一步熔盐法可控制备二维/三维Fe2O3/RGO复合材料及其储能性质的研究

Due to the special thickness-dependant properties, graphene based 2D materials show excellent physicochemical properties which attract the broad attentions for their practical applications. The synergistic effect by coupling transition metal oxide with graphene based materials can significantly increase the energy storage performance of composites. As the reaction medium, molten salt which has the advantages for high ionic conductivity, high thermal/chemical stability and easy product morphology control takes the significant role in the field of metallurgical physicochemistry. Considering the complex processing and high cost of the conventional synthesis method, the current work proposes a one-step molten salt controllable fabrication protocol of 2D/3D iron oxide (Fe2O3)/reduced graphene oxide (RGO) composites and builds up the corresponding molten salt based framework. The current work without using any toxic solvent or reduction agent is advantageous in mild processing conditions, simple and straightforward procedures, and environmental benignity, etc, while one-step metal oxide crystallization/reduction of graphene oxide/activation is achieved. In addition, the ice-template is also used to assist one-step molten salt protocol for further tuning the microstructure and morphology of composites. By investigating the influence of detailed processing parameters on the structure, morphology and performance of the as-prepared materials, this work further explores the structure-function relationship for the energy storage applications of materials to deeply dive the detailed reaction mechanism and effectively develop the metallurgical physicochemical method for efficient fabrication of transition metal oxides/RGO composites.

石墨烯超薄的二维结构使其具备了前所未有的优异性能。将过渡金属氧化物与石墨烯复合，能显著提高材料的能源存储性能。熔盐作为反应介质，离子传递速率快，稳定性高，产物形貌可控，在冶金物理化学领域具有重要的作用。针对常规制备石墨烯基复合材料工艺繁冗复杂、成本高等缺点，本项目提出一步熔盐法可控制备二维/三维三氧化二铁（Fe2O3）/还原氧化石墨烯（RGO）复合材料，构建熔盐法制备复合材料的研究体系和方法。与常规方法相比，熔盐法不使用有毒溶剂和还原剂，具有制备条件温和、反应步骤简单、对环境影响小等显著优势，可一步实现氧化物结晶与形貌控制、氧化石墨烯还原及活化。同时辅以冰模板进一步调控复合材料的结构与形貌。本项目研究制备参数对Fe2O3/RGO复合材料结构、形貌和性能的影响以及储能过程中的构效关系，以期深入理解熔盐法制备的机理与过程控制，发展熔盐法制备过渡金属氧化物/RGO复合材料的冶金物理化学方法。

实现新能源的高效利用以及发展先进新能源材料制备技术是优化我国能源结构、促进冶金工业绿色低碳发展的关键。相较于传统液相制备方法，熔盐法具有离子传递速率快、反应能力强、易于实现对制备材料微结构有效调控等优势。然而目前对于利用熔盐法制备多维度碳基复合材料的基本结构调控机制与性能影响规律仍不清楚。本项目通过优化一步熔盐法可控制备多维度碳基材料、碳碳复合材料以及Fe2O3等过渡金属化合物/碳基复合材料，获得了一步熔盐法可控制备多维度碳基复合材料的过程规律；在此过程中，建立了熔盐介质种类、体量及反应条件对组分材料形貌、尺寸及电化学性质的影响规律，构建了熔盐法制备多维度碳基复合材料的熔盐系统；同时厘清了熔盐在构筑复合材料过程中所起的关键作用以及多维度异质结构的形成机理，获得了熔盐法制备多维度碳基复合材料的微结构与电化学活性之间的构效关系。本项目对于深入理解利用熔盐法制备先进碳基复合材料具有重要意义，同时发展了利用熔盐法制备多维度碳基复合材料的冶金物理化学方法，并为先进碳基新能源材料的设计与改性提供了有益参考。