Title Page
Contents
ABSTRACT 9
Ⅰ. Introduction 11
1.1. Background 11
1.2. Literature survey 14
1.3. Objective of the study 16
Ⅱ. Proposed tension control method 17
2.1. Tension control method considering thermal deformation 17
2.2. Temperature distribution of web in drying span 20
2.3. Finite element method-based tension control algorithm 21
Ⅲ. Tension control in drying span of roll-to-roll manufacturing system 25
3.1. Experimental setup 25
3.2. Measurement of temperature distribution in drying span 28
3.3. Measurement of tension change according to drying conditions 31
Ⅳ. Tension control performance analysis 33
4.1. Estimation on temperature distribution of web in drying span 33
4.2. Feed-forward tension control performance according to temperature estimation methods 35
4.3. Coating defects analysis according to tension control methods 41
Ⅴ. Conclusion 45
References 46
Abstract (in Korean) 53
Table 2-1. Simulation model boundary conditions. 24
Table 3-1. Roll-to-roll system process conditions in this study. 27
Table 3-2. Transverse direction standard deviation of measured temperature inside the dryer as to the location of the web. 30
Table 4-1. Temperature distribution estimation accuracy (RMSE) by estimation model. 34
Table 4-2. Drying span tension measurements compensated by the feed-forward tension controller. 39
Figure 1-1. Schematics of the structure of a lithium-ion battery. 12
Figure 1-2. (a) Roll-to-roll electrode manufacturing system schematic, (b) unwinding process, (c) coating process, (d) drying process, (e) winding process. 13
Figure 2-1. Web temperature distribution and span configuration. 19
Figure 2-2. Configuration of a feed-forward tension controller. 19
Figure 2-3. Heat transfer mechanism configuration of web within the drying span. 20
Figure 2-4. Simulation model for web temperature distribution in the drying span. 22
Figure 2-5. CFD-based dryer internal fluid analysis: (a) hot air dryer structure, (b) ambient web temperature distribution. 22
Figure 2-6. Dry span temperature distribution inputs for a feed-forward controller: (a) conventional exponential function assumed temperature... 23
Figure 2-7. Flowchart of FEM-based feed-forward tension control algorithm 23
Figure 3-1. (a) Schematic of a roll-to-roll electrode manufacturing system, and (b) span configuration. 26
Figure 3-2. (a) Elastic modulus, (b) thermal expansion coefficient as a function of temperature for copper foil. 27
Figure 3-3. Measurement of web temperature distribution for a drying span. 28
Figure 3-4. Web temperature distribution measurements according to drying temperature: (a) 80 °C, (b) 100 °C, and (c) 120 °C. 29
Figure 3-5. Drying span tension change measurement apparatus: (a) load cell located in the dry span, (b) tension data acquisition unit. 31
Figure 3-6. Measurement of drying span tension change due to heating of the web: (a) 80 ℃, (b) 100 ℃, (c) 120 ℃ 32
Figure 4-1. Temperature distribution of the web in drying span measured and estimated temperatures. 34
Figure 4-2. Tension change estimation error based on temperature distribution estimation model. 35
Figure 4-3. Conventional feed-forward tension controller performance analysis: (a) 80°C, (b) 100°C, (c) 120°C. 37
Figure 4-4. FEM-based feed-forward tension controller performance analysis: (a) 80°C, (b) 100°C, (c) 120°C. 38
Figure 4-5. (a) RMSE value of estimated temperature distribution, (b) equivalent elastic modulus estimation error according to temperature... 40
Figure 4-6. Fabrication of anode electrodes with roll-to-roll slot-die coating. 42
Figure 4-7. Micrographic images of the anode coating layer surface with different tension control schemes: (a) draw control, (b) conventional feed-... 43
Figure 4-8. Coating layer scratch defect area density comparison. 44