High Na⁺ Mobility in rGO Wrapped High Aspect Ratio 1D SbSe Nano Structure Renders Better Electrochemical Na⁺ Battery Performance

Abstract

We chose to understand the cyclic instability and rate instability issues in the promising class of Na + conversion and alloying anodes with Sb 2 Se 3 as a typical example. We employ a synthetic strategy that ensures efficient rGO (reduced graphene oxide) wrapping over Sb 2 Se 3 material. By utilization of the minimum weight of additive (5 wt.% of rGO), we achieved a commendable performance with a reversible capacity of 550 mAh g À 1 at a specific current of 100 mA g À 1 and an impressive rate performance with 100 % capacity retention after high current cycling involving a 2 Ag À 1 intermediate current step. The electrochemical galvanostatic intermittent titration technique (GITT) has been employed for the first time to draw a rationale between the enhanced performance and the increased mobility in the rGO wrapped composite (Sb 2 Se 3 -rGO) compared to bare Sb 2 Se 3 . GITT analysis reveals higher Na + diffusion coefficients (approx. 30 fold higher) in the case of Sb 2 Se 3 -rGO as compared to bare Sb 2 Se 3 throughout the operating voltage window. For Sb 2 Se 3 -rGO the diffusion coefficients in the range of 8.0 × 10 À 15 cm 2 s À 1 to 2.2 × 10 À 12 cm 2 s À 1 were observed, while in case of bare Sb 2 Se 3 the diffusion coefficients in the range of 1.6 × 10 À 15 cm 2 s À 1 to 9.4 × 10 À 15 cm 2 s À 1 were observed.

Heterojunction-Promoted Sodium Ion Storage of Bimetallic Selenides Encapsulated in a Carbon Sheath with Boosted Ion Diffusion and Stable Structure

“…Intriguingly, the MoSe 2 –Sb 2 Se 3 @C anode retains a steady capacity of 376.0 mA h g –1 under a 2.0 A g –1 upon 580 cycles, giving a high capacity retention of 77%. The rate capability of MoSe 2 –Sb 2 Se 3 @C is obviously better than that of other reported materials, indicating that the MoSe 2 –Sb 2 Se 3 @C composite has high potential for commercial application (Figure h). ,,,,,, Figure S8 displays the structure of the MoSe 2 –Sb 2 Se 3 @C anode electrode after cycling at 2 A g –1 for 200 cycles, showing good structural integrity.…”

“…In the survey spectrum in Figure c, it can be seen that the sample contains Sb, O, N, C, Mo, and Se. There are four divided peaks in the high-resolution XPS spectrum in Figure c1, in which the peaks at 530.4 and 539.8 eV correspond to Sb 3+ 3d 5/2 and Sb 3+ 3d 3/2 , and the ones at 530.5 and 531.4 eV are assigned to Mo–O/C–O and O–H of O 1s, respectively . In Figure c2, the deconvoluted peaks in the N 1s spectrum are indexed to pyridinic-N at 398.4 eV, pyrrolic-N at 400.3 eV, and graphitic-N at 403.4 eV, respectively. , Figure c3 shows the four fitted peaks assigned to C–C bonds at 284.6 eV, CC bonds at 285.3 eV, C–O/C–N (derived from polydopamine) bonds at 286.3 eV, and CO (derived from the residue of tartaric acid in the precursor) bonds at 288.7 eV .…”

“…The rate capability of MoSe 2 − Sb 2 Se 3 @C is obviously better than that of other reported materials, indicating that the MoSe 2 −Sb 2 Se 3 @C composite has high potential for commercial application (Figure 4h). 11,19,23,25,26,31,32 For the purpose of further investigating the reaction kinetics of the MoSe 2 −Sb 2 Se 3 @C composite as a SIB anode material, the CV curves at different scan rates were measured within 0.2−1.0 mV s −1 . The shapes of the CV curves shown in Figure 5a for the various scan rates are basically the same.…”

A new method of synthesis of Sb2Se3/rGO as a high-rate and low-temperature anode for sodium–ion batteries

“…15 The peak at 261 originated from rGO, indicating the presence of rGO in the composite. 33,34 Further evidence comes from XPS spectra of Sb 2 Se 3 /rGO. Fig.…”

Na ion batteries: An India centric review

“…The experiment revealed that the diffusion coefficients of Sb 2 Se 3 with rGO lie in the 8.0 × 10 −15 cm 2 s −1 to 2.2 × 10 −12 cm 2 s −1 range. At the same time, it lies between 1.6 × 10 −15 cm 2 s −1 to 9.4 × 10 −15 cm 2 s −1 in the case of only Sb 2 Se 3 [ 161 ].…”