Battery Top Cover Vent Structure for Short-Circuit Prevention

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Solution Overview

Problem

Secondary batteries face safety concerns due to potential external short-circuits caused by liquid infiltration, which can lead to electrical connections between positive and negative electrode plates, compromising safety and performance.

Innovation Solution

A secondary battery top cover assembly featuring a conductive plate with a gas hole surrounded by a protrusion portion, an insulating cover, and a deformable plate, where the gas hole's arc-shaped smooth transition portion reduces flow resistance and facilitates gas escape, preventing liquid from reaching the deformable plate and minimizing the risk of short-circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gas hole is provided in the conductive plate to facilitate gas escape, then the sensitivity and safety of the secondary battery are improved, but liquid may infiltrate through the gas hole and cause external short-circuits

Engineering Contradiction:
ImprovesafetyVSAvoidliquid infiltration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The gas hole is designed with an arc-shaped smooth transition portion that creates a curved surface profile. This curvature causes liquid to follow the arc shape and flow along the inner wall rather than directly entering the gas hole, while still allowing gas to escape efficiently through the opening.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The solution moves from a simple planar hole design to a three-dimensional arc-shaped structure. The arc-shaped smooth transition portion adds a dimensional element that redirects liquid flow along the curved surface, separating liquid infiltration paths from gas escape paths in the vertical and radial dimensions.

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

2Manufacturing precision

If the gas hole has a straight inner wall to simplify manufacturing, then the manufacturing precision is improved, but gas flow resistance increases and sensitivity decreases

Engineering Contradiction:
Improvegas hole geometryVSAvoidgas flow rate
Core Design Contradiction:
Manufacturing precisionVSSpeed

Solution Approach 1:

The arc-shaped smooth transition portion creates a curved flow path that reduces turbulence and resistance compared to a straight hole with sharp edges. The curved geometry allows gas to flow more smoothly and rapidly through the hole, enhancing the deformable plate's sensitivity to pressure changes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If the deformable plate is made highly sensitive to detect small pressure changes, then the safety response time is improved, but the plate may deform prematurely under normal operating conditions

Engineering Contradiction:
Improvesafety responseVSAvoidplate deformation stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The deformable plate is designed with non-uniform thickness, being thinner at the center and thicker at the edges. This local variation in geometry creates different mechanical properties in different regions, allowing the center to be more flexible and sensitive to pressure changes while the edges provide structural stability and prevent premature deformation.

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 design enhances the sensitivity and safety of the secondary battery by accelerating gas flow and preventing liquid ingress, thus avoiding external short-circuits and ensuring reliable operation.

Implementation Method 1

An inner wall of the gas hole includes an arc-shaped smooth transition portion

Methodology Applied
Scientific EffectFlow resistance reduction:

Implementation Method 2

the deformable plate is connected to the top cover plate... when a preset internal pressure is applied

Methodology Applied
Scientific EffectPressure-induced deformation: Deformation

Implementation Method 3

The insulating cover includes a covering portion disposed above the conductive plate and covering the protruding portion and the gas hole

Methodology Applied
Scientific EffectPhysical barrier/Insulation:

Implementation Method 4

A space defined between the cover and the first deformable plate has a negative pressure

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3598523B1Secondary battery top cover assembly, secondary battery and vehicle
Publication Date: 2023.12.13 CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
  • EP3598523B1 patent drawingFigure 1
  • EP3598523B1 patent drawingFigure 2
  • EP3598523B1 patent drawingFigure 3

AI summary

The present disclosure provides a secondary battery top cover assembly, a secondary battery and a vehicle. The top cover assembly includes: a top cover plate; an electrode terminal; and a short-circuit component including a deformable plate and a conductive plate disposed above the deformable plate. The deformable plate is connected to the top cover plate, and the conductive plate is connected to the electrode terminal. The conductive plate includes a body portion and a protrusion portion protruding upwardly from the body portion, the conductive plate is provided with a gas hole, and the gas hole cuts through the protrusion portion and the body portion, an inner wall of the gas hole includes an arc-shaped smooth transition portion.