Binder-Free Battery Separator With Inorganic Nanowire Composite Layer
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Solution Overview
Problem
Conventional battery separators using polymer-based organic binders suffer from chemical instability, leading to deformation, gas leaks, and performance deterioration due to reactions with electrolytes, resulting in shortened battery lifespan and increased risk of ignition or rupture from thermal events.
Innovation Solution
A separator with a porous inorganic composite layer formed on a substrate, comprising inorganic particles and one-dimensional inorganic materials like nanowires or nanofibers, which provides enhanced adhesive and chemical stability without using polymer-based organic binders, thereby preventing thermal issues and electrolyte contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a polymer-based organic binder is used to adhere the inorganic particle layer to the porous substrate, then the inorganic particles are bound and fixed effectively, but chemical reactions occur between the electrolyte and the binder, resulting in deformation, gas generation, and performance deterioration
Solution Approach 1:
The patent removes the polymer-based organic binder from the inorganic particle layer formulation, extracting the harmful component that causes chemical reactions with the electrolyte. The inorganic particle layer is formed without any organic binder, eliminating the source of chemical instability while maintaining particle binding through alternative mechanisms such as sintering or direct adhesion to the substrate.
Solution Approach 2:
The patent changes the compositional parameters of the inorganic particle layer by eliminating organic binder content and adjusting inorganic particle composition and distribution. This parameter change transforms the layer from an organic-inorganic composite to a purely inorganic structure, fundamentally altering its chemical stability profile toward the electrolyte.
2Strength
If a polymer-based organic binder is used in the inorganic particle layer, then the inorganic particles are bound together, but the binder is dissolved in the electrolyte, causing deterioration of electrolyte performance and battery performance
Solution Approach 1:
The patent extracts and removes the polymer-based organic binder from the inorganic particle layer, eliminating the component that dissolves in the electrolyte. This extraction prevents electrolyte performance deterioration while the inorganic particles maintain their binding through non-organic mechanisms such as mechanical interlocking or sintering bonds.
Solution Approach 2:
The patent changes the chemical composition parameters of the inorganic particle layer by setting organic binder content to zero and optimizing inorganic particle characteristics. This compositional transformation ensures the layer is chemically inert to the electrolyte, preventing dissolution and performance deterioration.
3Strength
If a polymer-based organic binder is used to form the inorganic particle layer, then the inorganic particles are fixed, but the organic binder swells due to the electrolyte, causing increase in battery volume
Solution Approach 1:
The patent removes the polymer-based organic binder from the inorganic particle layer formulation, eliminating the material that undergoes swelling when exposed to the electrolyte. Without the organic binder, the inorganic particle layer maintains dimensional stability and prevents battery volume increase.
Solution Approach 2:
The patent changes the physical and chemical parameters of the inorganic particle layer by eliminating organic components and optimizing inorganic particle packing and density. This parameter optimization ensures the layer is resistant to electrolyte-induced swelling, maintaining stable battery dimensions.
4Reliability
If the inorganic particle layer is formed without a polymer-based organic binder, then chemical stability is improved, but adhesive force between the inorganic particle layer and porous substrate may be insufficient
Solution Approach 1:
The patent introduces a porous substrate as an intermediary that provides both mechanical support and adhesion functionality. The porous structure of the substrate enables physical interlocking with the inorganic particle layer, while its surface properties facilitate strong adhesion without requiring organic binders. The substrate acts as a mediator that transfers and distributes mechanical stresses.
Solution Approach 2:
The patent utilizes the porous structure of the substrate to enhance adhesion of the inorganic particle layer. The porous morphology provides increased surface area and mechanical interlocking sites, allowing the inorganic particles to anchor into the substrate pores. This porous architecture enables strong bonding through physical mechanisms rather than chemical adhesion from organic binders.
5Ease of manufacture
If a conventional inorganic particle layer with polymer binder is used, then manufacturing is simplified, but thermal contraction occurs and heat resistance is insufficient, increasing risk of ignition or rupture
Solution Approach 1:
The patent removes the polymer-based organic binder from the inorganic particle layer, eliminating the component that limits thermal performance. Without the organic binder, the layer can withstand higher temperatures without decomposition, reducing thermal contraction and preventing ignition or rupture risks while maintaining manufacturing simplicity through direct deposition methods.
Solution Approach 2:
The patent changes the thermal parameters of the inorganic particle layer by eliminating organic components and optimizing inorganic particle composition, size distribution, and packing density. These parameter changes enhance the layer's thermal stability, reduce thermal contraction coefficients, and improve heat resistance while maintaining ease of manufacture through conventional coating and drying processes.
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 solution significantly improves heat resistance, electrochemical stability, and lithium ion conductivity, preventing performance degradation and ensuring safer battery operation by eliminating polymer binder-related issues such as clogging and swelling, while maintaining excellent adhesive forces.
Implementation Method 1
binding particles in an inorganic composite layer and adhering the inorganic composite layer to a porous substrate using a one-dimensional inorganic material
Implementation Method 2
preventing ignition or rupture of a battery caused by an abnormal phenomenon such as a rapid rise in temperature due to its improved heat resistance
Implementation Method 3
a chemical reaction occurs between an electrolyte of the battery and the polymer-based organic binder component, resulting in deformation of the components, generation of gas
Data Source
AI summary
The present invention relates to a separator including: (a) a porous substrate; and (b) an inorganic composite layer formed on one surface or both surfaces of the porous substrate, and including one or more inorganic particles and one or more one-dimensional inorganic materials, wherein the dimensions of the one or more inorganic particles and the one or more one-dimensional inorganic materials are different, wherein the one or more one-dimensional inorganic materials include inorganic nanowire(s) and/or inorganic nanofiber(s), wherein the one or more inorganic particles may be bound to each other, or the inorganic composite layer may be anchored and adhered to the porous substrate, by the one or more one-dimensional inorganic materials, and the inorganic composite layer does not include a polymer-based organic binder.