MoS₂/Graphene Composite Anodes with Enhanced Performance for Sodium‐Ion Batteries: The Role of the Two‐Dimensional Heterointerface

Abstract

1393wileyonlinelibrary.com the practical applications of SIBs have been hamstrung by the lack of suitable anode materials to host Na + , which has a larger radius than that of Li + . Graphite with a highly ordered structure is considered to be not suitable to accommodate Na + because Na hardly forms staged intercalation compounds with graphite. [ 2 ] Twodimensional layered metal sulfi des (LMSs) with analogous structures to graphite, such as MoS 2 , [ 3 ] WS 2 , [ 4 ] SnS, [ 5 ] and SnS 2 , [ 6 ] have been reported as potential electrode materials for SIBs. The open framework of these types of materials allows Na + to insert reversibly with acceptable mobilities. However, the further application of 2D LMSs is impeded by their inherent limitations. First, these semiconductor metal sulfi des have inherently low electronic conductivity, which affects their electrochemical performances for Na + storage. Second, owing to the high surface energy and interlayer van der Waals attractions, [ 7 ] these thermally unstable 2D nanomaterials have a tendency to restack to minimize the surface energy. Furthermore, the signifi cant volume change and mechanical stress as a concomitant of sodium-ion insertion and extraction can induce the failure of the electrode and the loss of contact between active materials and the current collector, resulting in poor cycling stability.Graphene has established itself as a promising candidate to circumvent these challenges. For example, WS 2 /graphene, [ 4 ] SnS/graphene, [ 5b ] and SnS 2 /graphene [ 6 ] nanocomposites have already been successfully applied as anode materials for SIBs, showing a synergistic effect for sodium-ion storage, including improved capacity, rate capability, and cycling stability. In these reports, it is generally recognized that the enhanced electrochemical performances are attributed to the good electronic conductivity and mechanical resilience of graphene as 2D conformal building blocks for these layered sulfi des. However, a fundamental understanding of the exact interaction mechanism between LMSs and graphene for improving Na + storage performance is still not clear. The heterointerface between LMSs and graphene has been proven to contribute to novel properties and new functionalities that cannot be achieved by individual constituting materials. [ 8 ] Therefore, investigations Graphene has been widely used as conformal nanobuilding blocks to improve the electrochemical performance of layered metal sulfi des (MoS 2 , WS 2 , SnS, and SnS 2 ) as anode materials for sodium-ion batteries. However, it still lacks in-depth understanding of the synergistic effect between these layered sulfi des and graphene, which contributes to the enhanced electroactivity for sodium-ion batteries. Here, MoS 2 /reduced graphene oxide (RGO) nanocomposites with intimate two-dimensional heterointerfaces are prepared by a facile one-pot hydrothermal method. The heterointerfacial area can be effectively tuned by changing the ratio of MoS 2 to RGO. When used as anode materials for sodiu...

Two-Dimensional (2D) Nanomaterials towards Electrochemical Nanoarchitectonics in Energy-Related Applications

“…292 Sheet-on-sheet structured MoS 2 /rGO nanocomposites show a reversible Na ion storage capacity of 338 mA h g ¹1 293 and 702 mA h g ¹1 , respectively. 294 The high abundance and low cost of Na and its low redox potential (0.3 V above that of lithium) makes rechargeable sodium ion batteries (SIBs) an alternative to LIBs. However, improvement of supercapacitor performance using novel electrode materials accompanied by low-cost production necessitates a deep fundamental understanding of the charge storage mechanisms, transport pathways of electrons and ions and electrochemically active sites.…”

Emerging nanostructured electrode materials for water electrolysis and rechargeable beyond Li-ion batteries

“…The most studied TMDC phases in energy storage application include MoS 2 [108][109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124][125], MoSe 2 [126][127][128][129][130][131], WS 2 [132][133][134][135], and WSe 2 [136][137][138]. MoS 2 , with the interlayer distance of 6.2 Å, is explored as an anode material for SIBs.…”

“…Many examples of the hybrid TMDC@carbon structures demonstrating enhanced electrochemical properties have been reported [115][116][117][118][119][120], however in this review we would like to highlight several successful strategies applied to integrate MoS 2 with carbon, which could be used to improve performance of other 2D materials in BLI energy storage systems.…”

Facile hydrothermal synthesis of ternary Ni–Co–Se/carbon nanotube nanocomposites as advanced electrodes for lithium storage

“…8,10 Thus the electrochemical performance of these compounds has to be improved via both structural and compositional engineering for real applications. [10][11][12][13] A viable solution is preparing the composites consisting of TMCs and carbonaceous materials (such as amorphous carbon, 14,15 graphene, 16,17 carbon nanotubes 18,19 ) to improve conductivity of electrodes. The carbonaceous materials are introduced to improve the electrical conductivity and enhance the electrochemical performance of the TMCs anodes.…”