Electrode Sheet Manufacturing Gravure Roll with Variable Recessed Portions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing electrode sheet manufacturing methods require a solvent-based process, leading to increased manufacturing time and costs, and result in sag parts at the ends of the electrode mixture layer, which can decrease cell characteristics.
Innovation Solution
An electrode sheet manufacturing apparatus using a gravure roll with an irregular outer surface and a back-up roll to form an electrode mixture layer on a current collector foil without solvents, employing electrostatic forces to distribute a mixed powder of active material and binder, and configuring recessed portions to optimize coating weights and reduce sag parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a solvent-based electrode mixture is used for manufacturing electrode sheets, then the electrode mixture can be easily formed and applied, but the manufacturing time increases and costs increase due to required drying steps
Solution Approach 1:
The invention extracts and eliminates the solvent from the electrode mixture formulation. By using a solvent-free mixed powder comprising electrode active material particles and binder particles, the patent removes the need for drying steps while maintaining ease of application through electrostatic charging mechanisms.
Solution Approach 2:
The invention changes the physical and chemical parameters of the electrode mixture by transitioning from a solvent-based slurry to a solvent-free dry powder mixture. This parameter change eliminates the drying process requirement while preserving the functionality of the electrode mixture.
2Device complexity
If a uniform coating is applied across the entire width of the current collector foil, then the manufacturing process is simple, but sag parts are formed at the ends of the electrode mixture layer decreasing cell characteristics
Solution Approach 1:
The invention applies local quality by varying the coating weight of the electrode mixture across the width of the current collector foil. Specifically, the coating weight is increased at the end portions compared to the intermediate portions, which compensates for the natural sagging effect and ensures uniform electrode mixture layer thickness across the entire width.
Solution Approach 2:
The invention applies preliminary anti-action by pre-compensating for the expected sagging at the end portions through increased coating weight. This anticipatory measure counteracts the gravitational sagging effect before the electrode mixture layer is formed, preventing the formation of thin spots that would degrade cell characteristics.
3Manufacturing precision
If the coating weight is increased at the end portions of the current collector foil, then sag parts are reduced and cell characteristics are enhanced, but the overall material usage increases
Solution Approach 1:
The invention applies local quality by varying the coating weight of the electrode mixture across the width of the current collector foil. Specifically, the coating weight is increased at the end portions compared to the intermediate portions, which compensates for the natural sagging effect and ensures uniform electrode mixture layer thickness across the entire width.
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
The apparatus effectively forms an electrode mixture layer on the current collector foil without solvents, reducing manufacturing time and costs, and minimizes sag parts, thereby enhancing cell characteristics.
Implementation Method 1
The mixed powder is moved from the gravure roll to the surface of the current collector foil by an electrostatic force working between the mixed powder and the current collector foil
Data Source
AI summary
In an electrode sheet manufacturing apparatus, in a state where a potential difference is caused between a gravure roll and a current collector foil conveyed by a back-up roll, a mixed powder is continuously supplied into recessed portions on an outer peripheral surface of the gravure roll such that the mixed powder is moved from the gravure roll to a surface of a current collector foil by an electrostatic force working between the mixed powder supplied into the recessed portions of the gravure roll and the current collector foil. In the gravure roll, a volume of first-end-side recessed portions per unit area in a first-end-side region and a volume of second-end-side recessed portions per unit area in a second-end-side region are made larger than a volume of intermediate recessed portions per unit area in an intermediate region.