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MoSe 2 ‐Covered N,P‐Doped Carbon Nanosheets as a Long‐Life and High‐Rate Anode Material for Sodium‐Ion Batteries
Author(s) -
Niu Feier,
Yang Jing,
Wang Nana,
Zhang Dapeng,
Fan Weiliu,
Yang Jian,
Qian Yitai
Publication year - 2017
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201700522
Subject(s) - materials science , pseudocapacitance , anode , composite number , electrochemistry , carbon fibers , chemical engineering , raman spectroscopy , calcination , transmission electron microscopy , sodium ion battery , doping , nanotechnology , electrode , composite material , supercapacitor , catalysis , chemistry , organic chemistry , optoelectronics , faraday efficiency , engineering , physics , optics
MoSe 2 grown on N,P‐co‐doped carbon nanosheets is synthesized by a solvothermal reaction followed with a high‐temperature calcination. This composite has an interlayer spacing of MoSe 2 expanded to facilitate sodium‐ion diffusion, MoSe 2 immobilized on carbon nanosheets to improve charge‐transfer kinetics, and N and P incorporated into carbon to enhance its interaction with active species upon cycling. These features greatly improve the electrochemical performance of this composite, as compared to all the controls. It presents a specific capacity of 378 mAh g −1 after 1000 cycles at 0.5 A g −1 , corresponding to 87% of the capacity at the second cycle. Ex situ Raman spectra and high‐resolution transmission electron microscopy images confirm that it is element Se, rather than MoSe 2 , formed after the charging process. The interaction of the active species with modified carbon is simulated using density functional theory to explain this excellent stability. The superior rate capability, where the capacity at 15 A g −1 equals ≈55% of that at 0.5 A g −1 , could be associated with the significant contribution of pseudocapacitance. By pairing with homemade Na 3 V 2 (PO 4 ) 3 /C, this composite also exhibits excellent performances in full cells.