Preparation And Research On Spinel Co-Mn Oxide For Supercapacitor Electrode

Supercapacitor as a new energy storage device has been paid more attention all over the world, which is environment friendly, high efficiency and low cost.Therefore, searching for new synthetic methods and application of new material are a key issue for energy storage device. Transition metal oxides are a kind of ideal pseudo-capacitor material, which have a high capacitance in theoretically.However, the poor electrical conductivity is a major defect to limit its development. So a hybrid structure with graphene as substrate is considerable. In this work, I prepared spinel structure（Mn,Co）3O4 load on reduced graphene oxide（r GO）, which act as the electrodes of asymmetric supercapacitors.In this work a simple method have been explored to prepare 3D porous graphene. The as prepared electrode materials shows a wide working voltage range of-1.2 0 V, the working voltage can be 1.2 V. And the highest specific capacity could be 206 F/g. The electrode materials can retain 98% of the initial capacity after 4000 cycles.Mesoporous CoMn₂O₄/rGO composite were successfully synthesized by solvothermal method, followed by a calcinations process. By the adjusting the solvent ratio of DMF: DI water, the surface morphologies can be tuned from nanofibers to nanoplates. And also the complex microstructure growth mechanism and the electrochemical properties have been studied.A hybrid capacitor have been fabricated by using 3D porous rGO as negative electrode and mesoporous CoMn₂O₄/rGO composite as positive electrode. And the CV test shows that the optimal working potential window is 1.6 V without obvious polarization on the electrode.A one-step route synthesis transition metal oxide（CoMn）（CoMn）₂O₄ with spinel structure coated on rGO have been demonstrated in this work. The highly crystallinity nanoscale metal oxide particles evenly attached on the surface of rGO sheet can be achieved just through one step hydrothermal. The hydird material also has displayed good performance when acting as capacitor electrode.In this work we have prepared composite electrode materials of Co-Mn oxides spinel structure supported on rGO and porous 3D r GO for electrode of asymmetric supercapacitors. Finally, we firstly developed a one-step route synthesis of（Co Mn）（CoMn）2/rGO complexes through hydrothermal process..