基于有机电解液锂空气电池的界面反应机理与电化学性能研究

Lithium-air battery has been attracted much more attention due to its advantages such as high energy density, low cost and friendly environment. It has scientific and practical significance for energy transformation and storage to understand the mechanism of interfacial reaction between porous electrode and electrolyte and improve the comprehensive performance of battery. In this project, various methods of electrochemistry and spectral analysis are employed to clarify the reaction principle on the interface, which can elucidate the bottleneck to development of Li-air battery. On the basis of these, bifunctional catalyst materials with highly catalytic reactivity and porous volume are synthesized by. After that, micro-structure and electrochemical properties of the prepared catalyst are characterized and optimized. In order to seek and design suitable electrolyte for Li-air battery, the physical and electrochemical properties of electrolyte on two phase interface are studied in detail. The compatibility of catalyst and electrolyte will be considerated elaborately. Besides these, plastic and cylinder prototypes of Li-air batteries will be fabricated and evaluated comprehensively. As a result, accomplishment of this project will lay a solid ground of theoretical research for Lithium-air battery.

锂空气电池以其能量密度高、成本低和对环境友好等优势受到广泛关注。深入理解锂空气电池的电化学反应机理，努力提升电池综合性能，对发展能量储存与转换技术有重要的科学意义和应用价值。本项目从研究多孔电极和电解液界面反应机理入手，澄清至今仍不明朗的锂空气电池工作机制，指出其性能提升的瓶颈；在此基础上，创新地将多孔催化材料与电解液的研究统一起来，在寻求高催化活性、高孔容的双功能催化材料与性能良好的电解液的同时，兼顾两者之间的匹配性，重点关注电解液在催化材料表面的物理与电化学特性，并对材料的微结构、电催化性能和工艺进行研究和优化，以提升锂空气电池的容量、寿命和效率；此外，空气环境中其他成分在电极表面的作用机制也将进行详细考察。本项目的实施将为锂空气电池实用化打下坚实的基础。

本申请项目主要以锂空气电池为研究对象，系统研究多孔电极/电解液界面的电化学反应机理，在此基础上，通过对催化材料、电解液及电池结构的优化设计和匹配，大幅度提高锂空气电池的各项性能。发展了多种在线分析演技手段，例如差分电化学质谱系统、原位拉曼增强光谱和石英晶体微天平技术。设计与制备一系列正极催化材料，包括纳米钌修饰的三维多阶孔道石墨烯气凝胶，单晶氧化镍，碳化菌丝自支撑正极，铂碳催化正极，纳米多层氧化铁/石墨烯复合材料。引入可溶性液相催化剂显著降低OER过程过电位：提出N-甲基吩噻嗪作为氧化还原电对，可将锂氧气电池充电电位压低1 V。采用锂硅合金负极来提高负极循环效率和安全性。成功合成锂硅合金负极，并组装了锂氧气电池。制备低体积效应的锂合金负极，研究活性相和界面保护层的微结构演变基本规律，研究电解质与正负极的相容性。研究空气中CO2，H2O和O2气氛下的电极电化学行为，包括CO2在空气电极表面还原和析出机理，碳酸锂的阳极氧化过程。研究电解液中少量的H2O对电池OER过程的催化作用，并解析了H2O在锂氧气电池中的反应机理。在本项目的支持下，共发表SCI论文30篇，申请专利6件。培养了多名研究生。本项目的顺利完成为锂氧气电池实用化奠定了理论基础。 ..