Polycrystalline TiO[sub 2] Anatase with a Large Proportion of Crystal Facets (001): Lithium Insertion Electrochemistry

Abstract

The electrochemical behavior of TiO2 anatase with a predominant (001) face (ANA001) was studied by cyclic voltammetry of Li insertion and chronoamperometry. Both voltammetric and chronoamperometric diffusion coefficients and rate constants proved the higher activity of ANA001 toward Li insertion compared to that of a reference anatase material (C240) with dominating (101) facets. The enhanced activity of the anatase (001) face for Li insertion stems from synergic contributions of a faster interfacial charge transfer at this surface and a facile Li transport within a more open structure of the anatase lattice in the direction parallel to the c -axis. Despite the larger particle size of ANA001, the values of integral charge capacity and Li-insertion coefficient further confirmed its improved Li-insertion properties. The results of this study further complete the analogous data published on single-crystal anatase electrodes and evidence their validity for nanocrystalline materials too.

Voltage enhancement in dye-sensitized solar cell using (001)-oriented anatase TiO2 nanosheets

“…The conclusion about flatband potential shift was later reproduced on polycrystalline electrodes [19]. Also, the improved Li insertion was subsequently confirmed on polycrystalline (001)-oriented nanosheets [20]. They were prepared hydrothermally in HF medium according to Yang et al [11], and the follow-up studies [14,15,[21][22][23] report on materials enriched up to 90 % with the (001) face.…”

Electron Kinetics in Dye Sensitized Solar Cells Employing Anatase with (101) and (001) Facets

“…The synthesis of anatase enriched with (0 0 1) facets [26] triggered deeper investigations of orientation-dependent effects in nanocrystalline anatase materials. They provided various inputs for photocatalysis [33][34][35], DSCs [36][37][38][39][40] and Li-ion batteries [31,41,42]. These results also activated theoretical studies to explain the observed differences between (1 0 1) and (0 0 1) facets [32,[43][44][45][46].…”

“…The phase-pure anatase (0 0 1) was prepared following the standard synthetic protocol for the TiO 2 nanosheets [26,32,42]. In the actual synthesis, 1.2 mL of 48% hydrofluoric acid was added to 10 mL of titanium(IV) butoxide.…”

Synthesis of sandwich-like TiO2@C composite hollow spheres with high rate capability and stability for lithium-ion batteries

“…Recently, anatase TiO 2 nanocrystals with {001} facets exposed have attracted great attention because of their superior physical and chemical properties [16,17]. In the synthesis procedure for TiO 2 -HS, we have introduced HF to control the exposed facets of anatase to obtain the active crystal facets.…”

“…Several theoretical studies have pointed out that due to the special crystal structure of anatase, Li þ insertion/extraction will be probably facilitated through the {001} facets. Anatase TiO 2 nanosheet with {001} facets exposed have been proved to be an ideal host structure for fast and efficient lithium insertion/extraction [16,17]. In order to obtain stable architectures, several hierarchical TiO 2 nanostructures with {001} facets exposed have also been fabricated and show excellent performance in the Li-ion batteries.…”