First-principles and experimental study of nitrogen/sulfur co-doped carbon nanosheets as anodes for rechargeable sodium ion batteries

Abstract

Heteroatom doped carbon materials have recently demonstrated an outstanding sodium storage ability and are being considered as the most promising candidates as anodes for sodium ion batteries.

N/S Co‐Doped 3 D Porous Carbon Nanosheet Networks Enhancing Anode Performance of Sodium‐Ion Batteries

“…Figure 2a displaysthe XRD patterns of PCNN and NSPCNN-2. [22] All the spectra exhibit broad Db ands ( % 1350cm À1 )a nd Gb ands ( % 1570 cm À1 ). The XRD patterns and Ramans pectra of NSPCNN-1 and NSPCNN-3a re shown in FigureS2( Supporting Information), the interlayer spacings of which are 3.49 and 3.73 ,r espectively.C learly,N SPCNN-2 possesses the largesti nterlayers pace.A ccording to theoretical calculations, ac ritical minimum spacing of 0.37 nm between graphitic layersi sr equired for good Na + insertion properties.…”

“…[10] However,a part from the interlayer spacing, the graphitization degree of ac arbonaceousm aterial can also affect itsN a + storage, so Raman spectroscopy was also conducted. [22] All the spectra exhibit broad Db ands ( % 1350cm À1 )a nd Gb ands ( % 1570 cm À1 ). Figure 3a,b that the PCNN and NSPCNN-2s amples both possessahighlyi ntercon-nected3 Dp orousn etwork structure with micrometer-sized macropores, revealing that the thin walls should have excellent mechanical flexibility,a nd provide abundant interpenetrating channels between nanosheets to allow effective infiltration of electrolyte into the electrode materials and shorten the Na + transportd istance.…”

Biomass‐Derived Carbons for Sodium‐Ion Batteries and Sodium‐Ion Capacitors

“…The O-and N-codoped carbonsh ave been widely used because they provide an additional charge-storage capacity by Na ions bonding to functional groups and improving the electrical conductivity by introducing more free electrons to the conduction band of the carbon. [63,139,140,[142][143][144] The N-, S-, andO -doped carbonc an be facially synthesized due to the chemicald iversity of natural resources. However,i ti sh ard to control the contento fd opants in biomass-derived carbon.R ecently,G uo et al introduced an air oxidation activation (AOA) technique to finely tune the elemental compositiono fb iomass-derived carbon.…”

Carbon and Carbon Hybrid Materials as Anodes for Sodium‐Ion Batteries

“…The diameter of Na + (0.98 Å) is larger than that of Li + (0.69 Å), which makes insertion of Na + into the interlayer of graphite difficult. Recently, as alternative carbon materials, various amorphous carbon materials such as one‐dimensional (1 D) carbon nanofibers/nanotubes, two‐dimensional (2 D) carbon nanoplates, heteroatom‐doped graphene, and three‐dimensional (3 D) porous carbon nanostructures have shown promise as anode materials for SIBs, owing to their large interlayer spacings and disordered structures, which can afford abundant sodium‐ion storage sites. Moreover, a number of elementary substances (P, Sn, Sb, etc.…”

“…Apart from using graphene as a precursor, choosing suitable carbon precursors and the right synthetic methods can allow for the preparation of 2 D graphene‐like carbon nanosheets. To control the thickness of production, carbon precursors with a low carbonization rate such as citric acid, urea, gelatin, and acetaldehyde are selected . Such carbon precursors usually consist of nitrogen/sulfur atoms, which thus easily results in heteroatom‐doped carbon.…”