Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor | Department of Industrial and Systems Engineering | en_US |
| dc.contributor.advisor | Xu, Zhenglong (ISE) | en_US |
| dc.creator | Yu, Jingya | - |
| dc.identifier.uri | https://theses.lib.polyu.edu.hk/handle/200/14099 | - |
| dc.language | English | en_US |
| dc.publisher | Hong Kong Polytechnic University | en_US |
| dc.rights | All rights reserved | en_US |
| dc.title | Surface engineering of zinc metal anodes in aqueous rechargeable batteries | en_US |
| dcterms.abstract | Global efforts to lessen the carbon footprint have stimulated the transition from fossil fuels to renewable energy sources and the adoption of electrified transportation. Aqueous zinc ion batteries are regarded one of the most promising next generation battery technologies for safe and low-cost energy storage applications. However, Zn metal anode faces challenges of dendritic deposition, surface passivation and hydrogen evolution in aqueous electrolytes, leading to short cycle life and low Coulombic efficiencies (CEs), particularly at high depth of discharge (DOD). This thesis aims to design a series of reliable artificial interface layers and to investigate their stabilization strategies and reaction mechanisms. This research supports the development of selection criteria for interface materials, which is of considerable significance for enhancing the stability and utilization efficiency of zinc anodes. | en_US |
| dcterms.abstract | Firstly, the MXene-porous polydopamine interfacial layer was designed to engineer the Zn metal surface. The MPP architecture leverages its high density of functional groups to sequester water molecules, thereby mitigating aqueous corrosion of Zn through dual desolvation and anticorrosion mechanisms. Integrated experimental and computational simulations demonstrate that the MPP coating simultaneously reduces nucleation overpotentials, achieves uniform electric field distribution, and regulates Zn2+ flux. These synergistic effects promote horizontally aligned, dendrite-free Zn deposition morphology. The optimized MPP-Zn electrodes demonstrate an extended cycle life exceeding 1000 hours (10-fold enhancement versus bare Zn) alongside superior rate performance in both symmetric and asymmetric cell configurations. When paired with NH4V4O10 cathodes in full-cell assemblies, the MPP-Zn anodes enable a specific capacity of 368 mAh g⁻¹ with minimal capacity degradation (<5%) over 300 cycles, electrochemical performance that surpass current benchmarks in Zn-ion battery literature. This multifunctional integration strategy presents a promising pathway toward practical implementation of high-performance Zn metal battery systems. | en_US |
| dcterms.abstract | Secondly, a bifunctional transition metal (TM) interface inspired by the Sabatier principle was constructed, enabling uniform zinc dissolution during discharge and dendrite-free zinc deposition during charge. Among various TM-coated Zn (TM@Zn) electrodes, Cu@Zn exhibits the highest reversibility and structural stability, attributed to the optimal interaction between Cu and Zn. The heteroatomic interaction-dependent electrochemical performance parallels the Sabatier principle. Morphological analyses reveal that bare Zn anodes display detrimental etching pits during stripping, which is different from the uniform dissolution for Cu@Zn electrodes. During subsequent plating, the conductive interface serves as a secondary current collector for uniform Zn deposition for Cu@Zn, thus demonstrating a bifunctional nature. Atomic observations disclose the working mechanisms of this interface as a gradual phase transition from Cu to CuZn5 during cycling. The Cu@Zn anodes exhibit an ultralong cycling lifespan of over 8000 h at a low current of 1 mA cm⁻² and over 250 h at a high depth of discharge of 80 %. They also demonstrate practical feasibility by maintaining 88.7 % capacity retention after 1000 cycles in Cu@ZnǁVO₂ full cells. This work provides new insights into the Sabatier chemistry inspired bifunctional layers for Zn metal battery system. | en_US |
| dcterms.abstract | Thirdly, a bilayer metal interface has been developed, integrating the dual advantages of buffering capacity and uniform zinc ion deposition. As commonly recognized in Zn ion battery research, the prevalent practice of applying excess zinc to maintain continuous active material supply at the anode inevitably results in severely compromised zinc utilization efficiency (<5%). This deliberate overengineering not only introduces substantial material cost penalties but also fundamentally constrains the achievable practical energy density of zinc-ion battery systems. Under electrochemical conditions, a hollow-structured Cu6Zn13 alloy was formed on the electrode surface. This phenomenon differs significantly from scenarios where single-layer metals are employed as buffer layers, which can be attributed to the ultrathin atomic sieve effect exhibited by the Ag interlayer. Owing to the dual protective mechanism, a stable zinc anode is attained even at high utilization rates. The Cu/Ag@Zn anodes exhibit an ultralong cycling lifespan of over 5500 h at a high current of 5 mA cm⁻² and over 500 h at a high depth of discharge of 90 %. They also demonstrate practical feasibility by maintaining 84.3 % capacity retention after 1000 cycles in Cu/Ag@ZnǁVO₂ full cells. This work proposes a novel strategy to enhance the utilization efficiency of zinc anodes and advance the commercialization of aqueous zinc batteries for large-scale energy storage applications. | en_US |
| dcterms.abstract | This thesis presents a series of research achievements addressing the critical challenges faced by zinc anodes in aqueous zinc-ion batteries. By constructing a multifunctional integrated interfacial layer on the anode surface, a dendrite-free zinc anode has been successfully achieved. Furthermore, guided by the Sabatier principle, this study establishes material selection criteria for optimal interfacial layers. Through rational selection of heterometallic materials, high utilization efficiency of zinc anodes has been realized. These strategies provide fundamental insights and practical solutions for developing high-performance, long-lasting zinc metal batteries. | en_US |
| dcterms.extent | xxiii, 148 pages : color illustrations | en_US |
| dcterms.isPartOf | PolyU Electronic Theses | en_US |
| dcterms.issued | 2025 | en_US |
| dcterms.educationalLevel | Ph.D. | en_US |
| dcterms.educationalLevel | All Doctorate | en_US |
| dcterms.accessRights | open access | en_US |
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