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

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 −1 at a specific current of 100 mA g −1 and an impressive rate performance with 100 % capacity retention after high current cycling involving a 2 Ag −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 −15  cm 2  s −1 to 2.2×10 −12  cm 2  s −1 were observed, while in case of bare Sb 2 Se 3 the diffusion coefficients in the range of 1.6×10 −15  cm 2  s −1 to 9.4×10 −15  cm 2  s −1 were observed.