Air Cell Conductive Ventilation Layer Reduces Internal Resistance
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Solution Overview
Problem
Existing air cells with high water-repellent films experience increased internal resistance, which affects the performance of assembled batteries, as mentioned in Patent Literature 1 does not adequately address this issue.
Innovation Solution
An air cell configuration with a positive electrode layer, an electrolyte layer, a negative electrode layer, and an electrically-conductive liquid-tight ventilation layer, where the ventilation layer is stacked on the positive electrode side of the electrolyte layer, and a flow path for oxygen-containing gas is interposed between the ventilation layer of one air cell and the negative electrode of an adjacent air cell, enhancing conductivity and reducing internal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a water-repellent film with high water-repellent performance is used, then water removal performance is improved, but internal resistance increases
Solution Approach 1:
The patent applies composite materials by combining PTFE porous film (water-repellent material) with conductive materials (carbon black, acetylene black, or metal particles) to create a water-repellent film that simultaneously provides water removal performance and electrical conductivity. This composite structure resolves the contradiction by integrating two previously separate functions into a single multi-functional layer.
Solution Approach 2:
The water-repellent film is designed to perform multiple functions simultaneously: water removal, electrical conduction, and ventilation. By making the film multi-functional, the patent eliminates the need for separate conductive layers and achieves both water-repellent performance and low internal resistance in a single component.
2Reliability
If a water-repellent film is placed on the air electrode side, then water removal is enhanced, but electrical conductivity decreases
Solution Approach 1:
The patent incorporates conductive materials (carbon black, acetylene black, or metal particles) into the PTFE porous film to create a composite water-repellent film that maintains both water removal capability and electrical conductivity. The conductive particles form conductive networks within the porous structure, enabling electron transport while the PTFE matrix provides water repellency.
Solution Approach 2:
The water-repellent film is designed with local quality variations where conductive particles are distributed within the PTFE matrix. This creates regions with different properties: the PTFE matrix provides water repellency while the conductive particle clusters provide electrical conductivity, allowing both functions to coexist in the same layer.
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 increases the width of the conduction path and decreases internal resistance, allowing for improved battery performance by maintaining electrical connectivity and gas flow while preventing electrolyte leakage.
Implementation Method 1
an electrically-conductive liquid-tight ventilation layer stacked on the positive electrode layer on the opposite side of the electrolyte layer
Implementation Method 2
a water-repellent film of a polytetrafluoroethylene (PTFE) porous film is placed on the opposite side of the separator on the air electrode side
Data Source
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AI summary
An air cell includes a positive electrode layer, an electrolyte layer stacked on the positive electrode layer, a negative electrode layer stacked on the electrolyte layer, and an electrically-conductive liquid-tight ventilation layer stacked on the positive electrode layer on an opposite side of the electrolyte layer. An assembled battery includes a plurality of air cells. The assembled battery is provided with a flow path through which oxygen-containing gas flows interposed between the electrically-conductive liquid-tight ventilation layer of a first air cell and the negative electrode layer of a second air cell adjacent to the first air cell. The first air cell is electrically connected to the negative electrode layer of the second air cell via the electrically-conductive liquid-tight ventilation layer.