Synthesis,regulation And Energy Storage Performance Of Transition Metal Compound/carbon Composites

Transition metal compounds have the high theoretical capacitance and low cost,which are highly suitable for energy storage.However,the practical capacitance of such materials is limited,mainly due to their low electrical conductivity and small active surface area.In this paper,from the perspective of reducing the size of energy storage materials and synergistically promoting their charge transport kinematics,we have compounded transition metal compounds with carbon-based nanomaterials which improved their conductivity,shortened their ion solid diffusion distance,increased their electrochemical active surface area and improved their charge transfer rate.Thereby,these features synergistically promoted their energy storage performance.It provides a reference for the optimization of energy storage performance of transition metal compounds by establishing the structure-performance relationship between electrode materials and energy storage performance.After research,the following progresses have been made:1.Co(OH)2/hNCNCs,CoO/hNCNCs and Co3O4/hNCNCs composites were prepared by microwave-assisted ethylene glycol method and heat-treatment process using hierarchical nitrogen-doped carbon nanocages(hNCNCs)as supports.We have studied the effects of preparation conditions on the energy storage performance of composites,such as support types,active materials mass loading,heat-treatment atmosphere and temperature,and got the best Co(OH)2/hNCNCs composite with excellent energy storage performance.We have also studied the energy storage characteristics and mechanism of different composites and revealed their structure-performance relationship.The optimized electrode material and activated carbon were assembled into an asymmetric supercapacitor,and such energy storage device had high energy density and power density.2.The K intercalated manganese oxide nanowires prepared in early were used as active materials.By co-ball milling the manganese oxide with carbon nanomaterials,We have reduced their particle size,shortened their ion solid diffusion distance and improved their conductivity.Then,we have improved their crystallinity by heat-treatment at high temperature in Ar.Finally,we have studied the effects of heat-treatment temperature,carbon nanomaterial and electrolyte types on the energy storage performance of manganese oxide/carbon composites.Through the above strategies,we have synthesized a novel Mn-based supercapacitor electrode material with high specific capacitance which provided a material basis for subsequent research.