Title Page

요약

Abstract

Contents

1. Introduction 11

2. Experimental and analysis 14

2.1. Preparation of SnO₂ electrode 14

2.2. Preparation of SnO₂@PANI 14

2.3. Material characterization 15

2.4. Electrochemical measurements 15

3. Results and discussion 17

3.1. Morphology characterization and structure analysis 17

3.2. Electrochemical analysis 33

4. Conclusions 40

5. References 41

Table 1. Impedance parameters for SnO₂, SnO₂ @PANI 80, SnO₂ @PANI 100 and SnO₂@PANI 120 after 50 cycles according to the equivalent electric circuit.[내용없음] 8

Figure 1. V-t curve of Sn electrodeposition with 10 mA cm-2 constant current density.[이미지참조] 20

Figure 2. SEM images of SnO₂ fabricated by anodization different voltage and time. 21

Figure 3. Electrochemical surface area(ECSA) of anodized SnO₂ which anodized at (a) 5 V, (b) 7 V, and (c) 10 V; (d) electrochemical double layer... 22

Figure 4. (a) I-t curve of electrodeposited Sn anodization. SEM images of (b) electrodeposited Sn and anodized SnO₂ during (c) 300 s, (d) 900 s, (e) 1200... 23

Figure 5. Photograph of SnO₂ @PANI electrodes folded several times(left) and not(right). 24

Figure 6. SEM images (a),(b) top view and (c),(d) cross sectional view of SnO₂ anodized at 10 V for 15min. 25

Figure 7. (a) XRD of electrodeposited Sn and anodized SnO₂. The XPS (b) Sn3d electrodeposited Sn and anodized SnO₂ and (c) O 1s of SnO₂. 27

Figure 8. Cyclic voltammetry graph: electropolymerization of aniline to polyaniline. 29

Figure 9. SEM images of aniline electropolymerized on SnO₂ at different cyclic voltammetry scan rate : (a) 60 mV/s, (b) 80 mV/s, (c) 100 mV/s, (d) 120... 30

Figure 10. (a) FT-IR spectra of SnO₂ and SnO₂ @PANI at various electropolymerization cyclic voltammetry scan rates. (b) XPS survey spectra... 32

Figure 11. Battery cycling performance of anodized SnO₂ depending on anodization voltage. 36

Figure 12. Electrochemical performance for lithium-ion batteries : (a)Cyclic voltammetry, (b) galvanostatic charge/discharge profiles of SnO₂ @PANI 100.... 37

Figure 13. Electrochemical impedance spectroscopy of SnO₂, SnO₂ @PANI 80, SnO₂ @PANI 100 and SnO₂ @PANI 120. 39

Scheme 1. Schematic illustration of the fabrication process of the SnO₂@PANI electrode. 19