| The requirement for energy storage devices becomes increasingly high due to the excessive exploitation of fossil fuels and serious environmental pollution.Sodium ion batteries(SIBs)have great potential in large-scale energy storage owing to the advantages of abundant sodium resources and low price.However,the large radius of sodium ion makes it more strict to find suitable electrode materials and it is very important to develop anode materials with excellent sodium storage properties.Carbon nanomaterial has a wide research space and research value because it is a kind of potential anode electrode material due to the advantages of good conductivity,good stability and long cycle life.In this paper,taking nitrogen-doped carbon nanosheets as an object,we explore its preparation methods and sodium storage perfomace.The main results are as follows:A nitrogen-doped carbon nanosheets are preapred by high temperature solid state pyrolysis method uisng NaCl as an template,glucose as carbon source,urea as nitrogen source,and KOH as activator.Structural and compositonal characterization indicate that this kind of carbon material exhibits porous structure with a N content about 5.55%.These features can inhibit self-aggregation very well and provide more active sites for sodium ion storage.When it is used as anode materials for SIBs,the prepared nitrogen-doped carbon nanosheets posseses superior sodium storage properties.After 100th cycle at a current density of 0.1 A g-1,a reversible capacity of 195 mAh g-1 is maintained and after 400th cycle at a current density of 0.5 A g-1,a high capacity retention of 94.2%is exhibited.In particular,at a high current density of 10 A g-1,the reversible capacity of 108 mAh g-1 is maintained.The cyclic voltammetry analysis at different scanning rates reveals this material has a remarkable capacitive charge storage effect,thereby leading to superior electrochemical performance.The prepared nitrogen-doped carbon nanosheets have potential application in SIBs. |
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