Battery Cell Vent Notch Structure for Internal Pressure Relief

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Solution Overview

Problem

Battery cells experience swelling due to increased internal pressure and heat generation during charging and discharging, leading to potential explosion or fire, necessitating a solution to control internal pressure.

Innovation Solution

A battery cell design featuring a vent notch portion with a straight and curved pattern, etched using a laser, which allows for pressure adjustment and includes a solidification region, varying widths, and a groove structure to enhance stability and production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a vent notch portion is formed separately after case manufacturing, then pressure control function is achieved, but production efficiency decreases and manufacturing complexity increases

Engineering Contradiction:
Improvepressure control functionVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The vent notch portion is integrated directly into the case manufacturing process, combining the case formation and vent notch creation into a single step. This eliminates separate post-processing operations, maintains pressure control functionality, and significantly improves production efficiency by reducing manufacturing steps and time

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If a simple vent notch is formed, then manufacturing is easy, but pressure control precision is insufficient

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidpressure control precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The vent notch portion is divided into multiple segments including a first vent notch, second vent notch, and third vent notch with different depths and positions. This segmentation allows precise control over pressure release characteristics while maintaining ease of manufacturing through integrated case formation, achieving both simplicity and precision

Inventive Principle:
Principle #1Segmentation

3Reliability

If the vent notch portion is formed deeper, then pressure control effectiveness increases, but manufacturing difficulty increases

Engineering Contradiction:
Improvepressure control effectivenessVSAvoidmanufacturing difficulty
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Different portions of the vent notch structure have different depths optimized for their specific functions. The first vent notch has a first depth for primary pressure control, while the second and third vent notches have different depths for secondary pressure management. This local differentiation achieves effective pressure control while keeping the overall structure manufacturable through integrated case formation

Inventive Principle:
Principle #3Local quality

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 vent notch portion effectively manages internal pressure, enhancing battery cell stability and improving production efficiency by integrating the notch during case manufacturing.

Implementation Method 1

etched using a laser

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4614708A1Battery cell and manufacturing method of battery cell case
Publication Date: 2025.09.10 SK ON CO LTD
  • EP4614708A1 patent drawingFigure 1~2
  • EP4614708A1 patent drawingFigure 3~4
  • EP4614708A1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a battery cell comprising a case body accommodating an electrode assembly, a case cover covering at least one face of the case body which is open, and a vent notch portion formed by being recessed at at least one of one surface of the case body or one surface of the case cover. The vent notch portion includes a straight portion having a straight pattern, and a curved portion connected to the straight portion and having a curved pattern. A width of the straight portion is different from a width of the curved portion.