Electrochemical performance of anatase TiO<inf>2</inf> nanotube arrays electrode in ionic liquid based electrolyte for lithium ion batteries

Abstract

Ternary electrolyte composed of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid (PYR14TFSI), γ-butyrolactone (GBL) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and anatase TiO2 nanotube arrays (NTAs) electrode are investigated for the application in new generation of lithium-ion batteries (LIBs). The electrical conductivity and viscosity are measured in the whole composition range at several temperatures. Also, cyclic voltammetry experiments are performed at different temperatures and scan rates. At all scan rates, up to 100 mV · s−1 Ti4+/Ti3+ redox peaks appear designating exceptionally fast intercalation/deintercalation reaction. At the end of cycling the intercalation/deintercalation capacity was 144.8/140.7 mAh · g−1 at current rate 3 C. The diffusion coefficient for Li+ extraction from TiO2 nanotubes (NTs) have been calculated for temperatures from (25 to 55) ◦C. Activation energy for diffusion was found to be 54.7 kJ/mol (0.57 eV).