Flame-Retardant Battery Cap for Redirecting Vent Discharge Gas
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Solution Overview
Problem
Existing battery packs with lithium-ion batteries face safety concerns due to high-temperature discharge gases ejected from the discharge valve, which can ignite and cause damage to the exterior case.
Innovation Solution
A battery pack design featuring a flame-retardant cap with a collision plate and peripheral wall, along with a diffusion gap and reverse ejection gap, to redirect and attenuate the high-temperature discharge gas, preventing it from directly ejecting outside the case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a heat-resistant spacer (mica plate) is disposed at the discharge valve side end surface to prevent exterior case damage, then the exterior case is protected from direct collision with discharge gas, but the high-temperature discharge gas (>400°C) still vigorously collides with the inner surface of the exterior case after redirection, causing thermal melting and damage
Solution Approach 1:
A flame-retardant cap is introduced as an intermediary component between the battery and exterior case. This cap includes a collision plate that intercepts discharge gas and a peripheral wall that contains it, preventing the high-temperature gas from reaching the exterior case inner surface. The flame-retardant material of the cap itself can withstand the thermal environment, serving as a protective mediator.
Solution Approach 2:
The protective structure is segmented into distinct functional components: a collision plate for intercepting discharge gas, a peripheral wall for containing the gas, and a flame-retardant cap housing these elements. This segmentation allows each component to perform its specific function optimally - the collision plate stops the gas flow, the peripheral wall contains it, and the flame-retardant material withstands thermal exposure.
2Stress or pressure
If the discharge gas is allowed to eject to the outside of the case through damaged portions, then pressure relief is achieved, but the gas contacts air and ignites, creating fire hazards
Solution Approach 1:
The flame-retardant cap creates a controlled environment that prevents the discharge gas from contacting air. By containing the gas within the cap structure during the ejection process, the gas does not mix with oxygen in the air, thereby preventing ignition. The flame-retardant material also provides a barrier that maintains this protective environment.
3Reliability
If a flame-retardant cap with collision plate and peripheral wall is introduced to redirect discharge gas, then the discharge gas is prevented from damaging the exterior case and igniting, but the device structure becomes more complex
Solution Approach 1:
The collision plate and peripheral wall are merged into a single integrated flame-retardant cap component. This combining of functions into one piece reduces the number of separate parts that need to be assembled and managed, simplifying the overall structure while maintaining the protective functions of intercepting and containing the discharge gas.
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 effectively suppresses the adverse effects of high-temperature discharge gases, improving safety by preventing ignition and damage to the exterior case, while ensuring the safe exhaustion of discharge gases.
Implementation Method 1
the discharge gas ejected from the discharge valve collides with collision plate 6A of flame-retardant cap 6
Implementation Method 2
fills expansion space 25 via diffusion gap 28
Data Source
AI summary
In the battery pack, battery cell including a discharge valve is housed in case, and flame-retardant cap is disposed at a position facing discharge valve side end surface of battery cell. Flame-retardant cap includes collision plate disposed at a position facing discharge valve side end surface and wall formed around collision plate, the discharge valve of the battery cell and a region in proximity are arranged inside peripheral wall, and reverse ejection gap is provided between battery cell and peripheral wall. An expansion space of the discharge gas flowing in from reverse ejection gap is provided inside case. In the expansion space, the discharge gas ejected from the discharge valve collides with collision plate of flame-retardant cap, and fills the expansion space via diffusion gap and reverse ejection gap.