This thesis examines electrode materials such as mesoporous carbons, manganese oxides, iron oxides and their nanohybrids with graphene. It also explores several of the key scientific issues that act as the governing principles for future development of supercapacitors, which are a promising class of high-efficiency energy storage devices for tackling a key aspect of the energy crisis. However, critical technical issues, such as the low energy density and reliability, need to be addressed before they can be extended to a wide range of applications with much improved performance. Currently available material candidates for the electrodes all have their disadvantages, such as a low specific capacitance or poor conductivity for transition metal oxide/hydroxide-based materials. This thesis addresses these important issues, and develops a high-performance, flexible asymmetric supercapacitor with manganese oxides/reduced graphene oxide as the positive electrode and iron oxide/reducedgraphene oxide as the anode, which delivers a high energy density of 0.056 Wh cm-3.

Autorentext

Dr. Yating HU received both of her Bachelor and Doctoral degrees in Department of Materials Science and Engineering from the National University of Singapore (in the year of 2011 and 2017, respectively). From the year of 2011 to 2012, she worked as a process engineer in solar cell industry but her passion for research in materials science had driven her to come back to the university and pursue her Ph.D. degree.

Her supervisor during Ph.D. studies is Prof. John Wang and her research focused on nanomaterials for energy storage application. She mainly used carbon, manganese oxides and iron oxides based materials to develop various electrodes for supercapacitors. After obtaining her Ph.D., she has been working as a research fellow in the same group. Currently, she is working on manganese compound based nanomaterials for energy storage and electrocatalysis applications.

Inhalt

Introduction.- Experimental Section.- Nitrogen Doping of Mesoporous Carbon Materials.- Improving the Surface Area and Loading Mass of MnOx Based Electrode materials.- Mn3O4 Nanomaterials with Controllable Morphology and Particle Sizes.- Optimized Hybrid Mn3O4 Nanofiber/rGO Paper for High Performance Flexible ASCS.- Hybrid Fe2O3 Nanoparticle Clusters/rGO Paper for Flexible Supercapacitors.- Conclusions and Recommendations.