Battery Cell End Cap Structure for Vibration-Safe Pressure Relief

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Solution Overview

Problem

Existing battery cells face safety issues due to premature rupture of pressure relief mechanisms caused by electrode assembly components impacting fragile portions during vibration, leading to potential failure and safety hazards.

Innovation Solution

The end cap is designed with a protruding portion to support the electrode assembly tab, creating an avoidance clearance to prevent the tab from crushing the fragile portion, and incorporates a current collecting member to ensure uniform current flow and reduce internal resistance, while the housing serves as an output electrode for simplified structure and enhanced safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the electrode assembly is allowed to move freely during vibration, then the battery cell structure is simpler, but the fragile portion of the end cap may be crushed by the electrode assembly, leading to premature rupture and safety hazards

Engineering Contradiction:
Improvebattery cell structureVSAvoidfragile portion reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A protruding portion is added to the end cap that acts as an intermediary component between the electrode assembly and the fragile portion. This protruding portion supports the electrode assembly tab and creates a buffer zone, preventing direct contact between the electrode assembly and the fragile portion during vibration, thereby eliminating the need for complex constraint mechanisms while protecting the fragile portion from crushing

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protruding portion is pre-positioned on the end cap to establish an avoidance clearance before vibration occurs. This preliminary structural arrangement ensures that when vibration happens, the electrode assembly already has a cleared path and supporting structure in place, preventing it from crushing the fragile portion during dynamic movement

Inventive Principle:
Principle #10Preliminary action

2Volume of moving object

If the tab is positioned close to the cap body to reduce space, then the battery cell volume is reduced, but the tab may crush the fragile portion during vibration, causing premature rupture

Engineering Contradiction:
Improvebattery cell volumeVSAvoidvibration impact on fragile portion
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The solution introduces a new spatial dimension by adding the protruding portion that extends from the cap body toward the electrode assembly. This creates a three-dimensional avoidance clearance zone that separates the tab and fragile portion paths, allowing compact overall volume while preventing harmful contact through vertical spacing rather than horizontal separation

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If the fragile portion is made thinner to facilitate easier rupture at threshold pressure, then the pressure relief function is improved, but the fragile portion becomes more susceptible to crushing by the electrode assembly

Engineering Contradiction:
Improvepressure relief responsivenessVSAvoidfragile portion resistance to crushing
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The protruding portion serves as a protective intermediary that physically separates the electrode assembly from the fragile portion. This allows the fragile portion to maintain its thin, pressure-sensitive structure for responsive pressure relief while the protruding portion prevents crushing by bearing the mechanical load during vibration

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The protruding portion provides beforehand cushioning by creating a protective buffer zone that absorbs and distributes mechanical stresses before they can reach the fragile portion. This pre-positioned structural element cushions the fragile portion against vibration-induced crushing while preserving its pressure relief capability

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

This design reduces the risk of fragile portion failure, improves stability and safety by preventing premature rupture, enhances current density uniformity, and simplifies the battery cell structure, thereby increasing safety and efficiency.

Implementation Method 1

A fragile portion is disposed on the cap body. The end cap is configured to rupture along the fragile portion when an internal pressure of the battery cell reaches a threshold, so as to release the internal pressure.

Methodology Applied
Scientific EffectPressure threshold rupture: Fracture Mechanics

Data Source

PatentEP4187690B1Battery cell and method and system for manufacturing same, and battery and electric device
Publication Date: 2026.01.07 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4187690B1 patent drawingFigure 1~2
  • EP4187690B1 patent drawingFigure 3~4
  • EP4187690B1 patent drawingFigure 5~6

AI summary

Embodiments of this application provide a battery cell, a method and system for manufacturing same, a battery, and an electrical device. The battery cell includes: a housing, on which an opening is made; an electrode assembly, accommodated in the housing, where a first tab is disposed on the electrode assembly at an end oriented toward the opening; and an end cap, configured to fit and cover the opening. The end cap includes a cap body and a first protruding portion connected to the cap body. A fragile portion is disposed on the cap body. The end cap is configured to rupture along the fragile portion when an internal pressure of the battery cell reaches a threshold, so as to release the internal pressure. The first protruding portion protrudes from the cap body toward the electrode assembly, and is configured to support the first tab so that an avoidance clearance configured to avoid the fragile portion is formed between the first tab and the cap body. This application reduces the risk that the first tab crushes the fragile portion, and improves the sealing performance and safety performance of the battery cell.