Rechargeable Battery Electrode Stretching for Stable Exposed Portions
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Solution Overview
Problem
The manufacturing process of rechargeable battery electrode plates faces challenges in achieving dimensional stability due to excessive plastic deformation during the stretching step, leading to difficulties in accurately positioning and stacking the exposed portions for welding, which can result in breakage and reduced stability of the electrode terminal.
Innovation Solution
A method involving forming, pressing, and stretching of the electrode substrate, where the stretching step applies stress greater than or equal to the yield stress or 0.2% proof stress of the substrate, but less than its tensile strength, to correct edge curves and minimize deformation, while ensuring the insulating layer undergoes sufficient plastic deformation to maintain mechanical strength and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If excessive force is applied to the extension portion during the stretching step to correct edge curves, then the curves of the electrode substrate are corrected, but the extension portion becomes undulated in the thickness-wise direction and dimensional stability deteriorates
Solution Approach 1:
The patent applies a specific stress range parameter (yield stress to tensile strength) to the extension portion during stretching, controlling the deformation to remain within uniform plastic deformation region and avoid non-uniform deformation that causes undulation. This parameter control resolves the contradiction by precisely managing the stretching force.
Solution Approach 2:
The patent applies stress greater than or equal to yield stress or 0.2% proof stress to ensure sufficient plastic deformation for curve correction, but limits it to less than tensile strength to prevent excessive deformation causing undulation. This partial application of stress resolves the contradiction between adequate correction and avoiding over-deformation.
2Shape
If the extension portion is stretched to correct curves in the widthwise direction, then the edge alignment is improved, but the exposed portion becomes difficult to position and stack accurately
Solution Approach 1:
By controlling the stress applied during stretching to be within the specific range (yield stress to tensile strength), the patent achieves curve correction while maintaining uniform deformation that preserves the flatness of the exposed portion, thereby maintaining positioning accuracy for subsequent welding operations.
Solution Approach 2:
The patent employs a stretching device that applies controlled tension to the extension portion, using mechanical force distribution to correct edge curves while maintaining the dimensional stability of the exposed portion for accurate positioning.
3Shape
If the insulating layer is not sufficiently deformed during stretching, then the curve correction is inadequate, but if overstretched the mechanical strength of the insulating layer deteriorates
Solution Approach 1:
The patent specifies applying stress greater than or equal to yield stress or 0.2% proof stress but less than tensile strength to the insulating layer during stretching. This controlled stress parameter range ensures sufficient plastic deformation for effective curve correction while preventing excessive deformation that would compromise mechanical 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
This approach improves the dimensional stability of the electrode terminal by minimizing undulating deformation and maintaining mechanical strength, enhancing the accuracy and reliability of the electrode assembly process.
Implementation Method 1
the extension portion is subject to excessive plastic deformation that corresponds to a non-uniform plastic deformation region of a stress-strain curve
Implementation Method 2
obtain an elongation amount taking into consideration deformation caused by spring back
Data Source
AI summary
A method for manufacturing a rechargeable battery includes forming a mixture layer and an insulating layer on an electrode substrate having an edge extending in a specified direction so that an exposed portion where the electrode substrate is exposed extends between the edge and the insulating layer; pressing the mixture layer; and stretching an extension portion, located between the edge and the mixture layer, and the insulating layer in the specified direction. The stretching includes applying a stress greater than or equal to yield stress of the electrode substrate or greater than or equal to 0.2% proof stress of the electrode substrate and less than tensile strength of the electrode substrate to the extension portion, and applying a stress greater than or equal to yield stress of the insulating layer or greater than or equal to 0.2% proof stress of the insulating layer to the insulating layer.