Battery Cell Pressure Relief Structure for Predictable Venting
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Solution Overview
Problem
Existing battery technologies face challenges in ensuring safety, particularly during thermal runaway, as pressure relief mechanisms fail to effectively discharge pressure and temperature, leading to potential explosions and fires.
Innovation Solution
A battery cell design featuring a pressure relief mechanism with a weak portion, body portion, and connecting portion, where the weak portion is designed to break at a threshold pressure, accompanied by a concave portion to concentrate stress, ensuring timely pressure release and enhancing safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure relief mechanism uses a uniform thickness design, then the structural strength is maintained, but the pressure relief mechanism cannot effectively break at threshold pressure to relieve internal pressure
Solution Approach 1:
The pressure relief mechanism employs different thickness values in different regions: the first thickness in the pressure relief region and the second thickness in the connection region. This local quality differentiation allows the pressure relief region to break at threshold pressure while the connection region maintains sufficient strength to support the overall structure.
2Reliability
If the weak portion thickness is reduced to enable easier breaking, then pressure relief becomes more effective, but the manufacturing precision and consistency of breaking threshold are compromised
Solution Approach 1:
The patent specifies a particular thickness ratio range (0.1≤W1/B1≤0.5) between the weak portion thickness and connection portion thickness. This parameter optimization ensures the weak portion is thin enough to break at threshold pressure but maintains sufficient manufacturing precision and breaking consistency.
3Reliability
If the pressure relief mechanism is designed with complex stress concentration features, then the breaking predictability improves, but the device complexity increases
Solution Approach 1:
The pressure relief mechanism is segmented into distinct functional regions: a pressure relief region with a specific thickness designed to break, and a connection region with greater thickness for structural support. This segmentation simplifies the overall design while achieving predictable breaking behavior through the thickness ratio.
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 design allows for timely discharge of pressure and temperature, preventing explosions and fires by ensuring the weak portion breaks predictably, thus improving safety and stability.
Implementation Method 1
a sudden change in a cross section occurs at the weak portion, stress concentration occurs in the weak portion
Data Source
AI summary
Examples of the present application relate to a battery cell, a manufacturing method and a manufacturing system thereof, a battery, and a powered device. The battery cell includes: a shell, where the shell has a wall portion; an electrode assembly accommodated in the shell; and a pressure relief mechanism. The pressure relief mechanism is provided on the wall portion, the pressure relief mechanism includes a weak portion, a body portion, and a connecting portion. The weak portion is configured to be damaged when pressure inside the shell reaches a threshold so as to relieve the pressure. The body portion is located in a region defined by the weak portion. The connecting portion is located on an outer side of the weak portion and configured to connect the wall portion.