Battery End Cap Chamfered Groove for Impact-Resistant Pressure Relief

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Solution Overview

Problem

Existing battery end caps suffer from poor impact resistance, leading to localized stress concentration and premature failure of the pressure relief zones, which affects the service life of the battery cell.

Innovation Solution

The end cap design incorporates a groove with chamfered corners and edges to distribute stress evenly, featuring varying radius chamfer faces that transition smoothly, enhancing the strength and durability of the pressure relief zone.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a groove is provided in the end cap to form a pressure relief zone, then the pressure relief function is improved, but the impact resistance deteriorates due to localized stress concentration at the groove corners

Engineering Contradiction:
Improvepressure relief functionVSAvoidimpact resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by providing chamfer faces at the corners of the groove. These chamfer faces create localized structural modifications that redistribute stress away from the sharp corners, thereby improving impact resistance in the critical corner regions while preserving the overall pressure relief function of the groove.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The chamfer faces introduce curved transitions at the groove corners instead of sharp angles. This curvature eliminates stress concentration points by creating smooth transitions, allowing stress to distribute more evenly across the pressure relief zone during impact events.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Manufacturing precision

If the groove corners are left sharp to simplify manufacturing, then the manufacturing precision is improved, but the stress distribution deteriorates causing localized stress concentration

Engineering Contradiction:
Improvegroove formation accuracyVSAvoidstress distribution
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The chamfer faces are applied selectively at the groove corners rather than throughout the entire groove structure. This localized approach modifies only the critical stress concentration areas while maintaining the overall groove geometry and manufacturing simplicity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4318769B1End cap, battery cell, battery and power consuming device
Publication Date: 2025.12.31 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4318769B1 patent drawingFigure 1~2
  • EP4318769B1 patent drawingFigure 3
  • EP4318769B1 patent drawingFigure 4~5

AI summary

Embodiments of the present application provide an end cap, a battery cell, a battery and a power consuming device, which relate to the technical field of batteries. The end cap includes a cap body and a groove. The cap body has a first surface. The groove is provided in the cap body to form a pressure relief zone in a region of the cap body where the groove is provided. The groove is recessed from the first surface in a thickness direction of the cap body, and groove side faces of the groove include corner faces at corners of the groove. Each corner face is connected to the first surface via a first chamfer face. The provision of the first chamfer face weakens the strength of the pressure relief zone at the corner of the groove, equalizes the strength of the pressure relief zone at the corner and an edge of the groove, and reduces the risk of local stress concentration in the pressure relief zone, so that the pressure relief zone can be well protected, improving the impact resistance of the end cap.