Battery Cell Casing Dual-Notch Venting for Larger Pressure Relief

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Solution Overview

Problem

The existing battery shells have pressure relief openings that are too small, hindering effective gas discharge and increasing the risk of explosion due to excessive internal pressure.

Innovation Solution

A shell design with a first score and a second score on the same wall, where the second score is located in the width direction of the first score, and the thickness of the first score is less than the second score, allowing the shell to fold and create a larger opening for gas discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single score is provided on the battery shell for pressure relief, then the shell can crack to release internal pressure, but the opening formed is relatively small which is not conducive to efficient gas discharge

Engineering Contradiction:
Improvegas discharge efficiencyVSAvoidexplosion risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The pressure relief function is segmented into two distinct scores: a first score that initiates cracking and a second score that enables folding. This segmentation allows the shell to first crack at the first score and then fold at the second score to form a larger opening, thereby improving gas discharge efficiency while maintaining structural integrity during normal operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second score is pre-formed on the shell surface at a position where the shell thickness is greater than at the first score. This preliminary action creates a predetermined folding line that will activate after cracking occurs at the first score, enabling the shell to automatically form a larger opening without requiring additional components or complex mechanisms

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the shell thickness is reduced at the first score to facilitate cracking, then pressure relief is enabled, but the overall shell strength may be compromised

Engineering Contradiction:
Improvepressure relief capabilityVSAvoidshell strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The shell exhibits non-uniform thickness distribution: the first score region has reduced thickness to facilitate cracking initiation, while the second score region has greater thickness to provide structural strength and serve as a robust folding hinge. This local quality variation allows the shell to be weak where needed for pressure relief and strong where needed for overall structural integrity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cracking function is extracted and localized to the first score region with reduced thickness, separating it from the structural support function. The second score region with greater thickness retains the structural strength while providing the folding mechanism. This functional extraction allows independent optimization of each region for its specific purpose

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4675809A1Casing, battery cell, battery and electric device
Publication Date: 2026.01.07 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP4675809A1 patent drawingFigure 1~2
  • EP4675809A1 patent drawingFigure 3
  • EP4675809A1 patent drawingFigure 4~5

AI summary

A casing (10), a battery cell (20), a battery (100) and an electric device. A first notch (11) and a second notch (12) are formed on the same wall of the casing (10), the second notch (12) is located on one side of the first notch (11) in the direction of width, the projections of the first notch (11) and the second notch (12) in the direction of thickness of the casing (10) are spaced apart from each other, and the thickness of the casing (10) at the first notch (11) is less than the thickness of the casing (10) at the second notch (12). When the pressure inside the casing is extremely large, the casing (10) can preferentially crack at the first notch (11) and is folded at the second notch (12) to form an opening for pressure relief, thereby reducing the risk of explosion of the battery cell (20).