Pouch Battery Cell Bend Structure for Shark-Fin Edge Reduction
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Solution Overview
Problem
Existing pouch-type secondary battery cells have protrusions or 'shark-fins' that reduce space utilization and energy density due to their protruding edges, which also affect cooling efficiency in battery modules.
Innovation Solution
The battery cell design incorporates a bend portion that reduces or eliminates the protruding edges by bending the protrusion inward, utilizing a folding and sealing technique to minimize outward protrusion, and uses an adhesive member to maintain the bent shape, enhancing energy density and cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the pouch is sealed with conventional sealing portions at edges, then the battery cell structure is simple and easy to manufacture, but protrusions are generated at the edges reducing space utilization rate and energy density
Solution Approach 1:
The sealing portion is divided into multiple segments: a first sealing portion extending from the edge toward the folded portion, and a second sealing portion extending from the folded portion toward the first sealing portion. This segmentation allows the sealing structure to adapt to the folded configuration without generating protrusions, thereby improving space utilization and energy density while maintaining manufacturing feasibility.
Solution Approach 2:
The sealing portion is configured to extend in multiple directions (first direction from edge to folded portion, second direction from folded portion to first sealing portion) rather than simply along the edge. This multi-dimensional configuration allows the sealing structure to follow the folded contour, eliminating protrusions and improving space utilization without significantly increasing manufacturing complexity.
2Quantity of substance
If the battery cell size is increased to improve energy density, then the energy density improves, but the protrusions occupy more space and reduce cooling efficiency
Solution Approach 1:
The folded portion, which initially creates a protrusion problem, is utilized as a beneficial feature by configuring the sealing portion to extend along it. This converts the potentially harmful protrusion into a space-efficient configuration that improves both energy density and cooling efficiency, as the sealed structure maintains close contact with the battery module without unnecessary extensions.
3Reliability
If the sealing portion extends along the entire edge including folded portions, then complete sealing is achieved, but the edge protrudes beyond the folded portion reducing space utilization
Solution Approach 1:
The sealing portion has different configurations in different regions: in the first region it extends from the edge toward the folded portion, and in the second region it extends from the folded portion toward the first sealing portion. This localized adaptation to the folded geometry ensures complete sealing while preventing edge protrusion, thereby achieving both sealing reliability and optimal space utilization.
Data Source
AI summary
A battery cell includes an electrode assembly including a plurality of electrode plates; and a pouch surrounding the electrode assembly, wherein the pouch includes a folded portion folded along one edge of the electrode assembly; a sealing portion formed along a remaining edge of the electrode assembly; and a bend portion including a portion in which the sealing portion and the folded portion meet, therein the portion is bent toward the sealing portion.