Pouch Battery Electrode Lead Margin for Swelling Displacement
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Solution Overview
Problem
The disconnection or damage of electrode leads in battery modules due to swelling is a significant issue, particularly at the first bent part where the degree of bending exceeds the designed level, leading to weakened welding strength and potential disconnection between the electrode leads and busbars.
Innovation Solution
Incorporating a margin with a predetermined section on the electrode leads that allows for deformation, ensuring the electrode leads extend when tensioned, thereby maintaining welding strength and preventing disconnection or damage during swelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electrode lead is bent at a high degree to accommodate swelling, then the battery cell can expand, but the welding strength between the electrode lead and busbar deteriorates
Solution Approach 1:
The electrode lead is divided into multiple sections with different properties: a first bent part with high bending degree for swelling accommodation, a second bent part with low bending degree for maintaining welding strength, and a straight part for electrical connection. This segmentation allows each section to fulfill its specific function without compromising the others.
Solution Approach 2:
Different sections of the electrode lead are given different local qualities: the first bent part has high flexibility to accommodate swelling, while the second bent part and straight part have sufficient rigidity to maintain welding strength and electrical connection stability. This local differentiation resolves the contradiction between adaptability and strength.
2Adaptability or versatility
If the electrode lead is bent at a high degree to accommodate swelling, then the battery cell can expand, but the electrode lead structure becomes more complex
Solution Approach 1:
The electrode lead is segmented into three distinct parts (first bent part, second bent part, straight part), each with a specific function. This segmentation makes the complex structure manageable and manufacturable by defining clear boundaries and functions for each section.
Solution Approach 2:
Instead of making the entire electrode lead flexible to accommodate swelling, the invention inverts the approach by making only the first bent part highly flexible while keeping the other parts relatively rigid. This reduces the overall complexity compared to a fully flexible design.
3Adaptability or versatility
If the electrode lead is made more flexible to accommodate swelling, then swelling displacement is absorbed, but the welding strength with busbar deteriorates
Solution Approach 1:
The electrode lead is segmented into a first bent part with high flexibility for absorbing swelling displacement and a second bent part with sufficient rigidity for maintaining welding strength. This segmentation allows the system to absorb displacement without compromising welding integrity.
Solution Approach 2:
Different local qualities are assigned to different sections: the first bent part has high flexibility to absorb swelling displacement, while the second bent part has sufficient rigidity to maintain welding strength. This local differentiation resolves the contradiction between displacement absorption and welding strength.
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 margin design effectively prevents disconnection and damage to electrode leads by controlling the degree of spring back, maintaining welding strength and ensuring the integrity of the battery module despite swelling-induced displacement.
Implementation Method 1
the degree of spring back, thereby controlling the degree of bending of the electrode leads
Data Source
AI summary
The present disclosure provides: a structure of a pouch type battery cell provided with electrode leads protruding from lengthwise ends thereof, respectively, wherein the pouch type battery cell includes a margin capable of extending the electrode leads by deforming as end portions of the electrode leads are tensioned; and a structure of a battery module with a battery cell stack accommodated therein formed by stacking at least one of above-described battery cells.