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Free‐Standing Nitrogen‐doped Graphene Paper as Electrodes for High‐Performance Lithium/Dissolved Polysulfide Batteries
Author(s) -
Han Kai,
Shen Jingmei,
Hao Shiqiang,
Ye Hongqi,
Wolverton Christopher,
Kung Mayfair C.,
Kung Harold H.
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201402329
Subject(s) - polysulfide , graphene , x ray photoelectron spectroscopy , faraday efficiency , raman spectroscopy , inorganic chemistry , sulfide , electrolyte , thermogravimetric analysis , chemistry , lithium (medication) , dielectric spectroscopy , electrode , chemical engineering , materials science , electrochemistry , nanotechnology , organic chemistry , medicine , physics , optics , endocrinology , engineering
Free‐standing N‐doped graphene papers (NGP), generated by pyrolysis of polydiallyldimethylammonium chloride, were successfully used as binder‐free electrodes for the state‐of‐the‐art Li/polysulfide‐catholyte batteries. They exhibited high specific capacities of approximately1000 mA h g −1 (based on S) after 100 cycles and coulombic efficiencies great than 98 %, significantly better than undoped graphene paper (GP). These NGP were characterized with XRD, X‐ray photoelectron spectroscopy, thermogravimetric analysis, AFM, electron microscopy, and Raman and impedance spectroscopy before and after cycling. Spectroscopic evidence suggested stronger binding of sulfide to NGP relative to GP, and modelling results from DFT calculation, substantiated with experimental data, indicated that pyrrolic and pyridinic N atoms interacted more strongly with Li polysulfides than quaternary N atoms. Thus, more favorable partition of polysulfides between the electrode and the electrolyte and the corresponding effect on the morphology of the passivation layer were the causes of the beneficial effect of N doping.