碳插层类石墨烯层状过渡金属硫化物超级电容器电极材料的构筑及性能研究

Supercapacitors have been widely application in electric vehicle and smart grids due to their unique energy storage mechanisms, and the new planar layered graphene carbon/metal sulfide electrode materials is one of the hotspots in this field. However, this layer structure may easily interlayer self-stack, causing the instability of microstructure during charge/discharge which leads to a fast capacity loss. As one of the supercapacitor electrode materials, carbon materials has advantages include of a large specific surface, high chemical stability and rich source. The combination of carbon with mental sulfide may result in improved the electrochemical stability. The present project design highly stable, high dispersed porous structure of the carbon intercalation composite materials by hydrothermal intercalation at the nanoscale level to achieve its optimal match and improve synergetic effect. Furtherly, the microstructure, electrochemical characterization and electrochemical performance of carbon/mental sulfides are researched by modern spectroscopy, electrochemical technology and test. Finally, combined with density functional theory calculation, we constructed the microstructure model of carbon intercalation composite materials and elucidated its synergetic effect and structure-performance relationship with porous structure. These findings of the present research provide theoretical guidance and experiment basis for the development of high performance electrochemical supercapacitors.

超级电容器因其独特的储能机制在电动汽车、智能电网等领域具有广泛应用前景。类石墨烯二维层状金属硫化物电极材料是目前超级电容器的研究热点之一，但由于二维层状结构易于发生层间自堆积，导致其在充放电过程中微观结构不稳定，致使材料容量衰减快。本项目拟采用水热插层法将碳材料引入金属硫化物层状结构，利用碳的插层效应，解决二维层状结构层间自堆积问题。在分子水平上设计多级多孔结构碳插层金属硫化物复合电极材料，碳插层结构提供了电子/离子的快速传输通道，提高复合材料的比电容和循环稳定性。通过研究复合材料微观结构、电极/电解液界面性质、动力学性能及其超级电容器性能，构建碳插层复合材料微观结构模型，阐明碳插层与多孔结构的协同作用规律以及复合材料的构效关系，实现金属硫化物和碳材料的合理匹配，提高超级电容器性能，为开发高性能超级电容器提供理论指导与实验依据。

电极材料是超级电容器的核心组成部分，二维层状硫化铜作为电极材料成为研究的热点，但是其片层之间易于发生卷曲，产生层间自堆积，影响其循环稳定性。本项目首先拟在分子尺度上设计和制备结构可控的CuS，并研究其储能机理；其次采用一步溶剂热法制备CuS-碳复合材料，探究其最佳制备参数和制备规律，并进行物理化学表征和电化学性能测试。CuS-AC和CuS-CNTs复合材料表现出优良的电化学性能：比电容高达798.14 F g-1和440.22 F g-1(1 A g-1)，经5000充放电后电容保持率分别为92%和86%，表现出良好的循环稳定性。碳材料的加入不仅可以有效避免了充放电过程中CuS单层的卷曲，提高了其循环寿命，同时，提高了材料的比表面积和导电性。本项目的开展为层状硫化物作为超级电容器电极材料拓展了新思路。