Sb/SnO@C composite prepared by electrospinning for high performance sodium ion battery anodes

Energy Band-Modulated SnO Anodes with Improved Rate Capacity and Initial Coulombic Efficiency for Sodium-Ion Batteries

“…In the initial three discharge/charge cycles, the first wide cathode band extended in the range 0.70–0.20 V is obviously different from the others, which is attributed to the formation of a solid electrolyte interface (SEI). The cathodic peaks at ∼0.67, ∼0.45, and ∼0.04 eV, respectively, are attributed to the gradual alloying of Bi to form NaBi and Na3 Bi, as well as Sn to NaxSn. ,,, By contrast, in the subsequent anodic scanning, two sharp oxidation peaks at 0.62 and 0.75 V are ascribed to the dealloying of Na3 Bi to NaBi and NaBi to Bi, respectively. Similarly, the weak peak at 0.08 V is due to the dealloying of the NaxSn phase. ,,, In addition, it should be pointed out that the reduction peak at 0.04 V and the oxidation peak at 0.08 V, which come from the alloy and dealloy of Sn, respectively, appeared in the SnO@Bi@C anode but were not observed in the SnO@C anode, indicating that the presence of Bi facilitates more NaxSn phase generation in the SnO anode, which is beneficial to improve the ICE and reversible Na+ ion storage.…”

“…The cathodic peaks at ∼0.67, ∼0.45, and ∼0.04 eV, respectively, are attributed to the gradual alloying of Bi to form NaBi and Na3 Bi, as well as Sn to NaxSn. 16,17,28,29 By contrast, in the subsequent anodic scanning, two sharp oxidation peaks at 0.62 and 0.75 V are ascribed to the dealloying of Na3 Bi to NaBi and NaBi to Bi, respectively. Similarly, the weak peak at 0.08 V is due to the dealloying of the NaxSn phase.…”

“…Similarly, the weak peak at 0.08 V is due to the dealloying of the NaxSn phase. 16,17,28,29 In addition, it should be pointed out that the reduction peak at 0.04 V and the oxidation peak at 0.08 V, which come from the alloy and dealloy of Sn, respectively, appeared in the SnO@Bi@C anode but were not observed in the SnO@C anode, indicating that the presence of Bi facilitates more NaxSn phase generation in the SnO anode, which is beneficial to improve the ICE and reversible Na+ ion storage. Particularly, under the same voltage range, the redox peaks of the SnO@Bi@C anodes become very obvious, suggesting that the addition of the Bi element does improve the reaction kinetics, leading to the elevated reversibility and improved ICE.…”