Cylindrical Battery Vent Structure for Thermal Runaway Exhaust
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Solution Overview
Problem
Existing cylindrical batteries fail to ensure sufficient venting during thermal runaway, leading to potential damage to the battery body and compromising safety during safety accidents.
Innovation Solution
A cylindrical battery design with a winding center hole and explosion-proof valve region, where the diameter ratios of the winding center hole and the explosion-proof valve region are proportionally designed to provide a large vent channel, ensuring effective venting and maintaining battery integrity during thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the diameter of the winding center hole is increased to improve venting, then the venting efficiency is improved, but the structural strength of the cover plate is reduced
Solution Approach 1:
The cover plate is designed with non-uniform thickness: the first region (around the winding center hole) has a smaller thickness to facilitate venting, while the second region (peripheral area) has a larger thickness to maintain structural strength. This local quality variation allows the cover plate to simultaneously achieve effective venting and sufficient strength.
2Object-generated harmful factors
If the diameter of the explosion-proof valve region is increased to improve venting, then the venting channel is enlarged, but the cover plate becomes more prone to damage
Solution Approach 1:
The explosion-proof valve region is designed with optimized diameter and thickness characteristics that balance venting capacity and structural integrity. The cover plate thickness in this region is carefully controlled to prevent excessive thinning while still allowing effective venting during thermal runaway events.
3Object-generated harmful factors
If the cover plate thickness is reduced to facilitate venting, then the venting efficiency is improved, but the mechanical strength is reduced
Solution Approach 1:
The cover plate employs variable thickness design where the first region has reduced thickness for efficient venting and the second region has increased thickness for mechanical strength. This local differentiation allows the structure to optimize both venting performance and structural integrity simultaneously.
Solution Approach 2:
The cover plate is segmented into functionally distinct regions: a first region optimized for venting (smaller thickness) and a second region optimized for strength (larger thickness). This segmentation allows each region to perform its specific function optimally without compromising the overall structure.
Data Source
Figure 1~2
Figure 3
AI summary
The disclosure provides a cylindrical battery (100), a pack (1002), and an electronic device (1000). The cylindrical battery (100) includes a housing (200) having an opening (205) at one end in a height direction (Hd) of the cylindrical battery (100); an electrode assembly (120) located in the housing (200) and having a winding center hole (120c); a cover plate (220) covering the opening of the housing (200) and having an explosion-proof valve region (222) formed by being surrounded by explosion-proof valves (350). The winding center hole (120c) is located within a range of an orthogonal projection of the explosion-proof valve region (222) of the cover plate (220) in the height direction (Hd). The winding center hole (120c) has a diameter D1, a partial region of the cover plate (220) has a diameter D2, and 35%≥D1/D2≥10%.