基于黑磷量子点铝离子电池反应机理的研究

The rechargeable aluminium-ion batteries are widely studied due to their superior properties, e.g. high capacity, low cost, long cycle life, safety and environmental benignity. However, the ultrafast rechargeable aluminium-ion battery are still limited due to the voltage for the charging platform of aluminum ion battery is higher than the voltage for the electrolyte decomposition, leading to gas generation during charging and discharging processes; the key scientific issue is the reaction mechanism in charge and discharge processes of aluminium-ion battery has not been fully clarified. This study aims to resolve the above issues, including: 1) study the growth mechanism of black phosphorus quantum dots- graphene composites as cathode for aluminium-ion battery, and to optimize the synthesis conditions(our previous study has demonstrated that using black phosphorus as cathode the charge volatge platform of aluminium is lower than the volatge of the electrolyte decomposition); 2) to explore the optimized ratio between graphene and black phosphorus quantum dots, the impacts of charge and discharge current(including fast charge and slow discharge) and temperature effects on the capacity, rate and cycle life of the aluminum ion battery; 3) using the first principle calculation and in-situ study to establish the conversion mechanism of aluminium-ion battery from at atomic level by of the evolution of Al ionic cluster (e.g. coordination numbers, next nearest neighbour and chemical enviornments) and crystal structure change of the cathode materials during charge and discharge processes. This project will provide technical and theoretical support for the flexible high performance aluminium-ion battery.

铝离子电池因理论容量高、成本低、寿命长、安全可靠等优点而被广泛研究。当前可快速充放电的铝离子电池充电电压平台高于电解液的分解电压，使得电池在充放电过程中因电解液的分解而产生气体，造成电池胀气而不便于实际应用，其关键科学问题是充放电过程中电池正极反应本质不确定。针对这些问题本项目将：1）研究黑磷量子点复合石墨烯的铝离子电池正极材料的生长机理（我们前期已证明黑磷为正极的铝离子电池充电电压平台低于电解液的分解电压），掌握其最佳制备条件；2）研究正极材料的配比、充放电电流（包括快充慢放）、环境温度等对铝离子电池容量、倍率、循环稳定性等的影响；3）利用第一性原理计算结合原位显微技术，研究铝离子电池充放电过程中含铝基团嵌入正极材料后基团成键模式与结构的动态变化、正极材料成分与结构的演化规律，以期从原子水平掌握铝离子电池正极反应的本质。本项目的实施将为构建新型柔性高性能铝离子电池提供技术和理论基础。

铝离子电池因理论容量高、成本低、寿命长、安全可靠等优点而被广泛研究。在铝离子电池的充放电过程中，正极都为大基团阴离子的嵌入与脱出。从电子排布的角度分析，目前仅有石墨能够很高嵌入与脱出大基团阴离子。但传统石墨在充放电过程中易粉化，从而造成了电池容量的衰减。我们制备了一系列新型石墨，包括三维石墨烯量子点、石墨烯纸、螺旋状石墨烯、石墨烯管等应用于铝离子电池正极。新型石墨因具有良好的导电性、大的比表面积同时在充放电过程中能提供大的膨胀空间，展现了良好的储阴离子性能（高容量、长寿命、高倍率）。利用第一性原理计算结合原位显微技术研究了铝离子电池正极在充放电过程中铝基团嵌入和脱出后的成键模式与结构演化，探究里铝离子电池正极的反应机制，为高性能铝离子电池的发展提供了一定的理论基础和借鉴意义。（在制备新型石墨烯过程中，发现新型石墨也具有良好的钾离子电池性能。）发表了高水平论文近50余篇。