Fabrication of flower-like mesoporous TiO2 hierarchical spheres with ordered stratified structure as an anode for lithium-ion batteries

In this study, flower-like mesoporous TiO 2 hierarchical spheres (FMTHSs) with ordered stratified structure and TiO 2 nanoparticles (TNPs) were synthesized via a facile solvothermal route and an etching reaction. Multilamellar vesicles (MTSVs) and unilamellar TiO 2 /SiO 2 vesicles (UTSVs) were prepared using cetyltrimethylammonium bromide and didodecyldimethylammonium bromide as structure-directing agents under different solvothermal conditions. FMTHSs and TNPs were obtained from the etching reactions of MTSVs and UTSVs, respectively, in an alkaline system. FMTHSs display flower-like, ordered stratified structures on each petal. The thickness of the ordered stratified structure is approximately 3–6 nm, and the number of layers is approximately 2–4. The FMTHSs2 electrode exhibits the first discharge capacity of 212.4 mA h g −1 at 0.2 C, which is higher than that of TNPs electrode (167.6 mA h g −1 ). The discharge specific capacity of FMTHSs2 electrode after 200 cycles at 1 C is 105.9 mA h g −1 , which is higher than that of TNPs electrode (52.2 mA h g −1 ) after the same number of cycles. The outstanding performance of FMTHSs2 electrode is attributed to the advantages of FMTHSs. In particular, their own stratified structure can provide additional active sites for reactions. The hierarchical structure can provide short diffusion length for Li + , large electrolyte–electrode contact area, and superior accommodation of the strain of Li + intercalation/deintercalation.