Pouch Battery Spacer Structure for Uniform Folded Case Shape
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Solution Overview
Problem
Pouch-type secondary batteries often form 'bat ears' during the folding process, leading to deviations in the degree of folding and reduced energy density due to wasted space.
Innovation Solution
A film- or sheet-shaped spacer is interposed between the upper and lower pouches of the pouch-type case, applying a predetermined force to spread or flatten the bridge, thereby forming a uniform shape along the folding line and minimizing bat ear formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a pouch-type case is folded along a folding line to form an accommodation space, then the battery achieves a compact pouch shape, but bat ears form due to deviations in the degree of folding, reducing energy density
Solution Approach 1:
A bridge structure is introduced as an intermediary element connecting the first pouch and second pouch along the folding line. This bridge includes a connecting portion that spans between the two pouches and provides structural support during folding, ensuring uniform folding behavior and preventing bat ear formation while maintaining the compact pouch configuration
2Productivity
If the pouch-type case is folded to achieve high energy density, then space utilization improves, but the folding process creates bat ears due to uneven folding degrees
Solution Approach 1:
The bridge acts as a mediator that enforces uniform folding across the pouch-type case. By providing a rigid connecting portion between the first and second pouches, it ensures both sides fold to the same degree, eliminating bat ears and maximizing space utilization for high energy density
Solution Approach 2:
The bridge structure changes the mechanical parameters of the folding process by providing a fixed reference point and structural constraint. This ensures consistent folding angle and degree across the entire pouch-type case, transforming an uncontrolled folding process into a precise geometric transformation
Data Source
AI summary
A secondary battery includes: a pouch-type case including a first pouch and a second pouch connected to each other, the pouch-type case being folded along a folding line such that an accommodation space surrounded by the first pouch and the second pouch is formed; an electrode assembly accommodated in the accommodation space; and a film- or sheet-shaped spacer that is spaced apart from the electrode assembly in the direction of the folding line and interposed between the first pouch and the second pouch. The spacer includes a material having a different physical property from an innermost sealant layer of the first pouch and the second pouch.