Controllable synthesis of FeS2 with different morphologies and their sodium storage performances
As a typical conversion reaction-type anode material for sodium-ion batteries(SIBs),FeS2,which possesses the merits of nontoxic,low-cost,and high theoretical specific capacity,has become a potential anode material for SIBs.However,owing to the large atomic radius and mass of Na+,the Na storage process of FeS2 features sluggish kinetics,which hinders its practical applications.In this study,we synthesize FeS2 with different morphologies through a solvothermal method.The morphology can be easily controlled by changing the molar ratio of Fe and S in the precursor.Characterization results reveal that as-obtained FeS2 with different molar ratios of Fe and S presents an irregular spherical particle and a mixture of an irregular spherical particle and regular cubes.Furthermore,the Na storage performances of as-obtained samples were systematically investigated.FeS2 with a regular cubic morphology reveals a superior Na storage performance.A reversible discharge specific capacity of 354.5 mAh/g can be maintained at a current density of 0.1 A/g.Long-term cyclic tests reveal that after 500 cycles,a discharge specific capacity of 246.3 mAh/g can be obtained,which is 1.2 times higher than that of the control sample.A Na storage mechanism analysis indicates that FeS2 with a regular cube morphology presents a capacitive-dominated Na storage process,which promotes an enhanced rate capability and fast Na+diffusion coefficient.This study can provide theoretical reference for fabricating high-performance anode materials for SIBs.
sodium ion batterymorphology controlanode materialsFeS2soidum storage mechanisms
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