Oligomer-derived Carbon And Carbon-anchored Manganese Oxide For Advanced Electrochemical Energy Storage

Multi-dimensional porous carbon materials have exhibited broad application prospects in the field of electrochemical energy storage for the well-developed pore structure,abundant heteroatoms and fast kinetics.In view of the comprehensive demand of new-generation energy storage equipment for key performances such as capacity,rate and cycle life of electrode materials,traditional graphite electrodes have been difficult to meet the development needs of the times,so there is an urgent need to develop new porous carbon materials.In this work,a nitrogen-doped carbon@RGO composite electrode material has been synthesized using glycoluril as the carbon source and RGO as the framework.The effects of carbonization temperature and RGO framework on the sodium storage performances of the nitrogen-doped carbon@RGO composite were systematically studied.Further,using nitrogen-doped carbon@RGO as the conductive framework,manganese oxide materials anchored in the nitrogen-doped carbon@RGO framework were prepared by in-situ composite strategy,and the effects of calcination atmosphere,conductive framework,and other factors on the lithium storage performances of manganese oxide were studied in detail.A nitrogen-doped carbon@RGO composite electrode material with mesopores-macropores hierarchical pore structure and ultra-high nitrogen doping level(10.29 at.%)has been synthesized using glycoluril as the carbon source and RGO as the framework.Serving as the anode for sodium ion batteries,nitrogen-doped carbon@RGO composite exhibits high reversible specific capacity(281.5 mAh g-1 at 0.05 A g-1),excellent rate performance,long lifespan(about 200 mAh g-1 after 3000 cycles at 5 A g-1)and fast kinetics.The mixed valence manganese oxide anchored in nitrogen-doped carbon@RGO network was prepared by in-situ hydrothermal composite strategy.The composite obtained by calcination in reducing atmosphere(Ar/H2)demonstrates a micro-cubic morphology formed by stacking nanosheets anu,specific surface area of 216.2 m2 g-1,and the phase composition is dominated by MnO with high electrochemical activity.In a Li half-cell configuration,the composite exhibits an initial reversible specific capacity of 778.2 mAh g-1 at 0.1 A g-1,and the reversible specific capacity is 402 mA h g-1 after 1000 cycles at 1 A g-1.Porous carbon with micropores-mesopores hierarchical pore structure and specific surface area up to 2961.11 m2 g-was prepared by using glycoluril as carbon source and KOH as activator at 800?.With this porous carbon as the cathode,sodium ion hybrid capacitors and lithium ion hybrid capacitors were assembled using the above two composite materials as anodes,respectively.Both hybrid energy storage devices deliver extraordinary energy/power density and excellent cycle performance.