Ultrasmall SnS₂nanoparticles anchored on well-distributed nitrogen-doped graphene sheets for Li-ion and Na-ion batteries

Abstract

Well-distributed graphene sheets doped with nitrogen (NGS) were prepared via a thermal annealing strategy with the existence of cyanamide. The cyanamide can efficiently restrain the conglomeration of the resultant graphene sheets and synchronously make sure the doping of nitrogen. Followed by the next-step of low-temperature solvothermal route, uniform ultrasmall tin sulfide (SnS 2 ) nanocrystals were readily grown on the preformed NGS (denoted as SnS 2 -NGS).Benefiting from the synergistic function between NGS and SnS 2 , the resultant composites exhibit excellent electrochemical performance. In case of estimation as anode materials for lithium-ion batteries (LIBs), SnS 2 -NGS with moderate weight ratio of SnS 2 deliver outstanding electrochemical outcomes giving the high reversible capacity of 1407 mA h g -1 at 200 mA g -1 after 120 cycles. The composites can also maintain a reversible capacity of about 200 mA h g -1 at a high current density of 10 A g -1 . The lithium-ion storage ability of prepared SnS 2 -NGS electrode is at the top rank in comparison with the other works. The obtained composites also achieve good sodium storage ability.

A Simple One‐Pot Strategy for Synthesizing Ultrafine SnS2 Nanoparticle/Graphene Composites as Anodes for Lithium/Sodium‐Ion Batteries

“…During the simple one-pot preparation of SnS 2 /graphene composites, we added more graphene oxide for SG75. [3,8,26,33,[38][39][40][41][42][43] Such great electrochemical performance showst hat the simple and one-pot synthesized SG75 composite has great potential in large-scale applications as the anode for LIBs. [37] Thus, the SG75 electrode obtained am ore stable cycling performance (thec ycling performance of pure graphene oxide and commercialS nS 2 is shown in Figure S6).…”

“…[8] The excellent LIB electrochemical performance of 1407mAh g À1 at ac urrent density of 0.2 Ag À1 after 120 cycles was obtained as ar esult of the combined effect of ultrafine SnS 2 nanoparticles and the introductiono f nitrogen-doped graphene. For example, Xi and co-workers prepared ultrasmall SnS 2 nanoparticles/nitrogen-doped graphene sheets by as olvothermalr oute.…”

“…[1][2][3] Amongv arious SnS 2 -based materials, SnS 2 /graphene composites have been extensively studied owing to the fact that the electrochemical performance of pristine SnS 2 could be efficiently improved by the introduction of graphene. [8][9][10] However,the rapid capacity decrease, which is induced by volume change and exfoliation of active materials during the lithium storage process,a nd the low inherent conductivity,h ave dramatically hindered the application of SnS 2 anodes. [8][9][10] However,the rapid capacity decrease, which is induced by volume change and exfoliation of active materials during the lithium storage process,a nd the low inherent conductivity,h ave dramatically hindered the application of SnS 2 anodes.…”

Metallic‐State SnS2 Nanosheets with Expanded Lattice Spacing for High‐Performance Sodium‐Ion Batteries

“…This is an important reasonf or the low initial coloumbic efficiency (ICE)o fp ure SnS 2 .T he subsequentc athodic peak at approximately 0.54 Vw as attributed to the conversion of SnS 2 into Sn andN a 2 S[ Eq. [20,34,36,37] (3)],a long with the formation of an irreversible solid electrolyte interphase (SEI) film in the first cycle.…”

“…[4][5][6][7][8][9][10][11][12] Among these materials,S nS 2 can deliver ah igh theoretical capacity up to 1137 mAh g À1 and good reversibility owing to its meritss uch as large interlayer spacing and high reversible conversion efficiency. [14,16,[18][19][20] However,t hese methods cannota ddress the electronic conductivity issues of SnS 2 semiconductors from am aterialp erspective.R ecently,t he approach of dopingm etal ions hasp rovenv ery fruitful and effective for improving the electrochemical performance by increasing the electronic conductivity and ion mobility.F or example, Se and Fe (or Co and Ni)c o-doped NbS 2 nanosheets showed significantly improved Li + /Na + storage properties compared with those of pure NbS 2 . Therefore, many strategies have been employed to realize high rate capability and as atisfactory lifespan by improvingt he electronic conductivity,s uch as utilizing advanced carbon composite materials.…”