Dual-Width Pouch Sealing for Battery Gas Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pouch-type secondary batteries face safety issues due to gas generation from electrolyte decomposition, leading to swelling and potential explosion, necessitating efficient gas discharge mechanisms.
Innovation Solution
A pouch-type secondary battery design featuring a sealing part with a first and second sealing width, where the second sealing part acts as a vent for gas discharge, thermally fused with a thermoplastic resin, and inclined portions to facilitate rapid gas release, preventing explosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pouch case is sealed completely to prevent leakage, then safety against external contamination is improved, but gas discharge capability deteriorates leading to swelling and explosion risk
Solution Approach 1:
The sealing part has non-uniform width with a first sealing part of first width and a second sealing part of second width. The second sealing part with smaller width creates a localized weak point that serves as a gas discharge path, while other sealing regions maintain full sealing strength. This local variation in sealing quality resolves the contradiction between complete sealing and gas discharge capability.
2Strength
If the sealing part width is uniform to ensure sealing strength, then sealing reliability is improved, but gas discharge efficiency deteriorates
Solution Approach 1:
The sealing part implements local quality variation by having different widths in different regions. The first sealing part maintains sufficient width for strong sealing, while the second sealing part has reduced width to facilitate gas discharge. This localized differentiation allows the sealing structure to simultaneously achieve both sealing strength and gas discharge efficiency.
Solution Approach 2:
The sealing part is segmented into functionally distinct regions: the first sealing part for primary sealing and the second sealing part for gas discharge. This segmentation allows each segment to be optimized for its specific function, with the first sealing part providing structural integrity and the second sealing part providing pressure relief capability.
3Ease of manufacture
If the pouch case structure is simple to reduce manufacturing complexity, then manufacturing cost is improved, but gas discharge control capability deteriorates
Solution Approach 1:
The solution introduces local quality variation in the sealing part width without fundamentally changing the overall pouch case structure. This approach maintains manufacturing simplicity while achieving controlled gas discharge functionality through the differentiated first and second sealing parts with different widths.
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 ensures safe discharge of generated gas, preventing explosion and improving safety by allowing rapid vaporization and escape of electrolyte, as demonstrated by experiments at high temperatures.
Implementation Method 1
the first case part and the second case part are in contact with each other in an edge portion surrounding the first and second accommodating parts and are sealed by a sealing part formed in a band shape on at least a part of the edge portion
Implementation Method 2
the sealing part includes a first sealing part having a first width and a second sealing part having a second width smaller than the first width
Data Source
AI summary
A secondary battery according to an exemplary embodiment of the present invention includes: an electrode assembly; and a pouch case in which the electrode assembly is embedded, in which the pouch case includes a first case part formed with a first accommodating part in which a part of the electrode assembly is embedded, and a second case part formed with a second accommodating part in which the remaining part of the electrode assembly is accommodated, the first case part and the second case part are in contact with each other in an edge portion surrounding the first and second accommodating parts and are sealed by a sealing part formed in a band shape on at least a part of the edge portion, the sealing part includes a first sealing part having a first width and a second sealing part having a second width smaller than the first width, and a central portion of the second sealing part in a longitudinal direction coincides with a central portion of a long side of the electrode assembly.