title: Iron Telluride-Decorated Reduced Graphene Oxide Hybrid Microspheres as Anode Materials with Improved Na-Ion Storage Properties.
abstract: Transition-metal telluride materials are studied as the anode materials for Na-ion batteries (NIBs). The FeTe2-reduced graphene oxide (rGO) hybrid powders (first target material) are prepared via spray pyrolysis and subsequent tellurization. The H2Te gas treatment transforms the Fe3O4-rGO powders to FeTe2-rGO hybrid powders with FeTe2 nanocrystals (various sizes <100 nm) embedded within the rGO. The FeTe2-rGO hybrid powders contain 5 wt % rGO. The Na-ion storage mechanism for FeTe2 in NIBs is described by FeTe2 + 4Na(+) + 4e(-)↔Fe + 2Na2Te. The FeTe2-rGO hybrid discharge process forms metallic Fe nanocrystals and Na2Te by a conversion reaction of FeTe2 with Na ions. The discharge capacities of the FeTe2-rGO hybrid powders for the first and 80th cycles are 493 and 293 mA h g(-1), respectively. The discharge capacities of the bare FeTe2 powders for the first and 80th cycles are 462 and 83 mA h g(-1), respectively. The FeTe2-rGO hybrid powders have superior Na-ion storage properties compared to bare FeTe2 powders owing to their high structural stability and electrical conductivity.
authors.affiliation: Department of Materials Science and Engineering, Korea University , Anam-Dong, Seongbuk-Gu, Seoul 136-713, Republic of Korea.
authors.forename: Jung Sang
authors.initials: JS
authors.lastname: Cho
authors.affiliation: Department of Materials Science and Engineering, Korea University , Anam-Dong, Seongbuk-Gu, Seoul 136-713, Republic of Korea.
authors.forename: Seung Yeon
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Chemical Engineering, Konkuk University , 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701, Republic of Korea.
authors.forename: Jung-Kul
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Korea University , Anam-Dong, Seongbuk-Gu, Seoul 136-713, Republic of Korea.
authors.forename: Yun Chan
authors.initials: YC
authors.lastname: Kang
keywords: carbon hybrid; graphene; iron telluride; sodium ion batteries; spray pyrolysis