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. 2026 Sep 4. Online ahead of print. doi: 10.1039/d6sc05962g

Bismuth-guided cavity confinement breaks the stability–utilization trade-off in zinc powder anodes

Yunxuan Jiang a, Ziyuan Lan a, Can Li a, Xiaoning Li b,✉, Bo-Tian Liu a,✉
PMCID: PMC13573158  PMID: 42741258

Abstract

The practical application of aqueous zinc-ion batteries (AZIBs) is severely hindered by the poor reversibility of the Zn anode, which stems from a self-amplifying cycle involving dendrite growth, interfacial side reactions, and electrically isolated “dead Zn” formation. Here, we report a spray-assembled three-dimensional copper mesh-supported particulate Zn anode, in which Zn particles are encapsulated by an inner bismuth interlayer and an outer carbon confinement shell (3D-C/Bi@Zn-p). Unlike conventional surface stabilization strategies, this surface-engineered architecture enables a unique interface-guided, cavity-confined inward deposition mechanism. During stripping, Zn is selectively extracted from the particle core, leaving behind a robust bismuth–carbon composite shell embedded with isolated internal cavities. In the subsequent plating step, the passivated carbon outer layer effectively suppresses parasitic reactions and prevents Zn nucleation on the external surface, while the inner bismuth layer provides a highly zincophilic interface that kinetically directs Zn2+ to undergo plating exclusively in the cavity interior. Consequently, Zn plating is spatially confined within isolated cavities, effectively suppressing outward dendrite propagation and eliminating the risk of short circuits. Benefiting from this cavity-confined inward deposition behavior, the 3D-C/Bi@Zn-p anode delivers a coulombic efficiency approaching 100% and enables record-high stable cycling for over 10 000 h at 1 mA cm−2 under high zinc utilization of 10.8%. Notably, stable Zn plating/stripping can still be maintained at an ultrahigh Zn utilization of 108%, far beyond the <1% Zn utilization commonly employed in most laboratory-scale studies. Furthermore, when paired with an oxygen-deficient V2O5−x cathode, the full cell delivers 211.6 Wh kg−1 and 81.2% capacity retention after 1000 cycles under lean-anode conditions (N/P = 2.4, ∼30.3% Zn utilization), outperforming most reported AZIBs. This interface-guided cavity-confined inward deposition strategy establishes a new spatial confinement paradigm for reversible metal anodes.

Spatial confinement enables Zn plating within carbon cavities via Bi layers, ensuring stable cycling by suppressing dendrite growth. The 3D-C/Bi@Zn-p anode achieves >10 000 h cycling with 22.9 mV hysteresis, outperforming conventional Zn anodes.graphic file with name d6sc05962g-ga.webp

1. Introduction

Lithium-ion batteries (LIBs) have dominated the global energy storage market for decades, owing to their high energy and power densities and long cycle life.1–4 However, concerns regarding limited lithium resources, high cost, and safety risks associated with flammable organic electrolytes have hindered their scalability for grid-level energy storage applications. Sodium- and potassium-ion batteries (SIBs and KIBs) have emerged as promising alternatives, leveraging the earth-abundant nature of Na and K.5–10 Nevertheless, these systems still rely on flammable and toxic organic electrolytes and continue to face challenges related to manufacturing costs, safety, and long-term reliability. Consequently, increasing attention has been directed toward aqueous battery chemistries, which offer intrinsic safety, low cost, environmental benignity, and the potential for exceptional cycling stability.11–13

Among them, aqueous zinc-ion batteries (AZIBs) stand out as promising candidates for grid-scale energy storage, combining the high theoretical capacity of metallic zinc (820 mAh g−1), the intrinsic safety of aqueous electrolytes, and low material cost. In most reported AZIBs, planar zinc foil serves simultaneously as the current collector and the active material.14–16 However, this configuration drives a self-reinforcing cycle between dendrite growth and side reactions at the electrode–electrolyte interface, resulting in irreversible formation of “dead Zn” and low Zn utilization. Although various surface modification and Zn alloying strategies have been developed to mitigate interfacial issues, zinc utilization remains intrinsically limited by the pronounced kinetic asymmetry between Zn plating and stripping.17–26 Specifically, Zn deposition typically suffers from sluggish nucleation kinetics and uneven Zn2+ flux distribution, leading to localized dendrite growth and poor electrochemical reversibility, whereas Zn stripping proceeds comparatively fast and less restrictively. As a result, most laboratory-scale studies rely on a large excess of zinc metal to compensate for irreversible zinc loss and maintain acceptable cycling stability under full-cell conditions. This practice leads to an excessively high negative-to-positive electrode capacity ratio (N/P ratio), typically exceeding 10 : 1, which starkly contrasts with commercial LIBs that generally operate at N/P ratios below 2 : 1. Consequently, the practical energy density of AZIBs is severely compromised. For example, although AZIBs based on MnO2 cathodes possess a theoretical specific energy approaching 400 Wh kg−1, a practical battery typically delivers up to 80–120 Wh kg−1 depending on battery-design considerations and Zn utilization efficiency. This substantial gap between theory and practice underscores the critical need for advanced Zn anode architectures.21–23,27,28

Zinc powder (Zn-p) offers a low-cost and processable alternative to conventional zinc foil anodes. Unlike dense planar zinc, Zn-p features a high specific surface area that reduces the local current density and promotes a more uniform electric field distribution.29–34 This characteristic facilitates homogeneous Zn plating and stripping, which is essential for achieving high reversibility in zinc metal anodes. However, the enlarged surface area simultaneously increases electrochemical complexity and accelerates particle agglomeration driven by van der Waals interactions, thereby compromising electrode homogeneity and transport kinetics. Moreover, unlike self-supporting Zn foil, Zn-p must be integrated into a composite architecture, in which both electrochemical performance and economic viability are dictated by powder packing configuration and interfacial engineering. Recent efforts have therefore focused on three-dimensional (3D) structuring of Zn-p to simultaneously suppress agglomeration, enhance plating/stripping reversibility, and further bridge the gap between laboratory-scale promise and practical energy storage applications.34–39,43,44 For example, Parker et al. demonstrated that a 3D spongy Zn anode fabricated by stacking Zn powders exhibits high porosity, an interconnected network, and mechanical integrity. This architecture promotes uniform Zn2+ flux and effectively suppresses dendrite formation, delivering a 50% improvement in cycling stability compared to conventional Zn-powder-based composite anodes.39 However, such physically stacked structures still suffer from long-term structural instability and remain vulnerable to gradual structural collapse during extended cycling. To further enhance structural stability, various robust 3D scaffolds have been employed as hosts for Zn powder, with electrodes fabricated by 3D printing or deposition techniques. These scaffolds possess rich specific surface area and electrical conductivity, and uniform deposition of Zn2+ can be achieved by adjusting the electric field. Whether composed of pure Zn or composite formulations, 3D Zn anodes consistently outperform conventional Zn foil in key electrochemical metrics, such as specific capacity, utilization, and cycle life, primarily by suppressing dendritic growth. Nevertheless, even these rationally engineered 3D architectures fail to fully eliminate dendrite formation, as physical structuring alone cannot provide deterministic interfacial control over Zn2+ deposition behavior.

Here, we report a spray-assembled zinc powder anode consisting of Zn powders encapsulated by an inner bismuth interlayer and an outer carbon confinement shell, supported on a three-dimensional copper mesh (denoted as 3D-C/Bi@Zn-p). This surface-engineered architecture features an outer passivated carbon layer and an inner zincophilic bismuth interlayer. The outer passivated layer suppresses parasitic reactions and external nucleation, whereas the inner bismuth surface forms a highly zincophilic interface that kinetically directs Zn2+ reduction exclusively toward the cavity interior. This interface-guided, cavity-confined inward electrodeposition spatially confines Zn plating within isolated internal cavities, thereby suppressing dendrite growth toward the separator and eliminating the risk of short circuits. Meanwhile, the 3D Cu scaffold provides robust electrical percolation and effectively accommodates volume changes during cycling. As a result, the 3D-C/Bi@Zn-p anode achieves a record-high cycling stability, operating for over 10 000 h with a low average voltage hysteresis of 22.9 mV at 1 mA cm−2 under a high zinc utilization of 10.8%, significantly outperforming previously reported conventional Zn foil and powder-based anodes. Notably, stable Zn plating/stripping can still be maintained at an ultrahigh Zn utilization of 108%, far beyond the <1% Zn utilization commonly adopted in most laboratory-scale AZIB studies. More importantly, the asymmetric cell (3D-C/Bi@Zn-p‖Ti) shows superior reversible properties and higher CE compared with those of Zn‖Ti in plating/stripping of Zn, resulting from powder-based anodes and Zn foil anodes in aqueous media. Furthermore, the 3D-C/Bi@Zn-p anode is paired with an oxygen-deficient V2O5−x cathode (N/P = 2.4) to deliver superior long-term cycle stability with a capacity retention of 81.2% after 1000 cycles. It should be noted that the Zn powder loading in the 3D-C/Bi@Zn-p anode (∼6.4 mg, equivalent to ∼7.9 µm for a 12 mm diameter electrode) is even lower than that of the thinnest commercially available Zn foil (10 µm, ∼8.1 mg), thereby enhancing the potential for practical energy density at the full-cell level. This work presents a rational spatial-confinement strategy for developing lean-Zn, dendrite-free Zn anodes, offering a viable pathway toward high-energy density and practically relevant AZIBs.

2. Materials and methods

2.1. Materials

Bismuth nitrate pentahydrate (Bi(NO3)3·5H2O), vanadium oxide (V2O5), anhydrous ethanol (EtOH), ethylene glycol (EG), xylene, N-methyl-2-pyrrolidone (NMP), hydrogen peroxide (H2O2, 30 wt% in H2O), phenoxy resin (C54H60O9X2), epoxy resin (C10H19O6P), propylene glycol phenyl ether, Super P carbon black, and polyvinylidene fluoride (PVDF, MW ≈ 530 000) were purchased from Sigma-Aldrich Chemical Reagent Co., Ltd. All of which were of analytical grade and used without any further treatment or purification. Zinc powder (Zn ≥ 99%), Zn foil (80 µm), copper mesh (100 µm thick, 100 mesh) and stainless-steel mesh (500 mesh) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. All aqueous solutions used in this work were prepared using deionized (DI) water.

2.2. Synthesis of Bi@Zn-p

Zinc powder (20 g) was ultrasonically cleaned in 50 mL of anhydrous ethanol for 20 min. The cleaned Zn powder was collected by vacuum filtration and dried under vacuum at 60 °C for 24 h. Separately, bismuth nitrate pentahydrate (0.728 g) was dissolved in 10 mL of ethylene glycol under magnetic stirring for 30 min. Subsequently, 20 mL of anhydrous ethanol was added, and the mixture was subjected to ultrasonication for 30 min, followed by an additional 30 min of magnetic stirring. The pre-cleaned zinc powder (10 g) was then immersed in the above solution for 5 min. The resulting Bi@Zn-p was collected by vacuum filtration, washed three times with anhydrous ethanol, and finally dried under vacuum at 60 °C. For comparison, a Bi@Zn foil anode was prepared identically using 30 µm Zn foil instead of Zn powder.

2.3. Synthesis of the 3D-C/Bi@Zn-p anodes

Epoxy resin (0.25 g) and polyamide resin (0.20 g) were placed in a 50 ml beaker with 3 mL of xylene and stirred until homogeneous. Propylene glycol phenyl ether (0.10 g) was then added, and the solution was stirred at room temperature for 1 h until fully dissolved. The as-prepared Bi@Zn-p powder (10 g) was subsequently introduced into the above solution, and stirring was continued for 2 h to afford a homogeneous precursor dispersion. This dispersion was transferred into an airbrush spray canister and uniformly sprayed onto copper mesh under compressed gas flow. The coated electrode was first dried under vacuum at 110 °C for 8 h to remove residual solvents, and then thermally treated at 360 °C for 4 h (ramp rate: 5 °C min−1) under an Ar atmosphere to carbonize the polymer matrix, yielding a 3D-C/Bi@Zn-p anode with a mass loading of 6.4 mg (Fig. S20). To evaluate the effect of carbonization temperature, 3D-C/Bi@Zn-p anodes were prepared identically at 270, 320, 360, and 400 °C. As an additional control, 3D-Bi@Zn-p anodes without carbon coating were fabricated via the conventional slurry-coating process with identical mass loading and processing conditions.

2.4. Synthesis of the oxygen-deficient V2O5−x cathodes

V2O5 (12.5 mmol) was dissolved in a mixed solution of 187 mL deionized water and 31 mL H2O2 under continuous stirring at room temperature until a dark red homogeneous solution formed. The solution was then transferred into a 300 mL Teflon-lined autoclave and heated at 200 °C for 72 h. The resulting precipitate was collected by centrifugation, washed repeatedly with deionized water, and dried at 80 °C in a vacuum oven overnight. The final cathode active material was obtained after calcination at 400 °C for 1 h under an N2 atmosphere. The working electrode was prepared by casting a slurry composed of the as-synthesized active material (80 wt%), Super P carbon black (10 wt%), and PVDF binder (10 wt%) in NMP onto a 500-mesh stainless-steel current collector, achieving an active mass loading of approximately 3.2 mg.

2.5. Materials characterization

Morphology and composition were analyzed by SEM (Zeiss, 5.0 kV) and TEM/STEM (JEOL JEM-2100F, 200 kV) with EDX. XPS was recorded on an ESCALAB 250 spectrometer (Thermo Scientific). XRD patterns were collected using a Bruker D8 Advance diffractometer with a Cu-Kα radiation source (λ = 0.15406 nm). TG-DSC analysis was performed using a Netzsch STA 449 with air flow at a heating rate of 10 °C min−1 from room temperature to 800 °C.

2.6. Electrochemical evaluations and calculations

Symmetric cells (Zn‖Zn, 3D-C@Zn-p‖3D-C@Zn-p, and 3D-C/Bi@Zn-p‖3D-C/Bi@Zn-p), asymmetric cells (Zn|Ti, 3D-C@Zn-p‖Ti, and 3D-C/Bi@Zn-p‖Ti) and full cells (3D-C/Bi@Zn-p‖V2O5−x and 3D-C@Zn-p‖V2O5−x) were fabricated based on CR2025-type coin cells to measure the electrochemical performances. The coin cells were assembled with 12 mm (in diameter) as-prepared disks as electrodes and glass fiber as separators in 2 M ZnSO4 aqueous solution. The full cells were conducted in air and left for 12 h before electrochemical measurements. Galvanostatic charge–discharge (GCD) cycling of symmetric and asymmetric cells was performed on a Neware battery-testing system. Coulombic efficiency (CE) measurements were carried out on asymmetric cells at a current density of 4 mA cm−2 with a capacity of 1 mAh cm−2. Electrochemical impedance spectroscopy (EIS) was recorded on an IviumStat electrochemical workstation over a frequency range of 100 kHz to 0.01 Hz with a 5 mV AC amplitude. Cyclic voltammetry (CV), linear sweep voltammetry (LSV), and Tafel polarization curves were obtained in a standard three-electrode configuration (Pt foil as the counter electrode and Ag/AgCl as the reference electrode). CV curves were measured at a scan rate of 3 mV s−1 in 2 M ZnSO4; Tafel plots were recorded between −0.68 and −1.2 V vs. Ag/AgCl at a scan rate of 5 mV s−1; LSV for hydrogen evolution was conducted in 1 M Na2SO4 at a scan rate of 1 mV s−1, while Zn deposition overpotentials of 3D-C@Zn-p and 3D-C/Bi@Zn-p anodes were determined by discharging at fixed current densities of 5 mA cm−2 in 2 M ZnSO4. All tests were performed at room temperature.

Zn utilization rate was calculated using the following equation:2.6.where Ccycle is the capacity set for galvanostatic cycling (in mAh), Ctheoretical is the theoretical gravimetric specific capacity of Zn (820 mAh g−1), and mZn is the mass loading of the Zn powder (unit of g).

The specific capacity of the full battery was calculated using the following equation:2.6.where i is discharge current, t is the discharge time, and mV2O5−x is the mass of the active material on the cathode.

The energy density of the full battery was calculated using the following equation:2.6.

The power density of the full battery was calculated using the following equation:2.6.where E is the calculated energy density and t is the discharge time.

The mass of zinc deposited on the anode during cycling was determined by gravimetry:mZn = 0.0289 g − 0.0225 g = 0.0064 g

Using the theoretical specific capacity of Zn (820 mAh g−1, based on Zn ↔ Zn2+ + 2e−), the anode capacity is:Canode = 0.0064 g × 820 mAh g−1 = 5.25 mAh

The total cathode coating mass was 0.0203 g − 0.0156 g = 0.0047 g. Assuming an active material content of 80 wt%, the mass of active V2O5 is:mV2O5−x = 0.0047 g × 80% = 3.76 mg

Based on the theoretical specific capacity of the cathode (assume that 100% of the active cathode material was V2O5 (588 mAh g−1) and involved in the electrochemical process), the cathode capacity is:Ccathode = 3.76 mg × 588 mAh g−1 = 2.21 mAh

The negative-to-positive (N/P) capacity ratio is therefore:2.6.

2.7. Computational details

Density functional theory (DFT) calculations were performed using the Cambridge Serial Total Energy Package (CASTEP). The exchange–correlation functional was treated within the generalized gradient approximation (GGA) using the Perdew–Burke–Ernzerhof (PBE) parametrization. A plane-wave basis set with a kinetic energy cutoff of 348.4 eV was employed. The convergence tolerances were set as follows: 2 × 10−5 eV per atom for the total energy, 0.005 eV Å−1 for the maximum force on atoms, 0.1 GPa for the maximum stress, and 0.002 Å for the maximum atomic displacement. Zinc nucleation energy barriers were evaluated by computing the adsorption energy of a single Zn atom on representative surface models of bismuth (Bi (001)) and amorphous carbon faces, which serve as the Bi-decorated interface and carbon shell, respectively. A representative Bi (001) slab model was constructed based on its conventional bulk crystal structures to simulate the Bi interfacial layer. For the amorphous carbon model, carbon atoms were randomly distributed within a periodic simulation cell, followed by geometry optimization to generate a disordered carbon surface structure. The Bi and amorphous carbon models contained 28 and 64 atoms, respectively. A vacuum layer of 15 Å was used to minimize inter-slab interactions. The Brillouin zone was sampled using a Γ-centered 3 × 3 × 1 k-point mesh. During structural optimization, the upper three atomic layers and the adsorbed Zn atom were fully relaxed, while the bottom atoms were fixed to maintain the bulk-like structure of the slabs. For each surface, a single Zn atom was placed at representative adsorption sites, and the most stable optimized configuration was selected for adsorption-energy calculations. The Zn adsorption energy (Eads) was calculated according to the following equation:Eads = Eslab+Zn − (Eslab + EZn)where Eslab+Zn, Eslab, and EZn are the total energies of the slab with an adsorbed Zn atom, the clean slab, and an isolated Zn atom in the gas phase, respectively. A more negative adsorption energy indicates stronger binding and a lower nucleation barrier for Zn nucleation.

3. Results and discussion

3.1. Structure characterization of the 3D-C/Bi@Zn-p anode

Fig. S1 illustrates the fabrication process for the 3D-C/Bi@Zn-p anode. First, Bi-coated Zn particles (Bi@Zn-p) were synthesized via a galvanic displacement reaction between Zn powder and Bi3+ ions (3Zn + 2Bi3+ → 3Zn2+ + 2Bi). Notably, this synthetic process is readily scalable and enables large-scale production of Bi@Zn-p powder with a particle-size distribution centered at ∼12.5 µm (Fig. S2). This powder was airbrush-sprayed onto a 3D porous Cu scaffold and calcined under Ar at 270, 320, 360 and, 400 °C for 4 h to form the integrated anode. The carbon shell derives from pyrolysis of the resin precursor during this thermal treatment. Electrochemical impedance spectroscopy (EIS) identifies 360 °C as the optimal temperature. It exhibits the lowest charge-transfer resistance (Rct = 39.1 Ω vs. 68.6 Ω at 270 °C, 54.4 Ω at 320 °C and 189.1 Ω at 400 °C), suggesting an optimal balance between carbonization, charge/ion transport, and structural integrity (Fig. S3). Thermogravimetric analysis (TGA) in air was further performed on this optimal anode to determine its composition (Fig. S4). Bi@Zn-p and C/Bi@Zn-p exhibited weight gains of 120.1% and 111.2%, respectively.

Based on the TGA results, the carbon content in the C/Bi@Zn-p was estimated to be approximately 7.4 wt%. Fig. 1a–c show that the resulting C/Bi@Zn-p particles are homogeneously dispersed on the surface of the porous Cu scaffold with a narrow size distribution centered at a mode of ∼17.5 µm (quantified from Fig. 1a; see Fig. S5), forming a well-integrated 3D conductive framework. The phase composition of the 3D-C/Bi@Zn-p anode was examined by X-ray diffraction (XRD), as shown in Fig. 1f. The diffraction peaks can be indexed to metallic Bi (JCPDS No. 98-000-0118), Zn (JCPDS No. 98-000-0482), and Cu (JCPDS No. 99-000-0814), confirming the successful integration of Zn-based active material onto the 3D Cu current collector.

Fig. 1. Morphology and structure characterization of the 3D-C/Bi@Zn-p electrode and C/Bi@Zn-p particle. (a and b) Low-magnification top-view SEM images of the 3D-C/Bi@Zn-p sample; (c) a high-magnification SEM image and (d) a HAADF-TEM image of the C/Bi@Zn-p particle obtained from the 3D-C/Bi@Zn-p electrode, along with corresponding elemental mapping for C, Bi, Zn, and O; (e) HRTEM image of the C/Bi@Zn-p particle; (f) XRD patterns of the 3D-C/Bi@Zn-p anode; (g–j) XPS spectra of the C/Bi@Zn-p particle and the corresponding high-resolution spectra of Bi 4f, C 1s and Zn 2p.

Fig. 1

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The surface chemistry of the C/Bi@Zn-p powder was further investigated by X-ray photoelectron spectroscopy (XPS). The survey spectrum of C/Bi@Zn-p indicates the presence of Zn, Bi, C, and O species as the dominant surface elements (Fig. 1g–j). The high-resolution Bi 4f spectrum shows two doublets at 158.9 eV (Bi 4f7/2) and 164.2 eV (Bi 4f5/2), characteristic of metallic Bi0. Similarly, the Zn 2p spectrum exhibits a doublet at 1021.8 eV (Zn 2p3/2) and 1044.9 eV (Zn 2p1/2) with a spin–orbit splitting of 23.1 eV, which is consistent with metallic Zn0.40–42 The coexistence of metallic Bi and Zn species on the particle surface is in good agreement with the crystalline phases identified by XRD in the electrode. It should be noted that the surface of the sample exhibits a pronounced carbon signal, further implying that the Bi@Zn-p particles are fully encapsulated by carbonaceous shells. The high-resolution C 1s spectrum could be deconvoluted into three components corresponding to C–C (284.7 eV), C–O (286.3 eV), and O–C Created by potrace 1.16, written by Peter Selinger 2001-2019 O (288.3 eV), respectively. These oxygen-containing carbon species likely originate from the structural reconstruction and carbonization of the resin-based organic precursor during thermal treatment.

Further structural evidence was obtained from high-angle annular dark-field transmission electron microscopy (HAADF-TEM) and energy-dispersive X-ray spectroscopy (EDS) elemental mapping of the C/Bi@Zn-p powder (Fig. 1d). The elemental distributions clearly reveal a well-defined core–shell architecture, in which Zn is concentrated in the inner core, Bi forms an intermediate interfacial layer, and carbon is predominantly distributed on the outermost surface. High-resolution TEM (HRTEM) imaging further reveals distinct lattice fringes corresponding to the crystalline Bi (202) and Zn (103) planes, along with an amorphous carbon layer (Fig. 1e). These observations further corroborate the core–shell morphology identified by EDS mapping and confirm the presence of metallic Bi, metallic Zn, and a carbonaceous shell, consistent with the XRD and XPS analyses. Importantly, the exposed inner Bi surface within the cavity acts as a highly zincophilic nucleation interface that kinetically guides directional Zn deposition toward the cavity interior, while the outer carbon shell passivates electrochemically inactive surface areas, thereby suppressing electrolyte decomposition and dendrite formation. This cavity-confined inward deposition behavior not only suppresses dendrite initiation but also restricts any residual dendritic growth within confined spatial domains, thereby providing dual protection against short-circuit failure.

3.2. Electrochemical performance of the 3D-C/Bi@Zn-p anode

To investigate the role of the Bi interfacial layer in stabilizing the Zn anode, the Zn plating/stripping behaviors of Zn foil, 3D-C@Zn-p, and 3D-C/Bi@Zn-p anodes were evaluated in symmetric cells using 2 M aqueous ZnSO4 electrolyte across a range of current densities and areal capacities. As shown in Fig. 2a, the 3D-C/Bi@Zn-p anode delivers an exceptionally stable voltage profile over 10 000 h (corresponding to a cumulative capacity of 10 000 mAh cm−2) at a current density of 1 mA cm−2 under a high zinc utilization of 10.8%. In sharp contrast, the 3D-C@Zn-p anode fails after only ∼170 h under identical conditions, while bare Zn foil undergoes irreversible short-circuit failure within ∼30 h despite operating at a nearly tenfold lower Zn utilization (∼1.1%, corresponding to 80 µm thick Zn foil). Compared with previously reported Zn metal anodes, this cycling stability represents a new record for continuous Zn plating/stripping under practically relevant high-utilization conditions (Table S1). These contrasting results indicate that 3D structural engineering is insufficient to ensure long-term Zn reversibility, whereas Bi-guided interfacial regulation plays a decisive role in enabling long-term, high-utilization Zn electrochemistry.

Fig. 2. Electrochemical performance of Zn‖Zn, 3D-C@Zn-p‖3D-C@Zn-p, and 3D-C/Bi@Zn-p‖3D-C/Bi@Zn-p symmetrical cells. (a) Cycling stability at a current density of 1 mA cm−2 with an areal capacity of 0.5 mAh cm−2; (b) electrochemical impedance spectra of different cycling times/stages in (a), including the early stage (before testing), the intermediate stage (after 5000 cycles), and the late stage (after 10 000 cycles) at 1 mA cm−2 with 0.5 mAh cm−2; (c) voltage hysteresis as a function of current density ranging from 0.25 to 5 mA cm−2; (d) comparison of the voltage hysteresis for the 3D-C/Bi@Zn-p anode with previously reported Zn anodes in the literature;45–52 (e) rate performance under different current densities (0.25–5 mA cm−2) with a fixed areal capacity of 0.5 mAh cm−2.

Fig. 2

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Additionally, as shown in Fig. 2c and e, the 3D-C/Bi@Zn-p anode exhibits a significantly smaller voltage hysteresis than the 3D-C@Zn-p anode across a wide current density range from 0.25 to 5 mA cm−2, indicating superior rate capability and Zn plating/stripping reversibility. The excellent rate capability and reversibility of the 3D-C/Bi@Zn-p anode can be ascribed to the zincophilic interfacial layer formed by Bi, which homogenizes Zn2+ flux distribution and lowers the kinetic barrier for reversible Zn plating/stripping. Moreover, the voltage hysteresis of the 3D-C/Bi@Zn anode was compared with those reported in the literature for zinc foil-based anodes, 3D zinc anodes and zinc powder-based anodes, including 3D@Zn-W,45 3DGs@Zn,46 Cu@Zn,47 MPS05@Zn,48 ND@Zn,49 C-840@Zn,50 ZIF-7/SA@Zn,51 and CS@Zn-p.52 Notably, the as-prepared 3D-C/Bi@Zn-p anode consistently exhibits lower voltage hysteresis across multiple current densities than most previously reported Zn-based anodes, highlighting the effectiveness of the Bi-guided interfacial engineering strategy in regulating Zn deposition behavior (Fig. 2d).

To rigorously exclude potential artifacts arising from soft short circuits, a common concern in long-term symmetric-cell testing, we monitored the evolution of overpotential and electrochemical impedance spectroscopy (EIS) spectra for the 3D-C/Bi@Zn-p symmetric cell at multiple cycling stages following protocols established in recent studies (Fig. 2b).53–55 Notably, both the overpotential and the Rct remain virtually unchanged throughout prolonged cycling, indicating highly stable interfacial charge-transfer kinetics and suppressed side reactions. This conclusively confirms that the exceptional stability observed is not compromised by parasitic soft shorts but rather stems from genuine improvements in interfacial electrochemistry.

To further verify the above findings, cyclic voltammetry (CV) measurements were performed using Zn foil‖Ti, 3D-C/Bi@Zn-p‖Ti and 3D-C@Zn-p‖Ti configurations to evaluate the reversibility of Zn plating/stripping behavior. As shown in Fig. 3a, the 3D-C/Bi@Zn-p anode exhibits significantly more symmetric cathodic/anodic redox peaks than bare Zn foil, indicative of enhanced electrochemical reversibility. Moreover, 3D-C/Bi@Zn-p displays a smaller peak separation (∼0.28 V) than the 3D-C@Zn-p anode (∼0.35 V), reflecting reduced polarization and faster Zn plating/stripping. Notably, the peak separation of the 3D-C/Bi@Zn-p anode gradually decreases from the first to the tenth cycle, suggesting progressive interfacial stabilization and continuously improved reaction kinetics upon cycling (Fig. S6). These results collectively demonstrate that the 3D-C/Bi@Zn-p anode enables highly reversible and kinetically favorable Zn electrochemistry.

Fig. 3. Electrochemical performance and interfacial behavior of Zn-based anodes in both asymmetric cells (Zn‖Ti, 3D-C@Zn-p‖Ti, and 3D-C/Bi@Zn-p‖Ti) and three-electrode configurations. (a) CV curves at a scan rate of 3 mV s−1; (b) calculated adsorption energy of Zn on Bi (001) and amorphous carbon surfaces; (c–e) CE at a current density of 4 mA cm−2 with an areal capacity of 1 mAh cm−2 and the corresponding voltage profiles; (f) LSV curves at a scan rate of 1 mV s−1 in 1 M aqueous Na2SO4 electrolyte; (g) nucleation overpotential of Zn deposition on 3D-C@Zn-p and 3D-C/Bi@Zn-p anodes at a current density of 5 mA cm−2 with a capacity of 1 mAh cm−2; (h) Tafel profiles for the 3D-C/Bi@Zn-p and 3D-C@Zn-p anodes; (i) contact-angle measurements of Zn foil and the 3D-C/Bi@Zn-p anode.

Fig. 3

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As expected, the 3D-C/Bi@Zn-p anode maintains an average coulombic efficiency (ACE) approaching 100% over 500 cycles (Fig. 3c). The typical galvanostatic charge/discharge (GCD, potential versus capacity) profiles of the 3D-C/Bi@Zn-p and 3D-C@Zn-p anodes at 4 mA cm−2 are illustrated in Fig. 3d and e, respectively. Specifically, the 3D-C/Bi@Zn-p anode maintains highly stable and overlapping voltage profiles from the 1st to the 100th cycle with a low polarization of only ∼61 mV, whereas the 3D-C@Zn-p anode shows unstable and diverging profiles within just 60 cycles, accompanied by a much higher polarization (∼130 mV). These observations indicate that the Bi-modified interface facilitates highly reversible Zn plating/stripping behavior and suppresses interfacial degradation during repeated cycling, thereby providing direct mechanistic insight into the exceptional cycling stability observed in symmetric cells.

This conclusion is further corroborated by nucleation overpotential measurements and complementary density functional theory (DFT) calculations to evaluate Zn adsorption behavior on representative Bi and carbon surfaces. The initial nucleation plays a decisive role in determining the subsequent Zn deposition morphology and interfacial reversibility. The nucleation overpotentials of different anodes at a current density of 5 mA cm−2 with a plating capacity of 1 mAh cm−2 were measured (Fig. 3f). The 3D-C/Bi@Zn-p anode exhibits an ultralow nucleation overpotential of ∼14 mV, substantially lower than those of the 3D-C@Zn-p (∼109 mV) and 3D-Zn-p (∼131 mV) counterparts. The relatively small decrease from ∼131 mV for 3D-Zn-p to ∼109 mV for 3D-C@Zn-p indicates that carbon coating only modestly improves Zn nucleation kinetics. In contrast, the pronounced decrease to ∼14 mV upon introducing Bi demonstrates that Bi is the primary zincophilic component responsible for promoting Zn nucleation, whereas the carbon layer mainly functions as the outer confinement shell. This reduction indicates significantly enhanced Zn nucleation kinetics, primarily enabled by the Bi interfacial layer (Fig. 3g and S7), while the carbon layer only slightly enhances the kinetics. This enhancement persists even when structural and carbon-related contributions are decoupled via controlled experiments, confirming that the accelerated Zn nucleation kinetics originate intrinsically from the Bi interfacial layer (Fig. S8). Consistently, DFT calculations reveal that Zn adsorption on the Bi surface exhibits a more negative adsorption energy (−0.77 eV) than that on the carbon surface (−0.61 eV), indicating stronger zincophilicity and a thermodynamic preference for Zn nucleation at the Bi interface (Fig. 3b). Together, the electrochemical and theoretical analyses demonstrate that the engineered Bi interfacial layer not only effectively lowers the kinetic barrier for uniform Zn nucleation but also promotes reversible Zn plating/stripping.

Furthermore, to systematically investigate the electrochemical stability of the 3D-C/Bi@Zn anode under different utilization rates, symmetric cells were further tested over a wide Zn utilization range from 10.8% to 108% (Fig. S9). Remarkably, the symmetric cells maintain highly stable voltage profiles together with fully recoverable overpotentials throughout prolonged cycling, demonstrating exceptional Zn plating/stripping reversibility even under extreme operating conditions. These results confirm that the Bi-guided cavity-confined inward deposition mechanism effectively suppresses dendrite formation and parasitic interfacial reactions, thereby enabling highly stable Zn electrochemistry at an ultrahigh Zn utilization of 108%. Notably, this utilization level far exceeds the <1% Zn utilization typically employed in most laboratory-scale AZIB studies, representing a substantial step toward practically relevant Zn metal battery configurations.

To further understand the origin of the exceptional cycling stability of the 3D-C/Bi@Zn-p anode, the corrosion behavior, hydrogen evolution reaction (HER) activity, and interfacial wettability of different electrodes were systematically investigated by linear sweep voltammetry (LSV), Tafel polarization measurements and contact-angle analysis (Fig. 3f–i). Superior corrosion resistance is essential for achieving long-term Zn anode stability because uncontrolled anodic dissolution continuously accelerates interfacial degradation during cycling. Tafel polarization curves reveal that the 3D-C/Bi@Zn-p anode has a higher corrosion potential (∼−0.995 V vs. Ag/AgCl) and a lower corrosion current density than the 3D-C@Zn-p anode (∼−1.013 V vs. AgCl), indicating significantly suppressed corrosion behavior. These results demonstrate that the introduction of the Bi interlayer effectively mitigates anodic Zn dissolution and interfacial degradation during repeated cycling. Moreover, effective suppression of parasitic HER is equally important for maintaining long-term Zn electrochemical reversibility, as unmitigated HER accelerates electrolyte consumption, local pH fluctuations, and interfacial degradation. LSV measurements conducted in aqueous Na2SO4 electrolyte show that the 3D-C/Bi@Zn-p anode displays a HER onset potential of −1.084 V vs. Zn/Zn2+, which is markedly more negative than those of 3D-C@Zn-p (−1.064 V). This pronounced cathodic shift confirms the effective suppression of the HER on the Bi-engineered interface, thereby reducing undesired electrolyte decomposition and improving interfacial stability.

Meanwhile, the outer carbon confinement layer significantly reduces electrolyte wettability, as evidenced by a water contact angle of 115.1°, which is substantially higher than that of bare Zn foil (94.9°). This engineered hydrophobic surface effectively suppresses direct electrolyte contact with the outer electrode surface and spatially guides Zn2+ ion flux toward the inner Bi-based zincophilic interface. As a result, Zn deposition preferentially occurs within the internal cavities, which is thermodynamically consistent with the DFT-calculated preferential Zn adsorption on the Bi surface. Collectively, the synergistic combination of an elevated corrosion potential, suppressed HER activity, and directional ion transport establishes a robust electrochemical microenvironment that simultaneously minimizes parasitic reactions and inhibits dendrite nucleation, thereby enabling ultralong cycling stability.

3.3. Structural and composition evolution of Zn deposition on the 3D-C/Bi@Zn-p anode

To gain a better understanding of the Bi interface in guiding Zn2+ deposition and suppressing side reactions, the morphology and phase evolution of different cycled electrodes were examined by SEM and XRD. As shown in Fig. 4a and b, the Bi interfacial layer functions as a zincophilic “ion-directing layer” that spatially guides Zn2+ flux toward the cavity interiors, thereby enabling spatially confined and highly uniform Zn plating, while the passivated outer carbon layer suppresses parasitic reactions and inhibits extraneous Zn nucleation. As expected, comparative analysis reveals that the 3D-C@Zn-p anode exhibits a severely corroded surface with porous, mossy deposits and abundant insulating byproducts, zinc hydroxysulfate ((Zn4SO4)(H2O)6·5H2O, JCPDS No. 00-039-0688) (Fig. 4c and e). These severe structural degradations indicate uncontrolled Zn deposition behavior together with continuous interfacial side reactions during prolonged cycling. In striking contrast, even after tenfold longer cycling, the 3D-C/Bi@Zn-p anode maintains a compact, uniform morphology with negligible parasitic byproducts (Fig. 4d and f). Moreover, EDS analysis of the cycled anode reveals signal intensity relationships among Bi, C, and Zn consistent with the pristine architecture shown in Fig. 1d. Specifically, the relatively weaker Bi signal compared to Zn is attributed to its significantly lower mass loading as an interfacial modifier, whereas Zn constitutes the bulk active material (Fig. S10). Despite being located in the inner layer, the high Zn content generates sufficient characteristic X-rays under the applied accelerating voltage. Meanwhile, the distinct C signal verifies the intact surface carbon coating, as low-energy C Kα X-rays can only be efficiently detected when present at the outermost surface. This pronounced morphological difference provides direct experimental validation of our proposed design strategy. To further validate the cavity-confined deposition mechanism, ex situ SEM characterization was performed on 3D-C/Bi@Zn-p electrodes at various states of charge after 1000 plating/stripping cycles. The persistently smooth and dendrite-free outer surface observed across all states, with no obvious external Zn accumulation, strongly supports that Zn plating occurs predominantly within the internal cavities (Fig. S11).

Fig. 4. Zn deposition mechanism and corresponding morphological/compositional evolution of Zn powder-based anodes during long-term Zn plating/stripping at a current density of 1 mA cm−2 with an areal capacity of 0.5 mAh cm−2: (a and b) Schematic illustrations of the Zn plating/stripping mechanisms in the 3D-C/Bi@Zn-p and 3D-C@Zn-p anode, respectively; (c) SEM images of the pristine 3D-C@Zn-p anode and the corresponding morphologies after 100, 500 and 1000 cycles; (d) SEM images of the pristine 3D-C/Bi@Zn-p anode and the corresponding morphologies after 1000, 5000 and 10 000 cycles; (e) XRD patterns corresponding to the samples shown in (c); (f) XRD patterns corresponding to the samples shown in (d).

Fig. 4

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3.4. Electrochemical properties of full cells

To further explore the practical application of the 3D-C/Bi@Zn-p anode in full-cell configurations, oxygen-deficient V2O5−x cathodes were synthesized and characterized by XRD and SEM (Fig. S12 and S13). The V2O5−x cathode was selected because oxygen vacancies can induce expanded interlayer spacing together with enhanced electronic/ionic conductivity, which enable high specific capacity and fast Zn2+ diffusion kinetics, making it a well-matched counterpart for high-performance AZIBs. These cathodes were subsequently paired with the 3D-C/Bi@Zn-p anode to assemble full AZIBs (Fig. S14). To address the practical challenge of achieving practically relevant high energy density, the full cells were deliberately designed with a low negative-to-positive (N/P) capacity ratio of 2.4 (see detailed calculation in the Electrochemical evaluations and calculations section), which is substantially lower than the N/P ratios (>10) commonly used in laboratory-scale AZIB studies. Notably, even when the cathode capacity is conservatively estimated based on an average vanadium oxidation state of +4.65 (corresponding to a specific capacity of ∼485 mAh g−1), the N/P ratio remains relatively low at ∼3.3 (Fig. S15), further underscoring the practical relevance of this configuration. Such a low N/P ratio is highly desirable for practical zinc battery systems because it minimizes excess Zn inventory while maximizing the attainable device-level energy density. This stringent condition severely limits Zn excess, placing exceptional demands on anode reversibility and thereby underscoring the robustness of the 3D-C/Bi@Zn-p design.

As shown in Fig. 5a, the CV curves of the full cells were measured at a scan rate of 0.1 mV s−1. Notably, the 3D-C/Bi@Zn-p‖V2O5−x full cell displays smaller potential gaps between anodic and cathodic peaks than the 3D-C@Zn-p‖V2O5−x full cell, indicating enhanced reaction kinetics and improved electrochemical reversibility. This enhanced electrochemical kinetics is further corroborated by EIS spectra, as equivalent circuit fitting reveals that the Rct of the 3D-C/Bi@Zn-p‖V2O5−x full cell is significantly lower than that of the 3D-C@Zn-p‖V2O5−x cell, consistent with the reduced polarization observed in CV curves (Fig. S18). Furthermore, the 3D-C/Bi@Zn-p‖V2O5−x full cell shows superior rate capabilities and higher discharge capacities than its 3D-C@Zn-p‖V2O5−x counterpart (Fig. 5b–d). The 3D-C/Bi@Zn-p‖V2O5−x full cell exhibits excellent rate performance, delivering specific capacities of 226.9, 194.2, 186.8, and 165.9 mAh g−1 at current densities ranging from 1 to 5 A g−1. Notably, upon returning the current density to 1 A g−1, the discharge capacity immediately recovered to 228.2 mAh g−1, indicating outstanding reversibility and structural stability.

Fig. 5. Electrochemical performance of the full cells. (a) Typical CV curves at a scan rate of 0.1 mV s−1 for full cells constructed using 3D-C/Bi@Zn-p and 3D-C@Zn-p as anodes, and V2O5−x as the cathode (in 2 M ZnSO4 electrolyte); (b) rate performance of 3D-C/Bi@Zn-p‖V2O5−x and 3D-C@Zn-p‖V2O5−x full cells at various current densities from 1 to 5 A g−1; (c) GCD curves of the 3D-C@Zn-p‖V2O5−x full cell at various current densities from 1 to 5 A g−1; (d) GCD curves of the 3D-C/Bi@Zn-p‖V2O5−x full cell at various current densities from 1 to 5 A g−1; (e) Ragone plot of power density vs. energy density for the 3D-C/Bi@Zn-p‖V2O5−x cell based on total active material mass of the anode and cathode, compared with previously reported AZIBs, such as ZnO(002)@Zn‖V2O5, Cu@Zn‖VO2, MXS@Zn-p‖V2O5, ND@Zn‖MnO2, MPSO5@Zn‖NH4V4O10, CuZn5@Zn‖NH4V4O10, 3DGs@Zn‖V2O5, MXene@Zn-p‖FeHCF, and Bi@Zn‖MnO2;33,46–49,56–58 (f) optical images of an LED illuminated by 3D-C/Bi@Zn-p‖V2O5−x full cells; (g) cycling stability of 3D-C@Zn-p‖V2O5−x or 3D-C/Bi@Zn-p‖V2O5−x full cells at a current density of 2 A g−1.

Fig. 5

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Long-term cycling stability represents a key bottleneck for practical AZIBs, especially in zinc-lean designs that offer high energy density but impose stringent demands on Zn anode durability. As shown in Fig. 5g and S16, the 3D-C/Bi@Zn-p‖V2O5−x full cell achieves a remarkable capacity retention of 81.2% after 1000 cycles at 2 A g−1, far outperforming the 3D-C@Zn-p‖V2O5−x full cell (42.5%). Moreover, optical images (Fig. S17) reveal that the thickness of the 3D-C/Bi@Zn-p‖V2O5−x full cell remains virtually unchanged after cycling, whereas the 3D-C@Zn-p‖V2O5−x full cell exhibits significant swelling due to parasitic side reactions. More importantly, the low N/P ratio of 2.4 enables a high practical energy density of 211.6 Wh kg−1, calculated based on the total mass of both anode and cathode active materials. This energy density corresponds to an areal capacity of 1.95 mAh cm−2, achieved with a 12-mm-diameter electrode delivering 2.21 mAh. Although this value remains below areal capacities typically targeted for practical grid-scale energy storage applications (∼5 mAh cm−2), it is significantly higher than the typical areal capacities employed in most laboratory-scale AZIB studies, thereby representing a more application-relevant benchmark. Critically, the ultra-low N/P ratio (2.4) combined with a high Zn utilization rate of 30.3% ensures that this metric reflects a realistic, application-relevant energy density (Fig. 5e). Importantly, this energy density was calculated using the total active-material mass under low-N/P and high-Zn-utilization conditions, thereby providing a more realistic assessment of practical device-level performance. This value surpasses those of most previously reported AZIBs,33,46–49,56–58 including ZnO(002)@Zn‖V2O5, Cu@Zn‖VO2, MXS@Zn-p‖V2O5, ND@Zn‖MnO2, MPSO5@Zn‖NH4V4O10, CuZn5@Zn‖NH4V4O10, 3DGs@Zn‖V2O5, MXene@Zn-p‖FeHCF, and Bi@Zn‖MnO2. In addition, the practical application of the 3D-C/Bi@Zn-p‖V2O5−x device was demonstrated by powering a light-emitting diode (LED) system. As shown in Fig. 5f, the 3D-C/Bi@Zn-p‖V2O5−x full cell successfully powered an “AZIBs” logo composed of red LEDs connected in parallel, demonstrating its high energy and power delivery capabilities as well as its practical application potential. More importantly, the 3D-C/Bi@Zn-p anode utilizes low-cost carbon and commercially available bismuth (Bi price < $12.2 kg−1), thereby avoiding expensive coatings or complex fabrication processes. Consequently, the introduction of the interfacial layer imposes only a minimal cost penalty, and the resulting active-material cost for AZIBs is substantially lower than that of Li-ion systems and approaches the material-cost range of lead-acid batteries (Fig. S19), highlighting the potential economic advantage of this chemistry for large-scale energy storage. Collectively, these results demonstrate that the powder-based Zn anode architecture presents a promising and scalable pathway toward high-performance, industrially viable AZIBs.

4. Conclusion

In summary, we have developed a highly reversible Zn powder anode architecture via a simple and scalable spray-deposition process followed by thermal annealing, enabling dual coating of Zn powder with bismuth (Bi) and amorphous carbon. Distinct from previously reported Zn alloying or carbon encapsulation approaches, this design features an engineered interfacial asymmetry: the outer Bi surface is passivated by a thin carbon overlayer that suppresses zincophilicity and raises the Zn nucleation barrier, while the inner side exposes a region with strong zincophilicity. This asymmetry establishes a directional nucleation-energy gradient that spatially guides Zn2+ flux toward the cavity interior, enabling cavity-confined inward Zn deposition. Consequently, parasitic side reactions and uncontrolled dendrite growth are intrinsically suppressed, yielding highly reversible Zn plating/stripping and exceptional long-term cycling stability. The resulting 3D-C/Bi@Zn-p anode delivers an ultralong cycling life exceeding 10 000 h (cumulative capacity: 10 000 mAh cm−2) with low voltage hysteresis at a high Zn utilization of 10.8%. Such a 3D-C/Bi@Zn-p anode also endows the full cell with the long-term stability of over 1000 cycles and high energy density when paired with a vanadium-based cathode at a low negative/positive electrode capacity ratio of 2.4. This work presents a rationally designed lean-Zn, dendrite-free Zn anode achieved by interfacial-engineering spatial control of Zn2+ flux, thereby confining Zn plating within designated regions and enabling practical high-energy AZIB systems.

Author contributions

Yunxuan Jiang: investigation, methodology, formal analysis, data curation, visualization, writing – original draft. Ziyuan Lan: investigation, methodology, validation. Can Li: investigation, formal analysis. Xiaoning Li: conceptualization, supervision, funding acquisition, writing – review & editing. Bo-Tian Liu: conceptualization, supervision, project administration, funding acquisition, writing – review & editing.

Conflicts of interest

There are no conflicts to declare.

Supplementary Material

SC-OLF-D6SC05962G-s001

Acknowledgments

We acknowledge funding support from the National Natural Science Foundation of China (21805056) and Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials (EMFM20221104). X. L. acknowledged the support from the Australian Research Council (DE250100232) and the assistance from the RMIT Advanced Cloud Ecosystem.

Data availability

The data supporting this article have been included as part of the supplementary information (SI). Supplementary information: electrode preparation; morphology and particle size distributions; EIS, TGA, CV, and nucleation overpotential data; cycling performance at different Zn utilization rates; post-cycling elemental mapping and ex situ SEM characterization at different states of charge; SEM, XRD, and XPS characterization of V2O5−x cathodes; full-cell assembly, component masses, GCD profiles, thickness comparison, and EIS data; raw material cost comparison; comparison of cycling stability with previously reported Zn-based anodes, etc. See DOI: https://doi.org/10.1039/d6sc05962g.

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Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

SC-OLF-D6SC05962G-s001
SC-OLF-D6SC05962G-s001.pdf (1.4MB, pdf)

Data Availability Statement

The data supporting this article have been included as part of the supplementary information (SI). Supplementary information: electrode preparation; morphology and particle size distributions; EIS, TGA, CV, and nucleation overpotential data; cycling performance at different Zn utilization rates; post-cycling elemental mapping and ex situ SEM characterization at different states of charge; SEM, XRD, and XPS characterization of V2O5−x cathodes; full-cell assembly, component masses, GCD profiles, thickness comparison, and EIS data; raw material cost comparison; comparison of cycling stability with previously reported Zn-based anodes, etc. See DOI: https://doi.org/10.1039/d6sc05962g.

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