Sodium storage and transport properties in pyrolysis synthesized MoSe 2 nanoplates for high performance sodium-ion batteries

Constructing monodispersed MoSe2 anchored on graphene: a superior nanomaterial for sodium storage

“…From the first cathodic sweep, we could see two cathodic peaks at 0.65 and 0.44 V, respectively. The peak at 0.65 V is attributed to the sodium insertion to MoSe2 to form NaxMoSe2 while the next peak at 0.44 V is due to the reduction of Mo 4+ to Mo metal accompanied by the forming of Na2Se and the irreversible decomposition of the electrolytes [16,34]. During the anodic scan, we could see two oxidation peaks at 0.8 and 1.75 V and this phenomenon is due to the partial oxidation of Mo and Na2Se [17].…”

“…During the anodic scan, we could see two oxidation peaks at 0.8 and 1.75 V and this phenomenon is due to the partial oxidation of Mo and Na2Se [17]. Meanwhile, after the first cycle, one peak at 1.4 V shows up, and the two peaks at 0.44 and 0.65 V in the first cathodic sweep disappear, which may result from the reversible reaction of Mo 4+ + 2Na2Se ↔ MoSe2 + 4Na + [16,35]. No obvious changes can be observed for the following redox peaks, demonstrating the excellent stability of the electrode.…”

“…Transition metal dichalcogenides (TMDs) MX2 (M = Mo or W, X = S or Se) with the similar feature of layered structure to graphite have great potential as alternative anode materials for sodium ion energy storage [11][12][13][14][15][16][17][18]. In general, each layer of M atoms are sandwiched between two layers of hexagonally close-packed X atoms and the nearby X layers are connected by weak van der Waals interaction.…”

“…Over the past few years, great attention has been paid to molybdenum sulfide (MoS2) due to its high theoretical specific capacity and good cycling performance in sodium storage. However, as a close analogue to the layer structured MoS2, the electrochemical sodium storage performance of MoSe2 has been rarely investigated [16][17][18][19]. In addition, it is reported that MoSe2 has smaller band gap and larger inter-planar space compared with MoS2, suggesting its smaller structure resistance for intercalating and de-intercalating of Na ion from the layered MoSe2 structure when used as anode material for SIBs [20].…”

“…Recently, Wang et al [16] reported both experimental and theoretical assessment of layered MoSe2 nanoplates as the anode material possessing a reversible sodium storage capacity of 369 mA h g −1 at a rate of 0.1 C (about 0.042 A) af-ter 50 cycles. Ko et al [17] synthesized hierarchical MoSe2 yolk-shell microspheres via a facile selenization of MoO3 microspheres, which possessed a reversible sodium storage capacity of 433 mA h g −1 after 50 cycles at a current density of 0.2 A g −1 .…”