Stack Cell Edge Taping for Uniform Electrode Laminate Pressure
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Solution Overview
Problem
Existing manufacturing methods for secondary batteries face challenges in applying uniform pressure to the edges of electrode laminates, leading to potential damage, gaps between the electrode and separator, and lithium precipitation, which can cause battery explosions.
Innovation Solution
The use of step relief tapes attached to the edges of electrode laminates to relieve steps caused by fixing tapes, ensuring uniform pressure application and minimizing gaps between the active material and separator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the pressing press is spaced apart from the edge of the upper surface of the half-cell by a distance equal to the height of the step, then the fixing tape can be applied, but the pressure of the pressing press is hardly applied to the two edges of the electrode laminate
Solution Approach 1:
A step relief tape is introduced as an intermediary component between the fixing tape and the electrode laminate edge. This step relief tape has a thickness that matches the step height, allowing the pressing press to apply uniform pressure across the entire electrode laminate surface including the edges, while the fixing tape remains properly positioned.
2Ease of manufacture
If the two edges of the electrode laminate are pressed by the jig device during taping, then the electrode laminate can be fixed, but a step as high as the thickness of the fixing tape is present at the edge of the upper surface of the half-cell
Solution Approach 1:
The step relief tape serves as a mediator that compensates for the surface irregularity created by the fixing tape. By placing this tape at the edge where the step occurs, it provides a smooth transition surface that eliminates the height difference and maintains overall surface flatness.
3Ease of manufacture
If a gap or space is present between the electrode and the separator at the two edges of the electrode laminate, then the electrode laminate can be assembled, but lithium may be precipitated into the gap or space causing explosion
Solution Approach 1:
The step relief tape is applied in advance during the assembly process to ensure that when the pressing press operates, uniform pressure is immediately applied to eliminate gaps between the electrode and separator at the edges, preventing lithium precipitation before it can occur.
4Ease of manufacture
If the sliding part of the active material layer is formed at the two edges of the electrode, then the active material layer can be coated, but a gap or space is easily formed between the electrode and the separator at the sliding part
Solution Approach 1:
The step relief tape acts as a mediator at the sliding part location, providing the necessary pressure transmission to ensure the separator maintains intimate contact with the electrode edge where the sliding part exists, thereby preventing gap formation despite the coating process.
Data Source
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AI summary
Disclosed is a stack cell. The stack cell of the present invention comprises: an electrode stack; at least one fixing tape that wraps around the circumference of the electrode stack and fixes the electrode stack; and a step-removing tape that is attached to each of the edge portions of the upper surface of the electrode stack so as to remove a step portion between the fixing tape and the upper surface of the electrode stack.