Pouch Battery Current Blocking Structure for Swelling Rupture Control
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Solution Overview
Problem
Pouch type secondary batteries face risks of ignition or explosion due to swelling phenomena caused by internal pressure increases from temperature rises, necessitating a mechanism to interrupt current flow effectively.
Innovation Solution
A pouch type secondary battery design featuring an electrode assembly, electrode tap, and pouch exterior with a rupture portion connecting area that includes linear-shaped grooves and triangular grooves on the electrode tap, allowing for precise stress concentration and rupture to disconnect the electrode lead from the electrode assembly when stress is applied, thereby interrupting current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electrode connection is made strong and secure to ensure reliable electrical connection, then the electrical connection reliability is improved, but the ability to interrupt current flow during swelling becomes compromised
Solution Approach 1:
The electrode tap is segmented into a first tap body portion (strongly connected to electrode assembly) and a second tap body portion (weakly connected to electrode lead), with a rupture portion between them. This segmentation allows the connection to be strong where needed for reliability while having a controlled weak point for current interruption during swelling events.
2Ease of manufacture
If the electrode tap structure is made simple for ease of manufacture, then the manufacturing complexity is reduced, but the precision of stress concentration and rupture control is compromised
Solution Approach 1:
The rupture portion is designed with specific local geometric features (reduced thickness, grooves, or notches) that create precise stress concentration points. This local quality change allows controlled rupture at specific locations while maintaining overall structural simplicity and ease of manufacture.
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
The design ensures accurate and smooth rupture of the electrode connection, preventing continuous swelling and associated risks by effectively interrupting current flow, thus enhancing safety.
Implementation Method 1
a rupture portion connecting area (120) which connects the second weld area (F2) and the electrode connection part (112), and which is configured to rupture and separate the second weld area (F2) from the electrode connection part (112) when a predetermined amount of stress occurs
Implementation Method 2
the rupture line (124) extends in a shape of a triangular groove having a third oblique surface (c) and a fourth oblique surface (d), wherein the third and fourth oblique surfaces define a predetermined second internal angle (B) and have a height (h) that is a length in a direction perpendicular to the surface of the electrode tap (110)
Data Source
AI summary
A current interrupt structure in which a double rupture structure, which has a rupture groove with a triangular shape and a rupture line with an extending shape of a triangular groove, such that when a swelling phenomenon occurs, stress is concentrated on the rupture line by the rupture groove, which enables accurate and smooth rupture and current flow interruption.