Pouch Battery Case Trimming to Reduce Dead Space and Gas Retention
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Solution Overview
Problem
Conventional pouch type secondary batteries suffer from inefficient space utilization due to internal dead spaces, which can trap gas and compromise stability, especially when subjected to external pressure.
Innovation Solution
A pouch type case design with trimming portions indented towards the electrode assembly to minimize internal dead space, allowing for improved space utilization and stability, and incorporating a holder to secure the battery pack structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional pouch type battery case design is used, then manufacturing is simple, but internal dead space is large causing poor space utilization and gas retention
Solution Approach 1:
The case is divided into multiple portions including a body portion and a sealing portion, with the sealing portion further segmented into first and second sealing portions. This segmentation allows each portion to be optimized independently - the body portion accommodates the electrode assembly while the sealing portions create trimming portions that eliminate dead space without complicating the overall manufacturing process.
Solution Approach 2:
The invention introduces trimming portions by modifying the sealing portion in a direction perpendicular to the main body, creating a multi-level structure. The first sealing portion extends in a first direction while the second sealing portion extends in a second direction different from the first, effectively utilizing three-dimensional space to eliminate dead areas without increasing the battery's overall footprint.
2Volume of moving object
If internal dead space is reduced through case design modifications, then space utilization improves, but case structure becomes more complex
Solution Approach 1:
The sealing portion combines multiple functions: it seals the battery case, creates the trimming portions to eliminate dead space, and provides structural support. By merging the sealing function with the space-optimization function into a single integrated portion, the design achieves improved space utilization without proportionally increasing structural complexity.
Solution Approach 2:
The sealing portion serves multiple purposes simultaneously: it acts as a seal, creates trimming portions for dead space elimination, and provides mounting surfaces for holders. This multi-functionality reduces the need for separate components, thereby improving space utilization while limiting the increase in overall structural complexity.
3Reliability
If trimming portions are added to the case, then gas retention is reduced and stability improves, but manufacturing precision requirements increase
Solution Approach 1:
The trimming portions are pre-formed as integral parts of the sealing portion during case manufacturing, rather than being added as separate components. The first and second sealing portions are configured in advance to create the trimming portions that eliminate dead space, ensuring consistent precision without requiring additional post-manufacturing operations.
4Productivity
If space utilization is maximized by reducing dead space, then cell density increases, but risk of gas trapping during operation increases
Solution Approach 1:
The invention extracts or removes the harmful dead spaces from the case interior by creating trimming portions that indent into the sealing portion. This extraction of dead space eliminates the pockets where gas could be trapped during battery operation, thereby allowing maximum cell density without the harmful side effect of gas retention.
Data Source
AI summary
The present invention relates to a pouch type case having trimming portions formed on both sides or four corners thereof and a battery pack including the same. The trimming portions are formed on the corners of the pouch type case such that the trimming portions are indented toward an electrode assembly accommodating part to reduce a unit area so as to increase pressure applied to unit cells when a battery pack is assembled, thereby facilitating assembling of the battery pack and increasing cell capacity per unit area. Furthermore, the unit cells can be fixed in the battery pack more stably. The pouch type case reduces the unit area so as to include a relatively large number of cells for pressure applied to the cells when the battery pack is assembled to thereby increase the cell capacity.