铝-空气电池阳极新体系的构建及其电化学行为研究

In order to solve the problems that the practical engergy density and power density of Aluminium-air battery are much lower thantheir theoretical value, a new anode system will be designed and investigated. Considering the demand of recycling use of aluminium, 99.9% chemical pure prouse aluminum cast is selected as basic anode materials, soldium aluminate solution is choosed as electrolyt . To assemble a electrode with high current density, the principle of design and preparation of 3D electrod will be studied by elelctrochemical method and the First Principle calculation and molecular dynamic simulation.In order to obtain high efficiency inhabitor to prevente the anode from slef-corresion and passivation, the mechanism of anode self-corresion and passivation will be researched by in-situ Raman analysis and frequency response analysis as well as SECM ; an interaction model to reflect the slef-corroding effects and passivated effects will put forward; the chemical principle of controlling slef-corresion and passivation will be formed and novel bi-functionlized inhabitors will be selected. In order to eliminate the harmful effect of hydrogen on the battery, an auxiliary electrode of hydrogen will be assembled. Based on above researcch, a new anode system with high energy effeciency will be organized and the fundamental peinciple for desiging anode system of metal-air battery will be established. The research will provide the theoretcial data for make commerical aluminium-air battery and promote the development of solution chemistry of aluminates and elctrochemistry of aluminium .

针对铝-空气电池阳极钝化和自腐蚀导致电池功率密度和能量密度远低于理论值的难题，兼顾电池回收需求，以99.9%化学纯多孔铝为阳极基底，铝酸钠溶液为电解质，将第一性原理、分子动力学模拟与电化学分析方法相结合，研究铝阳极材料微结构与电化学性能的关系，研制三维阳极，提高电极电流密度。采用实时拉曼谱、交流阻抗谱和扫描电化学显微镜分析，研究多孔阳极在铝酸钠电解质溶液中钝化与自腐蚀反应机理及动力学规律，建立多孔阳极钝化与自腐蚀交互作用关系，提出阳极钝化和自腐蚀化学控制原理，设计无机-有机杂化双功能缓蚀剂，实现抑制阳极析氢气的同时阻止钝化膜形成。组装氢气辅助电极，消除残余氢气对电池系统的副作用。通过上述研究，构建高性能铝空气电池阳极新体系，突破现有铝-空气电池能量密度和功率密度远低于理论值的局限，形成铝-空气阳极体系设计基本理论,为铝-空气电池规模化制备提供理论支撑,推动铝酸盐溶液化学和铝材电化学的发展。

碱性铝-空气电池能量密度理论值最高达8.1kWh/kg。然而，由于阳极自腐蚀，实际只达到0.23~0.35Wh/kg（2014年文献数据）。本项目针对铝-空气电池阳极钝化和自腐蚀性导致电池功率密度低、能量密度远低于理论值的问题，兼顾后续铝空气电池回收需求，以NaOH-Na2O-H2O溶液为电解质，以工业纯泡沫铝为阳极基底，提出以浸渍石墨烯的多孔三维铝阳极替代传统高纯铸铝或铸铝合金阳极，通过提高电极比表面积和高导电性来提高阳极电流密度，提升电池功率密度，构建了高功率密度的铝-空气电池用阳极新体系。以Zn类无机-有机杂化双功能缓蚀剂，在匹配的电解质溶液体系中，该阳极（纯度为95.17%泡沫铝阳极）组装的铝空气电池（Pt-C为阴极）最大功率密度为80.6 mW cm-2，最佳为比容量高达1983 mAh g-1，比能量为1388 WhKg-1，阳极利用率为84.63%。同时，设计开发了一种新颖的以环保 chitosan 水凝胶膜作为隔膜的可循环可回收利用及无污染排放的扣式铝空气电池，为铝空气电池的未来发展提供了方向。通过理论化学计算结果，提出基于HOMO轨道与Al(OH)3的LUMO轨道匹配的原则筛选抑制剂的基本思路。针对钝化反应和自腐蚀产氢反应，提出表面成膜盖部分水（而不是OH-）还原反应活性位点的抑制机理，分别筛选具有催化作用的无机阳离子以阻止阳极自腐蚀反应。从廉价富氮、碳化合物出发，结合高温热解法和自发的气泡发泡技术及自组装技术构筑了多种具有独特结构和高活性的碳基氧还原催化剂NCNs。NCNs展现出能够媲美Pt/C的高功率密度（333 mW cm-2）和高工作电压平台（1.16 V）。根据实验并结合密度泛函理论计算初步探讨了N掺杂碳基催化剂的氧还原反应机理和活性位点，绘制了以过电势为判据的ORR活性火山形曲线，为设计和开发高效的碳基氧还原催化剂提供了参考依据和理论指导。本项目在Small,Carbon, Journal of Power Sources等国际学术期刊发表论文16篇，申请专利3项。