title: Insight into the Capacity Fading Mechanism of Amorphous Se2S5 Confined in Micro/Mesoporous Carbon Matrix in Ether-Based Electrolytes.
abstract: In contrast to the stable cycle performance of space confined Se-based cathodes for lithium batteries in carbonate-based electrolytes, their common capacity fading in ether-based electrolytes has been paid less attention and not yet well-addressed so far. In this work, the lithiation/delithiation of amorphous Se2S5 confined in micro/mesoporous carbon (Se2S5/MPC) cathode was investigated by in situ X-ray near edge absorption spectroscopy (XANES) and theoretical calculations. The Se2S5/MPC composite was synthesized by a modified vaporization-condensation method to ensure a good encapsulation of Se2S5 into the pores of MPC host. In situ XANES results illustrated that the lithiation/delithiation reversibility of Se component was gradually decreased in ether-based electrolytes, leading to an aggravated formation of long-chain polyselenides during cycling and further capacity decay. Moreover, ab initio calculations revealed that the binding energy of polyselenides (Li2Sen) with carbon host is in an order of Li2Se6 > Li2Se4 > Li2Se. The insights into the failure mechanism of Se-based cathode gain in this work are expected to serve as a guide for future design on high performance Se-based cathodes.
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Gui-Liang
authors.initials: GL
authors.lastname: Xu
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.|Materials Science Program, University of Rochester , Rochester, New York 14627, United States.
authors.forename: Tianyuan
authors.initials: T
authors.lastname: Ma
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Cheng-Jun
authors.initials: CJ
authors.lastname: Sun
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: Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Lei
authors.initials: L
authors.lastname: Cheng
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ren
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Steve M
authors.initials: SM
authors.lastname: Heald
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
authors.affiliation: Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Larry
authors.initials: L
authors.lastname: Curtiss
authors.affiliation: Center for Nanoscale Materials, Nanoscience Technology, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wen
authors.affiliation: Center for Nanoscale Materials, Nanoscience Technology, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Miller
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: X-ray Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zuo
authors.affiliation: Department of Physics, Central Michigan University , Mt. Pleasant, Michigan 48859, United States.
authors.forename: Valeri
authors.initials: V
authors.lastname: Petkov
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Zonghai
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Khalil
authors.initials: K
authors.lastname: Amine
keywords: Se2S5/MPC cathode; ab initio calculations; batteries; capacity fading; ether-based electrolytes; in situ XANES