Diffusional and electrochemical investigation of combustion synthesized BaLi2Ti6O14 titanate anode for rechargeable batteries

Abstract

Energy-savvy auto-combustion synthesis was used to form the porous BaLi2Ti6O14 titanate anode. It registered the lowest calcination temperature (800 degrees C) along with the shortest calcination duration (2 h). Rietveld analysis confirmed the purity of the orthorhombic (s. g. Cmca) product phase. The bond valence site energy analysis indicated a 1D ionic conduction along c axis with low activation energy and 2D pathways along (010) with high activation energy. AC conductivity analysis revealed a bulk conductivity of 2.41 x 10(-4) S/cm (at 300 degrees C) with a moderate activation energy barrier (0.68 eV). From cyclic voltammetry, the Li+ diffusion coefficient was calculated to be 10(-11)-10(-12) cm(2)/s. The as-synthesized BaLi2Ti6O14 reversibly intercalated; similar to 1.3 Li+ involving a 1.42 V Ti4+/Ti3+ redox activity delivering capacity; similar to 100 mA h/g with good cyclability over 100 cycles. Furthermore, BaLi2Ti6O14 was found to reversibly intercalate similar to 0.89 Na+. With suitable diffusional and electrochemical performance, BaLi2Ti6O14 form a safe titanate anode for secondary batteries.