Electrode Insulation Coating Composition for Slurry Sliding Control
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Solution Overview
Problem
Existing electrode insulating coatings do not adequately reduce the sliding length of the electrode active material layer, particularly in high energy density batteries, due to insufficient wet-thickness and adhesion issues.
Innovation Solution
A composition for insulating coating comprising inorganic particles, a rubber-based binder, a fluorine-based binder, and a dispersant, with specific weight ratios and viscosities, is applied to the current collector to form an insulating layer that suppresses sliding and enhances adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the wet-thickness of the insulating coating composition is increased to reduce sliding length, then the sliding length reduction improves, but the coating complexity and manufacturing difficulty increase
Solution Approach 1:
The patent employs a composite coating composition containing ceramic particles (alumina, silica), rubber-based binder (SBR), fluorine-based binder (PVDF), and dispersant (tannic acid). This composite formulation achieves sufficient wet-thickness and adhesion without requiring overly complex coating processes, resolving the contradiction between sliding length reduction and coating complexity
Solution Approach 2:
The patent optimizes specific parameter ranges: ceramic content (50-80 parts by weight), rubber-based binder (10-30 parts by weight), fluorine-based binder (5-15 parts by weight), and dispersant (0.1-5 parts by weight). These parameter optimizations enable effective sliding length control while maintaining manageable coating composition and process complexity
2Reliability
If the adhesion of the insulating layer is improved to prevent detachment, then the reliability improves, but the manufacturing precision requirements increase
Solution Approach 1:
The patent uses a composite binder system combining rubber-based binder (SBR) and fluorine-based binder (PVDF) with ceramic particles. This composite approach enhances adhesion through multiple bonding mechanisms while the dispersant (tannic acid) ensures uniform distribution, achieving both high reliability and manufacturing precision
Solution Approach 2:
The dispersant (tannic acid) acts as an intermediary substance that facilitates uniform distribution of ceramic particles and enhances interfacial adhesion between the coating layers and current collector. This mediator enables improved adhesion without requiring excessive manufacturing precision
3Object-affected harmful factors
If the insulating layer thickness is increased to protect from heat, then the thermal protection improves, but the sliding length reduction effectiveness decreases
Solution Approach 1:
The patent optimizes the thickness parameter of the insulating layer within a specific range (5-20 micrometers). This parameter optimization provides sufficient thermal protection through ceramic particles while maintaining the layer's ability to control sliding length effectively, resolving the contradiction between heat protection and sliding control
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 composition significantly reduces the sliding length of the electrode active material layer, improves adhesion, and maintains insulating performance even at high temperatures, leading to higher energy density batteries with enhanced safety.
Implementation Method 1
the fluorine-based binder is included in an amount of 7 parts by weight or less with respect to 100 parts by weight of solid content excluding the solvent... The composition for insulating coating according to one embodiment, has a viscosity of 2,500 cps or more, as measured at a shear rate of 2.5/s at 25°C
Implementation Method 2
a rubber-based binder; a fluorine-based binder... improves adhesion
Implementation Method 3
By forming the insulating layer on the outer portion of the electrode active material layer, the electrode active material layer can be protected from heat generated during driving of the electrode
Implementation Method 4
a dispersant... The composition for insulating coating according to one embodiment, wherein at 1 Hz, the phase angle a before shear is 1° to 9°
Data Source
Figure 1
Figure 2~3
AI summary
A composition for insulating coating according to the present disclosure includes inorganic particles; a rubber-based binder; a fluorine-based binder; a dispersant; and a solvent, wherein the fluorine-based binder is included in an amount of 7 parts by weight or less with respect to 100 parts by weight of solid content excluding the solvent. The composition for insulating coating according to the present disclosure when applied to the current collector, has a thicker wet thickness, thereby suppressing the sliding phenomenon in which the slurry for electrode flows down, and has the effect of significantly reducing the sliding length of the electrode active material layer.