## 2 Results and Discussion  
As shown in Figure 1a-c,g-i, by analyzing the cross-sectional scanning electron microscopy (SEM) images of the electrolyte membranes, it is evident that, compared to the PVDF-HFP electrolyte membrane without MOFs, the PVDF-HFP matrix with added ZIF-8 forms a well-connected porous network structure. In the subsequent conductivity test, the conductivity of PHZ film was one unit higher than that of PVDF-HFP film. It indicates that the incorporation of MOFs into PVDF-HFP facilitates the construction of effective ion transport channels, thereby enhancing lithium-ion conduction [29]. Meanwhile, in contrast to membranes without MOFs, the surface SEM images of PHZ electrolyte membranes exhibit a smooth morphology and seamless integration between ZIF-8 and PVDF-HFP, demonstrating strong mutual integration between the two components. Furthermore, as shown in Figure 1j,k,l the uniform distribution of Zn elements further confirms that the adopted preparation method ensures a homogeneous dispersion of ZIF-8 within the composite material. The XRD patterns of the PHZ electrolyte membrane are shown in Figure 2a. The XRD spectrum of PVDF-HFP primarily exhibits a broad peak around \(2\theta\approx 18^{\circ}\) to \(20^{\circ}\), indicating its low crystallinity and high amorphous content [30]. After the incorporation of ZIF-8,  
Figure 1: (**a–c**) Sectional view SEM images of PHZ electrolyte membranes. (**d–f**) Surface SEM images of PHZ electrolyte membranes. (**g–i**) Cross-sectional and surface SEM images of PVDF-HFP electrolyte membranes. (**j–l**) Elemental distribution of Zn and O in PHZ electrolyte membranes. the peak disappears and the amorphous region increases, suggesting that ZIF-8 hinders the orderly arrangement of PVDF-HFP molecular chains, suppressing nucleation and crystal growth, ultimately leading to a decrease in crystallinity [31]. A higher proportion of the amorphous region reduces the entanglement of molecular chains and increases the inter-chain voids (free volume), providing space for segmental motion and Li+ migration, thereby enhancing lithium-ion transport [32]. In order to further investigate the interaction between polymers and MOFs, FTIR spectroscopy analysis was performed on PHZ electrolyte membranes and PVDF-HFP. The FTIR spectrum provides the following insights: the peak at 3537 cm\({}^{-1}\) corresponds to the coordination of the C-O-C bond, which is typically attributed to the interaction between Li+ and ether oxygen. The peaks at 2938 cm\({}^{-1}\) (C-H stretching vibration), 1329 cm\({}^{-1}\) (C-F stretching vibration), and 626 cm\({}^{-1}\) (CF\({}_{2}\) out-of-plane bending vibration) confirm the presence of the PVDF-HFP backbone. The peak at 875 cm\({}^{-1}\) suggests that the HFP copolymer effectively reduces crystallinity. The peak at 1659 cm\({}^{-1}\) corresponds to the C=O stretching vibration in PVDF. Additionally, the peak at 475 cm\({}^{-1}\) is attributed to the vibration between the metal and organic ligand, representing the Zn-N stretching vibration in ZIF-8, confirming its successful incorporation into the polymer matrix. The peaks at 1171 cm\({}^{-1}\) (C-F stretching vibration) and 1070 cm\({}^{-1}\) indicate the presence of ClO\({}_{4}\)\({}^{-}\) in the polymer [33]. Thermogravimetric analysis (TGA) reveals that below 300 \({}^{\circ}\)C, the composite material undergoes mass loss due to the desorption of adsorbed water, residual solvents, or low-molecular-weight volatile components, as well as the decomposition of lithium salt. The intermediate stable stage (350-450 \({}^{\circ}\)C) indicates that the main structure (PVDF-HFP  
Figure 2: (**a**) XRD patterns of ZIF-8, PVDF-HFP, and their composite. (**b**) FTIR spectra of PHZ and its synthetic materials. (**c**) Thermogravimetric (TG) curves of PHZ materials with different proportions of ZIF-8 added. (**d**) Differential Scanning Calorimeter (DSC) curves of PHZ materials with different ratios of ZIF-8 added. crystalline region and ZIF-8 maintains good thermal stability within this temperature range.