Lithium-Ion Battery Separator Permeability Layout for Metal Deposition Control
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Solution Overview
Problem
In lithium-ion rechargeable batteries, the low breathability of certain separator portions leads to uneven lithium ion movement and metal deposition, affecting input/output properties and imposing limitations on input performance.
Innovation Solution
The separator's gas permeability is designed to be higher at one end than the other, with a configuration that increases gas permeability by 105% or more in one direction compared to the other, reducing lithium ion concentration and metal elution at specific points, thereby dispersing ion movement and improving battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the separator has high breathability at the first separator portion, then the replenished amount of non-aqueous electrolyte increases, but lithium ion movement concentrates at the ends of the positive electrode mixture layer causing metal elution and deposition
Solution Approach 1:
The separator is designed with different breathability characteristics at different locations: the first separator portion (central region) has high breathability to ensure adequate electrolyte replenishment, while the second separator portion (end regions) has low breathability to prevent metal elution and deposition. This spatial variation in breathability allows the single separator to simultaneously address both the electrolyte replenishment need and the metal deposition prevention requirement.
2Object-generated harmful factors
If the separator has low breathability at the second separator portion, then aluminum ion passage is reduced minimizing metal deposition, but lithium ion movement becomes uneven affecting input/output properties
Solution Approach 1:
The separator implements location-specific breathability control where the second separator portion at the end regions has low breathability to minimize aluminum ion passage and metal deposition, while the first separator portion in the central region maintains high breathability to ensure uniform lithium ion movement and preserve input/output properties. This localized differentiation resolves the contradiction between preventing metal deposition and maintaining reliable battery performance.
3Ease of manufacture
If the separator breathability is uniform across all portions, then manufacturing is simplified, but either metal deposition occurs (if high breathability) or electrolyte replenishment is insufficient (if low breathability)
Solution Approach 1:
The separator incorporates spatially varying breathability with the first separator portion (central region) having high breathability and the second separator portion (end regions) having low breathability. This local differentiation in breathability characteristics prevents both metal deposition and insufficient electrolyte replenishment, while the overall separator structure remains relatively simple to manufacture using conventional techniques.
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 configuration enhances the input properties of the lithium-ion rechargeable battery by dispersing lithium ion movement and limiting metal deposition, maintaining superior input/output properties.
Implementation Method 1
The separator has a gas permeability that is greater at a portion facing an end of the positive electrode mixture layer in the second width direction than a portion facing an end of the positive electrode mixture layer in the first width direction
Data Source
AI summary
A lithium-ion rechargeable battery includes a negative electrode plate including a negative electrode substrate and a negative electrode mixture layer applied to the substrate, a positive electrode plate including a positive electrode substrate and a positive electrode mixture layer applied to the substrate, a separator arranged between the negative electrode plate and the positive electrode plate, and a non-aqueous electrolyte. The negative electrode substrate includes a negative electrode connection portion that projects from the negative electrode mixture layer in a first width direction. The positive electrode substrate includes a positive electrode connection portion that projects from the positive electrode mixture layer in a second width direction. The separator has a gas permeability that is greater at a portion facing an end of the positive electrode mixture layer in the second width direction than a portion facing an end of the positive electrode mixture layer in the first width direction.