Investigation of oxygen-related defect engineering in nonstoichiometric vanadium oxides for electrochromic zinc-ion batteries with superior electrochromic- electrochemical performance
- 주제(키워드) Oxygen defect , optical bandgap , e-ESS , Zinc ion battery , electrochromic
- 주제(DDC) 547
- 발행기관 아주대학교 일반대학원
- 지도교수 윤태광
- 발행년도 2025
- 학위수여년월 2025. 8
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000034830
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Electrochromic energy storage systems, which allow visual monitoring of electrochemical charge and discharge behavior, are receiving growing attention for advanced technological applications. Among these option, electrochromic aqueous zinc-ion batteries attracted interest as a prospective solution because of their eco-friendly nature, high volumetric energy density, and excellent cycle stability. In this work, we developed a V2O5 cathode with a non-stoichiometric composition, aiming to enhance both electrochromic and electrochemical property by controlling the concentration of oxygen defects. By adjusting the thermal annealing condition, the oxygen defect levels were precisely modulated, which led to improved Zn ion transport within the V2O5’s layered structure and facilitated enhanced reversibility in energy storage reactions. Specifically, Ec-VO 350, featuring an optimal amount of oxygen defects, delivered a specific capacity of 384 mAh/g, representing 160% increase in comparison with V2O5. The structural adjustments caused by oxygen defects also contributed to outstanding cycle stability, with a retention of 98% after 500 cycles at 2 A/g, demonstrating excellent long-term reversibility. Although the presence of defect states can influence the electron configuration and adversely impact electrochromic features like coloration efficiency and transmittance change, Ec-VO 350 attained a coloration efficiency of 46.8 cm2/C and a transmittance change of 65%. This improvement is attributed to enhanced Zn diffusion despite a decreased optical bandgap. The proposed method for designing non-stoichiometric vanadium oxide cathodes offers a promising approach for advancing the performance of electrochromic energy storage systems in future applications.
more목차
Chapter 1. Introduction 1
Chapter 2. Experimental section 5
2.a. Reduction to V2O5-x 5
2.b. Electrochemical measurements 5
2.c. Electrochromic measurements 6
Chapter 3. Result and Discussion 7
3.a. Examination of structural and morphological alterations in Ec-VOs 7
3.b. Analysis of structural and reactive characteristics for detecting oxygen defects in Ec-VOs 15
3.c. Electrochemical properties of Ec-VOs 24
3.d. Electrochemical behavior alterations induced by enhanced oxygen defect concentrations in Ec-VOs 32
3.e. Electrochromic properties of Ec-VOs 40
Chapter 4. Conclusion 51
Reference 52
