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    葡萄糖衍生硫掺杂碳包覆锑/钼硫化物的制备及其储钠性能

    High-performance sodium-ion storage based on glucose-derived S-doped carbon coated Sb/Mo-sulfide composites

    • 摘要: 面向大规模储能对高性价比、长循环稳定钠离子电池(SIBs)的迫切需求,开发高性能碳基负极材料至关重要。针对金属硫化物负极在储钠过程中体积膨胀严重、循环稳定性差的核心挑战,提出了一种简易绿色的材料设计策略:以葡萄糖(C6H12O6)为碳源,硫代乙酰胺为硫源,对双金属氧化物前驱体进行一步水热硫化及后续煅烧处理,成功制备了硫掺杂碳包覆的Sb-Mo-S复合材料(Sb2S3/Mo2S3@SC),并将其应用于SIBs的负极。结果表明:当碳源葡萄糖添加比例合适时,成功制备了由金属硫化物纳米花与稳定碳层组成的复合结构。该碳层不仅作为机械骨架有效缓冲了充放电过程中的体积膨胀,抑制了材料粉化,还显著增强了电子传导,优化了反应动力学。电化学测试结果显示:当前驱体Sb2MoO6和葡萄糖的投料比为1∶3时,所得的Sb2S3/Mo2S3@SC-3具有优异的储钠性能,在0.2和1 A/g的电流密度下分别循环200圈和500圈后,其比容量分别为678.47和589.77 mAh/g,具有出色的循环性能。在0.05和5 A/g的电流密度下,比容量分别为629.84和484.73 mAh/g,当电流密度恢复到0.05 A/g后,比容量为645.36 mAh/g,具有优异的倍率性能。动力学分析进一步揭示,其电荷存储以赝电容行为为主导,并具有较高的钠离子扩散系数。本工作通过巧妙的碳包覆与硫掺杂协同设计,为开发兼具高容量、长寿命和优异倍率性能的钠离子电池负极材料提供了新思路。

       

      Abstract: The pressing need for low-cost long-cycling sodium-ion batteries (SIBs) for large-scale energy storage underscores the critical importance of high-performance carbon-based anode materials. Targeting the core challenges of severe volume expansion and poor cycling stability in metal sulfide anodes during sodiation/desodiation, this study proposes a facile and green material design strategy. Using glucose (C6H12O6) as the carbon source and thioacetamide as the sulfur source, a one-step hydrothermal sulfidation followed by calcination was employed to synthesize a sulfur-doped carbon-coated Sb-Mo-S composite (Sb2S3/Mo2S3@SC) from a bimetallic oxide precursor for application as an anode in SIBs. Structural and morphological characterizations confirm that with an appropriate ratio of the carbon source, a composite structure consisting of metal sulfide nanoflowers encapsulated by a stable carbon layer was successfully fabricated. This carbon layer not only acts as a mechanical skeleton to effectively buffer volume expansion during cycling and inhibit material pulverization but also significantly enhances electron conduction and optimizes reaction kinetics. Electrochemical tests show that with a precursor (Sb2MoO6) to glucose mass ratio of 1∶3, the obtained Sb2S3/Mo2S3@SC-3 exhibits excellent sodium storage performance. After 200 cycles at a current density of 0.2 A/g and 500 cycles at 1 A/g, the electrode delivered specific capacities of 678.47 and 589.77 mAh/g, respectively, demonstrating exceptional sodium-ion storage capabilities. This anode exhibits reversible capacities of 629.84 and 484.73 mAh/g at 0.05 and 5 A/g, respectively, corresponding to a high-rate capacity. Notably, upon reverting to 0.05 A/g, the specific capacity recovered to 645.36 mAh/g, indicating superb rate performance and structural reversibility. Kinetic analysis further reveals that the charge storage is dominated by pseudocapacitive behavior, accompanied by a high sodium ion diffusion coefficient. This work, through the ingenious cooperative design of carbon coating and sulfur doping, provides a new approach for developing anode materials for SIBs that combine high capacity, long lifespan, and superior rate performance.

       

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