Battery Cover Plate Venting With Staged Explosion-Proof Grooves

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Solution Overview

Problem

Existing battery explosion-proof structures cause thermal runaway and explosions due to interactions between combustible and combustion gases when the explosion-proof structure opens.

Innovation Solution

An explosion-proof structure with a cover plate featuring first and second sub-grooves of varying thicknesses, opening at different pressure thresholds to time-divide the discharge of combustible and combustion gases, preventing excessive pressure buildup and thermal runaway.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single explosion-proof membrane is provided on the cover plate, then the battery can be protected from explosion, but the combustible gas and combustion gas interact when the membrane explodes, increasing the degree of thermal runaway

Engineering Contradiction:
Improveexplosion-proof protectionVSAvoidthermal runaway degree
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The single explosion-proof membrane is divided into two separate membranes: a first explosion-proof membrane and a second explosion-proof membrane. The first membrane opens at a lower pressure threshold to discharge combustible gas, while the second membrane opens at a higher pressure threshold to discharge combustion gas. This segmentation prevents the interaction between different gas types that would otherwise occur in a single-membrane system, thereby reducing thermal runaway degree while maintaining explosion-proof protection.

Inventive Principle:
Principle #1Segmentation

2Stress or pressure

If the explosion-proof structure opens to release pressure, then the internal pressure can be reduced, but the interaction between combustible gas, combustion gas, and battery substances causes explosion

Engineering Contradiction:
Improveinternal pressureVSAvoidexplosion hazard
Core Design Contradiction:
Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The pressure relief function is segmented into two distinct stages through two separate explosion-proof membranes with different opening pressure thresholds. The first membrane opens at a lower pressure to release combustible gas, and the second membrane opens at a higher pressure to release combustion gas. This staged segmentation allows pressure reduction while preventing the harmful interaction between different gas phases that would lead to explosion.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the cover plate thickness is uniform, then the manufacturing is simple, but it cannot achieve time-division discharging of different gases

Engineering Contradiction:
Improvecover plate manufacturingVSAvoidtime-division discharging capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cover plate transitions from uniform thickness to non-uniform thickness, with different thickness values at different locations. Specifically, the first region has a first thickness and the second region has a second thickness, allowing the first explosion-proof membrane to open at a different pressure threshold than the second membrane. This local quality variation enables time-division discharging of different gases while maintaining manufacturing feasibility through standard forming processes.

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 structure effectively prevents battery explosions by sequentially releasing combustible and combustion gases, ensuring safe pressure relief without triggering thermal runaway.

Implementation Method 1

the thickness of the part of the cover plate where the first sub-groove is located is smaller than the thickness of the part of the cover plate where the second sub-groove is located. When the internal pressure of the battery is increased, the part of the cover plate where the first sub-groove is located is first opened, and the part of the cover plate where the second sub-groove is located is then opened

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4579896A1Explosion-proof structure, battery and battery pack
Publication Date: 2025.07.02 HUIZHOU EVE POWER CO LTD
  • EP4579896A1 patent drawingFigure 1~3
  • EP4579896A1 patent drawingFigure 4~6
  • EP4579896A1 patent drawingFigure 7~8

AI summary

An explosion-proof structure, a battery, and a battery pack are provided. The explosion-proof structure includes a cover plate (110) and an explosion-proof groove (120) including one or more first sub-grooves (121) and one or more second sub-grooves (122). H1<H2, in which H1 denotes a thickness of a part of the cover plate where the first sub-groove is located, and H2 denotes a thickness of a part of the cover plate where the second sub-groove is located. The part of the cover plate where the first sub-groove is located is opened under a first pressure denoted by P1, and the part of the cover plate where the second sub-groove is located is opened under a second pressure denoted by P2, in which the first pressure satisfies 0.5Mpa<P1<1.5Mpa; and the second pressure satisfies 1.5Mpa≤P2<2.5Mpa.