title: Enhancing the Cycling Stability of Sodium Metal Electrodes by Building an Inorganic-Organic Composite Protective Layer.
abstract: Owing to the natural abundance of sodium resources and their low price, next-generation batteries employing an Na metal anode, such as Na-O2and Na-S systems, have attracted a great deal of interest. However, the poor reversibility of an Na metal electrode during repeated electrochemical plating and stripping is a major obstacle to realizing rechargeable sodium metal batteries. It mainly originates from Na dendrite formation and exhaustive electrolyte decomposition due to the high reactivity of Na metal. Herein, we report a free-standing composite protective layer (FCPL) for enhancing the reversibility of an Na metal electrode by mechanically suppressing Na dendritic growth and mitigating the electrolyte decomposition. A systematic variation of the liquid electrolyte uptake of FCPL verifies the existence of a critical shear modulus for suppressing Na dendrite growth, being in good agreement with a linear elastic theory, and emphasizes the importance of the ionic conductivity of FCPL for attaining uniform Na plating and stripping. The Na-Na symmetric cell with an optimized FCPL exhibits a cycle life two times longer than that of a bare Na electrode.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Yun-Jung
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Hongkyung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Hyungjun
authors.initials: H
authors.lastname: Noh
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Jinhong
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biological Engineering, Hanbat National University , Yuseong-gu, Daejeon 34158, Republic of Korea.
authors.forename: Seokwoo
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biological Engineering, Hanbat National University , Yuseong-gu, Daejeon 34158, Republic of Korea.
authors.forename: Myung-Hyun
authors.initials: MH
authors.lastname: Ryou
authors.affiliation: Department of Chemical and Biological Engineering, Hanbat National University , Yuseong-gu, Daejeon 34158, Republic of Korea.
authors.forename: Yong Min
authors.initials: YM
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
authors.forename: Hee-Tak
authors.identifier: http://orcid.org/0000-0003-4578-5422
authors.initials: HT
authors.lastname: Kim
keywords: cycling stability; dendrite formation; electrolyte decomposition; free-standing composite protective layer; sodium metal electrode