Separator Sheet Bending via Air Blowing for Battery Assembly
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Solution Overview
Problem
The manufacturing process of lithium ion polymer batteries often results in low voltage issues due to the separation of the separator sheet from unit cells during the assembly, leading to defects in the electrode assembly.
Innovation Solution
An electrode assembly manufacturing device is designed with a lower air blowing unit to bend the end part of the separator sheet upward and an upper air blowing unit to bend it downward, preventing hyphen-shaped folds and minimizing defects by controlling the air pressure and timing during the winding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the separator sheet is wound around unit cells during manufacturing, then the electrode assembly is formed, but the separator sheet separates from unit cells causing low voltage issues
Solution Approach 1:
The end part of the separator sheet is bent in advance before the winding process to create a predetermined shape that prevents separation during assembly. This preliminary shaping ensures the separator maintains proper contact with unit cells throughout the manufacturing process.
Solution Approach 2:
The separator sheet end part is bent into a curved or folded configuration rather than remaining flat. This curvature creates a mechanical interlock or increased contact area with the unit cells, preventing separation and ensuring stable electrode contact during winding and operation.
2Ease of manufacture
If the separator sheet end part remains flat during winding, then the manufacturing process is simple, but hyphen-shaped folds occur causing defects
Solution Approach 1:
The separator sheet end part is pre-bent to a predetermined shape before the winding operation. This preliminary action eliminates the need for complex real-time folding control during winding, maintaining manufacturing simplicity while preventing hyphen-shaped folds and associated defects.
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
This solution effectively prevents separator sheet separation and reduces low voltage issues, enhancing the manufacturing process and quality of the electrode assembly by ensuring proper contact between electrodes.
Implementation Method 1
a lower air blowing unit located below the cutter and configured to spray air onto an end part of the separator sheet so that the end part of the cut separator sheet is able to be bent in an upward direction from the ground
Implementation Method 2
the lower air blowing unit located below the cutter and configured to spray air onto an end part of the separator sheet
Data Source
Figure 1a
Figure 1b
Figure 2
AI summary
Provided is a device for manufacturing an electrode assembly including: a lower air blowing unit for spraying air onto an end part of a separator sheet so that the end part of the cut separator sheet can be bent in an upward direction from the ground during a first winding; and an upper air blowing unit for spraying air onto the end part of the separator sheet so that the end part of the separator sheet can be bent in a downward direction toward the ground of a first unit cell while the first unit cell is firstly wound, thereby preventing a hyphen-shaped fold of the separator sheet during a manufacturing process of an electrode assembly and minimizing defects due to low voltage issues caused by contact between electrodes.