Ceramic Separator Sugar Additive Coating Quality
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Solution Overview
Problem
Conventional ceramic separators for electrochemical cells often suffer from coating defects and wetting errors, leading to porosity control issues and unwetted dead zones, which hinder their performance in high-performance battery systems.
Innovation Solution
A separator with a porous, non-electrically conductive coating made of oxide particles bonded to a substrate using an inorganic adhesive, where at least one oxide is selected from Al2O3, SiO2, and a sugar such as polyhydroxy aldehydes, monosaccharides, or polysaccharides is incorporated, reducing defects and improving wettability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ceramic slip is used for coating the separator substrate, then the coating process can be performed, but coating defects and wetting errors occur leading to poor coating quality
Solution Approach 1:
A surfactant is introduced as an intermediary substance between the ceramic slip and the polyolefin substrate. The surfactant modifies the surface properties of the substrate, enabling better wetting and adhesion of the ceramic coating, thereby eliminating coating defects and wetting errors without changing the fundamental coating process
Solution Approach 2:
The surface energy parameters of the polyolefin substrate are changed by treating it with a surfactant. This parameter change allows the ceramic slip to properly wet and adhere to the substrate, transforming the coating process from defective to high-quality
2Ease of manufacture
If the separator coating has defects, then the production process is simpler, but porosity control becomes difficult and unwetted dead zones are created
Solution Approach 1:
The surfactant treatment is performed as a preliminary action before applying the ceramic slip. This pre-treatment ensures that the substrate surface is properly prepared to receive the coating, preventing defects that would later compromise porosity control, while still maintaining a simple overall process
3Reliability
If ceramic coating is applied to isolate cathode from anode, then electrical isolation is achieved, but coating defects create unwetted dead zones
Solution Approach 1:
The surfactant acts as a mediator that ensures complete wetting of the ceramic coating by electrolyte. It modifies the interface between the coating and electrolyte, eliminating unwetted dead zones while preserving the electrical isolation function of the ceramic layer
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 exhibits significantly fewer defects, enhanced cycling behavior, and improved surface smoothness, with reduced particle size and increased porosity, enabling better performance and safety in lithium-ion batteries.
Implementation Method 1
a sol containing oxide particles dispersed in the sol, selected from the oxides of the elements Al and/or Si
Implementation Method 2
this is solidified by heating at least once on and in the substrate
Implementation Method 3
oxide particles which are bonded to one another and to the substrate by an inorganic adhesive
Implementation Method 4
The production of ceramic coatings on a nonwoven, for example a polyethylene terephthalate (PET) nonwoven, takes place in a roll-to-roll process. For production, ceramic slip, which contains aluminum oxide, silicon dioxide and silanes dispersed in water, is continuously coated on the fleece.
Data Source
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AI summary
The invention relates to a separator, which comprises on a substrate and in the intermediate spaces of the substrate, which substrate comprises fibres made of an electrically non-conductive material, a porous, electrically non-conductive coating made of oxide particles which include at least one oxide selected from Al2O3, SiO2 and are adhered by an inorganic glue to one another and to the substrate, characterised in that at least one sugar is present in the ceramic coating.