title: Electrospun FeS2@Carbon Fiber Electrode as a High Energy Density Cathode for Rechargeable Lithium Batteries.
abstract: In this study, an FeS2@carbon fiber electrode is developed with FeS2 nanoparticles either embedded in or attached to carbon fibers by using an electrospinning method. By applying this binder-free, metal-current-collector-free FeS2@carbon fiber electrode, both the redox reaction and capacity decay mechanisms for the Li-FeS2 system are revealed by changing the electrolyte (conventional carbonate electrolyte and a "solvent-in-salt"-type Li-S battery electrolyte) and working voltage ranges (1.0-3.0 V and 1.5-3.0 V vs Li/Li(+)). The FeS2@carbon fiber electrode shows stable cycling performance in both the conventional carbonate electrolyte and the solvent-in-salt-type Li-S battery electrolyte in the voltage range of 1.5-3.0 V. Electrochemical tests in the solvent-in-salt-type Li-S battery electrolyte indicate that the Li-FeS2 system becomes a hybrid of the Li-S cell and Li-iron sulfide cell after the initial cycle. Based on the understanding on the capacity decay mechanisms, the cycling stability of the Li-FeS2 system in the voltage range of 1.0-3.0 V is then significantly enhanced by coating the FeS2@carbon fiber electrode with a thin layer of Al2O3. The Al2O3-coated electrode demonstrates excellent cycling performance with high discharge energy densities at both the material level (∼1300 Wh/kg-FeS2) and the electrode level (∼1000 Wh/kg-FeS2 electrode).
authors.affiliation: School of Chemistry and Environment, Beihang University , Beijing 100191, People's Republic of China.|Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Xiulin
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Liumin
authors.initials: L
authors.lastname: Suo
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Chao
authors.initials: C
authors.lastname: Luo
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Tao
authors.initials: T
authors.lastname: Gao
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Wang
keywords: FeS2; atomic layer deposition; electrospinning; high energy density cathodes; lithium-ion batteries