Pouch Secondary Battery Sealing Structure for Electrode Restraint
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Solution Overview
Problem
Existing secondary batteries face issues with the movement of the electrode assembly within the pouch, particularly due to impacts, which can lead to potential short circuits and damage.
Innovation Solution
The secondary battery design incorporates a fixed sealing portion and an extended sealing portion to secure the electrode assembly, using insulating tape to prevent electrical contact and additional sealing portions to minimize movement, ensuring the pouch is securely sealed without overlapping the electrode or lead tabs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If only a fixed sealing portion is used to seal the pouch, then the manufacturing process is simple, but the electrode assembly can move during impacts causing short circuits
Solution Approach 1:
The sealing portion is divided into two distinct segments: a fixed sealing portion that seals the edge of the pouch, and an extended sealing portion that extends toward the electrode assembly to prevent movement. This segmentation allows each portion to perform its specific function independently, improving reliability without excessive complexity.
Solution Approach 2:
The sealing structure extends in the width direction of the pouch beyond the traditional edge sealing, creating an extended sealing portion that spans across the pouch width. This dimensional extension provides additional constraint on the electrode assembly, preventing movement during impacts while maintaining a relatively simple overall structure.
2Reliability
If the pouch is tightly sealed to prevent electrode assembly movement, then safety is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The extended sealing portion is designed to create preliminary constraint on the electrode assembly before impacts occur. By pre-positioning the sealing structure to contact or near-contact the electrode assembly, the system prevents movement without requiring high-precision sealing during manufacturing, as the constraint is built into the structure design rather than relying on precise sealing positions.
3Reliability
If insulating tape is added between the lead tab and pouch, then electrical insulation is improved, but the device complexity increases
Solution Approach 1:
An insulating tape is introduced as an intermediary component between the lead tab and the pouch. This thin insulating layer provides effective electrical insulation to prevent short circuits while adding minimal structural complexity. The insulating tape serves as a simple mediator that solves the electrical insulation problem without requiring complex design changes.
Data Source
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AI summary
Disclosed is a secondary battery capable of restraining movement of an electrode assembly located in a pouch. The secondary battery includes an electrode assembly including a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate, a pouch accommodating the electrode assembly, a lead tab connected to an electrode tab, the electrode tab extending from the electrode assembly and extending outwardly of the pouch, a fixed sealing portion configured to seal an edge of the pouch, and an extended sealing portion located between the fixed sealing portion and the electrode assembly to seal a portion of the pouch at which the electrode tab and the lead tab are not located.