Effect of solvents on the intercalation/de-intercalation behaviour of monovalent ionic species from non-aqueous solvents on polypropylene-graphite composite electrode

The intercalation/de-intercalation efficiency (IDE) of monovalent cationic (Li+, Na+, K+ and TBA+) and amonic (ClO4 −, BF4 −)species in different non- aqueous solvents are compared under otherwise identical experimental conditions using cyclic voltammetry, X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA). Dimethyl sulfoxide (DMSO), dimethylformamide (DMF) and propylene carbonate (PC) are found to be the solvents of choice for cationic intercalation. PC and acetonitrile (AN) are found to be the solvents of choice for anionic intercalation. Among the cations strongly solvated Li+ shows better IDE when compared with Na+ and K+. TBA+ appears to undergo efficient intercalation without a solvation sheath. The effect of concentration and intercalation potential on the overall IDE is also reported. A new intercalated phase is confirmed by XRD, TG and DTA.