School of Energy and Chemical Engineering , Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil , Ulsan 44919 , Republic of Korea.
ACS Appl Mater Interfaces. 2018 May 2;10(17):15270-15280. doi: 10.1021/acsami.8b02446. Epub 2018 Apr 23.
Sodium (Na) metal anodes with stable electrochemical cycling have attracted widespread attention because of their highest specific capacity and lowest potential among anode materials for Na batteries. The main challenges associated with Na metal anodes are dendritic formation and the low density of deposited Na during electrochemical plating. Here, we demonstrate a fluoroethylene carbonate (FEC)-based electrolyte with 1 M sodium bis(fluorosulfonyl)imide (NaFSI) salt for the stable and dense deposition of the Na metal during electrochemical cycling. The novel electrolyte combination developed here circumvents the dendritic Na deposition that is one of the primary concerns for battery safety and constructs the uniform ionic interlayer achieving highly reversible Na plating/stripping reactions. The FEC-NaFSI constructs the mechanically strong and ion-permeable interlayer containing NaF and ionic compounds such as NaCO and sodium alkylcarbonates.
钠（Na）金属阳极具有稳定的电化学循环，由于其在钠离子电池的阳极材料中具有最高的比容量和最低的电位，因此引起了广泛的关注。与钠金属阳极相关的主要挑战是枝晶的形成和电化学电镀过程中沉积的 Na 的低密度。在这里，我们展示了一种基于氟代碳酸乙烯酯（FEC）的电解质，其中包含 1 M 双（氟磺酰基）亚胺（NaFSI）盐，可在电化学循环过程中稳定且致密地沉积 Na 金属。这里开发的新型电解质组合避免了电池安全的主要关注点之一的树枝状 Na 沉积，并构建了均匀的离子中间层，实现了高度可逆的 Na 电镀/剥离反应。FEC-NaFSI 构建了含有 NaF 和离子化合物（如 NaCO 和 烷基碳酸纳）的机械强度高且离子可渗透的中间层。
