ZIF-Derived N-Doping Porous Carbon Nanofibers Prepared By Electrospinning And Performance For Li/Na Storage

In recent years,the shortage of lithium metal resources has hindered the development of lithium-ion batteries(LIBs),making researchers increasingly interested in sodium-ion batteries(SIBs).SIBs have a rich sodium source,similar structure and working principle as LIBs.But the difference of radius between Li~+and Na~+,the electrochemical performance of SIBs and LIBs is quite different.Anode material is one of the critical factors for the successful development of lithium/soudium-ion batteries.Among various anode materials,carbon-based anode materials have attracted much attention due to rich resources and low cost.In this paper,the PAN-based carbon nanofibers(CNFs)and ZIF-based N-doping porous carbon nanofibers(N-PCNFs)are prepared by electrospinning technique,which proved that the N-PCNFs have porous structure and more N-doping.CNFs and N-PCNFs can be as self-supporting anode to test for LIBs and SIBs,respectively.For LIBs/SIBs,N-PCNFs has higher lithium/sodium storage performance than CNFs and has excellent rate performance.After a long cycle of 1000 and 600 cycles,respectively,the reversible capacity of N-PCNTs is not significantly attenuated,indicating that the N-PCNFs have good cycle stability.The electrochemical impedance(EIS)text shows that the N-PCNFs material improves the ions transport kinetics due to the porous structure.The synergistic effect of N-doping and porous structure in the N-PCNTs,which improves the conductivity of the material,ions transport kinetics and alleviates the volume expansion during charge and discharge,making N-PCNFs has excellent Li/Na storage properties and long cyclic stability.The paper also discusses the effect of carbonation temperature on the specific surface area,pore size distribution and N content of N-PCNFs.N-PCNFs at different carbonation temperatures are used as anode for SIBs to study the effect of carbonation temperature on electrochemical performance.The results show that the N-PCNFs have excellent electrochemical performance at a carbonization temperature of 700 ?.