# The Effect of TiO2 on the Electrochemical Performance of Sb2O3 Anodes for Li-Ion Batteries
## 3 Results and Discussion  
### Characterization  
Figure 1 displays low and high magnification SEM images of the synthesized Sb\({}_{2}\)O\({}_{3}\), TiO\({}_{2}\) and TiO\({}_{2}\)/Sb\({}_{2}\)O\({}_{3}\) with a (3:1) ratio after synthesis. The SEM images of the Sb\({}_{2}\)O\({}_{3}\) show that the sample consisted of chunks of material of various sizes (Figure 1A,B) while the TiO  
The elemental composition was determined using EDS and showed that the sample composition was 3.1% Cl, 61.6% O, 8.9% Sb and 26.4% Ti. The ratio between Sb and Ti was 2.97, indicating that the correct ratio was achieved from the synthesis. The data also indicated that the sample was not a pure mixture of TiO\({}_{2}\) and Sb\({}_{2}\)O\({}_{3}\). More importantly, the correlation between the elements in the maps shows a very homogenous sample, especially for the composite material. The EDS spectra for TiO\({}_{2}\), Sb\({}_{2}\)O\({}_{3}\) and (3:1) TiO\({}_{2}\)/Sb\({}_{2}\)O\({}_{3}\) samples are included in the SI file of the revised manuscript (Figure S6). Figure 5 shows the X-ray diffraction patterns for the (3:1) TiO\({}_{2}\)@Sb\({}_{2}\)O\({}_{3}\) synthesized sample, the TiO\({}_{2}\)--as synthesized hydrothermally at 175 \({}^{\circ}\)C--and the Sb\({}_{2}\)O\({}_{3}\) starting material. The LeBail fitting results of the samples are shown in Table 1. The TiO\({}_{2}\)@Sb\({}_{2}\)O\({}_{3}\) samples showed the development of the Antimony trichloride (Sb\({}_{4}\)O\({}_{5}\)Cl\({}_{2}\)) phase of Sb mixed with the rutile phase of TiO\({}_{2}\), as can be seen in Figure 5A and Table 1. It is important to note here that the Sb\({}_{2}\)O\({}_{3}\) was purchased and added to TiCl\({}_{4}\) in an aqueous solution and heated to 175 \({}^{\circ}\)C with the aim of coating TiO\({}_{2}\) on the Sb\({}_{2}\)O\({}_{3}\) particle surface. In fact, Sb\({}_{2}\)O\({}_{3}\) can dissolve in aqueous solutions and, as a result, Sb\({}_{2}\)O\({}_{3}\) and Sb\({}_{4}\)O\({}_{5}\)Cl\({}_{2}\) coated with TiO\({}_{2}\) were formed after the heat treatment at 175 \({}^{\circ}\)C. However, the amount of Cl in the Sb compound is small, which will not affect the electrochemical performance of the TiO\({}_{2}\)/Sb\({}_{2}\)O\({}_{3}\) composite electrodes. The XRD results in this work (Figure S5) show that for the (1:4) TiO\({}_{2}\)/Sb\({}_{2}\)O\({}_{3}\) sample, most of the Sb compound was Sb\({}_{2}\)O\({}_{3}\), while for the 1:1  
Figure 4: EDS mapping of the TiO\({}_{2}\)@Sb\({}_{2}\)O\({}_{3}\) 3:1 ratio sample showing SEM image (**A**), O (**B**), Ti (**C**), Sb (**D**) and Cl (**E**). Figure 3: EDS mapping of the TiO\({}_{2}\) sample showing SEM image of the mapped area (**A**), O (**B**) and Ti (**C**). Figure 5: Le Bail results for the fitting of the XRD patterns collected for the (**A**) (3:1) TiO2@Sb2O3, (**B**) TiO2 and (**C**) Sb2O3. The XRD results of the Sb\({}_{2}\)O\({}_{3}\):TiO\({}_{2}\) with a 3:1 ratio showed the P2\({}_{1}\)/C symmetry for the Sb\({}_{4}\)O\({}_{5}\)Cl\({}_{2}\) phase and the rutile phase for the TiO\({}_{2}\) with the P4\({}_{2}\)/mmm space group, which is consistent with XRD data reported in the literature [53]. The overall reduced \(\chi^{2}\) of the fitting was 1.28, which showed an excellent agreement between the data and the fitting. The TiO\({}_{2}\) nanomaterial synthesized using the hydrothermal technique showed the presence of the rutile phase in the sample (Figure 5B), with a space group of P4\({}_{2}\)/mmm where lattice parameters were consistent with the literature values (Table 1). The \(\chi^{2}\) of the fitting was 2.41 [52]. The XRD results of Sb\({}_{2}\)O\({}_{3}\) material showed the presence of two phases: the bulk of the Sb\({}_{2}\)O\({}_{3}\) was present as the cubic phase with the space group Pd-3m, and the minor phase was the orthorhombic phase with the Pccn space group (Figure 5C). These two phases have lattice parameters matching those reported in the literature in which the overall fitting had a \(\chi^{2}\) of 3.15 [54; 55].