title: Low-surface-area hard carbon anode for na-ion batteries via graphene oxide as a dehydration agent.
abstract: Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, hard carbon is very attractive due to its high capacity and low cost. However, hard carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for hard carbon, can effectively reduce the specific surface area of hard carbon to as low as 5.4 m(2)/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burnoff of sucrose caramel over a wider temperature range. The obtained low-surface-area hard carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles.
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.forename: Clement
authors.initials: C
authors.lastname: Bommier
authors.forename: Zelang
authors.initials: Z
authors.lastname: Jian
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Rich
authors.initials: R
authors.lastname: Carter
authors.forename: Sean
authors.initials: S
authors.lastname: Vail
authors.forename: Yuhao
authors.initials: Y
authors.lastname: Lu
authors.forename: Jong-Jan
authors.initials: JJ
authors.lastname: Lee
authors.forename: Xiulei
authors.initials: X
authors.lastname: Ji
keywords: Na-ion batteries; anode; hard carbon; high first-cycle Coulombic efficiency; low surface area