钠离子混合电容器“牺牲有机钠盐”实现原位预嵌钠的研究

3D porous framework carbon nanomaterials with large interlayer spacing, heteroatom doping, and excellent conductivity are ideal materials for sodium-ion storage. In this project, 3D porous framework carbon for sodium ion battery anode materials were synthesized by one-step thermo - solid - phase reaction derived from Organic alkali metal salt, which achieve the carbon source, doped atomic source, catalyst and template molecular level matching. Then, the effects of the sodium ion storage characteristics of as-prepared material on three-dimensional pore structure, carbon-oxygen ratio, layer spacing and conductivity were studied systematically. At the same time the key preparation technology of three-dimensional porous framework carbon materials were obtained. On this basis, nanoporous 3D network carbon cathode materials with excellent capacitance were fabricated by controllable chemical activation. Further, In-suit sodiation using sacrificial organic lithium salt was achieved by synthesizing different substituents of dihydroxybenzene disodium salt and screening of their oxidation potential. Meanwhile, The effects of different substituents and mass on the performance of sodium ion hybrid capacitors were studied systematically. Finally, due to electrolyte has a good matching with the identical carbon-based system with the same electrochemical stability and conductivity. By optimize electrochemical kinetics matching characteristics and the quality ratio of anode materials and cathode, the sodium ion hybrid capacitors with high energy density and power density and excellent cycle stability was constructed.

层间距宽、导电性好、适宜杂原子掺杂的三维多孔网络碳材料是理想的储钠材料。本项目拟利用有机碱金属配位盐的化学组成和结构特点（碳源、掺杂原子源、催化剂和模板四位一体），利用热固相烧结一步制备三维多孔网络碳钠电负极材料，系统研究材料的三维孔结构、杂原子掺杂、层间距和导电性与材料储钠特性之间的内在影响规律，获得三维多孔网络碳材料关键制备技术；在此基础之上，进一步采用可控化学活化技术制备具有优异电容特性的纳米多孔三维网络碳材料；通过合成不同取代基二羟基苯二钠盐，利用氧化电位的筛选实现有机钠盐牺牲原位预嵌，系统研究不同取代基和加入量对混合电容器性能的影响规律，利用双碳体系电化学稳定性、导电性与电解液匹配性好等特点，通优化正负极材料质量和动力学匹配特性，最终构筑出兼具高能量密度和功率密度且循环稳定性优异的双碳钠离子混合电容器。

为了实现高能量密度、功率密度和循环稳定性优异的双碳钠/钾离子混合电容器器件的构筑并形成关键技术，本项目重点通过制备条件优化实现了具有优异电化学性能三维网络碳负极以及三维多孔网络碳正极材料的可控制备，并进一步通过两极质量比优化和牺牲预嵌技术开发实现了高性能钠/钾离子混合电容器器件的构筑。相关研究结果如下：. 1）利用EDTA-4Na有机盐作为前驱，我们实现了基于氮掺杂的三维网络碳正负极钾离子混合电容器的构筑，器件表现出优异的能量/功率密度性能：163.5 Wh kg-1/210 W kg-1和76.4 Wh kg-1/21000 W kg-1，2.0 A g-1电流密度下，10000圈循环后容量保持率91.7%；我们开发了一种利用碳酸钠作为模板实现富氧掺杂的碳纳米薄片制备技术，将制备的碳纳米薄片作为负极，实现了高性能钠/钾离子混合电容器的构筑；采用蜡烛灰纯化的洋葱碳材料作为负极，实现了高性能钾离子混合电容器的构筑；. 2）利用MOF前驱和有机物包覆技术，我们实现了高性能双碳包覆TiO2钾离子负极的制备，同三维碳正极组装构筑了高性能钾离子混合电容器，该器件实现了114 Wh kg-1的高能量密度和21 kW kg-1的功率输出；. 3）通过可控合成和电化学性能筛选获得四种牺牲预嵌有机钠盐：方酸钠、柠檬酸钠、EDTA-4Na和NTA-3Na；. 4）选用我们制备的高电容特性的三维多孔碳作为正极，以及可控制备的T-Nb2O5/C、石墨烯@氧化锰和3D MXene@CNT负极，实现了多种高性能离子混合电容器的构筑；. 5）利用锌金属负极和构筑的无枝晶锂金属负极，采用高比表的三维多孔碳作为正极，构筑了新型的金属电容器器件。组装的锌离子混合电容器在9.3 kW kg−1的高功率密下保持了164 Wh kg−1的高能量密度，采用锂复合负极构建的锂金属电容器实现了超高的能量密度492 Wh kg-1。. 同时，我们在该项目经费的资助下，还研究了其他类型电极材料的开发以及储能器件构筑工作。包括：利用液氮淬冷技术实现MXene卷锂离子电池负极的制备，通过光热涂层复合以及电解液的调控实现低温储能器件构筑。