金属有机框架衍生FeS_(2)/NiS_(2)/C空心球的制备及其储钠性能

Preparation of MOFs-derived FeS_(2)/NiS_(2)/C hollow spheres and their sodium-ion storage performance

开发高性能钠离子电池负极材料,亟须解决过渡金属硫化物在充放电过程中存在的容量快速衰减问题。以Ni-MOF为前驱体,通过溶剂热处理引入Fe元素并进行气相硫化,制备了含双金属硫化物的FeS_(2)/NiS_(2)/C多孔空心球材料。电化学测试结果表明:该材料作为钠离子电池的负极,与NiS_(2)/C相比,其可逆比容量、循环稳定性以及倍率性能均得到显著提高;利用电化学阻抗测试和不同扫速下的循环伏安测试对电极材料的电子传输和离子扩散速率进行分析,证实复合材料优异的电化学性能表现归因于其增强的反应动力学。该研究表明,金属有机框架(Metal-organic frameworks,MOFs)衍生的双金属硫化物具有优异的电化学性能,是一种具有良好应用前景的高性能钠离子电池负极材料。

In order to develop high-performing anode material for sodium-ion batteries,it is imminent to solve the problem of rapid capacity decay of transition metal sulfides during charge and discharge.By using Ni-MOF as the precursor,Fe was introduced through solvent thermal treatment and sulfurized in the gas phase,and FeS_(2)/NiS_(2)/C porous hollow spheres containing bimetallic sulfide were prepared.The results of electrochemical test showed that the reversible specific capacity,cycling stability and rate capability of the hollow bimetallic sulfide FeS_(2)/NiS_(2)/C composite were significantly enhanced compared with NiS_(2)/C when it was used as the cathode of sodium-ion battery.What’s more,the electron transport and ion diffusion rate of the electrode materials were analyzed by electrochemical impedance measurements and cyclic voltammetry tests at different scanning speeds,which confirmed that the excellent electrochemical properties of the composite were attributed to their enhanced reaction kinetics.Our study suggests that the metal-organic frameworks(MOFs)-derived bimetallic sulfides exhibit excellent electrochemical properties,and are promising anode materials for high-performing sodium-ion batteries.