Surface-Treated Current Collector Adhesion Lithium Battery
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Solution Overview
Problem
Secondary batteries, particularly lithium secondary batteries, face issues with reduced charge and discharge capacities and lifespan due to separation of electrode active materials from current collectors during volume changes, which is exacerbated by excessive binder usage reducing conductivity and capacity.
Innovation Solution
A method of manufacturing electrodes with surface-treated current collectors having a surface roughness of 0.1 µm to 1 µm, achieved through rolling with embossed rollers, to enhance adhesion between the electrode active material and current collector, using a mixture of electrode active material, conductive material, and binder with organic solvent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a large amount of binder is used to enhance adhesion between electrode active material and current collector, then adhesion is improved, but conductivity of electrode is reduced and battery capacity is reduced
Solution Approach 1:
The invention changes the surface morphology parameter of the current collector by controlling the surface roughness Ra to be 0.05 µm to 5 µm. This parameter change in the current collector surface creates physical anchoring sites that enhance adhesion through mechanical interlocking, replacing the need for chemical adhesion provided by excessive binder. The surface treatment modifies the physical state of the current collector surface without affecting the electrochemical properties of the electrode materials.
2Stability of the object's composition
If a large amount of binder is used to suppress volumetric expansion during charging and discharging, then structural stability is improved, but battery capacity is reduced
Solution Approach 1:
The invention modifies the surface roughness parameter of the current collector to create a textured surface that physically constrains the electrode active material during volume changes. The increased surface area and surface irregularities provide mechanical support and stress distribution, enabling the electrode to withstand volumetric expansion and contraction without requiring excessive binder for structural stability.
3Ease of operation
If the electrode slurry is made too dilute to facilitate coating, then ease of coating is improved, but adhesion and coating quality are reduced
Solution Approach 1:
The invention changes the surface energy and surface topology of the current collector through controlled surface treatment that achieves Ra of 0.05 µm to 5 µm. This surface modification enhances the wettability and mechanical interlocking with the electrode slurry, allowing for effective coating even with less dilute slurries. The textured surface provides physical anchoring that compensates for reduced slurry concentration, maintaining adhesion while improving coating efficiency.
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 significantly increases adhesion and overall battery performance by distributing stress and maintaining conductivity, enhancing charging and discharging cycle characteristics.
Implementation Method 1
surface-treating the current collector so as to have a morphology with irregularities, wherein a surface roughness Ra of 0.001 µm to 10 µm is formed over an entire surface thereof
Implementation Method 2
adhesion between an electrode active material and the current collector is enhanced
Data Source
Figure 1A~1B
Figure 1C
AI summary
Disclosed are a method of manufacturing an electrode for secondary batteries that includes surface-treating a current collector so as to have a morphology wherein a surface roughness Ra of 0.001 µm to 10 µm is formed over the entire surface thereof to enhance adhesion between an electrode active material and the current collector and an electrode for secondary batteries that is manufactured using the method.