining organic substrate with inorganic coating particles (such as alumina, boehmite) and adhesive polymers. This composite approach enhances both adhesion uniformity and electrolyte transport uniformity while maintaining structural integrity, effectively resolving the technical contradiction.
2Reliability
If the separator structure is optimized for adhesion, then cycling performance improves, but manufacturing complexity increases
Solution Approach 1:
The inorganic coating and adhesive layers are pre-applied to the substrate in controlled amounts during separator manufacturing. By establishing the optimal particle quantity parameters (10≤A≤100 polymer particles per 100 μm², specific filler particle size ranges) in advance, the separator achieves excellent cycling performance while streamlining the manufacturing process through precise initial dosing.
Solution Approach 2:
The invention specifies precise parameter ranges for particle quantities and sizes (filler particle size Dv50-1, polymer particle size Dv50-2 with ratio 0.2≤Dv50-1/Dv50-2≤2.5) to optimize adhesion and cycling performance. These controlled parameter changes enable consistent high performance while maintaining manufacturability through standardized production parameters.
3Strength
If polymer particle quantity is increased, then adhesion force improves, but electrolyte transport uniformity deteriorates
Solution Approach 1:
The adhesive layer is designed with specific local characteristics: polymer particles are distributed at controlled densities (10≤A≤100 per 100 μm²) with specific size ranges (0.2Dv50-1≤Dv50-2≤Dv50-1). This local quality control ensures sufficient adhesion force while maintaining adequate pore spaces for uniform electrolyte transport, resolving the contradiction between these two requirements.
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 separator improves room-temperature and low-temperature cycling performance while ensuring good safety performance of lithium-ion batteries.
Implementation Method 1
the first surface of the separator has good adhesion uniformity to a surface of a positive electrode plate or a negative electrode plate
Implementation Method 2
lithium ions and an electrolyte have good transport and distribution uniformity in the separator
Implementation Method 3
ensuring good wettability of the separator
Implementation Method 4
This facilitates fast transport of the lithium ions
Data Source
AI summary
A separator includes a substrate, an inorganic coating layer, and an adhesive layer, where the inorganic coating layer and the adhesive layer are disposed on a first surface of the substrate. The inorganic coating layer is disposed between the substrate and the adhesive layer. The adhesive layer is disposed on a second surface of the substrate. The inorganic coating layer includes filler particles. The adhesive layer includes polymer particles. The separator includes a first surface provided with the inorganic coating layer and the adhesive layer. In a region with an area of 100 μm2 on the first surface, a quantity of the polymer particles is A, where 10≤A≤100. An average particle size of the filler particles is Dv50−1 μm, and an average particle size of the polymer particles is Dv50−2 μM, WHERE Dv50−1 AND Dv50−2 SATISFY 0.2≤Dv50−1/Dv50−2≤2.5 AND 0.2≤Dv50−1≤1.