Pouch Cell Tab Frangible Fuse Structure for Overcurrent Interruption
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Solution Overview
Problem
Existing battery assemblies lack a reliable mechanism to safely interrupt current flow in response to overcurrent conditions, potentially leading to unsafe conditions and damage.
Innovation Solution
A tab design for pouch-style battery cells featuring a frangible area covered by a tab film, which includes apertures that rupture to disrupt current flow when exceeding a threshold, acting as a fuse to prevent overcurrent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tab is used to electrically couple the electrode structure to external devices, then electrical connectivity is achieved, but the battery lacks a mechanism to safely interrupt current flow during overcurrent conditions
Solution Approach 1:
The tab is segmented into different regions with distinct properties: a frangible area with reduced cross-sectional area and a non-frangible area with normal thickness. This segmentation allows the tab to function both as a continuous electrical conductor and as a safety device that can be interrupted under overcurrent conditions.
Solution Approach 2:
The cross-sectional area parameter of the tab is changed along its length, creating a frangible area with reduced cross-sectional area. This parameter change enables the tab to have different mechanical and electrical properties in different regions, allowing it to act as a fuse while maintaining overall electrical connectivity.
2Reliability
If the frangible area is exposed, then current interruption is possible, but the frangible area is vulnerable to inadvertent activation or environmental damage
Solution Approach 1:
A tab film is applied to cover and protect the frangible area of the tab. This thin film layer shields the frangible area from environmental damage and inadvertent activation while allowing the frangible area to still function as intended when genuine overcurrent conditions occur.
Solution Approach 2:
The tab film provides beforehand protection to the frangible area, cushioning it against premature or inadvertent activation from external factors such as mechanical damage, moisture, or contamination before the battery is put into service.
3Reliability
If the tab has uniform thickness, then manufacturing is simple, but the tab cannot provide controlled current interruption
Solution Approach 1:
The tab fabrication process is segmented into steps that create distinct regions: a frangible area with reduced cross-sectional area and a non-frangible area with normal thickness. This segmentation enables controlled current interruption while maintaining manufacturability through established processes.
Solution Approach 2:
The tab is designed with local quality variations, where the frangible area has different physical properties (reduced cross-sectional area) compared to the rest of the tab. This local differentiation enables the specific function of controlled current interruption at the frangible area while the rest of the tab maintains its standard properties.
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 frangible area effectively interrupts current flow, protecting the battery assembly from overcurrent conditions and preventing potential damage, while maintaining structural integrity and safety.
Implementation Method 1
the frangible area configured to rupture to interrupt a flow of current through the tab in response to an overcurrent condition
Data Source
AI summary
A battery assembly includes a pouch containing an electrode structure, and a tab that electrically couples the electrode structure to a device outside the pouch. The tab extends from an interior of the pouch to an outside of the pouch. The tab includes a frangible area. A tab film covers at least the frangible area of the tab.