过渡金属氮化物/石墨化碳纳米复合结构的可控构筑及电容特性

It is a challengeable subject to develop the high efficient, cost-effective electrode materials for driving the commercial process of supercapacitor. The purpose of this project is to design and synthesize novel transition metal nitride/ graphite carbon composite for improving the energy density of the supercapacitor. In our project, we also found that the synergistic effect between graphite carbon and nitride could be fundamentally solve the problem of low energy for supercapacitor. Herein, graphite carbon is acted as host materials. Basing on the principle of group coordination, the solution containing metal salt precursor are infused into the interlayer and pores of graphite carbon by the ultrasound induced-vacuum assisted technique. Meanwhile, the metal ions anchored on the graphite carbon through electrostatic interactions. Following, metal oxides nanoparticles would uniformly grow in-situ on the carbon interlayers under the hydrothermal conditions. After nitride pyrolysis, the transition metal nitride/graphite carbon composites are obtained. It can control the transition metal nitrides morphology, size, crystal structure and dispersion effectively by changing the experimental parameters. Moreover, TEM, XAFS, SEM are conducted to clear the structure and interactions of the composite materials. The electrochemical methods of CV, GCD, EIS are combined to analysize the capacitance properties deeply. Finally, we will explore the relationship between structure and properties, reveal the essence of the electrode kinetics, and put forward the energy storage mechanism of composite electrode materials.

开发高性能、低成本电极材料是促进超级电容器商业化进程的挑战性课题。本项目以提高超级电容器能量密度为目标，拟设计合成新型过渡金属氮化物/石墨化碳复合电极材料，以其各组分间协同效应为主导，从根本上解决电容器能量密度低的难题。首先，以石墨化碳为载体，基于基团配位原理，采用超声诱导-真空辅助法，将前驱体金属盐离子引入石墨化碳层间和孔道中，并在静电作用下，使其与碳载体均匀而紧密的结合；经热压反应实现金属氧化物在石墨化碳上的原位生长；进一步经氮化热解得到过渡金属氮化物/石墨化碳复合体。调节实验条件以实现对过渡金属氮化物形貌、尺寸、晶型和分散性的有效调控。利用TEM、XAFS、SEM等手段表征材料的结构及相互作用，借助CV、GCD、EIS等电化学方法研究材料的电容特性，综合结构表征及电化学测试结果，深入探究材料结构与性能间的关系、揭示材料电极动力学过程的本质，提出复合体电极材料的电容储能机理。

发展高性能、低成本电极材料是推进超级电容器商业化进程的有效方法。本项目围绕提高超级电容器能量密度、降低材料成本这两个亟待解决的难题，开展了新型电极材料的设计制备、结构表征和性能测试等方面的工作。本项目以一系列高电容特性的碳材料（介孔碳、石墨烯、生物质碳等）为碳载体，采用超声诱导真空辅助的方法将过渡金属盐溶液引入到碳载体中，经热压氮化反应制备出一系列过渡金属氮化物/石墨化碳纳米材料（包括氮化铁/介孔碳和氮化钴/石墨烯复合材料等）。研究表明，过渡金属氮化物（氮化铁、氮化钴）与纳米碳（介孔碳、石墨烯）材料的有效复合可从根本上解决电容器能量密度低的难题。其中，碳材料的引入不仅提升复合体的导电性，而且使得过渡金属氮化物尺寸纳米化，从而有效的提高了复合材料的比电容、能量密度和循环稳定性。同时，综合结构表征和电化学测试结果，深入探究了复合电极材料各组分间的相互作用及电容储能机理。此外，基于基团配位原理，我们自廉价的生物质入手，获得了一系列高能量密度的新型生物质碳超级电容器电极材料。在本项目的支持下，在国内外学术期刊共发表论文12篇，出版专著2部，申请中国专利5项。获得省科学技术三等奖一项（第三名），现已顺利的完成项目的研究任务。