Battery Electrode Drying Profile for Crack-Free Edge Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing process of lithium secondary batteries often results in surface quality issues such as the rise, cracking, or wrinkling of the electrode side parts due to uneven drying rates, which can lead to reduced battery life and performance.
Innovation Solution
The electrode manufacturing process involves applying electrode slurries with controlled solid content ratios and viscosities to the center and side parts of the current collector, ensuring a We/Wc ratio less than 1, and using specific application methods like slot and mini-slot dies to maintain uniform drying rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If electrode slurry is applied and dried using conventional uniform drying methods, then manufacturing process is simple, but surface quality deteriorates with cracking and wrinkling on side parts
Solution Approach 1:
The patent applies different solid content ratios of electrode slurry to different regions (center vs. side parts) of the current collector. The side parts receive slurry with a lower solid content ratio (We/Wc < 1) compared to the center parts, creating local quality differences that prevent uneven drying and subsequent surface defects like cracking and wrinkling.
2Productivity
If uniform electrode slurry is applied across the entire surface, then application process is simple, but drying rate becomes uneven causing side part defects
Solution Approach 1:
The patent implements regional differentiation in slurry composition by applying electrode slurry with different solid content ratios to different areas. The side parts receive slurry with lower solid content (We/Wc < 1) while center parts receive slurry with higher solid content, optimizing both application efficiency and drying uniformity across different regions.
Solution Approach 2:
The patent changes the solid content ratio parameter of the electrode slurry based on position. By controlling the ratio of solid content in side parts (We) to center parts (Wc) to be less than 1, the patent optimizes drying characteristics and prevents surface defects while maintaining productive application processes.
3Quantity of substance
If high solid content slurry is used to improve electrode density, then electrode capacity increases, but drying rate increases causing more surface defects
Solution Approach 1:
The patent applies electrode slurry with position-dependent solid content ratios. Side parts receive slurry with lower solid content (We/Wc < 1) to maintain surface quality during drying, while center parts can have higher solid content. This local differentiation allows the electrode to achieve high overall active material content without suffering from drying-induced surface defects.
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 surface quality and life characteristics of the electrodes by minimizing cracking and wrinkling, enhancing productivity and overall battery performance.
Implementation Method 1
an electrode for a secondary battery is manufactured by applying an electrode slurry prepared by mixing and dispersing an electrode active material, a conductive material, and a binder in a solvent on a current collector and then drying
Data Source
AI summary
Provided are an electrode for a secondary battery, a method for manufacturing the same, and a secondary battery including the same. The present disclosure may improve surface quality of the electrode, increase productivity, and also improve life characteristics simultaneously, by controlling drying rates of a center part and a side part based on a width direction of the electrode similarly to solve problems such as a rise, cracks, or wrinkles of the side part which occur on a surface of an electrode. The present example embodiment may provide an electrode for a secondary battery including: a current collector; and an electrode active material layer placed on at least one surface of the current collector, wherein the following Relation 1 is satisfied: [Relation 1] Sa≤10.0 wherein Sa is an average surface roughness value of a side part based on a width direction of the electrode active material layer.