Hydrophobic Metal‐Organic Framework‐Based Ion‐Conductive Interfaces Toward Stabilizing Zn Metal for High‐Performance Aqueous Zinc‐Ion Batteries

Abstract

Aqueous zinc‐ion batteries (AZIBs) have received numerous attention due to their high safety, low cost, and environmental friendliness. However, Zn metal suffers from uncontrollable dendritic Zn growth, H₂ generation and Zn corrosion, etc., which seriously reduce the lifetime of aqueous zinc‐metal batteries. To overcome these challenges, an artificial hydrophobic metal‐organic framework (MOF)‐based ion‐conductive protective coating is constructed to stabilize the Zn metal anode for high‐performance AZIBs. The hydrophobic pores in zeolitic imidazolate framework (ZIF‐8) provide channels for rapid Zn‐ions migration, reduce the desolvation activation energy of Zn‐ions, and facilitate Zn uniform deposition, inhibiting dendrite growth. Meanwhile, the outer layer polydimethylsiloxane (PDMS) around ZIF‐8 prevents Zn metal from contacting water molecules, which suppresses H₂ generation, Zn corrosion, and by‐products formation. Thus, the lifetime of PDMS@ZIF‐8‐modified Zn anode extends over 1100 h at the current density/areal capacity of 2 mA cm⁻²/1 mAh cm⁻², significantly longer than that of bare Zn (80 h). Meanwhile, the full cells paired with a VO₂ cathode exhibit excellent long‐term cycling stability, maintaining 82.3% capacity retention after 870 cycles at 3A g⁻¹, which is much higher than that of bare Zn (61.3%). This facile strategy is applicable to other aqueous metallic batteries toward practical applications.

An artificial hydrophobic MOF‐based ion‐conductive protective coating was constructed toward stabilizing Zn metal anode. Thus, the lifetime of PDMS@ZIF‐8‐modified Zn anode extends over 1100 h at 2 mA cm^‐2/1 mAh cm^‐2, significantly longer than that of bare Zn (80 h). Meanwhile, the full cells exhibit excellent long‐term cycling stability with 82.3% capacity retention after 870 cycles at 3A g^‐1.

1. Introduction

Aqueous zinc‐ion batteries (AZIBs) have emerged as leading contenders for next‐generation energy storage, owing to their environmental friendliness, high safety, cost‐effectiveness, favorable redox potential (−0.76 V vs. SHE), and high theoretical capacity (820 mAh/g) [1, 2]. However, the practical application of Zn anodes in AZIBs faces significant challenges, including uncontrolled Zn dendrite growth, hydrogen evolution reaction (HER), Zn corrosion, and by‐products formation [3]. During cycling, water molecules react with Zn metal, generating hydrogen gas. This not only depletes the electrolyte but also raises the local pH, creating an alkaline environment that accelerates Zn corrosion and triggers the formation of irreversible by‐products (e.g., zinc hydroxysulfate) [4, 5, 6]. These by‐products deposit on the anode surface, forming an insulating layer that hinders Zn²⁺ transport and accelerates dendrite growth. Over time, the dendrites may penetrate the separator, leading to internal short circuits. As a result, achieving a stable electrolyte/Zn‐metal interface remains a critical challenge for AZIBs development [7, 8, 9].

To address these challenges, researchers have pursued multiple strategies, including structural design, electrolyte optimization, and engineered interfacial layers. For example, 3D conductive Zn hosts can homogenize charge distribution and reduce local current density by increasing the electrode's surface area, thereby promoting uniform Zn deposition and suppressing dendrite growth. However, the enlarged surface area also exposes more active sites to the electrolyte, exacerbating hydrogen evolution and parasitic reactions. Alternative approaches, such as deep eutectic solvents and water‐in‐salt electrolytes, change the solvation structure of Zn²⁺ to inhibit H₂ evolution and side reactions. Yet, their high cost and viscosity limit practical application in AZIBs. Another strategy involves constructing hydrophilic organic or inorganic interfacial layers to guide Zn deposition [10, 11, 12]. However, organic coatings often suffer from low ionic conductivity and high polarization, leading to poor cycling stability, while inorganic coatings lack the flexibility to accommodate Zn volume changes during plating/stripping [13, 14, 15]. An emerging solution is the in‐situ formation of a hydrophobic artificial solid electrolyte interphase (SEI) with ordered Zn²⁺ transport channels, which simultaneously suppresses dendrites, corrosion, and HER. Inspired by hydrophobic surfaces/interfaces in nature, hydrophobic Zn surfaces can be engineered through micro/nano‐structured scaffolds combined with low‐surface‐energy materials. The rough micro/nano‐structures not only facilitate uniform Zn deposition and fast ion diffusion but also a hydrophobic surface can minimize water contact, mitigating H₂ evolution and corrosion [16, 17, 18]. Recently, metal‐organic frameworks (MOFs) have gained significant attention as nanoscale porous materials for ion‐conductive interfaces, owing to their exceptional porosity and well‐ordered channel structures that promote efficient ion conduction and uniform ion flux distribution [19, 20, 21]. The inherent Lewis acid sites and nanochannels in MOFs not only facilitate ion transport but also lower the activation energy for ion migration [22, 23, 24]. Consequently, developing hydrophobic coatings based on MOF materials is crucial for achieving homogeneous Zn²⁺ nucleation and stable deposition, thereby improving the cycling performance of AZIBs.

In this paper, an artificial composited hydrophobic protective coating composed of zeolitic imidazolate framework (ZIF‐8) and polydimethylsiloxane (PDMS) is fabricated toward stabilizing Zn metal anode (PDMS@ZIF‐8@Zn). ZIF‐8 with exceptional porosity and well‐ordered hydrophobic channels inside provides rapid ion diffusion pathways, lowers the activation energy for ion migration, and promotes the homogeneous plating/stripping of Zn ions, thus inhibiting the growth of zinc dendrites. While low‐surface energy materials PDMS prevents direct contact between the zinc metal anode and water molecules, thereby suppressing H₂ generation, Zn corrosion, and by‐products formation. Thus, the symmetric cells based on the PDMS@ZIF‐8@Zn anode deliver a cycling life over 1100 h at a current density/areal capacity of 2.0 mA cm⁻²/1.0 mAh cm⁻² when compared to a bare zinc anode (80 h). Furthermore, when paired with a VO₂ cathode in a full battery configuration, the full cells demonstrate superior long‐term cycling stability with 82.3% capacity retention after 870 cycles at 3A g⁻¹.

2. Results and Discussion

Inspired by the lotus leaf effect, a hydrophobic Zn metal electrode was fabricated via ZIF‐8 particles coating to create surface roughness, and followed by PDMS modification to lower surface energy (Figure 1a). Bare Zn metal faced lots of challenges, including Zn dendrites formation, Zn metal corrosion, and H₂ and by‐products generation (Figure 1b), however, PDMS@Ag@Zn electrodes exhibited superior interfacial stability without these phenomena (Figure 1c), which is attributed to that porous structure in MOF provides channels for rapid migration and reduces the desolvation activation energy of Zn²⁺ and facilitates Zn uniform deposition, and meanwhile, the PDMS encapsulating MOF prevents Zn metal from contacting water molecules, thus, inhibiting dendrite growth, Zn corrosion, and hydrogen generation.

FIGURE 1.

a) Schematic illustration of the preparation process of the PDMS@ZIF‐8@Zn electrodes. Schematic illustration of the repeated plating/stripping on b) bare Zn and c) PDMS@ZIF‐8@Zn electrodes.

Bare Zn foil displays a smooth, hydrophilic surface with an electrolyte contact angle of 80.5°. In contrast, ZIF‐8@Zn exhibited hydrophobicity with a contact angle of ∼125.9° due to the hydrophobic nature of ZIF‐8. Whereas PDMS@ZIF‐8@Zn exhibited better hydrophobicity with a contact angle of ∼145.9° due to the abundant hydrophobic ‐CH₃ groups in PDMS. To investigate the microstructural morphology of the ZIF‐8@Zn anode and the PDMS@ZIF‐8@Zn anode, the electrodes were observed via field emission scanning electron microscope (SEM). Bare Zn displays a smooth surface (Figure 2a), the cubic ZIF‐8 particles with a size of 0.8 μm are uniformly coated on the zinc anode (Figure 2b), demonstrating a well‐defined “skeleton” framework. The hydrophobic pores inside ZIF‐8 provide rapid migration channels for Zn²⁺ deposition and facilitate the desolvation of Zn ions, effectively suppressing the growth of zinc dendrites. After PDMS spraying, numerous solidified PDMS particles are observed covering the surface of ZIF‐8 due to the evaporation of the THF solvent (Figure 2c). The small PDMS particles increase surface roughness, while the hydrophobicity of the PDMS layer isolates water molecules from directly contacting the zinc metal, thereby inhibiting hydrogen production, Zn corrosion, and by‐products formation. As shown in the cross‐sectional images of Figure 2d, the thicknesses of PDMS@ZIF‐8 layers on Zn metal are ≈16.1 μm. Besides, Zn, C, N, and Si elements are uniformly dispersed on the Zn metal surface (Figure S1), demonstrating that PDMS is uniformly coated on the surface of ZIF‐8 particles and Zn metal, further enhancing the hydrophobicity. As shown in Figure 2e, fourier transform infrared spectroscopy (FTIR) tests were conducted on the ZIF‐8@Zn and PDMS@ZIF‐8@Zn anodes to characterize the surface chemical composition. In the spectra, the C=N bond and the Zn—N bond appear at 1581 cm⁻¹ and 421 cm⁻¹, indicating successful fabrication of ZIF‐8. Si—O and Si—C bonds of PDMS appear at 1260 cm⁻¹ and 799 cm⁻¹ in the PDMS@Zn and PDMS@ZIF‐8@Zn electrode, indicating ZIF‐8 is encapsulated by PDMS [25, 26, 27]. As illustrated in Figure 2f and Figure S2, XPS tests are performed on the bare Zn anode and PDMS@ZIF‐8@Zn anode. Compared to bare Zn metal, N 1s, Si 2p, and Si 2s peaks appear at 386.8, 102.1 eV, and 154.5 eV, indicating the ZIF‐8 and PDMS have been deposited on Zn metal [28, 29, 30].

FIGURE 2.

SEM image of a) bare Zn, b) ZIF‐8@Zn, and c) PDMS@ZIF‐8@Zn. The inset picture is the corresponding electrolyte contact angle. d) Cross‐sectional SEM image of PDMS@ZIF‐8@Zn. e) FTIR spectra of PDMS@Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn anodes. f) XPS spectra of bare Zn and PDMS@ZIF‐8@Zn anode.

The Tafel tests for symmetric cells with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn electrodes are displayed in Figure 3a. It can be observed that the corrosion current density of the Zn anode is the highest, reaching 1.255 mA cm⁻², indicating severe current corrosion of the Zn anode. In contrast, the current densities for ZIF‐8@Zn and PDMS@ZIF‐8@Zn anodes are only 0.6683 mA cm⁻² and 0.4491 mA cm⁻², respectively, which are significantly lower than that of the Zn anode. The corrosion potentials of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn are −0.97886 V, −0.97818 V, and −0.97475 V. The PDMS@ZIF‐8@Zn has a lower corrosion current density than ZIF‐8@Zn and its corrosion potential shifts positively, indicating a lower tendency for corrosion reactions and a slower corrosion rate, demonstrating that the hydrophobic PDMS@ZIF‐8 coating contributes to improving the electrochemical performance of the battery via isolating the Zn metal from contacting the electrolyte. Figure 3b shows the results of linear sweep voltammetry (LSV) tests for Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn‐based symmetric cells. The PDMS@ZIF‐8@Zn exhibited the lowest potential (−1.477 V) than that of bare Zn (−1.327 V) and ZIF‐8@Zn (−1.431 V), indicating that the hydrophobic PDMS@ZIF‐8 protective layer effectively isolated water molecules from direct contact with zinc metal, thereby suppressing the HER. The CV curves of asymmetric batteries composed of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn anodes paired with Cu are shown in Figure 3c. The nucleation overpotential (NOP) of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn were −22 mV, −51 mV, and −79 mV, respectively. Higher NOP leads to finer Zn deposition particles, indicating that Zn²⁺ ions deposit more densely and uniformly on the electrode surface. These results suggested that the PDMS@ZIF‐8 coating promotes a more compact and uniform Zn deposition behavior during cycling [31, 32]. Chronocurrent method analysis (CAs) was conducted on symmetric cells of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn to analyze the diffusion behavior of Zn²⁺ in the electrolyte. As shown in Figure 3d, the current of the Zn‐based symmetric cells continuously increases, which is typical of 2D diffusion behavior [33, 34, 35]. This leads to a “tip effect,” causing Zn²⁺ to preferentially deposit at the tips, thus accelerating zinc dendrite growth. In contrast, the symmetric cells of ZIF‐8@Zn and PDMS@ZIF‐8@Zn electrodes are dominated by 3D diffusion (Figure 3e). Particularly, the current stops increasing after an extremely short period, indicating that Zn²⁺ can be deposited uniformly and smoothly on PDMS@ZIF‐8@Zn, effectively suppressing zinc dendrite growth. The activation energy (E_a) can be used to evaluate the desolvation capability of anodes based on the Arrhenius equation (Figure 3f). As shown in Figures S3–5, the EIS plots of symmetric cells with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn at different temperatures were analyzed. According to the Arrhenius equation, the calculated E_a for PDMS@ZIF‐8@Zn (41.18 kJ mol⁻¹) was significantly lower than that of bare Zn (53.81 kJ mol⁻¹) and PDMS@Zn (41.18 kJ mol⁻¹), indicating that the strong interaction between the hydrophobic PDMS coatings and free Zn²⁺ played a positive role in promoting the desolvation process and significantly reduces the desolvation energy barrier of Zn ions, thereby enhancing the plating/stripping rate of Zn ions [35, 36, 37]. Besides, the t_Zn ²⁺ of PDMS@ZIF‐8@Zn was 0.566, which was significantly higher than that of bare Zn (∼0.437) (Figure S9), indicating the fast Zn ions diffusion in PDMS@ZIF‐8@Zn electrode.

FIGURE 3.

a) Tafel and b) LSV, and c) cyclic voltammetry curves of symmetric cells with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn electrodes. d) Chronoamperometry curves of symmetric cells with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn anodes at an applied potential of −150 mV. e) Chronoamperometry curves of symmetric cells with ZIF‐8@Zn, and PDMS@ZIF‐8@Zn electrodes at an applied potential of −150 mV. f) Desolvation kinetics of symmetric cells with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn electrodes.

To observe the surface morphology changes of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn after cycling, symmetrical cells were assembled and cycled at a current density/areal capacity of 1 mA cm⁻²/1 mAh cm⁻² after 20 cycles. As shown in Figure 4a and b, the surface of the bare Zn anode was covered with many chaotic dendrites. As shown in the X‐ray diffraction analysis (XRD) spectra (Figure 4c), the representative peaks at 9.2°, 16.2°, and 24.3° indicated the formation of zinc hydroxide sulfate hydrate (Zn₄SO₄(OH)₆·4H₂O (ZHS)), which were mainly from the side reactions between the electrolyte and Zn metal. While a little dendrite formed on the ZIF‐8@Zn electrode (Figure S6), which is much flatter compared to the Zn anode, indicating that hydrophobic ZIF‐8 played a certain role in inhibiting zinc dendrite growth. Especially, the surface of the PDMS@ZIF‐8@Zn anode is flat and smooth, demonstrating that the hydrophobic PDMS@ZIF‐8 coating effectively suppressed dendrite formation, by‐products generation, and Zn corrosion, which is consistent with the XRD results. To evaluate the corrosion resistance of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn electrodes under static conditions, the electrodes were immersed in ZnSO₄ electrolyte for 5 days, and the surface morphology changes were observed. As shown in Figure S7, the bare Zn foil was covered with abundant hexagonal flakes with sizes spanning from hundreds of nanometers to tens of micrometers. The XRD spectrum revealed characteristic peaks at 9.2°, 16.2°, and 24.3°, confirming the formation of ZHS (Figure S7). This phase primarily resulted from side reactions between the electrolyte and Zn metal. A small amount of ZHS also formed on the ZIF‐8@Zn electrode, suggesting that ZIF‐8 effectively protects the anode (Figure S8). In contrast, there is no by‐products formation on the PDMS@ZIF‐8@Zn electrode, indicating that the hydrophobic PDMS@ZIF‐8 coating prevented the direct contact between Zn metal and electrolyte to avoid H₂ and by‐products generation. In‐situ optical microscopy (OM) was employed to evaluate the protective effect of the coating layer by monitoring real‐time morphological evolution and gas generation during Zn electroplating. Bare Zn electrodes exhibited rapid dendrite formation, with visible protrusions appearing within 10 min (Figure 4d). These dendrites continued growing while hydrogen bubbles evolved, accompanied by vertically oriented hexagonal flakes on the surface. In comparison, ZIF‐8@Zn electrodes showed significantly reduced dendrite formation and hydrogen evolution due to the uniform Zn²⁺ deposition (Figure 4e). Remarkably, PDMS@ZIF‐8@Zn maintained a completely smooth deposition layer throughout plating, with no observable bubbles, dendrites, or ZHS by‐products (Figure 4f) [38, 39, 40, 41].

FIGURE 4.

SEM images of a) bare Zn and b) PDMS@ZIF‐8@Zn electrodes after 20 cycles at a current density of 1 mA cm⁻²/1 mAh cm⁻² in symmetric cells. c) XRD spectra of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn electrodes after 20 cycles at a current density of 1 mA cm⁻²/1 mAh cm⁻². In‐situ optical images of Zn plating behaviors in d) bare Zn, e) ZIF‐8@Zn, and f) PDMS@ZIF‐8@Zn symmetric cells at a current density of 10 mA cm⁻².

Coulombic efficiency (CE) is a critical metric for evaluating the reversibility of batteries; thus, asymmetric cells with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn paired with Cu were assembled. As shown in Figure 5a, under a current density of 5 mA cm⁻²/1 mAh cm⁻², the PDMS@ZIF‐8@Zn electrodes can stably cycle over 500 times with an average CE exceeding 99%. The ZIF‐8@Zn electrodes can stably cycle for more than 200 cycles, whereas the bare Zn electrodes are dead after less than 50 cycles, leading to a significant decrease in CE. This indicates that PDMS@ZIF‐8 layer significantly enhances the cycling stability of Zn metal anode. Furthermore, the voltage profile of the PDMS@ZIF‐8@Zn//Cu asymmetric cells after 400 cycles remains overlapped with the original curves, further demonstrating its superior reversibility (Figure 5b). To test the reversibility of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn anode, symmetrical cells were assembled and subjected to constant current charge–discharge tests. As shown in Figure 5c, the Zn symmetrical cell cycles less than 100 h at current density/areal capacity of 2 mA cm⁻²/1 mAh cm⁻² due to zinc dendrite growth and the occurrence of side reactions. The ZIF‐8@Zn symmetrical cells could cycle for up to 240 h, indicating that ZIF‐8 could improve the stability and reversibility of the battery. In contrast, the PDMS@ZIF‐8@Zn symmetrical cell demonstrated a markedly enhanced performance with prolonged cycle life as high as 1100 h. The rate performance of the symmetric cells at different current densities ranging from 0.1 to 0.2, 0.3, 1.0, 2.0, and 3.0 mA cm⁻² was shown in Figure S10. Zn‐based symmetric cells displayed a short lifetime less than 100 h, and in comparison, symmetric cells using ZIF‐8@Zn and PDMS@ZIF‐8@Zn electrodes exhibited excellent rate performance because ZIF‐8 and PDMS contributed to suppressed dendrites formation, by‐products, and hydrogen production. Attributed to the advantages of PDMS@ZIF‐8 coating, the lifespan of the cells in this work was significantly competitive when compared to previously published works with various coatings at different current densities (Table S1). This shows that ZIF‐8 provide rapid migration pathways for Zn ions and reduce the desolvation energy barrier of Zn ions, suppressing the growth of zinc dendrites, while hydrophobic PDMS blocks water from contacting Zn metal, inhibiting hydrogen evolution, Zn corrosion, and by‐products formation.

FIGURE 5.

a) CE performance of asymmetric batteries with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn//Cu at a plating/stripping current density of 5 mA cm⁻² and a cutoff charge voltage of 0.5 V. b) Capacity–voltage curve of the PDMS@ZIF‐8@Zn//Cu asymmetric battery. c) Cycling performance of symmetric batteries with Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn at current density/areal capacity of 2 mA cm⁻²/1 mAh cm⁻². d) Rate capability of Zn//VO₂ and PDMS@ZIF‐8@Zn//VO₂ full cells. e) Long cycling performance of full cells at 3 A g⁻¹. f) Self‐discharge test of PDMS@ZIF‐8@Zn//VO₂ battery.

To verify the practical feasibility of PDMS@ZIF‐8@Zn, a full cell was assembled using VO₂ cathode. As shown in Figure S11, the impedance of the PDMS@ZIF‐8@Zn//VO₂ full cell is significantly lower than that of the Zn//VO₂ full cell, indicating an improvement in charge transfer kinetics and a reduction in charge transfer impedance. Meanwhile, at a scan rate of 0.5 mV s⁻¹, both the PDMS@ZIF‐8@Zn//VO₂ and Zn//VO₂ cells exhibit similar CV curves, suggesting that the protective layer on the PDMS@ZIF‐8@Zn anode has a negligible impact on the electrochemical performance of the zinc‐ion battery (Figure S12). The PDMS@ZIF‐8@Zn//VO₂ full cell displayed an excellent rate capability with high discharge specific capacities are 249.2, 226.6, 204.2, 145.2, 132.6, and 105.4 mAh g⁻¹ at current densities of 0.2, 0.3, 0.5, 2, 3, and 5 A g⁻¹, which are superior to those of Zn//VO₂ (Figure 5d). As illustrated in Figure S13, the charge–discharge profiles at different current densities show that the full cell exhibits a long plateau at ≈0.6 V. As shown in Figure 5e, the PDMS@ZIF‐8@Zn//VO₂ full cell exhibits a high capacity of 83.4 mAh g⁻¹ and superior cycling stability with a capacity retention rate of 82.3% after 870 cycles at a current density of 3 A g⁻¹. In contrast, the Zn//VO₂ full cell shows poorer cycling stability with a low capacity of 38.1 mAh g⁻¹ and retention of 61.3% after 870 cycles. To evaluate the self‐discharge behavior of the full cells, they were assembled and tested. After 24 h of rest, the CE of the cell with bare Zn anode is only 50.55% (Figure S14), whereas the CE of the cell with PDMS@ZIF‐8@Zn anode increases to 91.92% (Figure 5f). This demonstrates that the PDMS@ZIF‐8@Zn coating significantly suppresses the self‐discharge behavior of the full cell.

3. Conclusion

In conclusion, a hydrophobic porous PDMS@ZIF‐8 protective layer was constructed toward stabilizing Zn metal via regulating H₂O adsorption energy. The porous ZIF‐8 provides high‐speed channels for the rapid migration of Zn²⁺, reduces the desolvation energy barrier of Zn²⁺, and facilitates the uniform Zn plating, which effectively inhibits Zn dendrite growth. Hydrophobic PDMS significantly improves the hydrophobicity to prevent direct contact between water and Zn metal, thereby suppressing H₂ generation, Zn corrosion, and side reactions. Thus, the PDMS@ZIF‐8@Zn symmetric cells achieve an ultra‐long cycling lifetime of 1100 h at a current density/areal capacity of 2 mA cm⁻²/1 mAh cm⁻². Moreover, the full cells paired with VO₂ cathode exhibit a high capacity of 83.4 mAh g⁻¹ and superior cycling stability with a capacity retention rate of 82.3% after 870 cycles at a current density of 3 A g⁻¹ when compared to Zn//VO₂ full cell (a low capacity of 38.1 mAh g⁻¹ and retention of 61.3% after 870 cycles).

Supporting Information

Additional supporting information can be found online in the Supporting Information section. Supporting Fig. S1: a) Cross‐sectional SEM and b‐f) EDS elemental mapping images of PDMS@ZIF‐8@Zn. Supporting Fig. S2: High‐resolution Si 2p XPS spectrum of PDMS@ZIF‐8@Zn anode. Supporting Fig. S3: Impedance of Bare Zn at different temperatures. Supporting Fig. S4: Impedance of ZIF‐8@Zn at different temperatures. Supporting Fig. S5: Impedance of PDMS@ZIF‐8@Zn at different temperatures. Supporting Fig. S6: SEM images of ZIF‐8@Zn after 20 cycles. Supporting Fig. S7: XRD patterns of Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn anodes after soaking in ZnSO4 electrolyte for 5 days. Supporting Fig. S8: SEM images of a) bare Zn, b) ZIF‐8@Zn, and c) PDMS@ZIF‐8@Zn electrodes after soaking in ZnSO4 electrolyte for 5 days. Supporting Fig. S9: (a, b) EIS impedance spectra and (c, d) polarization curves before and after the I‐T test in ZnSO4 electrolyte for Zn and PDMS@ZIF‐8@Zn electrodes. Supporting Fig. S10: Rate capability of bare Zn, ZIF‐8@Zn, and PDMS@ZIF‐8@Zn symmetric cells at various current densities. Supporting Fig. S11: EIS plots of Zn//VO2 and PDMS@ZIF‐8@Zn full cell. Supporting Fig. S12: Cyclic voltammetry curves of Zn//VO2 and PDMS@ZIF‐8@Zn full cell. Supporting Fig. S13: (a) Charge‐discharge curves of Zn//VO2 full cell. (b) Charge‐discharge curves of PDMS@ZIF‐8@Zn//VO2 full cell. Supporting Fig. S14: Self‐discharge test of Zn//VO2 full cell. Supporting Table S1: Performance comparison in this work to previously published works with various coatings.

Author Contributions

M. Ge, J. Shang, and Y. Zhao conceived the project and designed the experiments. N. Zhang, S. Li, H. Liu, and W. Zhang fabricated the samples, conducted the characterizations and performed the battery tests. T. Yan, R. Li, C. Cao, B. Fei, H. Liu, and M. Ge revised the manuscript. All authors analyzed the data and contributed to the discussions.

Conflict of Interest

The authors declare no conflicts of interest.

Supporting information

Supplementary Material

Ge Mingzheng, Shang Jing, Zhao Yanrui, Zhang Ni, Yan Tingting, Li Ruiqing, Li Shanshan, Zhang Wei, Liu Hui, Fei Bin, Liu Hongchao, Cao Chunyan, ChemSusChem 2026, 19, e202502555. 10.1002/cssc.202502555