Battery Electrode Notching Shear Geometry for Desorption Control
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Solution Overview
Problem
The existing rechargeable battery electrode notching processes often result in desorption of active material, leading to capacity ratio imbalances between negative and positive electrodes, increased short circuit defects, and reduced battery lifespan due to foreign materials and voltage deviations.
Innovation Solution
A rechargeable battery electrode substrate notching device and method utilizing a punch with specifically designed shear angles for both straight and round parts, minimizing desorption by forming inclines in the composite layer that control the desorption phenomenon within defined dimensions, thereby reducing foreign materials and defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional notching process is used to manufacture electrodes, then the electrode substrate can be shaped into desired forms, but active material separates from the substrate causing desorption and capacity ratio imbalances
Solution Approach 1:
The patent applies parameter changes by modifying the shear angle of the punch tool. Specifically, it sets the shear angle within a precise range of 10° to 45°, with optimal values between 15° to 30°. This parameter optimization changes the cutting mechanism from a conventional perpendicular cut to an inclined shear cut, which reduces the mechanical stress that causes active material desorption while still achieving the desired electrode shape.
Solution Approach 2:
The patent introduces dynamics by implementing a multi-stage notching process with progressive depth control. The punch is divided into multiple sections (first punch, second punch, third punch) that operate at different depths and stages. This dynamic, staged approach allows the material to gradually deform and separate along the inclined shear plane, preventing sudden force application that would cause active material detachment.
2Manufacturing precision
If the notching process creates clean cuts, then electrode shape is precise, but desorbed active material floats and adheres to equipment creating foreign materials
Solution Approach 1:
The patent converts the potentially harmful desorption phenomenon into a beneficial controlled process. By using the inclined shear angle, the active material separation is redirected to occur along a controlled inclined plane rather than detaching as floating particles. The desorption that would normally create foreign materials is transformed into a predictable material flow that adheres to the electrode substrate or is collected in a controlled manner, turning a harmful effect into an acceptable byproduct.
3Device complexity
If a simple punch design is used, then the device complexity is low, but it cannot control the desorption phenomenon effectively
Solution Approach 1:
The patent applies segmentation by dividing the punch tool into multiple functional sections: a first punch section for initial cutting, a second punch section for intermediate shaping, and a third punch section for final refinement. Each section has specific geometric parameters optimized for its stage of operation. This segmented design allows precise control over the notching process at each stage while maintaining a relatively simple overall tool structure that can be manufactured using conventional methods.
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
The solution effectively minimizes desorption, maintains capacity ratios, lowers short circuit defects, and extends battery lifespan by precisely controlling the notching process with shear angles, ensuring the notched electrodes have desorption parts within optimal dimensions.
Implementation Method 1
An active material may be separated from the electrode substrate in the notching process, and this phenomenon may be referred to as desorption
Data Source
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AI summary
A rechargeable battery electrode substrate notching device includes a die (10) and a punch (20) notching an electrode substrate into an electrode having a straight part and a round part by being lifted toward the die while the electrode substrate is installed on the die, wherein the punch includes a round shear (RS) part corresponding to the round part.