Wave Corner Sealed Joints for Deep-Draw Pouch Cells
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Solution Overview
Problem
Conventional pouch cell manufacturing methods are limited by the maximum draw depth of metal laminated film, restricting the overall height and active material capacity of pouch cells, and often result in unreliable seals due to material overstress and pleating.
Innovation Solution
A forming device and method using a die block and punch with specific surface features to form tray-shaped case halves without overstressing the metal laminated film, allowing for deeper recesses and reliable seals by shaping excess material into undulating waves along the flange, preventing pleating and ensuring a secure connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the draw depth of metal laminated film is increased to form deeper pouch cell housings, then the overall height and active material capacity of pouch cells can be increased, but the metal layer tears due to material overstress and stretching
Solution Approach 1:
The patent applies curvature by forming wave patterns (ridges and channels) in the flange regions of the pouch cell housing. These curved wave patterns allow the metal laminated film to accommodate depth increases without experiencing excessive stress concentration that would cause tearing, thereby resolving the contradiction between increased height and maintained material strength.
Solution Approach 2:
The patent changes the geometric parameters of the flange region by introducing wave patterns with specific ridge and channel dimensions. This parameter modification allows the material to distribute stress more effectively during the drawing process, enabling deeper draws without compromising metal layer integrity.
2Ease of manufacture
If conventional drawing processes are used to form pouch cell housings, then the manufacturing process is simple, but the maximum draw depth is limited to 6-8 mm resulting in cell heights of only 10-16 mm
Solution Approach 1:
The wave patterns introduced in the flange regions provide a geometric solution that maintains manufacturing simplicity while enabling greater draw depths. The curvilinear wave profiles are formed using standard drawing equipment, thus preserving ease of manufacture while achieving cell heights exceeding 16 mm.
3Quantity of substance
If the pouch cell housing depth is increased beyond conventional limits, then the active material storage capacity increases, but material overstress causes tearing and unreliable seals
Solution Approach 1:
The wave patterns with ridges and channels distribute stress away from the seal regions, preventing material failure and ensuring reliable seals even at increased depths. The curved geometry allows the housing to accommodate larger active material volumes without compromising seal integrity.
Solution Approach 2:
By modifying the flange geometry to include wave patterns, the patent changes the stress distribution parameters in the housing structure. This enables increased active material capacity while maintaining seal reliability through improved stress management in critical sealing regions.
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
Enables the production of pouch cells with greater overall depth and reliable seals, exceeding conventional height limits while preventing material overstress and ensuring a secure, unpleated seal joint, even at larger depths.
Implementation Method 1
The die block and punch are movable between a first position in which the die block and the punch are spaced apart a first distance, and a second position in which the die block and the punch are spaced apart a second distance that is less than the first distance
Implementation Method 2
The at least one alternating die ridge and die channel are disposed along the corner radius of each apex, and define a curvilinear profile when viewed in cross section
Data Source
AI summary
A forming device is configured to form metal laminated sheet material into a tray-shaped case half while allowing the material to form pleats in the corners of the recess during the forming process while preventing formation of pleats along the flange. The device forms the flange so that excess material in the corners of the case halves is arranged in an undulating shape. As a result, the flange has a waved or ruffled configuration at each corner. Two such case halves are sealed together along the flange to form a reliably sealed package. A method of forming pouch cell is also described.