Tailoring Interfacial Chemistry Using S═O Bonds and Sulfur Vacancies of MoS₂‐PEO for Stable Zinc Anode

ABSTRACT

Although aqueous zinc‐ion batteries (AZIBs) have attracted considerable attention due to their high safety and low cost, their commercial application is hindered by dendrite formation and hydrogen evolution. Herein, a multifunctional artificial interphase protection layer of MoS₂‐PEO with sulfur vacancies (SVs) and S═O bonds was constructed on the zinc anode, where SVs accelerate interfacial charge transfer and polyethylene oxide (PEO) chains reduce the desolvation energy barrier of Zn²⁺, while the S═O bonds combine with PEO to reconstruct the interfacial hydrogen‐bonding network. Based on these synergistic effects, this can achieve three‐dimensional dense nucleation of Zn deposition and effectively suppress the hydrogen evolution side reaction. As a result, the symmetric cell achieves stable cycling over 500 h at 20 mA cm⁻². The full cells maintain 80.76% capacity retention after 2400 cycles at 0.2 A g⁻¹. Moreover, the pouch cell achieves 99 mAh g⁻¹ and 98.86% capacity retention after 300 cycles. The work opens a new avenue for the development of dendrite‐free anodes in aqueous metal batteries.

The work presents a MoS₂‐PEO artificial interface layer. The synergistic effect of sulfur vacancies (SVs) and PEO enables 3D dense Zn nucleation, while the S═O groups and PEO reconstruct the H–bonding network to suppress water reactivity. Consequently, the AZIB retains 80.76% of its capacity after 2400 cycles, and the pouch cell offers 99 mAh g⁻¹ with over 98% retention.

1. Introduction

Currently, aqueous zinc‐ion batteries (AZIBs) have emerged as a promising candidate for next‐generation electrochemical energy storage technologies due to their inherent high safety, good environmental stability, low cost, and low redox potential of zinc metal anodes (‐0.76 V vs. SHE) [1, 2]. Nonetheless, its practical applications still face serious challenges, including by‐product accumulation, hydrogen evolution, and uncontrollable zinc dendrite growth, which lead to poor anode utilization and poor coulombic efficiency [3]. Therefore, the development of high‐performance and highly stable zinc anode materials is of great significance for advancing the commercialization of AZIBs.

To date, several approaches have been investigated by researchers to stabilize zinc anodes, mainly including electrolyte engineering [4, 5], separator modification [6, 7, 8, 9], and artificial interfacial layers [10, 11, 12]. Among these, the artificial interfacial layer has drawn significant interest because it provides uniform and comprehensive coverage across the electrode surface [13]. Previous research predominantly focused on single component protective layers (inorganic or organic). For instance, Jiao et al. constructed a Sn@Zn anode that exhibited a cycle lifespan of 1000 h at 0.5 mA cm⁻² [14]. Cui et al. developed a multifunctional polymer interfacial layer composed of polyamide (PA) and zinc trifluoromethanesulfonate (Zn(TfO)₂) [15]. Notwithstanding, it remains challenging for either inorganic or organic materials alone to simultaneously achieve high ionic conductivity, excellent mechanical strength, and electrochemical stability. Recently, increasing efforts are devoted to designing organic–inorganic hybrid interphase layers and focused on the discussion of physical synergistic effects in material composites. Xu et al. constructed a hybrid molecular sieve interfacial layer that leverages physical confinement and size‐sieving effects to regulate water molecule diffusion [16]. Notably, microscopic chemical regulation is also crucial, particularly regarding the modulation of the interfacial chemical environment. Critically, harnessing this chemical environment to achieve synergistic regulation of dendrite growth and the hydrogen evolution reaction (HER) represents a highly promising strategy.

In the work, we construct artificial interphase protection layer of MoS₂‐PEO with sulfur vacancies (SVs) and S═O bonds, and achieved synergistic protection and enhancement, namely Zn²⁺ transport, nucleation regulation, and interfacial stabilization. Not only does it overcome the limitations of single‐component interface layers, but it also offers advantages such as the flexibility to buffer volume expansion and the ability to reconfigure the chemical environment at the interface. On the one hand, the synergistic effect between SVs and polyethylene oxide (PEO) enables dual regulation of interfacial ion transport and nucleation behavior. SVs introduce localized charge‐rich regions within the MoS₂ lattice, enhancing electrostatic adsorption of ions and promoting the preferential enrichment and uniform nucleation of Zn²⁺, thereby achieving a uniform distribution of ion flux. Concurrently, the ether oxygen groups in the PEO chains coordinate with Zn²⁺, restructuring the solvation environment and lowering the desolvation energy barrier, which further accelerates ion transfer and transport. On the other hand, the S═O functional groups on the MoS₂ surface interact synergistically with PEO, effectively breaking the hydrogen‐bond network between water molecules, converting free water into bound water, and suppressing the HER. This synergistic effect enables the MoS₂‐PEO@Zn anode to exhibit excellent electrochemical performance. As a result, the symmetric cell achieves stable cycling over 500 h at 20 mA cm⁻². The full cells maintain 80.76% capacity retention after 2400 cycles at 0.2 A g⁻¹.

2. Experimental Section

2.1. Materials

Polyethylene oxide (PEO, Mw = 1 000 000) was supplied by BASF (China) Co., Ltd. N‐Methyl‐2‐pyrrolidone (NMP), manganese sulfate (MnSO₄, 99%), potassium permanganate (KMnO₄, 89%), zinc sulfate hexahydrate (ZnSO₄·6H₂O, 99.5%), manganese dioxide (MnO₂, 99.95%), and N,N‐dimethylformamide (DMF, 99.5%) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. n‐Butyllithium (2.5 M) was provided by Tianjin Kaio Chemical Reagent Co., Ltd. Zinc metal was purchased from North China Technology Metal Materials Co., Ltd. All chemicals were used as received without further purification.

2.2. Synthesis of MoS₂ Nanosheets

Commercial MoS₂ powder was dispersed in N,N‐dimethylformamide (DMF) solvent and subjected to ultrasonication for 12–16 h to exfoliate the layered MoS₂ structure through the synergistic effect of interfacial regulation by the phase separation inducer and ultrasonic cavitation. The resulting suspension after exfoliation was separated by centrifugation, then transferred to a high‐pressure autoclave and hydrothermally treated with n‐butyllithium to further promote the dissociation of the nanosheets. After naturally cooling to room temperature, the hydrothermal product was continuously stirred magnetically for 8–12 h to stabilize its surface state. Finally, the product was washed multiple times with organic solvents to remove residual solvent and impurities, and then placed in a vacuum drying oven to obtain functionalized MoS₂ nanosheet powder.

2.3. Preparation of MnO₂

MnSO₄·H₂O (0.76 g) and KMnO₄ (0.47 g) were dissolved in deionized water and stirred for 10–20 min. The resulting mixed solution was then transferred into a 100 mL Teflon‐lined autoclave and heated at 160°C in a homogeneous reactor for 12 h. After the reaction was complete, the autoclave was allowed to cool naturally to room temperature. Once the autoclave had cooled completely to room temperature, the product was collected by filtration and washed with deionized water 3–5 times. The obtained product was dried in an oven at 80°C until completely dry. The as‐synthesized manganese dioxide product was obtained as a black powder.

2.4. Preparation of Relevant Electrodes

Zinc foil was first polished, then cleaned with an organic solvent and dried to obtain the Bare@Zn anode. The obtained functionalized MoS₂ nanosheet powder was dispersed in DMF and stirred under ultrasonication at room temperature for 8–12 h to form a uniformly dispersed slurry. The resulting slurry was then uniformly coated onto the surface of zinc foil at room temperature and dried to obtain the MoS₂‐DMF@Zn anode. The functionalized MoS₂ nanosheet powder was combined with PEO via ultrasonic‐assisted liquid‐phase exfoliation to form a composite. The resulting composite was then dispersed in a measured amount of acetonitrile (ACN) and stirred under ultrasonication at room temperature for 8–12 h to obtain a uniformly dispersed slurry. This slurry was subsequently coated uniformly onto the surface of zinc foil at room temperature and dried to yield the MoS₂‐PEO@Zn anode.

2.5. Preparation of the Cathode

The as‐synthesized manganese dioxide, Kochen black, and PVDF were uniformly mixed in 1‐methyl‐2‐pyrrolidinone (NMP) at a mass ratio of 7:2:1. The resulting mixture was then coated onto titanium foil and dried at 80°C to obtain the cathode sheet.

2.6. Electrochemical Measurements

CR2025 coin cells were assembled in ambient air at room temperature to evaluate the electrochemical performance. Zn//Zn symmetric cells were constructed using zinc foil as both the anode and cathode, with 2 M aqueous ZnSO₄ solution as the electrolyte. Zn//Cu asymmetric cells were fabricated using zinc foil as the anode and copper foil as the cathode. Additionally, full cells were assembled with zinc foil as the anode and manganese dioxide as the cathode. All galvanostatic measurements were conducted on a temperature‐controlled Neware battery testing system. Linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), Tafel plots, and cyclic voltammetry (CV) data were obtained using an electrochemical workstation (DH7001, Donghua Analysis, Jiangsu, China). Unless otherwise stated, all electrochemical tests were performed at 30 °C under controlled temperature conditions.

The ionic conductivity of the samples was measured using an AC impedance spectrometer (DH7001, Donghua Analysis, Jiangsu, China) over a frequency range of 0.01 Hz–1000 kHz. The ionic conductivity was calculated using the following equation:

$$\sigma =\frac{d}{RS}$$ (1)

where σ, d, R, and S represent the ionic conductivity, thickness, bulk resistance, and surface area, respectively.

The Zn²⁺ transference number (t_Zn ²⁺) was calculated according to the following equation:

$$t_{Z{n}^{2+}}=\frac{I_s(\mathrm{\Delta }V-I_0{R}_0)}{I_0(\mathrm{\Delta }V-I_s{R}_s)}$$ (2)

where I_o and Is denote the initial current and steady‐state current, respectively. ΔV is the polarization potential (10 mV). Ro and Rs represent the initial resistance and steady‐state resistance, respectively.

The activation energy for the desolvation process of Zn²⁺ ions was calculated using the Arrhenius equation:

$$\frac{1}{{\mathrm{R}}_{e\mathrm{t}}}=A\exp \left(-\frac{E_a}{RT}\right)$$ (3)

where R _ct is the charge transfer resistance, R is the gas constant, E_a is the activation energy, and A is the pre‐exponential factor.

2.7. Material Characterization

The surface morphology and microstructure of the prepared materials were observed using field‐emission scanning electron microscopy (FE‐SEM, Hitachi SU8010) and transmission electron microscopy (TEM, JEM‐F200). The phase structure of the samples was examined by x‐ray diffraction (XRD, SmartLab SE) over a 2θ range of 10°–80°. x‐ray photoelectron spectroscopy (XPS, Thermo Scientific K‐Alpha). The crystal structure of the samples was analyzed by Fourier transform infrared spectroscopy (FTIR, Netzsch DSC 200F3) in the range of 600–4000 cm⁻¹. Sulfur anion vacancies were identified through electron paramagnetic resonance (EPR, Bruker EMXplus‐6/1) measurements. The wettability of the electrodes was evaluated by contact angle testing (Dingsheng, JY‐82C). All anodes were rinsed with alcohol to remove residual zinc salts prior to characterization. In‐situ optical microscopy analyses were carried on an optical microscope (XJ‐550).

2.8. COMSOL Multiphysics

For ion concentration analysis, a comparable simplified two‐dimensional model was established, where the electrode length was 10 µm, and the interelectrode spacing was 8 µm. Transient simulations were performed using the tertiary current distribution physics interface. The ion concentration evolution was described on the basis of Fick's first law of diffusion and the Nernst–Planck equation for ion electromigration. Boundary conditions were determined by the applied potentials at the positive and negative electrodes. The initial Zn²⁺ concentration was set as 2 mol L⁻¹, with an effective diffusion coefficient of 1×10⁻¹³ m² s⁻¹. The exchange current density of the cell was fixed at 8 A cm⁻², the system temperature was maintained at 293.15 K, and the current density at the electrode‐electrolyte interface was set to 2 mA cm⁻².

3. Results and Discussion

3.1. Synthesis and Characteristics of MoS₂‐PEO@Zn

To simultaneously achieve regulation of Zn²⁺ deposition and enhanced interfacial stability, the work designed a composite interphase layer composed of MoS₂‐PEO. Using an ultrasound assisted liquid phase exfoliation strategy, we first pretreat commercial MoS₂ with N,N‐dimethylformamide (DMF) to obtain MoS₂‐DMF, and subsequently introduce PEO fabricate the MoS₂‐PEO composite (Figure S1). High‐resolution scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images reveal that MoS₂‐PEO displays thinner and more few‐layer nanosheet structure compared to MoS₂‐DMF (Figures 1a, S2–S4), significantly shortening the interface diffusion pathways for Zn²⁺ while exposing more active edge sites. Furthermore, corresponding energy‐dispersive x‐ray spectroscopy (EDS) mapping of elements demonstrates the uniform distribution of carbon, oxygen, sulfur and molybdenum within the MoS₂‐PEO composite (Figure 1b), confirming the successful integration of PEO with MoS₂. High‐resolution transmission electron microscopy (HRTEM) images further reveal the expand interface spacing of MoS₂‐PEO 0.89 nm, larger than that of MoS₂‐DMF (0.81 nm) and commercial molybdenum disulfide (0.62 nm) (Figures 1c, S5) [17]. The x‐ray diffraction (XRD) pattern of MoS₂‐PEO presents obvious shift of the characteristic peak (002), further confirming the expanded interface spacing (Figure 1d) [18, 19, 20]. Fourier‐transform infrared (FTIR) spectroscopy (Figure 1e) exhibit a characteristic S═O peak at 1120 cm⁻¹ [21], which modulate the arrangement of interfacial water molecules, collectively reducing the probability of HER [22, 23]. The x‐ray photoelectron spectroscopy (XPS) analysis (Figures 1f–g, S6–S7) demonstrates the mixed 1T/2H phase and enriched SVs. Electron paramagnetic resonance (EPR) measurements (Figure 1 h) further reveal presence of SVs [24, 25, 26, 27], which will guiding uniform deposition [28, 29]. Subsequently, we coat MoS₂‐PEO onto zinc foil under equal mass and identical doctor blade height to construct multifunctional zinc anode with thickness of 4.67 µm, where exhibits a uniform and dense surface, compared the localized fine cracks and particle agglomeration of MoS₂‐DMF (Figures 1i–j, S8).

FIGURE 1.

(a) TEM image showing the surface morphology of MoS₂‐PEO (b) EDS of MoS₂‐PEO, presenting the distribution of Mo, S, C, and O; (c) TEM image of the interlayer structure of MoS₂‐PEO; (d) XRD patterns of MoS₂ and MoS₂‐PEO; (e) FTIR spectra of MoS₂ and MoS₂‐PEO; XPS analysis of MoS₂‐PEO (f) S, (g) Mo; (h) EPR spectra of MoS₂ and MoS₂‐PEO; Cross‐sectional SEM image of (i) MoS₂‐PEO@Zn, (j) MoS₂‐DMF@Zn; (k) Schematic diagram illustrating contact angle comparisons.

Based on our optimization, this thickness (4.67 µm) was determined to be the most favorable for achieving stable electrochemical performance. To evaluate the mechanical flexibility of the hybrid coating, bending tests were performed on MoS₂‐DMF@Zn and MoS₂‐PEO@Zn electrodes. As shown in Figure S9, the MoS₂‐PEO coating exhibited no cracks, whereas the MoS₂‐DMF@Zn coating showed visible cracks when the bending angle exceeded 90°. The result is highly consistent with the uniaxial tensile test observations (Figure S10), where the MoS₂‐PEO@Zn electrode exhibited a significantly higher fracture elongation compared to Bare Zn and MoS₂‐DMF@Zn. Collectively, these results demonstrate that the incorporation of PEO significantly enhances the flexibility of the hybrid coating. Meanwhile, the MoS₂‐PEO@Zn indicate good hydrophilicity (Figures 1k). It should be noted that although the MoS₂‐PEO coating exhibits improved hydrophilicity, which facilitates electrolyte wetting and uniform ion flux, the S═O functional groups synergize with the PEO chains to reconstruct the interfacial hydrogen‐bonding network, converting highly active free water into bound water. This enables effective HER suppression even on a hydrophilic surface.

3.2. Dendrite Suppression and Anticorrosion Behavior

To directly examine how Zn deposits behave on various electrode surfaces, the surface evolution of symmetric Zn//Zn cells was tracked using in situ optical microscopy under a current density of 10 mA cm⁻². Figure 2a reveals that all three electrodes initially exhibited uniform and smooth surfaces. In the case of the bare Zn electrode, as deposition proceeded, increasingly distinct irregular bumps appeared on its surface, ultimately leading to nonuniform Zn deposition accompanied by continuous dendritic growth after 60 min. In contrast, MoS₂‐PEO@Zn displayed a dendrite‐free and homogeneous Zn plating layer throughout the entire deposition process. This demonstrates its excellent capability to maintain a stable deposited Zn interface and to suppress both detrimental side reactions and dendrite formation [30, 31]. Because the durability of electrodes during repeated zinc plating and stripping is strongly influenced by how zinc is deposited, SEM was employed to examine the electrode surfaces after cycling. Figures 2b–d show that after 50 charge‐discharge cycles at 10 mA cm⁻² and 1 mAh cm⁻², MoS₂‐PEO@Zn retained a dense and even morphology with no signs of dendrites. In contrast, Bare@Zn exhibited extensive dendritic growth. In addition, XRD was performed to determine the crystallographic orientation of the deposited zinc (Figure S11). From a thermodynamic perspective, among all crystal planes of Zn, the (002) plane is the close‐packed plane with the lowest surface energy. Therefore, Zn tends to preferentially nucleate on this plane to minimize the total system energy [32, 33] A closer look at the data reveals that on MoS₂‐PEO@Zn surface, zinc deposition preferentially followed the (002) plane, whereas Bare@Zn showed a preference for the (101) plane. In comparison with MoS₂‐PEO@Zn, MoS₂‐DMF@Zn exhibited a weaker (002) preference. To track changes in zinc texture more systematically, the I(002)/I(101) peak intensity ratios before and after cycling were calculated for each specimen (Figure S12) [34]. After cycling, the I(002)/I(101) ratio for MoS₂‐PEO@Zn increased from 0.89 to 1.24. This upward trend benefits from the synergistic regulation, where the layered MoS₂ structure enables epitaxial deposition [35], SVs act as zincophilic sites to reduce the nucleation barrier, and PEO mediates Zn²⁺ flux homogenization via coordination between ether oxygen groups and Zn²⁺ [16, 36, 37, 38]. As a result, a smooth and dense deposition layer is formed, which facilitates extended cycling and inhibits the emergence of dendrites.

FIGURE 2.

(a) In situ optical microscopy observations of zinc deposition behavior on MoS₂‐PEO@Zn, MoS₂‐DMF@Zn, and Bare@Zn; SEM images of (b) MoS₂‐PEO@Zn, (c) MoS₂‐DMF@Zn, and (d) Bare@Zn after 50 cycles at 10 mA cm⁻² and 1 mAh cm⁻²; In situ Raman spectra of (e) Bare@Zn and (f) MoS₂‐PEO@Zn; (g) COMSOL finite element simulation showing the dynamic distribution of Zn²⁺ concentration.

To clarify the effect of MoS₂‐PEO, we performed finite element analysis (Figure 2 g) via COMSOL simulation to model the evolution of Zn²⁺ concentration during the deposition process. As shown in the figure, the simulation results reveal that MoS₂‐PEO enables a highly uniform Zn²⁺ concentration distribution on the electrode surface without obvious local enrichment or concentration gradients. This uniformity is attributed to two synergistic effects. First, the ether oxygen groups of PEO chains coordinate with Zn²⁺, suppressing overly rapid Zn²⁺ transfer kinetics and preventing local depletion or enrichment. Second, SVs act guiding Zn²⁺ deposition onto flat areas. In contrast, an extremely inhomogeneous Zn²⁺ distribution is observed on the electrode in the bare Zn system, with distinct local enrichment at surface protrusions and defects. Compared with Bare Zn, MoS₂‐DMF affords an improvement due to SVs, but still exhibits local concentration variations because it lacks the PEO chains needed for kinetic regulation of Zn²⁺ flux. To further investigate corrosion behavior of the electrode interface during cycling, in‐situ Raman spectroscopy was employed to monitor the evolution of water molecules at the interface (Figures 2e–f, S13). Initially, all exhibited typical O–H stretching peaks characteristic of free water in the 2800–3700 cm⁻¹ [39, 40]. Compared to Bare@Zn (48%) and MoS₂‐DMF@Zn (67%), the O–H peak intensity of MoS₂‐PEO@Zn retained over 85% of its initial intensity after 60 min, demonstrating its superior ability to suppress interfacial water consumption. This stability is attributed to the synergistic effect of S═O bonds and PEO chains, which reconstruct the interfacial hydrogen‐bonding network, converting highly active free water into less active bound water, thereby reducing HER. In contrast, MoS₂‐DMF lacks the continuous PEO matrix, so its ability to stabilize interfacial water is limited.

3.3. Interfacial Electrochemical Characteristics

To investigate the corrosion inhibition mechanism of the MoS₂‐PEO coating, the corrosion current density and corrosion potential in Zn symmetric cells were measured. The Tafel curves (Figure 3a) indicate that the corrosion current density of the cell with MoS₂‐PEO@Zn (0.177 mA cm⁻²) is lower than that of the cell with MoS₂‐DMF@Zn (0.339 mA cm⁻²) and Bare@Zn (0.776 mA cm⁻²), while the corrosion voltage follows the opposite trend [41, 42]. Corresponding to the surface morphology after 20 days of soaking (Figure S14) and XRD patterns (Figure 3b), further confirming the optimal corrosion inhibition effect of MoS₂‐PEO coating. To examine the effect of the MoS₂‐PEO coating on the HER, LSV tests were conducted on asymmetric cells. Figure 3c demonstrates that the hydrogen evolution potential of MoS₂‐PEO@Zn is lower than that of Bare@Zn. The characteristic helps suppress the HER. The suppression is attributed to the synergistic effect between S═O and PEO. Moreover, EIS measurements were performed with different systems under various temperatures ranging from 30°C to 60°C to assess charge transfer and desolvation processes of Zn²⁺ ions (Figures 3d–e, S15). This observed that the cell employing MoS₂‐PEO@Zn exhibits a much lower R _ct in the EIS spectra at each corresponding temperature compared to the cell with other systems, indicating the enhanced ion transport kinetics.

FIGURE 3.

(a) Tafel plots; (b) XRD patterns of MoS₂‐PEO@Zn, MoS₂‐DMF@Zn, and Bare@Zn anodes after 20 days of immersion; (c) LSV curves; (d) EIS spectra of MoS₂‐PEO@Zn at different temperatures; (e) Zn²⁺ desolvation activation energy for MoS₂‐PEO@Zn; (f) CV curves; (g) CA and EIS curves of MoS₂‐PEO@Zn before and after polarization; (h) Zn²⁺ transference numbers; (i) Zn²⁺ conductivity; (j) CA curves; (k) Schematic diagram illustrating Zn²⁺ deposition

According to the Arrhenius equation, the E _a for the desolvation process of hydrated Zn²⁺ ions in MoS₂‐PEO@Zn is calculated to be 30.88 kJ mol⁻¹, which is the lowest among all tested cells, demonstrating that MoS₂‐PEO@Zn effectively facilitates desolvation of hydrated Zn²⁺ ions by reducing the energy barrier. CV measurements (Figure 3f) reveal that, compared with Bare@Zn and MoS₂‐DMF@Zn, MoS₂‐PEO@Zn exhibits the lowest nucleation overpotential and the highest redox peak current, indicating a lower nucleation barrier and a smaller nucleation radius, and demonstrating significantly enhanced charge transfer kinetics and electrochemical reversibility. Zn²⁺ transference number calculations (Figures 3g–h, S16) show that the Zn²⁺ transference number values for Bare@Zn, MoS₂‐DMF@Zn, and MoS₂‐PEO@Zn are 0.24, 0.47, and 0.59, respectively, indicating that the composite coating significantly reduces the Zn²⁺ migration barrier. Ionic conductivity measurements (Figure 3i) demonstrate that the MoS₂‐PEO coating achieves the highest conductivity (19.9 mS cm⁻¹), benefiting from the synergistic promotion of ion transport by SVs and PEO.

Chronoamperometry tests (Figure 3j) reveal that MoS₂‐PEO@Zn stabilizes its current within 15 s, exhibiting the fastest stabilization of deposition kinetics and indicating that the coating effectively guides three‐dimensional uniform Zn²⁺ deposition and suppresses dendrite formation. Figure 3k illustrates the zinc deposition process on different sample surfaces. Compared with Bare@Zn, MoS₂‐PEO interphase layer establishes an ideal electrode‐electrolyte interface through a synergistic mechanism. First, the PEO chains promote the desolvation of hydrated Zn²⁺. Subsequently, the SVs accelerate interfacial charge transfer, efficiently delivering electrons to the vacancy sites and creating locally negatively charged centers, then attract the desolvated Zn²⁺ to the vacancy sites, where the reduction reaction occurs. This process significantly lowers the nucleation barrier of Zn²⁺, enabling a higher nucleation density under a given overpotential and leading to a more compact deposition layer [43].

3.4. Symmetric Cell Performance

To evaluate the electrochemical stability of the zinc anode, we conduct repeated plating/stripping tests on different electrodes in a 2 M ZnSO₄ electrolyte. As shown in Figure 4a, Bare@Zn exhibits a sudden voltage drop and significant fluctuations after approximately 200 h of cycling at 1 mA cm⁻² and 1 mAh cm⁻², indicating a battery short circuit. In contrast, MoS₂‐DMF@Zn extends the cycle life significantly to 2000 h, demonstrating a certain degree of interfacial protection. MoS₂‐PEO@Zn exhibits the most exceptional cycling stability, featuring a lower polarization voltage and a cycle life over 2700 h without noticeable decay, indicating that the artificial interphase layer effectively lowers the nucleation barrier of Zn²⁺, induces uniform deposition, and thereby suppresses dendrite growth and side reactions. Under higher current density (5 mA cm⁻²) and varying areal capacities (Figures 4b, S17), MoS₂‐PEO@Zn maintains excellent cycling capability. Further analysis of its stripping behavior (Figure 4c) reveals that the voltage profile during stripping can be divided into a stable stage and a rising stage [44]. Bare@Zn exhibits a distinct voltage peak after a brief stabilization period, reflecting incomplete stripping and substrate consumption, whereas MoS₂‐PEO@Zn maintains a stable voltage profile, demonstrating good plating/stripping reversibility. Even when the current density increases to 20 mA cm⁻² (Figure 4d), MoS₂‐PEO@Zn maintains stable cycling for 500 h with a polarization voltage of approximately 0.15 V. In contrast, the polarization voltage of MoS₂‐DMF@Zn rises significantly after 300 h, while the Bare@Zn electrode rapidly short‐circuits. Rate capability tests at different current densities (Figure 4e) further confirm the excellent rate performance of MoS₂‐PEO@Zn. We evaluate the Coulombic efficiency (CE) through Zn//Cu cell tests. As shown in Figure 4f, under conditions of 5 mA cm⁻² and 1 mAh cm⁻², Bare@Zn exhibits significant fluctuations and rapid decay in CE after 200 cycles. MoS₂‐DMF@Zn achieves an average CE of 86.6% over 1000 cycles, whereas MoS₂‐PEO@Zn maintains a stable CE above 99.7% for nearly 1500 cycles. The nucleation overpotential of MoS₂‐PEO@Zn is lower than that of Bare@Zn a (Figures 4 g, S18). Under higher current density and areal capacity of 10 mA cm⁻² and 1 mAh cm⁻² (Figure S19), MoS₂‐PEO@Zn still sustains stable cycling. Compared with existing anode coating modification systems for AZIBs, the MoS₂‐PEO@Zn anode demonstrates superior cycling stability (Figure 4h, Table S1).

FIGURE 4.

(a) Cycling performance at 1 mA cm⁻² and 1 mAh cm⁻²; (b) Cycling performance at 5 mA cm⁻² and 1 mAh cm⁻²; (c) Voltage profiles of symmetric cells at 1 mA cm⁻² and 1 mAh cm⁻²; (d) Cycling performance at 20 mA cm⁻² and 1 mAh cm⁻²; (e) Rate performance; (f) plating/stripping CE; (g) Voltage profiles of MoS₂‐PEO@Zn//Cu at the 50th/500th cycles; (h) Comparison of cycling performance with previously reported studies at different current densities.

3.5. Full Cell Performance

We analyze the phase composition of the MnO₂ cathode material using x‐ray diffraction (XRD). As shown in Figure S20, all diffraction peaks index to α‐MnO₂ with no detectable impurity peaks [45]. We assemble full cells using MnO₂ as the cathode and Bare@Zn, MoS₂‐DMF@Zn, and MoS₂‐PEO@Zn as the anodes, respectively. CV evaluates the electrochemical behavior of the full cells (Figure 5a). At the same scan rate, the oxidation peak potential of MoS₂‐PEO@Zn//MnO₂ shifts to a higher potential compared to that of Bare@Zn//MnO₂, while the reduction peak potential shifts to a lower potential. As shown in Figure 5b, the charge transfer resistance of MoS₂‐PEO@Zn//MnO₂ is significantly lower than that of Bare@Zn//MnO₂. We evaluate the rate performance of the three batteries (Figures 5c, S21). MoS₂‐PEO@Zn//MnO₂ delivers specific capacities of 210, 206, 197, and 189 mAh g⁻¹ at current densities of 0.2, 0.3, 0.5, and 1 A g⁻¹, respectively. When the current returns to 0.2 A g⁻¹, the capacity recovers to 208 mAh g⁻¹. MoS₂‐DMF@Zn//MnO₂ achieves capacities of 201, 193, 183, and 179 mAh g⁻¹, recovering to approximately 199 mAh g⁻¹, both outperforming Bare@Zn//MnO₂. In Figures 5d–e, the MoS₂‐PEO@Zn//MnO₂ full cell maintains stable cycling for approximately 2400 and 1200 cycles at current densities of 0.2 and 1 A g⁻¹, respectively, with higher capacity retention than the reference systems. MoS₂‐DMF@Zn//MnO₂ cycles for 1600 cycles at 0.2 A g⁻¹, whereas Bare@Zn//MnO₂ exhibits rapid capacity decay under the same conditions. The charge‐discharge profiles of the MoS₂‐PEO@Zn//MnO₂ cell at different cycling stages show small polarization and high overlap (Figures 5f–g, S22–S23). We assemble and test a pouch cell (Figure 5 h). Under high mass loading (13.5 mg cm⁻²), the MoS₂‐PEO@Zn//MnO₂ pouch cell delivers a reversible specific capacity of 99 mAh g⁻¹, maintaining a capacity retention above 98.86% after 300 cycles. The pouch cell system provides stable and continuous power output to commercial light‐emitting diodes (Figure 5i).

FIGURE 5.

(a) CV curves; (b) EIS spectra; (c) Rate capability at different current densities; Long term cycling performance (d) at 0.2 A g⁻¹; (e) at 1 A g⁻¹; (f) GCD profiles at 0.2 A g⁻¹; (g) GCD profiles at 1 A g⁻¹; (h) Long‐term cycling performance of a MoS₂‐PEO@Zn//MnO₂ pouch cell at 0.1 A g⁻¹; (j) Photographs of a LED.

4. Conclusions

In the work, we successfully fabricate functionalized MoS₂ nanosheets enriched with SVs and S═O bonds, and subsequently composite them with PEO to construct a trinity artificial solid‐electrolyte interphase layer for AZIBs. SVs with PEO to establish a dual transport mechanism for efficient charge transport, while S═O groups with PEO to reconstruct the interfacial hydrogen‐bonding network. These effects fundamentally shift zinc deposition from dendrite growth to dense nucleation, enhancing interfacial stability. Thus, the MoS₂‐PEO@Zn symmetric cell achieves stable cycling for over 500 h at 20 mA cm⁻² and 1 mAh cm⁻². The MoS₂‐PEO@Zn//MnO₂ full cell maintains excellent capacity retention and CE approaching 81.56% after 1200 cycles at 1 A g⁻¹. The work provides a new paradigm of zinc metal anodes that integrates deposition regulation, side reaction suppression, and mechanical stability through synergistic design.

Author Contributions

Gang Wang: methodology, Writing – review and editing. Zhihang Zhang: software. Guobao Xu: conceptualization, methodology, writing – review and editing. Hongjie He: investigation, data curation, writing – review and editing. Yiming Qie: data curation, investigation, writing – review and editing.

Conflicts of Interest

The authors declare no conflicts of interest.

Supporting information

Supporting File: smll74651‐sup‐0001‐SuppMat.docx.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.