Separator Coating via Pre-Dispersion for Mechanical Stability
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Solution Overview
Problem
Current methods for preparing separators for electrochemical devices, such as lithium secondary batteries, face challenges with weak mechanical strength and large pore sizes in non-woven fabric substrates, leading to potential leaks and reduced insulating properties, and inefficient dispersion processes that consume excessive energy and raw materials.
Innovation Solution
A method involving pre-dispersing inorganic materials and dispersion resins in a solvent, followed by mixing a binder to form a slurry, which is then coated onto a substrate, using specific cyano resins and solvents to enhance dispersion efficiency and phase stability, reducing particle sizes and agglomeration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a porous non-woven fabric substrate is used as a separator, then manufacturing costs are reduced, but mechanical strength becomes weak causing fracture during manufacturing
Solution Approach 1:
The patent applies composite materials by forming a coating layer on the porous non-woven fabric substrate that contains inorganic particles dispersed in a binder resin. This composite structure combines the cost advantage of the non-woven fabric with the mechanical strength provided by the coating layer, resolving the contradiction between low manufacturing cost and sufficient mechanical strength.
2Ease of manufacture
If a porous non-woven fabric substrate is used as a separator, then manufacturing costs are reduced, but pore sizes become large decreasing insulating property
Solution Approach 1:
The coating layer formed on the non-woven fabric substrate creates a composite structure where the binder resin and inorganic particles form a matrix that reduces the effective pore size while maintaining the underlying cost advantage of the non-woven fabric substrate, thereby improving insulating properties without sacrificing manufacturing cost efficiency.
Solution Approach 2:
The patent utilizes porous materials by controlling the pore structure of the coating layer to achieve appropriate ion conductivity while maintaining insulating properties. The porous structure allows ion transport necessary for battery operation while the coating layer prevents direct contact between electrodes, resolving the contradiction between cost and insulating property.
3Ease of manufacture
If inorganic material is dispersed by mixing with binder and dispersion resin, then coating layer can be formed, but excessive energy is consumed in dispersion process
Solution Approach 1:
The patent applies preliminary action by pre-dispersing the inorganic material in a solvent before adding the binder resin. This preliminary dispersion step ensures uniform distribution of inorganic particles, reducing the energy required for subsequent mixing and dispersion processes while still achieving effective coating layer formation.
4Ease of manufacture
If inorganic material is dispersed by mixing with binder and dispersion resin, then coating layer can be formed, but more dispersion resin than necessary is added
Solution Approach 1:
By pre-dispersing the inorganic material in a solvent before adding the binder resin, the patent achieves efficient dispersion with minimal dispersion resin. This preliminary action ensures that inorganic particles are already uniformly distributed, reducing the amount of dispersion resin needed to achieve effective coating layer formation and minimizing raw material waste.
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 approach results in a separator with improved mechanical and thermal stability, reduced energy consumption, and lower raw material costs, enhancing the performance and safety of electrochemical devices by preventing agglomeration and ensuring effective ion conductivity.
Implementation Method 1
by pre-dispersing a slurry inorganic material for forming a coating layer and a dispersion resin and then mixing a binder thereto to prepare slurry, the inorganic material may be efficiently surrounded with just a small amount of the dispersion resin enhancing dispersion efficiency
Implementation Method 2
obtaining a dispersion solution by dispersing an inorganic material and a dispersion resin into a solvent
Implementation Method 3
forming a coating layer by coating the slurry on at least one surface of a substrate
Data Source
AI summary
A method for preparing a separator, a separator prepared using the same, and an electrochemical device including the same. More specifically, stability of the separator may be reinforced by preparing the separator using a slurry prepared by pre-dispersing an inorganic material and a dispersion resin, and then mixing a binder thereto when preparing the separator.