Interplay among Hexafluorophosphate, Difluoro(oxalato)borate Anions and Ethylene Carbonate during Their Insertion into a Graphite Electrode

Jia Zhang; Congcong Chen; Dandan Zhu; Yunju Wang; Boyu Wang; Ying Wang; Shunchao Ma; Hongyu Wang

doi:10.1021/acs.langmuir.1c03485

Interplay among Hexafluorophosphate, Difluoro(oxalato)borate Anions and Ethylene Carbonate during Their Insertion into a Graphite Electrode

Langmuir. 2022 Mar 29;38(12):3824-3831. doi: 10.1021/acs.langmuir.1c03485. Epub 2022 Mar 16.

Authors

Jia Zhang¹, Congcong Chen¹, Dandan Zhu¹, Yunju Wang¹, Boyu Wang¹, Ying Wang, Shunchao Ma, Hongyu Wang¹

Affiliation

¹ School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China.

PMID: 35294194
DOI: 10.1021/acs.langmuir.1c03485

Abstract

Ethylene carbonate solutions dissolving mixed lithium salts composed of both difluoro(oxalato)borate (DFOB^-) and hexafluorophosphate (PF₆^-) anions are introduced into Li/graphite cells. The anions' intercalation procedures into the graphite positive electrode from these solutions are explored by charge/discharge, cyclic voltammetry, and impedance spectroscopic tests in combination with electrochemical in situ characterization including X-ray diffraction (XRD) and Raman spectroscopy. Furthermore, these solutions are characterized by ionic conductivity together with nuclear magnetic resonance measurements. The properties of the solutions are linked to the capacity values delivered by Li/graphite cells.