【作者】 张硕；

【导师】 乐英；

【作者基本信息】 华北电力大学 ， 机械硕士（专业学位）， 2025， 硕士

【摘要】 环境污染加剧与能源需求增长推动了可再生能源的发展。锂离子电池虽主导可充电电池市场,但受限于锂资源匮乏、成本高、有机电解质毒性及安全隐患,其大规模储能应用面临挑战。水系锌离子电池（AZIBs）因高安全性、低成本和环保特性成为潜在替代方案。锌负极具有高理论容量（820 m Ah g^-1）、低氧化还原电位（-0.76 V vs.SHE）和资源丰富等优势,但在弱酸性或中性电解液中易发生析氢腐蚀和副反应,导致可逆性降低及库仑效率下降;此外,锌枝晶生长可能引发短路,威胁安全性。这些问题严重制约了AZIBs的产业化。因此,本论文围绕锌负极界面调控策略开展了系统研究,主要研究内容如下:（1）原位改性PEO涂层金属锌负极界面调控为解决水系锌离子电池负极界面不稳定和锌枝晶生长问题,本研究提出了一种原位改性PEO涂层。通过引入丁二腈（SN）和Zn（TFSI）₂复合改性,优化了锌离子的溶剂化与迁移行为,有效抑制锌枝晶生成。PEO涂层不仅具备较好的离子导电性,还能通过与锌离子形成稳定的溶剂化结构,确保锌离子的均匀沉积,避免枝晶的生成。丁二腈通过其氰基（-CN）与锌离子的配位作用,优化了锌离子的溶剂化环境,减少了水合效应,进一步抑制锌枝晶的生长。Zn（TFSI）₂作为锌盐,增强了涂层的抗氧化性及电解质稳定性,提升了电池的循环性能。通过DFT计算吸附能、结合能证明了涂层的稳定形成;并通过分子动力学模拟溶液的溶剂化结构。实验表明,该涂层组装的对称电池在1.0 m A cm^-2 1.0 m Ah cm^-2条件下拥有长达5200 h的循环性能,Zn//Cu半电池在1.0 m A cm^-2电流密度下循环3000次后仍具备99.99%的库伦效率,与二氧化锰组装的全电池在1A g^-1的电流密度下能够循环超过2000次。（2）局部共轭涂层金属锌负极界面调控通过设计一种局部共轭结构来解决界面不稳定和锌枝晶生长问题,该结构由聚丙烯腈聚合物组成,并通过以Zn（TFSI）₂为诱导剂在120°C的温度下形成。锌负极上的PAN@Zn层富含适当的吡啶氮富集基团（共轭环状C=N）,展现出对Zn²⁺的显著亲和力,并提供丰富的沉积位点。该锌亲和骨架不仅作为保护层引导Zn²⁺的均匀沉积,还通过调节质子流,抑制氢气析出,从而减少副反应。此外,PAN@Zn层强大的附着力确保其在长期循环中持续保护锌金属。通过DFT计算各组分之间的吸附能、结合能和分子动力学模拟溶剂化结构。实验结果显示改性后的电极在全电池和对称电池中均表现出长周期寿命。NVO组装的全电池在5 A g^-1的电流密度下有超过5000次循环寿命;Zn//Zn对称电池在1.0m A cm^-2 1.0 m Ah cm^-2条件下显示出超过5400 h的循环寿命。研究结果表明两种策略能够有效提升水系锌离子电池的循环性能、抑制锌枝晶的生长,并大幅延长电池的使用寿命。为设计高性能水系锌离子电池提供了一种可行的途径。更多还原

【Abstract】 The increasing environmental pollution and growing energy demand have driven the development of renewable energy.Although lithium-ion batteries（LIBs）dominate the rechargeable battery market,their large-scale energy storage applications face challenges due to limited lithium resources,high costs,the toxicity of organic electrolytes,and safety concerns.Aqueous zinc-ion batteries（AZIBs）have emerged as a promising alternative due to their high safety,low cost,and environmental friendliness.The zinc anode exhibits advantages such as a high theoretical capacity(820 m Ah g^-1),low redox potential（-0.76 V vs.SHE）,and abundant natural reserves.However,in weakly acidic or neutral electrolytes,the zinc anode is prone to hydrogen evolution corrosion and side reactions,leading to reduced reversibility and low Coulombic efficiency.Additionally,zinc dendrite growth may cause short circuits,posing safety risks.These issues severely hinder the industrialization of AZIBs.Therefore,this thesis systematically investigates interface modulation strategies for zinc anodes,with the main research contents as follows:（1）Interface Engineering of In Situ Modified Polyethylene Oxide（PEO）-Coated Zinc Metal Anodes.In order to solve the problems of unstable anode interface and zinc dendrite growth in aqueous zinc ion batteries,an in situ modified PEO coating is proposed in this study.By introducing the composite modification of Succinonitrile（SN）and Zn（TFSI）₂,the solvation and migration behaviors of zinc ions were optimized,and the generation of zinc dendrites was effectively inhibited.The PEO coating not only possesses good ionic conductivity,but also ensures the homogeneous deposition of zinc ions through the formation of stable solvation structure with zinc ions and avoids dendrites generation.Butanedinitrile optimizes the solvation environment of zinc ions through its cyano（-CN）coordination with zinc ions,which reduces the hydration effect and further inhibits the growth of zinc dendrites,and Zn（TFSI）₂,as a zinc salt,enhances the antioxidant property of the coatings as well as the stability of the electrolyte,which improves the cycling performance of the batteries.The solvation structure was simulated by DFT calculations of adsorption and binding energies between the components and molecular dynamics.The experiments showed that the symmetric battery assembled with the coating possessed a cycling performance of up to 5200 h at 1.0 m A cm^-2,1.0 m Ah cm^-2,the Zn//Cu half-cell still possessed 99.99%Coulombic efficiency after 3000 cycles at a current density of 1.0 m A cm^-2,and the full-cell assembled with manganese dioxide was capable of cycling at a current density of 1 A g^-1 for over 2000 cycles at 1 A g^-1 current density.（2）Interface Engineering of Partially Conjugated Coating-Modified Zinc Metal Anodes.This challenge was addressed by designing a locally conjugated structure consisting of a polyacrylonitrile polymer and formed by using Zn（TFSI）₂ as an inducer at a temperature of 120°C.The PAN@Zn layer on the Zn anode was designed to provide a high level of Zn²⁺enrichment and to provide a high level of Zn²⁺enrichment.The PAN@Zn layer on the zinc anode is enriched with appropriate pyridine nitrogen-enriched groups（conjugated cyclic C=N）,exhibiting significant affinity for Zn²⁺and providing abundant deposition sites.This Zn-affinity backbone not only acts as a protective layer to guide the homogeneous deposition of Zn²⁺,but also inhibits hydrogen precipitation by regulating the proton flow,thus reducing side reactions.In addition,the strong adhesion of the PAN@Zn layer ensures its continuous protection of the zinc metal during long-term cycling.The solvation structure was simulated by DFT calculations of adsorption and binding energies between the components and molecular dynamics.Experimental results show that the modified electrodes exhibit long cycle life in both full and symmetric cells.the NVO-assembled full cell has a cycle life of more than 5000 cycles at a current density of 5A g^-1;the Zn//Zn symmetric cell shows a cycle life of more than 5400 h at 1.0 m A cm^-2 1.0 m Ah cm^-2 conditions.The results show that the two strategies can effectively improve the cycling performance of aqueous zinc ion batteries,inhibit the growth of zinc dendrites,and significantly extend the battery life.It provides a feasible way to design high-performance aqueous zinc ion batteries.更多还原