Battery Separator Adhesive Zoning for Winding Alignment
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Solution Overview
Problem
The manufacturing of electricity storage devices, such as batteries, faces challenges with productivity due to strong adhesion between electrodes and separators leading to distortion or misalignment during the winding process, especially when adhesive resins are used.
Innovation Solution
A method involving a separator with a partially applied adhesive layer having distinct adhesive regions, where the first adhesive region is 1.5 times thicker than the second, allowing for controlled adhesion during winding and pressing steps to prevent distortion and misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If adhesive resin is applied on the separator surface to improve adhesion during winding, then winding alignment is improved, but distortion and wrinkles occur during pressing due to excessive adhesion strength
Solution Approach 1:
The adhesive layer is designed with non-uniform thickness distribution, featuring a first adhesive region with greater thickness and a second adhesive region with lesser thickness. This local variation in adhesive properties allows the separator to adhere sufficiently during winding while permitting controlled movement during pressing, thereby preventing distortion and wrinkles.
2Manufacturing precision
If strong adhesion is used between electrode and separator, then winding misalignment is prevented, but inappropriate positional relationship changes occur during pressing
Solution Approach 1:
The adhesive layer thickness parameter is varied across different regions of the separator. The first adhesive region has a thickness that provides strong adhesion for winding alignment, while the second adhesive region has a reduced thickness that allows positional adjustment during pressing, thus maintaining both winding precision and pressing flexibility.
3Manufacturing precision
If adhesive layer is made uniformly thick to ensure strong adhesion, then winding alignment is improved, but productivity decreases due to separator distortion and rework
Solution Approach 1:
Instead of applying adhesive uniformly across the entire separator surface, the adhesive is applied with varying thickness in different regions. This local differentiation reduces separator distortion during pressing, minimizes defects, and improves manufacturing efficiency without compromising winding 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 enables the production of electricity storage devices with high productivity by ensuring appropriate positional relationships between electrodes and separators, reducing distortion and misalignment, and enhancing the manufacturing efficiency of wound electrode bodies.
Implementation Method 1
the separator partially having an adhesive layer on at least one surface thereof is used in the winding step, and the adhesive layer includes a first adhesive region and a second adhesive region
Data Source
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AI summary
Provided is a technology obtaining an electricity storage device including a wound electrode body with high productivity. A method of manufacturing an electricity storage device of one embodiment disclosed herein includes: a winding step S2 of winding a positive electrode 22 and a negative electrode 24 with a separator 26 interposed therebetween to produce a wound body 20A; and after the winding step S2, a pressing step S3 of pressing the wound body 20A to form each of wound electrode bodies 20a, 20b, and 20c having a flat shape, wherein the separator partially having an adhesive layer 6 on at least one surface thereof is used in the winding step S2, the adhesive layer 6 includes a first adhesive region 6A and a second adhesive region 6B, and the thickness T1 of the first adhesive region 6A is 1.5 times or more the thickness T2 of the second adhesive region 6B. The manufacturing method further includes a formation step S1 before the winding step S2.