title: Carbon-Encapsulated Hollow Porous Vanadium-Oxide Nanofibers for Improved Lithium Storage Properties.
abstract: Carbon-encapsulated hollow porous vanadium-oxide (C/HPV2O5) nanofibers have been fabricated using electrospinning and postcalcination. By optimized postcalcination of vanadium-nitride and carbon-nanofiber composites at 400 °C for 30 min, we synthesized a unique architecture electrode with interior void spaces and well-defined pores as well as a uniform carbon layer on the V2O5 nanofiber surface. The optimized C/HPV2O5 electrode postcalcined at 400 °C for 30 min showed improved lithium storage properties with high specific discharge capacities, excellent cycling durability (241 mA h g(-1) at 100 cycles), and improved high-rate performance (155 mA h g(-1) at 1000 mA g(-1)), which is the highest performance in comparison with previously reported V2O5-based cathode materials. The improved electrochemical feature is due to the attractive properties of the carbon-encapsulated hollow porous structure: (I) excellent cycling durability with high specific capacity relative to the adoption of carbon encapsulation as a physical buffer layer and the effective accommodation of volume changes due to the hollow porous structure, (II) improved high-rate performance because of a shorter Li-ion diffusion pathway resulting from interior void spaces and well-defined pores at the surface. This unique electrode structure can potentially provide new cathode materials for high-performance lithium-ion batteries.
authors.affiliation: Program of Materials Science & Engineering, Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology , Seoul 139-743, Korea.
authors.forename: Geon-Hyoung
authors.initials: GH
authors.lastname: An
authors.affiliation: Department of Materials Science and Engineering, Seoul National University of Science and Technology , Seoul 139-743, Korea.
authors.forename: Do-Young
authors.initials: DY
authors.lastname: Lee
authors.affiliation: Program of Materials Science & Engineering, Convergence Institute of Biomedical Engineering and Biomaterials, Seoul National University of Science and Technology , Seoul 139-743, Korea.|Department of Materials Science and Engineering, Seoul National University of Science and Technology , Seoul 139-743, Korea.
authors.forename: Hyo-Jin
authors.initials: HJ
authors.lastname: Ahn
keywords: Li-ion battery; carbon encapsulation; cathode; hollow porous structure; vanadium oxide