Battery Cell Electrode Tab Layout for Unobstructed Pressure Relief
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Solution Overview
Problem
Existing battery cells face safety issues during thermal runaway due to electrode tabs obstructing pressure relief mechanisms, leading to potential explosions or fires, as the tabs deform and block venting ports.
Innovation Solution
Incorporating an avoidance portion on the electrode tab, which can be a recessed region or a locally lower height area, ensuring that the pressure relief mechanism's projection falls within this area, thereby reducing the risk of obstruction and facilitating timely pressure release during thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode tab is designed with a standard structure, then the manufacturing process is simple, but the electrode tab may obstruct the pressure relief mechanism during thermal runaway
Solution Approach 1:
The electrode tab is designed with an avoidance portion that creates local structural differentiation. This avoidance portion is a specific region where material is removed or not formed, creating a localized feature that allows gas flow while the rest of the electrode tab maintains its standard structure for electrical function. This resolves the contradiction by adding safety functionality only where needed without complicating the entire electrode tab structure.
Solution Approach 2:
The electrode tab structure is segmented into functional zones: the main body for electrical connection and the avoidance portion for safety. By dividing the electrode tab into these distinct regions with different functions, the design achieves both structural simplicity for manufacturing and enhanced safety through the dedicated avoidance portion that prevents obstruction of the pressure relief mechanism.
2Reliability
If the avoidance portion is made large enough to cover the pressure relief mechanism projection, then obstruction risk is reduced, but the electrode tab structure becomes more complex
Solution Approach 1:
The avoidance portion is designed to extend beyond the minimum required coverage of the pressure relief mechanism projection. This excessive action ensures that even with manufacturing tolerances and variations in thermal runaway behavior, the avoidance portion will always provide sufficient clearance. The design intentionally creates more avoidance area than strictly necessary, prioritizing reliability over manufacturing precision requirements.
3Ease of operation
If the avoidance portion is added to ensure safety, then pressure relief is improved, but the electrode tab structure becomes more complex
Solution Approach 1:
The avoidance portion is created by removing material or not forming material in a specific region of the electrode tab. This extraction approach creates a clearance zone that facilitates gas flow without adding complex structural elements. Instead of adding components to prevent obstruction, the design removes material to create negative space that naturally allows gas to flow past the pressure relief mechanism.
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 avoidance portion design enhances the safety of battery cells by allowing smooth gas flow and pressure relief, reducing the risk of explosions and fires by preventing electrode tabs from blocking the pressure relief mechanism, thus ensuring timely and effective pressure release.
Implementation Method 1
the avoidance portion can have a deflecting function
Implementation Method 2
the gas inside the battery cell can flow from the central hole towards the avoidance portion, and then be discharged from the pressure relief mechanism
Data Source
AI summary
The embodiments of the present disclosure provide a battery cell, battery, and electrical device. The battery cell comprises a casing, having a first wall; a pressure relief mechanism, arranged on the first wall; and an electrode assembly, arranged inside the casing. The electrode assembly comprises an electrode tab, and the electrode tab comprises an avoidance portion. Along a thickness direction of the first wall, the projection of the pressure relief mechanism on the electrode assembly at least partially falls within the avoidance portion. The battery cell has relatively high safety.