Synthesis of CTS engineered Nb-W Oxide Anode for Enhanced Rocking-Chair Aqueous Zinc-Ion Battery
- 주제(키워드) Zinc ion batteries , Rocking-chair ZIBs , Zinc-metal free , Nb-W oxide , ZIB anode
- 주제(DDC) 547
- 발행기관 아주대학교 일반대학원
- 지도교수 윤태광
- 발행년도 2026
- 학위수여년월 2026. 8
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000036540
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Aqueous zinc-ion batteries （ZIBs）are promising candidates for safe and low-cost energy storage, yet conventional Zn-metal anode configurations suffer from dendrite growth, parasitic reactions, and low zinc utilization, which limit their practical cell-level performance. Herein, insertion-type Nb-W oxide anodes are developed for Zn-metal free ＂rocking-chair＂ aqueous ZIBs. Two structures -Wadsley-Roth（W-R） Nb₁₄W₃O₄₄ and tetragonal tungsten bronze （TTB） Nb₁₈W₁₆O₉₃-were synthesized through an electrospinning method and compared as Zn²⁺ storage hosts. The tunnel-structured TTB Nb₁₈W₁₆O₉₃ exhibited more favorable behavior, including clearer redox responses, lower impedance, better rate capability, and faster Zn²⁺ kinetics, retaining approximately 93% of its capacity during long-term cycle at low current density, 0.1 A/g. To further activate this framework, carbothermal shock （CTS; 700 °C, 5 s, 5 times） was applied to induce oxygen defects while preserving the TTB lattice. After CTS, the charge-transfer resistance decreased, and the EIS derived apparent Zn²⁺ diffusion coefficient increased by ≈16%. The reversible capacity is raised from 53.74 to 80.66 mAh/g （≈50% enhancement） with stable cycling at 0.1 A/g. Ex-situ XRD and XPS confirmed reversible Zn²⁺ insertion/extraction accompanied by W based redox reaction within the intact framework. Finally, a Zn-metal free full cell assembled with CTS-TTB and ZnₓMnO₂ cathode at a N/P ratio≈1 operated reversibly and delivered a cell-level energy density of 35.8 Wh/kg. It is more than 70 times that of a Zn-metal anode configuration, demonstrating CTS-engineered TTB（CTS-TTB） as practical insertion anodes for safer aqueous ZIBs. Finally, this study provides a foundation for developing safer, more practical rocking-chair aqueous ZIB systems beyond conventional Zn-metal anode configurations.
more목차
Chapter 1. Introduction 1
Chapter 2. Experimental Section 4
2.1. Synthesis of Nb-W Oxides 4
2.2. Carbothermal Shock Treatment of TTB Nb₁₈W₁₆O₉₃ 4
2.3 Characterizations 7
2.4 Electrochemical measurements 7
Chapter 3. Results and Discussion 9
3.1 Structural Characterization of Electrospun Nb-W Oxides 9
3.2 Electrochemical Comparison of Wadsley-Roth Nb₁₄W₃O₄₄ and TTB Nb₁₈W₁₆O₉₃ 17
3.3 CTS-Induced Defect Engineering of TTB Nb₁₈W₁₆O₉₃ 24
3.4 Electrochemical Performance and Zn²⁺ Storage Mechanism of CTS- TTB Nb₁₈W₁₆O₉₃ 30
3.5 Zn-metal free rocking-chair full-cell performance 34
Chapter 4. Conclusion 38
Reference 39
