title: Electrochemically Expandable Soft Carbon as Anodes for Na-Ion Batteries.
abstract: Na-ion batteries (NIBs) have attracted great attention for scalable electrical energy storage considering the abundance and wide availability of Na resources. However, it remains elusive whether carbon anodes can achieve the similar scale of successes in Na-ion batteries as in Li-ion batteries. Currently, much attention is focused on hard carbon while soft carbon is generally considered a poor choice. In this study, we discover that soft carbon can be a high-rate anode in NIBs if the preparation conditions are carefully chosen. Furthermore, we discover that the turbostratic lattice of soft carbon is electrochemically expandable, where d-spacing rises from 3.6 to 4.2 Å. Such a scale of lattice expansion only due to the Na-ion insertion was not known for carbon materials. It is further learned that portions of such lattice expansion are highly reversible, resulting in excellent cycling performance. Moreover, soft carbon delivers a good capacity at potentials above 0.2 V, which enables an intrinsically dendrite-free anode for NIBs.
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Zelang
authors.initials: Z
authors.lastname: Jian
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Xing
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Clement
authors.initials: C
authors.lastname: Bommier
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Lerner
authors.affiliation: Department of Chemistry, Oregon State University , Corvallis, Oregon 97331-4003, United States.
authors.forename: Xiulei
authors.initials: X
authors.lastname: Ji