Battery Separator Coating With Hollow Adhesive Particles Against Swelling
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Solution Overview
Problem
Conventional secondary battery separators face challenges in achieving strong adhesive strength to electrodes while minimizing the use of adhesive material, and they often suffer from swelling issues due to electrolyte interaction, leading to reduced battery performance and capacity limitations.
Innovation Solution
A separator with a coating layer comprising inorganic particles and hollow adhesive particles is used, where the hollow adhesive particles float on the surface due to their lower specific gravity, forming a strong adhesive layer without the need for a separate adhesive layer, and providing a buffer against electrolyte-induced swelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a separate adhesive layer is formed on the separator, then adhesive strength to electrodes is improved, but device complexity and manufacturing process complexity increase
Solution Approach 1:
The patent merges the adhesive layer and the separator into a single integrated structure. The adhesive layer is formed by coating a solution containing adhesive particles directly onto the separator surface, creating a combined component that eliminates the need for separate adhesive layers while maintaining strong adhesion to electrodes.
Solution Approach 2:
The separator is designed to perform multiple functions simultaneously: it acts as both the structural separator and the adhesive layer. By incorporating adhesive particles into the separator coating, the separator gains electrode-adhesion capability while maintaining its primary function of separating electrodes.
2Strength
If more adhesive material is used to improve adhesive strength, then bonding to electrodes is enhanced, but manufacturing cost and material usage increase
Solution Approach 1:
The patent optimizes the parameters of the adhesive layer by controlling particle size distribution, concentration of adhesive particles in the coating solution, and coating thickness. These parameter optimizations enable achieving sufficient adhesive strength with minimized adhesive material content.
Solution Approach 2:
The adhesive layer is formulated as a composite material containing adhesive particles dispersed in a solution. This composite structure allows efficient use of adhesive material while maintaining strong bonding performance through the combined properties of the particles and the solution matrix.
3Stability of the object's composition
If the separator structure is made more robust to prevent swelling, then structural stability is improved, but productivity and ease of manufacture decrease
Solution Approach 1:
The separator utilizes a porous structure that provides structural stability while maintaining flexibility. The porous design allows the separator to accommodate electrolyte penetration and volume changes without requiring complex reinforcement structures, thus maintaining manufacturing simplicity and productivity.
4Strength
If adhesive layer is applied separately before separator assembly, then adhesive strength is improved, but manufacturing time and process complexity increase
Solution Approach 1:
The adhesive layer application is merged with the separator manufacturing process. The adhesive-containing solution is coated onto the separator in the same production line, eliminating separate adhesive application steps and reducing overall manufacturing time while maintaining adhesive strength.
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
This solution enhances adhesive strength to electrodes, prevents swelling, and maintains battery performance by minimizing electrolyte elution, allowing for higher capacity and larger battery sizes with improved assembly and cycle life.
Implementation Method 1
the hollow adhesive particles, which have a lower specific gravity than the inorganic particles, float to form an adhesive layer
Implementation Method 2
hollow adhesive particles that function as a buffer to internally accommodate swelling caused by an electrolyte
Data Source
AI summary
Separators, methods for manufacturing the separators, and secondary batteries including the separators are disclosed. In one embodiment, a separator may include a porous substrate including a first surface and a second surface, and a coating layer disposed on at least one of the first surface or the second surface of the porous substrate and including inorganic particles and hollow adhesive particles.