Composite Battery Separator for Dendrite Blocking and Electrolyte Wetting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aqueous electrolyte batteries face challenges with water electrolysis during initial charge and the risk of internal short circuits due to lithium or zinc dendrites, requiring a separator that balances water shielding and electrolyte impregnation while maintaining flexibility and high energy density.
Innovation Solution
A composite membrane separator with a nonwoven fabric or self-supporting porous substrate, featuring a first and second composite layer with inorganic solid particles and a polymeric material, providing varying denseness along the thickness direction to retain electrolyte and prevent dendrite breakthrough.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the separator uses a dense structure to prevent dendrite breakthrough and provide water shielding, then safety is improved, but electrolyte impregnation ability deteriorates
Solution Approach 1:
The separator employs a multilayer structure where each layer has different density characteristics. The dense layer provides water shielding and dendrite prevention, while the loose layer ensures excellent electrolyte impregnation. This local differentiation of structural properties resolves the contradiction between safety and electrolyte impregnation ability.
Solution Approach 2:
The separator combines multiple materials with different properties: a dense layer made of specific porous ceramic material for safety, and a loose layer with different composition for electrolyte retention. This composite structure integrates the advantages of both dense and loose structures, achieving both safety and high electrolyte impregnation ability.
2Productivity
If the separator uses a loose structure to enhance electrolyte impregnation, then electrolyte retention is improved, but water shielding property deteriorates
Solution Approach 1:
The separator employs a multilayer structure where each layer has different density characteristics. The dense layer provides water shielding and dendrite prevention, while the loose layer ensures excellent electrolyte impregnation. This local differentiation of structural properties resolves the contradiction between safety and electrolyte impregnation ability.
Solution Approach 2:
The separator combines multiple materials with different properties: a dense layer made of specific porous ceramic material for safety, and a loose layer with different composition for electrolyte retention. This composite structure integrates the advantages of both dense and loose structures, achieving both safety and high electrolyte impregnation ability.
3Reliability
If the separator increases thickness to improve water shielding and dendrite prevention, then safety is improved, but flexibility and energy density deteriorate
Solution Approach 1:
The separator employs a multilayer structure where each layer has different density characteristics. The dense layer provides water shielding and dendrite prevention, while the loose layer ensures excellent electrolyte impregnation. This local differentiation of structural properties resolves the contradiction between safety and electrolyte impregnation ability.
Solution Approach 2:
The separator uses a thin film structure with multilayer configuration that provides enhanced safety performance without increasing overall thickness significantly. The flexible nature of the thin film structure maintains battery flexibility while the layered design improves water shielding and dendrite prevention capabilities.
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 achieves high denseness and electrolyte impregnation, reducing the risk of internal short circuits and enhancing the stability and capacity of secondary batteries.
Implementation Method 1
The composite membrane has a coefficient of air permeability of 1 × 10-14 m2 or less, retains aqueous electrolyte, and prevents water transport
Implementation Method 2
Development of aqueous electrolyte batteries in which aqueous electrolytes containing nonflammable aqueous solvents are used instead of the nonaqueous electrolytes has been promoted
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
According to one embodiment, a separator (4) is provided. The separator (4) includes a composite membrane (53). The composite membrane (53) includes a substrate layer (530), a first composite layer (531), and a second composite layer (532). The first composite layer (531) is located on one surface (S1) of the substrate layer (530). The second composite layer (531) is located on the other surface (S2) of the substrate layer (530). The composite membrane (53) has a coefficient of air permeability of 1 × 10-14 m2 or less. The first composite layer (531) has a first surface (FSC1) and a second surface (SSC1). The first surface (FSC1) is in contact with the substrate layer (530). The second surface (SSC1) is located on an opposite side to the first surface (FSci) . Denseness of a portion including the first surface (FSC1) is lower than denseness of a portion including the second surface (SSC1) in the first composite layer (531).