Facile synthesis of Sb@Sb₂O₃/reduced graphene oxide composite with superior lithium-storage performance

Abstract

Sb-based materials have been considered one of the most promising anode electrode materials for lithium-ion batteries, whereas they were commonly synthesized through time-consuming and costly processes. Here, Sb@Sb₂O₃/reduced graphene oxide (Sb@Sb₂O₃/rGO) composite was successfully synthesized by a facile one-pot chemical method at ambient temperature. Based on the XRD and TGA analysis, the mass fractions of Sb and Sb₂O₃ in the Sb@Sb₂O₃/rGO composite are ca. 34.05% and 26.6%, respectively. When used as an alternative electrode for lithium ion batteries, a high reversible capacity of 790.9 mA∙h/g could be delivered after 200 cycles with the capacity retention of 93.8% at a current density of 200 mA/g. And a capacity of 260 mA∙h/g could be maintained even at 2000 mA/g. These excellent electrochemical properties can be attributed to its well-constructed nanostructure. The Sb and Sb₂O₃ particles with size of 10 nm were tightly anchored on rGO sheets through electronic coupling, which could not only alleviate the stress induced by the volume expansion, suppress the aggregation of Sb and Sb₂O₃ particles, but also improve the electron transfer ability during cycling

摘要

锑基材料被认为是制备锂离子电池最具应用前景的负极材料之一,然而复杂而成本昂贵的制备过程严重限制了其应用。本文采用一锅化学还原的简便方法在室温下得到Sb@Sb₂O₃/还原氧化石墨烯(Sb@Sb₂O₃/rGO)复合材料。XRD 和TGA 结果表明,复合材料中Sb 和Sb₂O₃ 的质量分数分别为 34.0%和 26.6%。将该复合材料用作锂离子电池电极材料使用时,在 200 mA/g 电流密度下循环 200 次后可逆比容量仍保持在 790.9 mA∙h/g,容量保持率高达 93.8%; 在 2000 mA/g 电流密度下充放电时仍有 260mA∙h/g 的可逆比容量。优越的电化学性能得益于所制备复合材料良好的纳米结构,尺寸约为10 nm 的Sb 和Sb₂O₃ 颗粒通过电子耦合作用牢牢地锚定在还原氧化石墨烯片层上。该结构既能有效缓冲因储锂过程中产生体积膨胀而引起的应力作用,还可抑制 Sb 和Sb₂O₃ 纳米颗粒的团聚,更能提高活性材料的导电性。