Design Of Two-dimensional Nanomaterial System Based On Interfacial Chemistry And Study Of Its Electrochemical Performance

The ever-worsening global warming and energy scarcity issues call for not only urgent development of clean alternative energies and emission control of greenhouse gases, but also more advanced energy storage and management systems. Recently, electrochemical energy storage and conversion devices, including supercapacitors, lithium ion batteries, and fuel cells, demonstrates excellent potential for applications. Among these, nanostructured materials based supercapacitors, lithium ion batteries, and fuel cells show the best electrochemical activities. This thesis focused on the physical-chemical changing of interfaces in the nanostructured materials based electrochemical devices.The main results and conclusion can be summarized as following:(1) For supercapacitors, transition metal layered hydroxides were investigated as active materials for supercapacitors. The inter-layer effect on the electrochemical activity of a-Co(OH)2was firstly studied. The single-layer ?-Co(OH)2was firstly prepared by wet chemistry method. Furthermore, the reduced graphene oxide/single-layer ?-Co(OH)2layered composite was prepared by electrostatic force and demonstrated excellent electrochemical activity.(2) For lithium ion batteries, the polydopamine was firstly introduced to the electrode system as a buffer. By the assistance of polydopamine, the covalent bond was firstly formed in the electrode system. And the strength of the entire electrode was improved. As a result, the long-cycle-life electrode for lithium ion batteries was obtained. Furthermore, this method was also used in Li-S batteries. The covalent bond glued electrode for Li-S batteries was also prepared.(3) For electro-catalysis, the oxygen reduction and oxygen evolution activity of single-layer Co/Ni(OH)2was firstly investigated. The single-layer Ni(OH)2was further hybrid with commercial Pt/C catalyst and the improved activity was obtained.