Dry-Compressed Li-Ion Electrode Sheets With Precise Density Control
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Solution Overview
Problem
The existing manufacturing process for lithium-ion liquid battery electrode sheets is inefficient due to the use of solvents and apparatus that consume space and cost, and struggles to precisely control the thickness of the active material layer, affecting yield.
Innovation Solution
A dry mixing process forms electrode powder, which is then subjected to a thermal compression process using a mold to create dense electrode layers on opposite surfaces of a current collecting metal sheet, allowing precise control over the structure and density of the electrode layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a solvent-based coating-drying-pressing process is used to manufacture electrode sheets, then the active material layer can be formed on the current collector, but the process consumes much space and manufacturing cost due to solvent recyclers, ovens, rollers, etc.
Solution Approach 1:
The patent extracts and eliminates the solvent from the manufacturing process, using a dry mixing approach instead of a solvent-based slurry coating process. This removes the need for solvent recyclers, ovens, and rollers, directly reducing device complexity and manufacturing cost while maintaining the ability to form active material layers on current collectors
Solution Approach 2:
The patent replaces the mechanical coating-drying-pressing system with a thermal compression molding system. Instead of using rollers and ovens to process solvent-based slurries, the invention uses heated molds to directly compress and form the electrode layers from dry or minimally-bound active material, simplifying the overall manufacturing apparatus
2Manufacturing precision
If a coating-drying-pressing process is used to form the active material layer, then the electrode sheet can be manufactured, but it is challenging to precisely control the thickness of the active material layer, which makes it difficult to improve the yield
Solution Approach 1:
The patent performs preliminary action by pre-mixing the active material with binders and conductive agents in precise proportions during the dry mixing process, and by pre-heating the molds before compression. This preliminary preparation ensures that the subsequent thermal compression step produces electrode layers with consistent thickness and properties, improving both manufacturing precision and yield
Solution Approach 2:
The patent changes the physical parameters of the molding process, specifically using controlled temperature and pressure during thermal compression. By optimizing these parameters, the process achieves precise control over electrode layer thickness and density, directly improving manufacturing precision and consequently increasing yield
3Reliability
If the density of electrode layers is not controlled within the specified range, then the manufacturing process may be simpler, but the electrolyte infiltration efficiency and battery performance will be affected
Solution Approach 1:
The patent implements feedback control by monitoring the density of electrode layers during manufacturing and adjusting the thermal compression parameters accordingly. This ensures that the density remains within the optimal range for electrolyte infiltration, maintaining reliable battery performance while managing manufacturing complexity
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 reduces process tolerance, increases yield, and eliminates the need for solvent removal processes, thereby reducing manufacturing costs and improving the efficiency of electrolyte infiltration into the electrode sheets.
Implementation Method 1
A thermal compression process is performed by using the mold to form a first electrode layer and a second electrode layer from the electrode powder
Data Source
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AI summary
This disclosure provides a manufacturing method of an electrode sheet of a lithium-ion liquid battery. An electrode powder is formed from an active material by a dry mixing process. A current collecting metal sheet is disposed in a mold. The electrode powder is introduced into a cavity of the mold on opposite sides of the current collecting metal sheet. A thermal compression process using the mold is performed to form a first and a second electrode layer from the electrode powder, where the two electrode layers are respectively attached to a first and a second surface of the current collecting metal sheet. When a positive electrode sheet is manufactured, densities of the electrode layers are in a range of 1.6 g/cm3 to 3.4 g/cm3. When a negative electrode sheet is manufactured, densities of the electrode layers are in a range of 1.2 g/cm3 to 2.1 g/cm3.