3D Skeleton Separator Coating for Heat Resistance and Electrolyte Uptake
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Solution Overview
Problem
Existing secondary battery separators struggle to balance energy density, thermal safety performance, service life, and rate performance, often compromising on one or more of these characteristics.
Innovation Solution
A separator with a porous substrate coated with a three-dimensional skeleton structure and a filler composed of secondary particles formed by agglomeration of primary particles, which enhances heat resistance, bonding strength, electrolyte infiltration, and retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a coating layer with inorganic particles is applied on the porous substrate to improve heat resistance, then thermal safety performance is improved, but ion transport is hindered due to pore clogging by particles and binder
Solution Approach 1:
The patent employs a porous substrate with controlled pore structure as the base membrane, and applies a coating layer containing porous inorganic particles that maintain internal pore channels. This allows the coating layer to provide heat resistance while the porous structure prevents complete pore closure, enabling ion transport through the coating layer.
Solution Approach 2:
The patent creates a composite coating layer combining porous inorganic particles with a binder material. The inorganic particles provide thermal stability and heat resistance, while the binder matrix maintains structural integrity and allows ion permeation. This composite structure resolves the contradiction between heat resistance and ion transport.
2Quantity of substance
If the porous substrate is made thinner to increase energy density, then energy density is improved, but heat resistance and thermal safety performance deteriorate
Solution Approach 1:
The patent applies a coating layer containing heat-resistant inorganic particles onto the porous substrate surface. This coating layer provides enhanced thermal safety performance and heat resistance, allowing the use of thinner substrates for increased energy density while maintaining adequate thermal protection through the composite coating structure.
Solution Approach 2:
The patent creates a layered structure where the coating layer with inorganic particles is nested on the porous substrate surface. This nested configuration allows the thin substrate to maintain high energy density while the outer coating layer provides the necessary heat resistance and thermal safety performance.
3Temperature
If a coating layer is applied to improve thermal safety performance, then heat resistance is improved, but bonding strength decreases due to filler falling off during long-term charge and discharge
Solution Approach 1:
The patent develops a composite coating layer where inorganic particles are embedded in a binder matrix that provides adhesive properties. This composite structure ensures strong bonding between the coating layer and substrate, preventing filler detachment during battery operation while maintaining the heat resistance provided by the inorganic particles.
Solution Approach 2:
The patent uses a binder material as an intermediary between the inorganic particles and the porous substrate. This binder mediates the bonding interface, ensuring strong adhesion that prevents particle detachment during charge-discharge cycles while allowing the inorganic particles to maintain their heat resistance function.
4Temperature
If inorganic particles are used in the coating layer to improve heat resistance, then thermal safety is improved, but manufacturing complexity increases due to multiple coating steps required
Solution Approach 1:
The patent combines the inorganic particles, binder, and porous substrate into an integrated coating layer structure that can be applied in a streamlined manufacturing process. By merging these components into a single coating formulation, the patent reduces the need for multiple separate coating steps while maintaining the heat resistance benefits of inorganic particles.
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 proposed separator achieves high energy density, improved thermal safety performance, extended cycle life, and enhanced rate performance for secondary batteries.
Implementation Method 1
the filler is secondary particles formed by agglomeration of primary particles
Implementation Method 2
increasing the heat resistance of the separator, reducing the shrinkage of the separator when heated
Implementation Method 3
improve the electrolyte infiltration and retention characteristics of the separator
Data Source
AI summary
The present application provides a separator, a methods for preparing the same and a secondary battery and and electrical device related thereto. The separator includes a porous substrate and a coating layer disposed on one or more surfaces of the porous substrate, wherein the coating layer comprises a three-dimensional skeleton structure and a filler, and at least a portion of the filler is filled in the three-dimensional skeleton structure, and the filler is secondary particles formed by agglomeration of primary particles. The separator provided in this application has characteristics including excellent heat resistance, high bonding strength, good electrolyte infiltration and retention and the like, which enables secondary battery using the separator to have the combined characteristics of high energy density, high thermal safety performance, long cycle life, and good rate performance.