Battery Cell Pressure Relief Structure for Low-Pressure Crack Prevention
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Solution Overview
Problem
Existing pressure relief mechanisms in batteries fail to function properly under low air pressures, leading to reduced service life and compromised safety performance.
Innovation Solution
A pressure relief mechanism with a first part obliquely protruding into the battery cell and a second part extending away from the cell interior, where the thickness and shape of these parts are designed to inhibit cracking at low pressures and facilitate rapid relief at higher pressures by pressing and stretching a weak portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure relief mechanism uses a conventional design with a circular body, tapered slope section and convex segment, then the structure is simple and easy to manufacture, but the mechanism fails under low air pressure conditions leading to reduced service life
Solution Approach 1:
The pressure relief mechanism is divided into distinct functional segments: a first part with a first slope section for pressing the weak portion at low pressures, and a second part with a second slope section for stretching the weak portion at high pressures. This segmentation allows each part to specialize in specific pressure conditions, improving reliability without excessive complexity.
Solution Approach 2:
The mechanism employs dynamic geometric transformation where the first and second parts can rotate relative to each other around the weak portion. The slope sections are designed to change their angular positions based on internal pressure, automatically transitioning from a pressing configuration at low pressures to a stretching configuration at high pressures, adapting the mechanism's behavior to operating conditions.
2Reliability
If the pressure relief mechanism is designed to activate at low air pressure, then safety response time is improved, but the mechanism may fail due to creeping under normal operating conditions
Solution Approach 1:
The first slope section is specifically designed to press the weak portion during normal operating conditions (low pressure), creating a compressive pre-stress that counteracts the tensile stresses that would cause creeping. This preliminary anti-action prevents degradation during the battery's normal service life while maintaining readiness for safety activation.
Solution Approach 2:
The mechanism changes its mechanical action parameters based on pressure conditions: at low pressures the slope sections configure to press the weak portion, while at high pressures they rotate to stretch it. This parameter change allows the mechanism to exhibit different behavioral characteristics appropriate for different operational phases, preventing premature failure while ensuring safety.
3Ease of manufacture
If the first part and second part are made with uniform thickness, then manufacturing is simplified, but the mechanism cannot effectively press and stretch the weak portion under different pressure conditions
Solution Approach 1:
The first part and second part are designed with non-uniform thickness distributions tailored to their specific functions. The first part has greater thickness in regions that need to withstand compressive loads during pressing, while the second part has optimized thickness for tensile loading during stretching. This local quality differentiation ensures each component performs its specific function effectively without compromising manufacturing feasibility.
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 mechanism effectively prolongs the service life of the pressure relief mechanism by preventing cracking at low pressures and ensures rapid pressure relief at higher pressures, enhancing battery safety.
Implementation Method 1
the first part and/or the second part move away from the interior of the battery cell, or tend to move away from the interior of the battery cell... the weak portion is pressed by the first part and/or the second part... the first part changes from a state of protruding toward the interior of the battery cell to a state of protruding away from the interior of the battery cell, and the weak portion is stretched by the first part and/or the second part
Data Source
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AI summary
Embodiments of this application provide a pressure relief mechanism , a battery cell , a battery, an electric apparatus, and a manufacturing method thereof. A pressure relief mechanism is provided on a housing plate of a battery cell and includes: a connecting portion , where the connecting portion is located at an outer peripheral region of the pressure relief mechanism and is configured to connect the housing plate ; a first part, where an end of the first part is connected to the connecting portion, and another end protrudes obliquely toward an interior of the battery cell ; a weak portion , where the weak portion is provided at the protruding end of the first part ; and a second part ), where an outer edge region of the second part is connected to the weak portion , and the outer edge region extends obliquely away from the interior of the battery cell , where when an air pressure inside the battery cell is less than a first preset value, the weak portion is pressed by the first part ) and/or the second part . Service life of the pressure relief mechanism can be effectively extended by using a technical solution in the embodiments of this application.