Inverted Drying for Battery Electrode Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for preparing lithium secondary battery electrodes face challenges in achieving high capacity and stability due to inadequate electrode adhesion, which is compromised by the use of a small amount of binder, leading to increased internal resistance and decreased electron conductivity.
Innovation Solution
A method involving coating electrode slurry on both surfaces of a current collector with the first surface facing upward and then inverting it for drying, ensuring a greater binder presence near the current collector, thereby enhancing adhesion with a minimal binder amount, using specific viscosity ranges and drying conditions to prevent electrode separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a small amount of binder is used to maintain high capacity, then the electrode adhesion deteriorates and electrode separation occurs during coating, drying or rolling
Solution Approach 1:
The patent changes the temperature parameter during drying from conventional high temperature (70°C or higher) to low temperature (below 70°C). This parameter change prevents binder displacement and maintains adequate binder distribution near the current collector, achieving sufficient adhesion with minimal binder content (1-5 wt%), thus resolving the contradiction between high capacity and electrode adhesion.
2Reliability
If the binder content is increased to improve electrode adhesion, then internal resistance increases and electron conductivity decreases
Solution Approach 1:
By changing the drying temperature parameter to below 70°C, the patent achieves sufficient electrode adhesion with minimal binder content (1-5 wt%). This optimized binder content maintains low internal resistance and high electron conductivity while preventing electrode separation, thus resolving the contradiction between adhesion and energy loss.
3Productivity
If the electrode slurry is coated and dried at high temperature (70°C or higher), then the binder is displaced away from the current collector during drying, weakening adhesion
Solution Approach 1:
The patent changes the drying temperature parameter from high temperature (70°C or higher) to low temperature (below 70°C). This parameter change prevents binder displacement during drying, maintaining adequate binder distribution near the current collector and achieving sufficient adhesion, thus resolving the contradiction between drying efficiency and electrode adhesion.
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 electrode adhesion and overall battery performance by maintaining a sufficient binder distribution near the current collector, enhancing the stability and capacity of lithium secondary batteries.
Implementation Method 1
drying of the coated electrode slurry while the current collector is inverted to position the coating layer on the bottom surface of the current collector
Data Source
AI summary
A method for preparing an electrode for a secondary battery, includes preparing an electrode slurry having an electrode active material and a binder and producing a pre-electrode by coating a first surface of both surfaces of a current collector with the electrode slurry while the first surface is disposed in an upward direction. Additionally, the method includes drying the pre-electrode while the electrode slurry coated on the first surface of the current collector is inverted to be disposed in a downward direction.