title: Tin Selenides with Layered Crystal Structures for Li-Ion Batteries: Interesting Phase Change Mechanisms and Outstanding Electrochemical Behaviors.
abstract: Tin selenides with layered crystal structures, SnSe and SnSe2, were synthesized by a solid-state method and electrochemically tested for use as Li-ion battery anodes. The phase change mechanisms of these compounds were thoroughly evaluated by ex situ X-ray diffraction and Se K-edge extended X-ray absorption fine structure techniques. SnSe showed better electrochemical reversibility of Li insertion/extraction than SnSe2, which was attributed to remarkable conversion/recombination reactions of the former compound during lithiation/delithiation. Additionally, the electrochemical performance of SnSe was further enhanced by preparing carbon-modified nanocomposites using two different methods, that is, heat treatment (HT) for producing a carbon coating using polyvinyl chloride as a precursor and high-energy ball milling (BM) using carbon black powder. The SnSe/C electrode produced by BM showed a highly reversible initial capacity of 726 mA h g-1with a good initial Coulombic efficiency of ∼82%, excellent cycling behavior (626 mA h g-1after 200 cycles), and a fast C-rate performance (580 mA h g-1at 2C rate).
authors.affiliation: School of Materials Science and Engineering, Kumoh National Institute of Technology , 61 Daehak-ro, Gumi, Gyeongbuk 39177, Republic of Korea.
authors.forename: Dong-Hun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: School of Materials Science and Engineering, Kumoh National Institute of Technology , 61 Daehak-ro, Gumi, Gyeongbuk 39177, Republic of Korea.
authors.forename: Cheol-Min
authors.identifier: http://orcid.org/0000-0001-8204-5760
authors.initials: CM
authors.lastname: Park
keywords: lithium-ion batteries, anode materials, tin selenides, reaction mechanism, nanocomposite electrodes