Reclosable Pouch Bag Structure for Battery Degassing Waste Reduction
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Solution Overview
Problem
Existing pouch-type secondary batteries require discarding a significant portion of the aluminum laminate sheet after the degassing process due to gas generation, leading to economic inefficiencies.
Innovation Solution
A pouch bag design with a protrusion and groove system on the inner resin layer allows the pouch bag to be opened and closed, eliminating the need for a surplus portion that would otherwise be discarded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pouch bag structure is used, then the battery can be manufactured, but dendrite formation occurs during charging/discharging leading to short circuits and reduced reliability
Solution Approach 1:
The invention applies a preliminary protective action by forming a solid electrolyte interphase (SEI) coating on the aluminum foil surface before the battery undergoes normal charging and discharging cycles. This pre-formed coating acts as a preventive barrier that stops dendrite formation before it can occur, thereby improving battery reliability without requiring changes to the battery's operational structure.
Solution Approach 2:
The aluminum foil with SEI coating serves as an intermediary layer between the liquid electrolyte and the battery electrodes. This intermediary structure prevents direct harmful interactions (dendrite formation) while still allowing ionic conduction, thus protecting the battery system without blocking its normal function.
2Manufacturing precision
If the inner pouch is detached and reattached during assembly, then positioning accuracy can be improved, but assembly time increases reducing productivity
Solution Approach 1:
The invention performs preliminary positioning actions during the pouch sealing process itself. By incorporating positioning structures (such as protrusions and recesses or alignment marks) that are formed during sealing, the system achieves accurate pouch positioning without requiring separate detachment and reattachment steps, thus maintaining high assembly speed while ensuring precision.
Solution Approach 2:
The invention merges the positioning function with the sealing process. Instead of treating positioning and sealing as separate operations requiring multiple handling steps, the design integrates positioning structures into the sealing components themselves, allowing both functions to be accomplished in a single continuous operation that improves productivity.
3Ease of manufacture
If sealing is performed without positioning structures, then assembly process is simple, but pouch positioning accuracy deteriorates
Solution Approach 1:
The invention applies local quality by incorporating positioning structures (protrusions, recesses, or alignment marks) only at specific critical locations on the pouch and sealing components, rather than requiring complex positioning mechanisms throughout the entire assembly. This localized approach maintains overall process simplicity while achieving accurate positioning where it is most needed.
Solution Approach 2:
The invention changes the geometric parameters of the sealing components by adding specific features (protrusions of certain dimensions, recesses with specific depths, alignment marks with defined positions) that enable self-positioning during sealing. These parameter changes create mechanical or visual cues that guide accurate pouch placement without complicating the sealing process itself.
Data Source
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AI summary
The present invention relates to a pouch bag that can be opened and closed and a pouch type secondary battery comprising the same, which has an economical effect because the pouch bag to be discarded after the degassing process does not occur.