Effect of 0.5 M NaNO₃: 0.5 M KNO₃and 0.88 M LiNO₃:0.12 M LiCl Molten Salts, and Heat Treatment on Electrochemical Properties of TiO₂

The compounds, TiO 2 −1 & −2 were synthesized by 0.5 M NaNO 3 : 0.5 M KNO 3 (I) and 0.88 M LiNO 3 :0.12 MLiCl (II) salts at 510°C and 280°C, resp.., XRD studies show single anatase phase with characteristic tetragonal lattice parameter values of a ∼3.78 Å and c ∼ 9.51 Å. The TEM images show aggregates of 10–30 nm sized nanosquares (TiO 2 −1) and spherical particles (TiO 2 −2). Surface area of the TiO 2 powders were 74 and 200 m 2 g −1 , resp. for 1 and 2. Upon heat-treatment (TiO 2 −2) from 500°C to 850°C, the surface area decreases from 80 to 0.7 m 2 g −1 . Cyclic voltammetry studies show cathodic and anodic peaks at ∼1.7 and ∼ 2.0 V, resp. for both bare and heat treated TiO 2 up to 750°C. Galvanostatic cycling studies show that the first discharge-charge capacity values are 244 and 198 (±3) mAh g −1 resp. for TiO 2 −1 at a current of 33 mA g −1 in the voltage window, 1.0–2.8 V vs. Li/Li + . TiO 2 −2 nanoparticles show a less capacity fade during cycling and delivered first discharge-charge capacity values of 340 and 253 (±3) mAh g −1 , resp. at a current rate of 33 mA g −1 . The effects of heat-treatment and Li-cycling at a cutoff voltage (0.005 V) were studied and discussed reaction mechanism.