Degassing High-Solid Electrode Paste via Shear and Moderate Vacuum
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Solution Overview
Problem
High-solid-content electrode pastes with a ratio of 55 mass% or more face challenges in degassing, leading to remaining bubbles and striation defects during the application process, as existing methods struggle to effectively remove bubbles at higher solid content ratios without causing the paste to dry out.
Innovation Solution
A degassing method involving the introduction of the electrode paste into a decompressed container where a shear force is applied, with a pressure range of -50 kPa ≤ P ≤ -20 kPa, allowing for effective degassing and suppression of both bubble retention and drying, enhancing product yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the solid content ratio of the electrode paste is increased to 55 mass% or more to reduce drying time and enhance productivity, then productivity is improved, but it becomes difficult to release bubbles during degassing
Solution Approach 1:
The patent changes the pressure parameter during degassing from conventional high vacuum (-90 kPa or more) to a moderate pressure range (-50 kPa to -20 kPa). This parameter change enables effective bubble removal from high-solid-content paste (55 mass% or more) without causing excessive drying, thus resolving the contradiction between productivity improvement through high solid content and degassing effectiveness.
2Reliability
If the degree of vacuum is increased to -90 kPa or more to remove bubbles from high solid content paste, then bubble removal is improved, but the electrode paste becomes likely to be dried in the degassing process causing striation defects
Solution Approach 1:
The patent modifies the pressure parameter from high vacuum (-90 kPa or more) to moderate vacuum (-50 kPa to -20 kPa). This parameter adjustment maintains effective bubble removal capability while preventing excessive drying of the high-solid-content paste, thereby avoiding striation defects and maintaining surface quality.
3Device complexity
If conventional degassing at -90 kPa is applied to electrode paste with 55 mass% or more solid content, then the process is simple, but bubbles generated by decompressing still remain causing transparency defects
Solution Approach 1:
The patent adjusts the pressure parameter from -90 kPa to a range of -50 kPa to -20 kPa. This modified parameter setting effectively prevents bubble formation during decompression of high-solid-content paste while maintaining process simplicity, thus eliminating transparency defects without complicating the degassing process.
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 method effectively degases electrode pastes with high solid content ratios, reducing bubble retention and drying issues, thereby improving product yield and reducing defects such as transparency and striation defects in the application process.
Implementation Method 1
bubbles in the electrode paste are removed by decompressing the degassing tank
Implementation Method 2
degassing the electrode paste while a shear force is applied to the electrode paste
Data Source
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Figure 2
Figure 3~4
AI summary
Provided is a degassing method for an electrode paste that introduces the electrode paste formed by kneading a solid content containing an electrode active material and a dispersion medium into a decompressed container and degassing the electrode paste while a shear force is applied to the electrode paste. A ratio of the solid content in the electrode paste is set to be 55 mass% or more, and a pressure in the decompressed container is set to be -50 kPa or more. It is possible to suppress both remaining bubbles and dry of the electrode paste, thus enhancing a product yield.