Properties of Li4Ti5O12 as an anode material in non-flammable electrolytes

Abstract

Two non-flammable electrolytes 1 M LiPF 6 in sulfolane (TMS) ? 5 wt% VC and 0.7 M lithium bis(trifluoromethanesulphonyl)imide (LiNTf 2 ) in N-methyl-Npropylpyrrolidinium bis(trifluoromethanesulphonyl)imide (MePrPyrNTf 2 ) ? 10 wt% gamma-butyrolactone (GBL) were tested with Li 4 Ti 5 O 12 (LTO) as highly promising anode material for application in lithium-ion batteries. The results were compared for the titanium anode in the classic electrolyte: 1 M LiPF 6 in propylene carbonate ? dimethyl carbonate (PC ? DMC, 1:1). The performances of LTO/ electrolyte/Li cell were tested using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge and scanning electron microscopy (SEM). SEM images of electrodes and those taken after electrochemical cycling showed changes which may be interpreted as a result of solid-state interface formation. Good charge/discharge capacities and low capacity loss at medium C rates preliminary cycling was obtained for the Li 4 Ti 5 O 12 anode. For LTO/1 M LiPF 6 in PC ? DMC/Li system, the best capacity was obtained at C/10 and C/3 (145 and 154 mAh g -1 , respectively). In the case of a system working on the basis of a TMS solution (1 M LiPF 6 in TMS ? 5 wt% VC) the best value was obtained at a C/5 current and an average of more than 150 mAh g -1 (86 % of theoretical capacity). For the 0.7 M LiNTf 2 in MePrPyrNTf 2 ? 10 wt% GBL electrolyte, the highest capacitance value (at C/20 current) of about 150 mAh g -1 was observed. The 1 M LiPF 6 in TMS ? 5 wt% VC and 0.7 M LiNTf 2 in MePrPyrNTf 2 ? 10 wt% GBL electrolytes had a relatively broad thermal stability range and no decomposition peak was observed below 150°C.

Development of Acidic Imidazolium Ionic Liquids for Activation of Kraft Lignin by Controlled Oxidation: Comprehensive Evaluation and Practical Utility

“…To this end, electrodes were prepared and subjected to a series of analyses (cyclic voltammetry (CV), impedance spectra, and several charge/discharge cycle tests). The change in morphology of the fibers was characterized by SEM . Battery rate capability and cycling stability were analyzed by means of galvanostatic cycling tests .…”