FeS_(2)/CoS_(2)异质结的可控构筑及储钠特性研究  

Controllable synthesis and sodium storage properties of FeS_(2)/CoS_(2)heterojunctions

作　　者：陈珂君 方菲 CHEN Kejun;FANG Fei(Xinxiang University,Xinxiang Henan 453000,China)

机构地区：[1]新乡学院,河南新乡453000

出　　处：《电源技术》2025年第2期408-415,共8页Chinese Journal of Power Sources

摘　　要：采用构筑FeS_(2)/CoS_(2)异质结的策略优化材料电化学性能。使用离子交换方法对前驱体MIL-88A进行离子交换,通过控制离子交换时间,实现Co^(2+)含量调控,随后通过高温硫化的方法,得到了目标产物。表征结果显示,离子交换时间会对产物的形貌产生重要影响,离子交换时间过长会导致前驱体的棱柱状结构坍塌并发生团聚。电化学性能测试结果表明,离子交换时间为4 h的样品(FC-4)表现出最优的电化学性能,在2 A/g电流密度下能够保持312.6 mAh/g的比容量,在1 A/g下循环1000次后,能够保持169.5 mAh/g的放电比容量。储钠机理和动力学特性分析表明,FC-4表现出赝电容储钠贡献占主导的储钠机理,相比于对照样品,该样品的钠离子扩散系数显著提升,这对提升电化学性能是十分有益的。The strategy of constructing FeS_(2)/CoS_(2)heterojunction was applied to optimize the electrochemical properties of the materials.The ion exchange of MIL-88A precursor was conducted by ion exchange method,and the time of ion exchange was controlled to achieve Co^(2+)content control.The target samples were obtained by high temperature vulcanization process.The characterization results reveal that the target materials with different ion exchange duration present different morphologies.The immoderate ion exchange leads to the collapse and agglomerate of the prismatic structure of the precursor.The electrochemical tests reveal that the sample with ion exchange treatment for 4 h(FC-4)presents the optimal electrochemical performance,it has a discharge specific capacity of 312.6 mAh/g at 2 A/g,and after 1000 cycles at 1 A/g,FC-4 still can maintain a discharge specific capacity of 169.5 mAh/g.The sodium storage mechanism and kinetics analysis reveal that FC-4 presents the sodium storage dominated by the contribution of pseudocapacitors.Besides,the Na+diffusion coefficient of FC-4 is higher than that of the control samples,which is beneficial for the electrochemical performance.

关 键 词：钠离子电池 负极材料 异质结 转化材料 反应机理 

分 类 号：TM912.9[电气工程—电力电子与电力传动]