石墨烯基电化学储能系统电极设计及其制造过程工程基础研究

The project aim at the construction of large-capacity lithium-ion batteries and other electrochemical energy storage systems, to create novel and high capacity composite electrode materials which based on graphene / metal oxide graphene / metal alloy. By using a variety of electrochemical test methods, the electrochemical characteristics of the prepared electrode materials will be measured. To combine with in situ XRD and TEM measurements, the relationship between material structure and electrochemical properties change will be explored. Clarify the molecular design method, electrode kinetics and electrochemical energy storage mechanism for the large capacity graphene-based electrode active material. To establish the graphene based electrode material synthesis process kinetics and thermal processing theory, three of the operating characteristics of the key unit operation for graphene base electrode manufacturing process including mixing, coating, drying and rolling will be studied. Mathematical and statistical models will be constructed to study the effects of electrode slurry viscosity, wet film thickness of the coating, drying temperature, drying rate, t the strength of rolling on the electrode quality. The airflow and temperature field distribution within the coating and drying unit will be revealed. The heat and mass transfer phenomena during the electrode molding and drying process and scale up theory the electrode manufacturing process will be also investigated. By screening a suitable electrolyte, the compatibility between graphene-based electrode and electrolyte may be addressed. A new graphene-based electrochemical energy storage unit will be developed. The results will provide a theoretical basis for the development of the next generation high-capacity electrochemical energy storage system.

本项目针对新能源利用的大容量锂离子电池及相关电化学储能体系构建，创制高比能石墨烯/金属氧化物、石墨烯/金属合金等复合电极材料，采用各种电化学测试方法对所制备电极材料电化学特征进行系统研究，结合原位XRD和TEM等手段，探索材料结构与电化学性能变化关系。阐明大容量石墨烯基电极活性物分子设计、电极动力学及其电化学储能机理。建立大容量石墨烯基电极材料合成反应过程动力学及热加工理论，研究石墨烯基电极制造过程中的混合、涂布干燥和滚压三个关键单元操作特性。建立数学统计模型，研究电极浆料粘度、涂布的湿膜厚度、干燥温度、干燥速率、滚压强度对电极成膜质量的影响规律，揭示涂布干燥单元中气流场、温度场分布和物料传送速度对电极成型与干燥过程中热质传递现象，形成电极制造过程放大理论。筛选合适的电解液，研究石墨烯基电极与电解质的匹配性，设计与研制基于石墨烯新型电化学储能单元，为发展新一代大容量电化学储能体系提供基础。

本项目合成了一系列石墨烯基复合电极材料，并应用于锂离子电池（石墨烯包覆Co2(OH)3Cl、三维CoO/石墨烯、三维Fe2O3/石墨烯和AgVO3/石墨烯气凝胶复合材料），超级电容器（Co-Al 层状双氢氧化物/石墨烯复合气凝胶、Ni-Fe 层状双氢氧化物/石墨烯复合气凝胶），混合型电池电容（石墨烯包覆Li4Ti5O12微球||活性炭）和锂空气电池（三维氮掺杂的镂空石墨烯球）。考察了以上石墨烯基电极材料合成过程特性，电化学反应机制机理及其作为电极材料在电化学器件中的性能表现。.针对钠离子电池应用，制备了RGO/P2- Na2/3[Ni1/3Mn2/3]O2和不同氧化石墨烯（GO）含量的RGO/普鲁士蓝复合材料。采用Na1.76Ni0.12Mn0.88[Fe(CN)6]0.98(PBMN)作为正极，硬碳作为负极，组成钠离子原型软包电池，能量密度和功率密度分别达到了81.72 W h/kg和90 W/kg。开展了层状结构NaNi1/3Fe1/3Mn1/3O2正极材料的公斤级合成技术研究，并基于NaNi1/3Fe1/3Mn1/3O2正极和硬碳负极，研制成功钠离子全电池。利用同步辐射X射线技术对NaNi1/3Fe1/3Mn1/3O2正极材料在充放电过程中的结构演变规律进行深入研究，发现了循环过程中两相共存及非平衡固溶体中间态，为发展长寿命钠离子电池奠定良好的基础。.基于过程系统工程方法，构建了高精度、高可靠的电池荷电状态（SOC）估计和健康状态（SOH）预测模型。创建了一种基于非线性半无限规划的多项式开路电压（OCV）模型，还建立了一种模型结构选择和参数估计的混合整数多目标优化模型，提出了显式和隐式两种全局优化策略，实现了等效电路模型结构和参数的同步优化，显著提高了模型预测精度，并降低了模型复杂度。提出一种纯数据驱动的多尺度高斯过程模型通用框架，实现了锂离子电池SOH的短期和长期精确预测，为电池的SOC估计和剩余可用寿命（RUL）预测奠定了坚实的理论和方法基础。.项目执行期间，发表学术论文68篇，申报专利12件，授权7件。培养博士研究生9名，硕士21名，博士后3名。马紫峰等人完成的“安全型长寿命动力锂电池制造及其应用关键技术”获2017年教育部科学技术进步一等奖，“磷酸铁锂动力电池制造及其应用过程关键技术”获2018年国家科技进步奖二等奖。