Pouch Battery Case Bridge Notch to Prevent Bat-Ear Deformation
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Solution Overview
Problem
Pouch-type battery cases face issues with undesired deformation and potential harm to electrode assemblies due to bridge portion rigidity, leading to defects, reduced energy density, and assembly complications.
Innovation Solution
A pouch-type battery case design with notched bridge portions and offset central sections to minimize deformation, preventing collisions with electrode assemblies and reducing bat-ear formation, enhancing energy density and assembly stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the bridge portion is made rigid to maintain structural stability, then the structural stability is improved, but deformation and bat-ear formation occur leading to electrode assembly damage
Solution Approach 1:
The bridge portion is designed with non-uniform thickness, featuring a thicker first section and a thinner second section. This local variation in quality allows the thicker section to provide structural support while the thinner section reduces rigidity to prevent deformation and bat-ear formation during pouch folding, thereby protecting the electrode assembly.
2Strength
If the bridge portion rigidity is increased to prevent pouch film deformation, then deformation resistance is improved, but assembly complexity increases due to bat-ear formation and collision risks
Solution Approach 1:
By making the bridge portion thickness non-uniform with a thinner second section, the design locally reduces rigidity in the area most prone to causing assembly issues. This prevents bat-ear formation and collision with the electrode assembly during folding, thereby simplifying the assembly process while maintaining overall structural integrity.
3Shape
If the pouch film is pressed to form cups, then cup formation is achieved, but bat-ear formation and energy density reduction occur
Solution Approach 1:
The non-uniform bridge portion design with a thinner second section prevents excessive rigidity in the bridge area during cup formation. This allows the pouch film to be pressed into cups without causing bat-ear formation at the bridge portion, thereby improving manufacturing precision and energy density.
4Manufacturing precision
If the bridge portion is made thinner to reduce bat-ear formation, then energy density is improved, but structural strength decreases
Solution Approach 1:
The bridge portion features a thicker first section that maintains structural strength and support, while the thinner second section reduces rigidity to prevent bat-ear formation. This local differentiation allows the structure to be both strong where needed and flexible where required, improving energy density without compromising overall strength.
Data Source
AI summary
A pouch-type battery case accommodates an electrode assembly having a electrodes and separators are alternately arranged, the battery case comprises a pouch film having a film thickness, a first surface and a second surface, a first cup portion formed in the pouch film having a recessed shape offset from the first surface towards the second surface; a second cup portion formed in the pouch film having a recessed shape offset from the first surface towards the second surface; and a bridge portion formed in the pouch film between the first cup portion and the second cup portion and connecting the first cup portion to the second cup portion; the bridge portion includes a notch formed in the first surface projecting towards the second surface.