Lithium bis fluorosulfonyl imide

Mesocarbon microbeads (MCMB) graphite and NCM622 were used as active materials for the anodes and cathodes, respectively. HOPG was purchased from Alfa Aesar. LiTFSI and lithium bis(fluorosulfonyl)imide (LiFSI) were purchased from Sigma-Aldrich, USA. N-methyl-2-pyrrolidone (NMP) was purchased from JUNSEI, Japan. Super P was purchased from Timcal, Switzerland. The electrolyte containing 1 M LiPF₆ in EC/DEC (50/50 = v/v) with 10 wt% FEC was purchased from Wellcos Corporation, South Korea. Styrene-butadiene rubber (SBR, Zeon) and sodium carboxy methyl cellulose (CMC, Sigma-Aldrich) binders were used for the graphite electrodes. Poly(vinylidene fluoride) (PVDF, Kynar) binder was used for the NCM622 electrodes.

Epoxidized soybean oil (ESO), lithium bis(fluorosulfonyl)imide (LiFSI; 99.9%), diethyl carbonate (DEC; ≥99.9%), ethylene carbonate (EC; ≥99%), lithium cobalt(III) oxide (LiCoO₂; ≥99.8%), N-methyl pyrrolidone (NMP; 99.5%), poly(vinylidene fluoride) (PVDF; average Mw~534,000), and carbon black (99.9%) were all ordered from Sigma-Aldrich (St. Louis, MO, USA), while the lithium iron(II) phosphate (LFP) power, graphite anode, and lithium were obtained from the MTI Company (Richmond, CA, USA).