Battery End Cover Venting Structure to Prevent Membrane Separation

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Solution Overview

Problem

Existing battery cells face safety hazards due to excessive gas pressure generated during charging and discharging, which can lead to separation of the gas permeable membrane from the cover plate, compromising sealing and safety performance.

Innovation Solution

An end cover assembly with a gas permeable membrane firmly attached to a cover plate via a fixing member, featuring a pressure relief hole and through holes that prevent the membrane from separating, ensuring timely gas discharge and maintaining gas pressure within safe limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a gas permeable membrane is used to discharge gas from the battery cell, then gas pressure is reduced, but the membrane may separate from the cover plate under excessive gas pressure

Engineering Contradiction:
Improvegas pressureVSAvoidsealing performance
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The edge part of the gas permeable membrane is divided into multiple sections that are embedded into separate through holes in the fixing member, creating multiple fixed points that prevent separation under gas pressure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The edge part of the gas permeable membrane is nested into the through holes of the fixing member, with the first portion extending into the gap between the fixing member and cover plate, and the second portion embedded into the through hole, creating a nested structure that secures the membrane firmly

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the edge part of the gas permeable membrane is firmly attached to the cover plate, then sealing performance is improved, but the membrane may still move or separate under gas pressure

Engineering Contradiction:
Improvesealing performanceVSAvoidmembrane position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

Different portions of the edge part have different functions: the first portion extends into the gap for positioning and preventing movement in the thickness direction, while the second portion is embedded into the through hole for firm attachment and preventing separation under gas pressure

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fixing structure utilizes multiple dimensions: the gap in the thickness direction provides positioning, while the through holes provide anchoring in the radial direction, creating a multi-dimensional constraint system that fully restrains the edge part

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

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 solution provides enhanced sealing and safety performance by preventing membrane separation under gas pressure, allowing for timely gas discharge and maintaining internal pressure, thus improving the safety and energy density of battery cells.

Implementation Method 1

The gas permeable membrane has a function of slow gas permeability, and can discharge gas generated inside the battery cell timely to reduce or maintain the gas pressure inside the battery cell

Methodology Applied
Scientific EffectGas permeability: Permeation

Data Source

PatentEP4120448B1End cover assembly, battery cell, battery and power-consuming apparatus
Publication Date: 2024.05.22 CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED
  • EP4120448B1 patent drawingFigure 1~2
  • EP4120448B1 patent drawingFigure 3
  • EP4120448B1 patent drawingFigure 4~6

AI summary

The present application provides an end cover assembly, a battery cell, a battery, an electric device and a method for preparing a battery cell and an apparatus for manufacturing a battery cell, and belongs to the technical field of battery manufacturing. The present application provides an end cover assembly, where the end cover assembly includes: a cover plate provided with a pressure relief hole; a fixing member fixed on the cover plate, the fixing member having a first through hole and a second through hole, and the first through hole being opposite to the pressure relief hole; and a gas permeable membrane covering at least a portion of the pressure relief hole, an edge part of the gas permeable membrane being connected to the fixing member, and a portion of the edge part being embedded into the second through hole, so as to prevent the edge part from moving relative to the fixing member. The present application further provides a battery cell, a battery and an electric device, all of which include the end cover assembly, thus having good safety performance and sealing performance. The present application further provides a method for preparing a battery cell and an apparatus for manufacturing a battery cell, which are used for manufacturing the above-mentioned battery cell.