Sealed Battery Cap Venting to Isolate Thermal Runaway Gas
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Solution Overview
Problem
In battery packs where batteries are connected in series or parallel, thermal runaway in one battery can disrupt the current interruption and explosion-proof mechanisms of adjacent batteries due to gas discharge, affecting their pressure and functionality.
Innovation Solution
A sealed battery design with a bottomed cylindrical outer housing and a sealing assembly that includes a current interruption mechanism sensitive to gas pressure, and an explosion-proof vent in the cap to create a sealed space, reducing the impact of gas discharge from adjacent batteries during thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gas discharge hole is provided in the cap for pressure relief, then the explosion-proof function is improved, but the current interruption mechanism and explosion-proof mechanism are thermally affected by discharged gas from adjacent batteries during thermal runaway
Solution Approach 1:
The patent divides the cap into two separate functional regions: a sealed space containing the current interruption mechanism and an explosion-proof vent for pressure relief. This segmentation isolates the current interruption mechanism from the discharged gas, allowing the explosion-proof function to operate without thermally affecting the current interruption mechanism.
Solution Approach 2:
The patent introduces a sealed space as an intermediary barrier between the current interruption mechanism and the external environment. This sealed space protects the current interruption mechanism from direct exposure to discharged gas while still allowing the explosion-proof vent to function for pressure relief.
2Quantity of substance
If batteries are arranged in the same plane to reduce occupying volume, then the energy density is improved, but the gas discharge from one battery directly affects adjacent batteries
Solution Approach 1:
The patent segments each battery's cap into an isolated sealed space and an explosion-proof vent region. This segmentation prevents gas discharged from one battery from directly entering and affecting adjacent batteries, even when batteries are arranged in the same plane for high energy density.
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 effectively isolates the current interruption and explosion-proof mechanisms from gas discharge, ensuring they remain functional even when an adjacent battery experiences thermal runaway, maintaining the reliability and energy density of the battery pack.
Implementation Method 1
a current interruption mechanism which is activated sensitive to a gas pressure in the battery
Implementation Method 2
the cap has an explosion-proof vent that opens sensitive to a gas pressure in the sealed space
Data Source
AI summary
A sealed battery comprises: a bottomed tubular outer can accommodating an electrode body; and a sealing body for sealing an opening of the outer can. The present invention is characterized in that: the sealing body includes a current blocking mechanism that seals the electrode body together with the outer can and is activated in response to gas pressure inside the battery, and a cap that forms a sealed space above the current blocking mechanism; and the cap includes an explosion-proof valve that opens in response to the gas pressure inside the battery.