Pyridine-regulated Sb@InSbS₃ ultrafine nanoplates as high-capacity and long-cycle anodes for sodium-ion batteries

Abstract

Sb-based materials exhibit considerable potential for sodium-ion storage owing to their high theoretical capacities. However, the bulk properties of Sb-based materials always result in poor cycling and rate performances. To overcome these issues, pyridine-regulated Sb@InSbS₃ ultrafine nanoplates loaded on reduced graphene oxides (Sb@InSbS₃@rGO) were designed and synthesized. During the synthesis process, pyridine was initially adopted to coordinate with In³⁺, and uniformly dispersed In₂S₃ ultrafine nanoplates on reduced graphene oxide were generated after sulfidation. Next, partial In³⁺ was exchanged with Sb³⁺, and Sb@InSbS₃@rGO was obtained by using the subsequent annealing method. The unique structure of Sb@InSbS₃@rGO effectively shortened the transfer path of sodium ions and electrons and provided a high pseudocapacitance. As the anode in sodium-ion batteries, the Sb@InSbS₃@rGO electrode demonstrated a significantly higher reversible capacity, better stability (445 mAh·g⁻¹ at 0.1 A·g⁻¹ after 200 cycles and 212 mAh·g⁻¹ at 2 A·g⁻¹ after 1200 cycles), and superior rate (210 mAh·g⁻¹ at 6.4 A·g⁻¹) than the electrode without pyridine (355 mAh·g⁻¹ at 0.1 A·g⁻¹ after 55 cycles and 109 mAh·g⁻¹ at 2 A·g⁻¹ after 770 cycles). Furthermore, full cells were assembled by using the Sb@InSbS₃@rGO as anode and Na₃V₂(PO₄)₃ as cathode, which demonstrated good cycling and rate performances and exhibited promising application prospects. These results indicate that adjusting the microstructure of electrode materials through coordination balance is A·good strategy for obtaining high-capacity, high-rate, and long-cycle sodium storage performances.

Graphical abstract

摘要

锑基材料具有较高的理论储钠容量, 在钠离子电池储能系统中存在较大的潜力。然而, 锑基材料的块状体积特性导致电池具有较差的循环稳定性和倍率性能。为了有效解决该问题, 本文在还原的氧化石墨烯表面负载了吡啶调控的Sb@InSbS₃超小纳米片(Sb@InSbS₃@rGO)。在制备过程中, 吡啶首先与In³⁺配位, 经过硫化后, 在rGO表面上生成均匀分散的In₂S₃超小纳米片, 然后将Sb³⁺交换In₂S₃中的部分In³⁺, 最后经过退火处理制备了Sb@InSbS₃@rGO。Sb@InSbS₃@rGO的超小纳米片结构可以有效缩短钠离子和电子的转移路径, 并提升赝电容贡献率。Sb@InSbS₃@rGO作为钠离子电池负极材料, 具有较高的可逆容量, 良好的稳定性(在0.1 A·g⁻¹下循环200次后, 可逆容量仍保持为445 mAh·g⁻¹, 在2 A·g⁻¹下循环1200次后, 可逆容量保持为212 mAh·g⁻¹)和较好的倍率性能(在6.4 A·g⁻¹下可逆容量为210 mAh·g⁻¹), 远超未使用吡啶的电极(在0.1 A·g⁻¹下循环55次后, 可逆容量仅为355 mAh·g⁻¹;在2 A·g⁻¹下循环770次后, 可逆容量仅为109 mAh·g⁻¹)。此外, 由Sb@InSbS₃@rGO负极和Na₃V₂(PO₄)₃正极组装的全电池也展现出良好的循环稳定性和倍率性能, 充分体现了Sb@InSbS₃@rGO较好的应用前景。以上结果表明, 借助配位平衡调控电极材料的微观结构是获得高容量、高倍率和长周期钠离子电池的良好策略。