title: Enhanced Electrochemical Properties of Li3VO4with Controlled Oxygen Vacancies as Li-Ion Battery Anode.
abstract: Li3VO4, as a promising intercalation-type anode material for lithium-ion batteries, features a desired discharge potential (ca. 0.5-1.0 V vs. Li/Li+) and a good theoretical storage capacity (590 mAh g-1with three Li+inserted). However, the poor electrical conductivity of Li3VO4hinders its practical application. In the present work, various amounts of oxygen vacancies were introduced in Li3VO4through annealing in hydrogen to improve its conductivity. To elucidate the influence of oxygen vacancies on the electrochemical performances of Li3VO4, the surface energy of the resulting material was measured with an inverse gas chromatography method. It was found that Li3VO4annealed in pure hydrogen at 400 °C for 15 min exhibited a much higher surface energy (60.7 mJ m-2) than pristine Li3VO4(50.6 mJ m-2). The increased surface energy would lower the activation energy of phase transformation during the charge-discharge process, leading to improved electrochemical properties. As a result, the oxygen-deficient Li3VO4achieved a significantly improved specific capacity of 495 mAh g-1at 0.1 Ag-1(381 mAh g-1for pristine Li3VO4) and retains 165 mAh g-1when the current density increases to 8 Ag-1.
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Kan
authors.initials: K
authors.lastname: Wang
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Changkun
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Haoyu
authors.initials: H
authors.lastname: Fu
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Liu
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Zhuoyu
authors.initials: Z
authors.lastname: Li
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Wenda
authors.initials: W
authors.lastname: Ma
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.
authors.forename: Xianmao
authors.initials: X
authors.lastname: Lu
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST), Beijing, 100083, P.R. China.|Department of Materials Science and Engineering, University of Washington, Seattle, WA, 98195-2120, USA.
authors.forename: Guozhong
authors.initials: G
authors.lastname: Cao
keywords: Li3VO4; conducting materials; hydrogen annealing; lithium-ion batteries; oxygen vacancies; surface energy