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Role of N-Propyl-N-Methyl Pyrrolidinium bis(trifluoromethanesulfonyl)imide as an electrolyte additive in sodium battery electrochemistry

journal contribution
posted on 01.11.2018, 00:00 authored by C V Manohar, Maria ForsythMaria Forsyth, D R MacFarlane, S Mitra
Electrolyte compatibility with sodium metal and known sodium-ion battery cathodes is of intense interest recently. In this work, electrolytes including an ionic liquid (IL) additive are formulated and shown to enhance the properties of the well-known Na3V2(PO4)3/C (NVP/C) cathode. NVP/C composite material was synthesized by a carbothermal reduction process and studied in cells containing either organic electrolyte (1 M NaClO4 in PC) or organic electrolyte with added [C3mpyr][NTf2] IL. In an electrolyte containing 5 wt % [C3mpyr][NTf2] IL, the cathode material exhibited a stable capacity of 107.0±0.7 mAh g−1 after 50 cycles at a C/2 rate; in contrast, the capacity obtained with the organic electrolyte was only 85±1 mAh g−1 after 50 similar cycles. In situ impedance spectroscopy revealed that the electrode-electrolyte charge-transfer resistance is lower in the organic electrolyte with IL. Consistent with this finding, XPS, SEM, EDX and TEM results indicate that the interfacial layer formed on the surface of the NVP/C cathode material in the presence of the IL is more compact than that formed in the organic electrolyte, and that reaction between cathode and electrolyte is suppressed by the IL.

History

Journal

Energy technology

Volume

6

Issue

11

Pagination

2232 - 2237

Publisher

Wiley

Location

Chichester, Eng.

ISSN

2194-4288

eISSN

2194-4296

Language

eng

Publication classification

C1 Refereed article in a scholarly journal