Electrode Coating Transfer Timing for Uniform Areal Weight
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Solution Overview
Problem
Current methods for manufacturing electrodes for secondary batteries, such as lithium ion batteries, fail to adequately reduce variations in the weight per unit area of the coating film transferred onto the electrode current collector, which affects the stability and quality of the electrode.
Innovation Solution
The method involves changing the speed ratio between the peripheral speed of the transfer roll and the conveying speed of the electrode current collector by adjusting the peripheral speed of the transfer roll based on the thickness of the coating film or the width of the gap, using a specific timing adjustment formula (t = t_const × (Bx/Bave) to minimize variations in the weight per unit area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the speed ratio between the transfer roll and conveying device is changed based on gap width or coating film thickness, then the variation in weight per unit area of the coating film is reduced, but the timing of speed ratio change is not optimized, resulting in insufficient reduction of weight variation
Solution Approach 1:
The patent implements a feedback control system where the coating film thickness is measured in real-time during the manufacturing process, and the measured thickness information is fed back to dynamically adjust the speed ratio between the transfer roll and conveying device. This closed-loop feedback mechanism ensures that speed ratio adjustments are precisely timed based on actual coating conditions, optimizing the reduction of weight per unit area variation.
Solution Approach 2:
The patent applies preliminary action by adjusting the speed ratio before the coating film completes its transfer cycle. By measuring the coating film thickness and proactively adjusting the speed ratio in advance (using the timing formula t = t_const × (Bx/Bave)), the system prevents weight variation from occurring in the first place, rather than correcting it after the fact.
2Manufacturing precision
If the peripheral speed of the transfer roll is adjusted to change the speed ratio, then the weight per unit area variation is reduced, but the complexity of speed control increases
Solution Approach 1:
The patent changes the operational parameters of the transfer roll by dynamically adjusting its peripheral speed based on measured coating film thickness. Instead of modifying the physical structure of the roll or adding complex mechanical components, the system achieves precise control by varying the rotational speed parameter, thereby reducing weight variation while maintaining relatively simple device architecture.
Solution Approach 2:
The patent replaces complex mechanical speed control mechanisms with an electronically controlled speed adjustment system. By using sensors to measure coating thickness and electronically controlling the transfer roll speed based on feedback signals, the system achieves precise manufacturing precision without requiring complex mechanical linkages or manual adjustment mechanisms.
3Manufacturing precision
If the speed ratio is changed based on coating film thickness measurement, then the weight per unit area variation is reduced, but the measurement and control timing must be precisely coordinated
Solution Approach 1:
The patent employs real-time feedback measurement where the coating film thickness is continuously monitored during the transfer process. The measurement system provides immediate feedback on coating thickness, which is then used to adjust the speed ratio with precisely coordinated timing, ensuring that speed changes occur at the optimal moment to minimize weight variation.
Solution Approach 2:
The patent performs preliminary measurement of the coating film thickness before the speed ratio adjustment is executed. By measuring the coating thickness in advance and calculating the required speed adjustment using the timing formula, the system ensures that the speed change is coordinated precisely with the coating transfer process, achieving optimal weight uniformity.
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 significantly reduces the variation in the weight per unit area of the electrode mixture layer, enhancing the stability and quality of the electrode by optimizing the transfer process.
Implementation Method 1
adhering the coating film to one of the rolls
Implementation Method 2
transferring the coating film onto an electrode current collector conveyed by a conveying device
Data Source
AI summary
A method for manufacturing an electrode disclosed herein includes: steps of forming a coating film composed of an electrode material by passing the electrode material through a gap between a rotating first roll and a rotating second roll; adhering the coating film to the second roll and conveying the coating film; and transferring the conveyed coating film onto an electrode current collector conveyed by a conveying device to form an electrode mixture layer composed of the coating film. The speed ratio between a peripheral speed of the second roll and a conveying speed of the electrode current collector is changed by changing the peripheral speed of the second roll on the basis of the thickness of the coating film or the width of the gap. The timing of the change in the speed ratio is allowed to be based on the Equation (1) described in the description.