Secondary Battery Electrode Winding With Pre-Wound Separators
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Solution Overview
Problem
Conventional methods for manufacturing secondary batteries with wound electrode bodies are inefficient due to the need to stop and slow the winding core multiple times, leading to increased tact time and reduced productivity.
Innovation Solution
A method that involves retaining separators on a winding core, winding them at a first speed, arranging the negative electrode inside and the positive electrode between the separators at a slower or stopped core speed, and then winding both electrodes at a faster speed, reducing the need to stop or slow the core multiple times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the winding core is stopped or slowed multiple times to arrange electrodes, then the stacking displacement and rubbing are prevented, but the tact time increases and productivity decreases
Solution Approach 1:
The separator is preliminarily wound onto the winding core before the electrodes are arranged. This preliminary action creates a stable base structure that allows subsequent electrode arrangement to proceed without requiring the winding core to stop or slow down, thereby maintaining continuous winding operation while ensuring proper stacking alignment
Solution Approach 2:
The winding process is segmented into distinct phases: first winding the separator alone, then arranging electrodes while the separator is already in place, and finally continuing the winding. This segmentation allows each component to be positioned correctly without requiring the entire process to halt, resolving the contradiction between precision and productivity
2Productivity
If the winding core rotates continuously at high speed, then the productivity increases, but the electrode arrangement precision and alignment deteriorate
Solution Approach 1:
The separator is wound onto the winding core in advance while the core rotates at high speed. This preliminary winding creates a stable reference structure that enables subsequent electrode arrangement to occur during continued rotation, maintaining both high productivity and precision
Solution Approach 2:
The separator acts as an intermediary element between the winding core and the electrodes. By first winding the separator onto the rotating core, it provides a stable intermediate layer that facilitates accurate electrode placement without requiring the core to slow down, thus maintaining high winding speed while ensuring proper alignment
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 approach shortens the winding time, enhances the reliability of the wound electrode body by minimizing stacking displacement, and improves the overall productivity of secondary battery production.
Implementation Method 1
rotating the winding core at a first rotational speed to wind the first separator and the second separator onto the winding core
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A method of manufacturing a secondary battery (100) disclosed herein includes: a step (S2) of winding a first separator (32) and a second separator (34) onto a winding core (210); a step (S3) of arranging a winding-start end (20s) of the negative electrode (20) such that the negative electrode (20) is located on an inner circumferential side of the first separator (32) and also arranging a winding-start end (10s) of the positive electrode (10) between an outer circumferential side surface of the first separator (32) and the second separator (34), in a state where the winding core (210) is stopped; and a step (S4) of winding the positive electrode (10) and the negative electrode (20) onto the winding core (210).