Deciphering the Role of Fluoroethylene Carbonate towards Highly Reversible Sodium Metal Anodes.

ABSTRACT: Sodium metal anodes (SMAs) suffer from extremely low reversibility (<20%) in carbonate-based electrolytes-this piece of knowledge gained from previous studies has ruled out the application of carbonate solvents for sodium metal batteries. Here, we overturn this conclusion by incorporating fluoroethylene carbonate (FEC) as cosolvent that renders a Na plating/stripping efficiency of >95% with conventional NaPF₆ salt at a regular concentration (1.0 M). The peculiar role of FEC is firstly unraveled via its involvement into the solvation structure, where a threshold FEC concentration with a coordination number>1.2 is needed in guaranteeing high Na reversibility over the long-term. Specifically, by incorporating an average number of 1.2 FEC molecules into the primary Na⁺ so

SUBMITTER: Zheng X 

PROVIDER: S-EPMC8817186 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature