粉末冶金法三维石墨烯/碳纳米管密实阵列复合结构的可控合成及其柔性储能性能

Graphene and carbon nanotubes (CNTs) show a wide application prospect in flexible energy storage fields due to their excellent physical, chemical and mechanical properties. However, the disadvantages, such as low effective specific surface area, low strength and space utilization, and large resistance, of the disordered composite structure composed with single carbon material limit its performance. In this project, we propose to in-situ synthesize three-dimensional network structural graphene foam (GF) by powder metallurgy method, and then in-situ prepare single-walled CNTs arrays (a-CNTs) on the inner and outer surfaces of GF pores by using chemical vapor deposition, obtaining a new ordered three-dimensional carbon nano composite structure. The electrochemical performance of the composites as electrode materials of flexible energy storage device will be investigated. To improve the strength and toughness of GF, few-walled CNTs will be introduced, and the effect factors and regulation approaches to in-situ growth of GF will also be studied. The mechanism for the enhanced mechanical and electrical properties of GF by introducing few-walled CNTs will be demonstrated through combining simulation and in-situ characterization. We will also investigate the in-situ growth of a-CNTs on graphene, as well as the interfaces structure between GF and a-CNTs, to reveal its controllable growth mechanism. The flexible energy storage mechanism of the three-dimensional ordered composite structure will be demonstrated, and the mechanism model will also be built. The results would be able to a provide theoretical basis and realization approach to the application of flexible energy storage devices with high mechanical and energy storage performance.

具有优异物理、化学和力学性能的碳纳米管和石墨烯在柔性储能领域极具应用前景，但由单一碳材料构成的无序复合结构的有效比表面积低、强度差、空间利用率低和内阻大等问题限制了其性能发挥。本课题拟以粉末冶金法原位合成三维网络结构石墨烯泡沫（GF），并在GF孔隙内、外表面采用化学气相沉积法原位合成单壁碳管阵列（a-CNTs）以提高电极空间利用率和比表面积，优化电子传输路径，从而获得三维碳纳米有序复合结构，并研究其作为柔性储能材料的电化学性能。为提高GF的强韧性，添加表面修饰的少壁碳管，并研究GF原位生长影响因素和调控途径，结合理论计算和原位表征，探明少壁碳管对GF力学和电学性能的增强机制；研究在石墨烯上a-CNTs的原位生长及其与GF界面结构，揭示可控生长机理；研究该三维有序复合结构的柔性储能机理，建立储能模型。该研究将为兼具高力学和储能性能的柔性储能器件的开发和应用提供理论依据和实现途径。

碳纳米管、石墨烯等新型碳纳米材料由于具有优异的物理、化学性能，在储能领域极具应用前景。然而，单一结构碳材料较低的比表面积、较差的结构稳定性、低空间利用率和导电性等问题，限制了其性能的发挥。因此，如何将单一结构的碳材料构建成三维网络状复合结构，同时与其它纳米材料相结合，克服单一材料由于自身结构的限制而带来的性能不足，实现复合材料结构和性能的可控，对开发高性能电化学储能器件意义重大。本项目将传统的粉末冶金工艺与化学气相沉积法相结合，开发了松散粉末冶金模板法、金属辅助盐模板法等可控制备三维石墨烯及其复合材料的新方法。同时，以镍粉、氯化钠等为石墨烯生长的模板和催化剂，以蔗糖、葡萄糖、柠檬酸等为固体碳源，以液相回流法制备的Fe3O4/AlOx纳米颗粒为碳纳米管生长的催化剂，可控合成了三维碳纳米管增强石墨烯泡沫、双功能模块化石墨烯泡沫、自增强石墨烯/碳纳米管阵列、三维石墨烯/碳纳米管阵列、碳纳米管阵列/氧化铁、氮硫共掺杂碳纳米管阵列等多种三维结构的复合材料。通过对前驱体种类、比例、生长温度、生长时间、灯丝功率等参数的调控，探明了三维复合结构的生长机理，实现了其结构和性能的可控。以所制备的多种三维复合结构为电极，开发了高性能柔性超级电容器、锂离子电容器、锂金属电池、锂氧气电池等储能器件，研究了材料的储能性能及其影响因素，结合机器学习，探明了储能机理，为先进碳纳米复合材料在储能领域的应用提供了有效途径。. 项目共发表SCIE检索论文11篇，ESCI检索论文1篇，申请国家发明专利4项，培养硕士生9人，博士生5人，职称晋升1人，达到预期目标，完成了项目规定的研究任务。