## 3 Results
### Electrochemical Properties
The meaning of  
Figure 4: **(a)** Cycling performances of CMC-FA@Sb\({}_{2}\)O\({}_{3}\), PVDF@Sb\({}_{2}\)O\({}_{3}\) and CMC@Sb\({}_{2}\)O\({}_{3}\) at 0.2 A g\({}^{-1}\); **(b)** Rate capabilities of CMC-FA@Sb\({}_{2}\)O\({}_{3}\), PVDF@Sb\({}_{2}\)O\({}_{3}\) and CMC@Sb\({}_{2}\)O\({}_{3}\) at current density ranging from 0.05 A g\({}^{-1}\) to 0.5 A g\({}^{-1}\); Nyquist plots of different electrodes: **(c)** before cycling; **(d)** after 200 cycles at current density of 0.2 A g\({}^{-1}\), inset shows electrochemical impedance spectroscopy (EIS) test circuitry. R\({}_{f}\) and CPE\({}_{2}\) in equivalent circuits were corresponding to the resistance and constant phase element of the SEI film. As we can see, although the discharge capacity of CMC-FA@Sb\({}_{2}\)O\({}_{3}\) electrode is much higher than the other two electrodes after 200 cycles at 0.2 A g\({}^{-1}\) (Figure 4a), they have quite similar overall impedance after 200 cycles, which could be ascribed to the Li anode contribution; the anode SEI file impedance and the anode charge-discharge resistance may have obvious change during cycling [50]. The R\({}_{\rm ct}\) decreased to \(\sim\)55 \(\Omega\), \(\sim\)74.6 \(\Omega\) and 90.1 \(\Omega\) for CMC-FA@Sb\({}_{2}\)O\({}_{3}\), PVDF@Sb\({}_{2}\)O\({}_{3}\), CMC@Sb\({}_{2}\)O\({}_{3}\) electrodes, respectively. This fact confirms that the CMC-FA binder could not only increase the connection within the electrode (Sb\({}_{2}\)O\({}_{3}\), super p, binder and Cu foil), but also reduce the particle shedding due to volume changes of Sb\({}_{2}\)O\({}_{3}\) electrode during cycling, enhancing the electrode's electrochemical performance. To further illustrate the performance of the binder, the morphology of electrodes was examined before and after 200 cycles at 0.2 A g\({}^{-1}\), as depicted in Figure 5. The morphologies of different electrodes before cycling were shown in Figure 5a-c, in which they exhibited similar morphology. Interestingly, a flower-like polymer network could be found in Figure 5c, which may be associated with cross-linking reactions. After 200 cycles, it can be easily found that there are many large cracks and pulverization in the PVDF@Sb\({}_{2}\)O\({}_{3}\) electrode and CMC@Sb\({}_{2}\)O\({}_{3}\) electrode, shown in Figure 5d,e. As a comparison, the CMC-FA@Sb\({}_{2}\)O\({}_{3}\) electrode has better structure integrity with smaller cracks as shown in Figure 5f, so that CMC-FA@Sb\({}_{2}\)O\({}_{3}\) has better cycling stability at same charge/discharge conditions. This result indicates that CMC-FA polymer network can mitigate the strain caused by lithiation/delithiation during cycling (Figure 6). Furthermore, we have compared the electrochemical properties of the CMC-FA@Sb\({}_{2}\)O\({}_{3}\) electrode with a reported study on Sb\({}_{2}\)O\({}_{3}\)-based composites as anodes for LIBs in Table 1. First, the Synthesis of the Sb\({}_{2}\)O\({}_{3}\) sample and cross-linked polymeric binder have the advantages of cheap raw materials, simple reaction and short reaction time, which can greatly reduce the production cost. Second, the superior capacity and long-term cycling performance of CMC-FA@Sb\({}_{2}\)O\({}_{3}\) can be explained as that CMC-FA polymer network could improve the integrity of electrode and could buffer the strain caused by volume change of Sb\({}_{2}\)O\({}_{3}\) during the recharging process. Figure 5: SEM images of electrodes before cycling: (**a**) PVDF@Sb\({}_{2}\)O\({}_{3}\), (**b**) CMC@Sb\({}_{2}\)O\({}_{3}\), (**c**) CMC-FA@Sb\({}_{2}\)O\({}_{3}\); SEM images of electrodes after 200 cycles at current density of 200 mAh g\({}^{-1}\): (**d**) PVDF@Sb\({}_{2}\)O\({}_{3}\), (**e**) CMC@Sb\({}_{2}\)O\({}_{3}\), (**f**) CMC-FA@Sb\({}_{2}\)O\({}_{3}\).