Design and development of artificial solid electrolyte interphase layer using spray pyrolysis for a stable and durable zinc anode in aqueous zinc-ion batteries = 수계 아연 이온 전지의 안정적이고 내구성 있는 아연 음극을 위한 분무열분해 기반 음극 표면 보호층 설계 및 개발

다국어 초록 (Multilingual Abstract)

Aqueous zinc-ion batteries (AZIBs) are highly attractive as energy- storage systems owing to their inherent safety, low cost, and simple assembly processes. However, the growth of Zn dendrites and side reactions at the Zn metal anode significantly degrade their electrochemical performance and long-term stability. To address these issues, this study introduced a surface modification approach to enhance the lifespan and cycling stability of AZIBs by constructing an artificial inorganic protective layer on the Zn anode using the spray pyrolysis deposition (SPD) technique. The research focuses on optimizing the coating conditions for the artificial zinc sulfide (ZnS) protective layer and elucidating its mechanism in suppressing dendrite growth and preventing side reactions on the Zn metal anode. Through experiments and density functional theory (DFT) simulations, the fundamental mechanism of uniform Zn plating underneath the ZnS protective layer is demonstrated. The ZnS protective layer promotes Zn atom adsorption while suppressing clustering, enabling uniform Zn deposition. In addition, defects within the thin ZnS coating layer modulate Zn2+ adsorption and diffusion, which facilitates Zn plating underneath the protective layer. This mechanism promotes uniform Zn nucleation and enhances the kinetics of Zn2+, preventing dendrite formation and side reactions, thereby improving the battery's stability and electrochemical performance. The resulting Zn@ZnS||Zn@ZnS symmetric cell achieves a extended cycle life of over 1600 hours and delivers excellent rate performance. Furthermore, the Zn@ZnS||MnO2 full cell maintains a high coulombic efficiency of 99.5% and a capacity retention of 80.1% after 1500 cycles at a current density of 0.5 A g⁻¹, demonstrating exceptional cycling stability. These insights into the development of effective artificial protective layers for uniform nucleation, offering a pathway to extend the lifespan and enable dendrite-free Zn anodes for advanced AZIBs. In addition, this approach holds promise as a foundation for addressing similar challenges in other metal electrodes, such as lithium and sodium.

목차 (Table of Contents)

• Table of Contents i
• List of Figures iii
• List of Tables vi
• Abstract vii
• Chapter 1. Introduction 1
• 1.1 Aqueous zinc-ion batteries (AZIBs) 1
• 1.2 Challenges and limitations of AZIBs 3
• Chapter 2. Theoretical background 5
• 2.1 Artificial protective layers for zinc anodes in AZIBs 5
• 2.2 Coating materials for metal anode surface modification 6
• 2.3 Spray pyrolysis deposition technique for metal anode surface modification 7
• Chapter 3. Zincophilic artificial protective layers enabling uniform
• nucleation and deposition for stable dendrite-free Zn anodes 8
• 3.1 Introduction 8
• 3.2 Experimental 11
• 3.2.1 Preparation of Zn@ZnS anodes 11
• 3.2.2 Preparation of MnO2 cathodes 13
• 3.2.3 Materials characterization 13
• 3.2.4 Cell assembly 14
• 3.2.5 Electrochemical measurements 15
• 3.2.6 DFT calculations 16
• 3.3 Results and discussion 17
• 3.3.1 Optimization of artificial ZnS protective layer thickness 17
• 3.3.2 Material characterization 21
• 3.3.3 Electrochemical analysis 28
• 3.3.4 Observation of the protective behavior of Zn@ZnS 38
• 3.3.5 Validation of Zn@ZnS protection mechanism using DFT calculations 44
• 3.3.6 Electrochemical performance of Zn@ZnS
• MnO2 full cells 48
• 3.4 Summary 56
• Reference 57
• 국문요지 65