Electrode Sheet Coating Layout to Prevent Sliding Portions
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Solution Overview
Problem
Existing electrode sheet manufacturing processes face issues with the formation of sliding portions during the coating of electrode active material, leading to separation of electrodes and separators, electrolyte depletion, and lithium precipitation, which are not adequately addressed by current methods such as attaching CPP films or laser etching.
Innovation Solution
An electrode sheet manufacturing apparatus and method that applies a hydrophobic first coating material to prevent the flow of a hydrophilic second coating material, which includes the electrode active material, by using non-overlapping nozzles and a drying process to volatilize the first material, ensuring uniform coating without sliding portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dam line coating layer is formed to prevent electrode slurry from flowing down, then sliding portion formation is prevented, but process time increases and coating precision requirements increase
Solution Approach 1:
The patent applies a binder layer to the current collector before coating the electrode slurry. This preliminary action creates a protective barrier that prevents the slurry from flowing down during the drying process, eliminating the need for subsequent dam line formation and reducing overall process time.
Solution Approach 2:
The binder layer acts as an intermediary substance between the current collector and the electrode slurry. It provides adhesion and structural support to the slurry during the drying process, preventing flow-down without requiring additional dam line structures or increasing process complexity.
2Manufacturing precision
If laser etching is used to remove sliding portions, then coating quality improves, but process complexity increases and pinholes may form
Solution Approach 1:
The binder layer is applied in advance to prevent sliding portion formation during the coating and drying process. This preliminary protective measure eliminates the need for subsequent laser etching operations, reducing process complexity while maintaining coating quality.
Solution Approach 2:
Instead of using laser etching to remove defective areas (sliding portions) after they form, the invention converts the approach by using the binder layer to prevent the defect from forming in the first place. This transforms a corrective process into a preventive one, eliminating the need for complex laser equipment and operations.
3Manufacturing precision
If CPP film is attached to sliding portions to compensate for thickness reduction, then thickness is restored, but bonding problems between electrode and separator persist
Solution Approach 1:
The binder layer is applied before the electrode slurry coating to maintain uniform thickness during the drying process. By preventing the flow-down that causes thickness reduction, the binder layer eliminates the need for CPP film attachment while ensuring proper bonding between the electrode and separator.
Solution Approach 2:
The binder layer serves as an intermediary that provides both structural support to maintain uniform thickness and bonding functionality to ensure proper adhesion between the electrode and separator. This single intermediary layer replaces the need for separate CPP film attachment while solving both thickness uniformity and bonding reliability issues.
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
Prevents the formation of sliding portions, ensuring complete bonding between electrodes and separators, thereby preventing electrolyte depletion and lithium precipitation, and simplifying the manufacturing process by integrating drying and removal steps.
Implementation Method 1
a drying member (500) located between the rewinder (200) and the second coating member (400), the drying member being configured to volatilize the first coating material (330)
Implementation Method 2
a first coating member (300) located at the rear of the rewinder (200), the first coating member being configured to apply a first coating material (330) to a predetermined area of the metal foil (110)... the first coating material (330) and the applied second coating material (430) do not overlap each other
Data Source
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AI summary
Disclosed are an electrode sheet manufacturing apparatus including a rewinder configured to wind a metal foil, a first coating member located at the rear of the rewinder, the first coating member being configured to apply a first coating material to a predetermined area of the metal foil, and a second coating member located between the rewinder and the first coating member, the second coating member being configured to apply a second coating material comprising an electrode active material, wherein the applied first coating material and the applied second coating material do not overlap each other, and an electrode sheet manufacturing method using the same, whereby it is possible to prevent a sliding portion from being formed at an outer periphery of an electrode.