Cable Battery Anode Polymer Layer Moisture Protection
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Solution Overview
Problem
Existing methods for manufacturing cable-type secondary batteries face challenges in protecting lithium metal from moisture while ensuring smooth transport of lithium ions, as polymer protective layers that prevent moisture ingress also hinder ion conduction.
Innovation Solution
A method involving the formation of a polymer layer on the outer surface of a lithium-containing electrode layer using a hydrophobic polymer, an ion conductive polymer, and a binder, applied through multi-lateral pressing at controlled temperatures and pressures, to create a protective yet conductive layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polymer protective layer is formed to protect lithium metal from moisture, then moisture protection is improved, but lithium ion transport is hindered
Solution Approach 1:
The patent applies composite materials by combining a hydrophobic polymer (for moisture protection) with an ion-conductive polymer (for lithium ion transport). This composite polymer layer simultaneously provides both moisture barrier functionality and ion conductivity, resolving the contradiction between protection and transport. The hydrophobic polymer component repels moisture while the ion-conductive polymer component creates pathways for lithium ion movement, achieving both required functions in a single integrated layer.
Solution Approach 2:
The patent applies local quality by creating regions with different properties within the polymer layer. The hydrophobic polymer provides local moisture-blocking properties while the ion-conductive polymer provides local ion-transport properties. This spatial differentiation of functional properties within the same layer allows simultaneous achievement of moisture protection and ion transport without requiring separate layers.
2Reliability
If lithium metal is exposed to moisture, then processability degrades due to rapid reaction forming LiOH, but forming a protective layer hinders ion conduction
Solution Approach 1:
The composite polymer layer combines hydrophobic and ion-conductive properties, providing moisture protection to prevent LiOH formation and maintain processability, while simultaneously allowing lithium ion conduction through the ion-conductive polymer component, thus avoiding the hindrance problem.
Solution Approach 2:
The patent changes the chemical and physical parameters of the protective layer by using a composite polymer system rather than a single polymer. This parameter change enables the layer to have both hydrophobic characteristics (for protection) and ion-conductive characteristics (for conduction), resolving the contradiction between processability and ion conduction.
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 allows for effective protection of the lithium-containing electrode layer from moisture while enabling efficient lithium ion transport, enhancing the safety and chemical stability of the battery.
Implementation Method 1
the polymer layer includes a hydrophobic polymer
Implementation Method 2
the polymer layer includes an ion conductive polymer
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is a method for manufacturing an anode for a cable-type secondary battery, including the steps of: forming a lithium-containing electrode layer on the outer surface of a wire-type current collector; and surrounding the outer surface of the lithium-containing electrode layer with a substrate for forming a polymer layer spirally, and pressing the outside of the substrate for forming a polymer layer to form a polymer layer on the lithium-containing electrode layer, wherein the polymer layer includes a hydrophobic polymer, an ion conductive polymer, and a binder for binding the hydrophobic polymer and the ion conductive polymer with each other. An anode obtained from the method and a cable-type secondary battery including the anode are also provided.