Inkjet Printing of All Aqueous Inks to Flexible Microcapacitors for High-Energy Storage

Due to the low energy density of commercial printable dielectrics, printed capacitors occupy a significant printing area and weight in printed electronics. It has long remained challenging to develop novel dielectric materials with printability and high-energy storage density. Herein, a novel strategy for inkjet printing of all aqueous colloidal inks to dielectric capacitors composed of carbon nanotube electrodes and polyvinylidene fluoride (PVDF)-based dielectrics is presented. The formulated dielectric ink is composed of negatively charged PVDF latex nanoparticles complexed with cationic chitosan molecules. Beyond the isoelectric point, the PVDF@Chitosan particles demonstrate excellent printability and film-forming properties. Chitosan serves as a strong binder to improve the printed film quality yet it introduces charged species. To mitigate the transport of mobile charges, the printed PVDF@Chitosan film is interlayered with a layer of boron nitride nanosheets. This layer is perpendicular to the electric field and serves as an efficient barrier to block the transport and the avalanche of charges, eventually leading to a recoverable energy density of 15 J cm⁻³ at 610 MV m⁻¹. This energy density represents the highest value among the waterborne dielectrics. It is also superior to most of the state-of-the-art dielectric materials printed from solvent-based formulations.     

Ultrahigh Energy Storage Capacitors Based on Freestanding Single-Crystalline Antiferroelectric Membrane/PVDF Composites

Inorganic/organic dielectric composites are very attractive for high energy density electrostatic capacitors. Usually, linear dielectric and ferroelectric materials are chosen as inorganic fillers to improve energy storage performance. Antiferroelectric (AFE) materials, especially single-crystalline AFE oxides, have relatively high efficiency and higher density than linear dielectrics or ferroelectrics. However, adding single-crystalline AFE oxides into polymers to construct composite with improved energy storage performance remains elusive. In this study, high-quality freestanding single-crystalline PbZrO₃ membranes are obtained by a water-soluble sacrificial layer method. They exhibit classic AFE behavior and then 2D–2D type PbZrO₃/PVDF composites with the different film thicknesses of PbZrO₃ (0.1-0.4 µm) is constructed. Their dielectric properties and polarization response improve significantly as compared to pure PVDF and are optimized in the PbZrO₃(0.3 µm)/PVDF composite. Consequently, a record-high energy density of 43.3 J cm⁻³ is achieved at a large breakdown strength of 750 MV m⁻¹. Phase-field simulation indicates that inserting PbZrO₃ membranes effectively reduces the breakdown path. Single-crystalline AFE oxide membranes will be useful fillers for composite-based high-power capacitors.     

Inkjet Printing of Latex‐Based High‐Energy Microcapacitors

Microenergy storage devices are appealing and highly demanded for diverse miniaturized electronic devices, ranging from microelectromechanical system, robotics, to sensing microsystems and wearable electronics. However, making high‐energy microcapacitors with currently available printing technologies remains challenging. Herein, the possibility to use latex polyvinylidene fluoride (PVDF) as aqueous ink for making dielectric capacitors at the microscale is shown. The dielectric properties of printed microcapacitors can be optimized based on a novel approach, i.e., mixing PVDF latex with polyvinyl alcohol (PVA) to realize dielectric organic nanocomposites. The PVA prevents the coalescence of PVDF nanoparticles and serves as a continuous matrix phase with high dielectric breakdown strength. While the well‐dispersed PVDF nanoparticles serve as highly polarizable and isolated domains, providing large electric displacement under high fields. Consequently, a high discharged energy density of 12 J cm^?3 is achieved at 550 MV m^?1. These printed microcapacitors demonstrate mechanical robustness and dielectric stability over time.     

A Facile In Situ Surface-Functionalization Approach to Scalable Laminated High-Temperature Polymer Dielectrics with Ultrahigh Capacitive Performance

High-temperature dielectric materials for capacitive energy storage are in urgent demand for modern power electronic and electrical systems. However, the drastically degraded energy storage capabilities owing to the inevitable conduction loss severely limit the utility of dielectric polymers at elevated temperatures. Herein, a new approach based on the in situ preparation of oxides onto polyimide (PI) films to high-temperature laminated polymer dielectrics is described. As confirmed by computational simulations, the charge injection at the electrode/dielectric interface and electrical conduction in dielectric films are substantially depressed via engineering the in situ prepared oxide layer in the laminated composites. Consequently, ultrahigh dielectric energy densities and high efficiencies are simultaneously achieved at elevated temperatures. Especially, an excellent energy density of 1.59 J cm⁻³ at a charge–discharge efficiency of above 90% has been achieved at 200 °C, outperforming the current dielectric polymers and composites. Together with its excellent discharging capability and cyclic reliability, the laminate-structured film is demonstrated to be a promising class of polymer dielectrics for high-power energy storage capacitors operating at elevated temperatures. The facile preparation method reported herein is readily adaptable to a variety of polymer thin films for energy applications under extreme environments.     

2D Fillers Highly Boost the Discharge Energy Density of Polymer-Based Nanocomposites with Trilayered Architecture

A new class of trilayered architecture blends polymer-based nanocomposites with excellent discharge energy densities (U_dis) is presented. The preferable energy storage performance is achieved in sandwich structured nanocomposite (PIP) films. The outer polarization-layers (P-layer) of the PIP film are composed of Sr₂Nb₂O₇ nanosheets (SNONSs) as well as boron nitride nanosheets (BNNSs) dispersed in poly(vinylidene fluoride) (PVDF)/ polymethyl methacrylate (PMMA) blend polymer matrix (BPM) to provide high dielectric constant, while PVDF/PMMA with BNNSs forms the central insulation-layer (I-layer) to offer high dielectric breakdown strength (E_b) of the resulting nanocomposite films. The dielectric performance, Weibull breakdown strength, and energy storage capacity of single and multi-layer nanocomposites as a function of filler content are systematically examined. The evolution of electric trees is simulated via finite element methods to verify the experimental dielectric breakdown results in single layer nanocomposite films. The PIP film with optimized filler content displays a discharge energy density of 31.42 J cm⁻³ with a significantly improved charge–discharge efficiency of ≈71% near the Weibull breakdown strength of 655.16 MV m⁻¹, which is the highest among the polymer-based nanocomposites under the equivalent dielectric breakdown strength at present.     

Ultrahigh Energy Density of Antiferroelectric PbZrO3-Based Films at Low Electric Field

Dielectric capacitors play a vital role in advanced electronics and power systems as a medium of energy storage and conversion. Achieving ultrahigh energy density at low electric field/voltage, however, remains a challenge for insulating dielectric materials. Taking advantage of the phase transition in antiferroelectric (AFE) film PbZrO₃ (PZO), a small amount of isovalent (Sr²⁺) / aliovalent (La³⁺) dopants are introduced to form a hierarchical domain structure to increase the polarization and enhance the backward switching field E_A simultaneously, while maintaining a stable forward switching field E_F. An ultrahigh energy density of 50 J cm⁻³ is achieved for the nominal Pb_0.925La_0.05ZrO₃ (PLZ5) films at low electric fields of 1 MV cm⁻¹, exceeding the current dielectric energy storage films at similar electric field. This study opens a new avenue to enhance energy density of AFE materials at low field/voltage based on a gradient-relaxor AFE strategy, which has significant implications for the development of new dielectric materials that can operate at low field/voltage while still delivering high energy density.     

High-Energy-Density Quinone-Based Electrodes with [Al(OTF)]2+ Storage Mechanism for Rechargeable Aqueous Aluminum Batteries

Rechargeable aqueous aluminum batteries (AABs) are potential candidates for future large-scale energy storage due to their large capacity and the high abundance of aluminum. However, AABs face the challenges of inferior rate capability and cycling life due to the high charge density of Al³⁺, which induces the sluggish intercalation/extraction dynamics and structure collapse of inorganic cathode materials during discharge–charge cycles. Here, the optimization of macrocyclic calix[4]quinone (C4Q) with a large cavity and multi-adjacent carbonyls structure from quinone compounds to become excellent cathode materials for high-energy-density AABs is reported. It exhibits a high capacity of 400 mAh g⁻¹, a high rate capability (300 mAh g⁻¹ at 800 mA g⁻¹), and an excellent low-temperature performance (224 mAh g⁻¹ at − 20  ° C). The combination of experiments and theoretical calculations proves that Al(OTF)²⁺ cations coordinate with the carbonyl groups of C4Q during the discharge process, which can reduce desolvation penalty. Moreover, the fabricated pouch-type Al-C4Q battery delivers an energy density of 93 Wh kg⁻¹_cell, showing great potential for large-scale applications. This work is expected to facilitate the application of organic cathode for AABs.     

3D HfO2 Thin Film MEMS Capacitor with Superior Energy Storage Properties

Capacitors are ubiquitous and crucial components in modern technologies. Future microelectronic devices require novel dielectric capacitors with higher energy storage density, higher efficiency, better frequency and temperature stabilities, and compatibility with integrated circuit (IC) processes. Here, in order to overcome these challenges, a novel 3D HfO₂ thin film capacitor is designed and fabricated by an integrated microelectromechanical system (MEMS) process. The energy storage density (ESD) of the capacitor reaches 28.94 J cm⁻³, and the energy storage efficiency of the capacitor is up to 91.3% under an applied electric field of 3.5 MV cm⁻¹. The ESD can be further improved by reducing the minimum period structure size of the 3D capacitor. Moreover, the 3D capacitor exhibits excellent temperature stability (up to 150 °C) and charge-discharge endurance (10⁷ cycles). The results indicate that the 3D HfO₂ thin film MEMS capacitor has enormous potential in energy storage applications in harsh environments, such as pulsed discharge and power conditioning electronics.     

Dielectric Modulated Glass Fiber Fabric-Based Single Electrode Triboelectric Nanogenerator for Efficient Biomechanical Energy Harvesting

Single-electrode triboelectric nanogenerators (SE-TENGs) are versatile tools for energy harvesting with simple structures and great practicability. However, low output performance hinders SE-TENGs in applications as portable power sources. Herein, a novel SE-TENG that utilizes glass fiber fabric (GFF) as tribo-materials, along with an inorganic ferroelectric film for the dielectric layer is proposed. The GFF is first shown to be a promising tribo-material for its highly positive tribo-polarity and unique chemical/mechanical/durable properties. Meanwhile, an inorganic dielectric film with high dielectric constant is introduced between the GFF and Al electrode for enhancing the charge trapping capability. Owing to the synergistic effect of optimized triboelectrification and dielectric properties, the specific designed SE-TENG delivers an open-circuit voltage of 1640 V and a short-circuit current density of 59.05 mA m⁻², which are superior to most reported SE-TENGs. With a maximum instantaneous power of 11.30 mW, the device can light up 1350 light-emitting diodes, charge a 47 µF capacitor into 10 V in 421 s, and power up a digital watch even without additional control circuits. This work provides new insights in designing high-performance SE-TENGs and facilitates their application in biomechanical energy harvesting and portable power sources.     

Enabling High-Energy-Density High-Efficiency Ferroelectric Polymer Nanocomposites with Rationally Designed Nanofillers

Ferroelectric polymers have been regarded as the preferred matrix for high-energy-density dielectric polymer nanocomposites because of their highest dielectric constants among the known polymers. Despite a library of ferroelectric polymer-based composites having been demonstrated as highly efficient in enhancing the energy density, the charge–discharge efficiency remains moderate because of the high intrinsic loss of ferroelectric polymers. Herein, a systematic study of the oxide nanofillers is presented with varied dielectric constants and the vital role of the dielectric match between the filler and the polymer matrix on the capacitive performance of the ferroelectric polymer composites is revealed. A combined experimental and simulation study is further performed to specifically investigate the effect of the nanofiller morphology on the electrica properties of the polymer nanocomposites. The solution-processed ferroelectric polymer nanocomposite embedded with Al₂O₃ nanoplates exhibits markedly improved breakdown strength and discharged energy density along with an exceptional charge–discharge efficiency of 83.4% at 700 MV m⁻¹, which outperforms the ferroelectric polymers and nanocomposites reported to date. This work establishes a facile approach to high-performance ferroelectric polymer composites through capitalizing on the synergistic effect of the dielectric properties and morphology of the oxide fillers.     

A Self-Limited Free-Standing Sulfide Electrolyte Thin Film for All-Solid-State Lithium Metal Batteries

All-solid-state (ASS) lithium metal batteries (LMBs) are considered the most promising next-generation batteries due to their superior safety and high projected energy density. To access the practically desired high energy density of ASS LMBs, an ultrathin solid-state electrolyte (SSE) film with fast ion-transport capability presents as an irreplaceable component to reduce the proportion of inactive materials in ASS batteries. In this contribution, an ultrathin (60  µ m), flexible, and free-standing argyrodite (Li₆PS₅Cl) SSE film is designed through a self-limited strategy. A chemically compatible cellulose membrane is employed as the self-limiting skeleton that not only defined the thinness of the sulfide SSE film but also strengthened its mechanical properties. The ionic conductivity of the SSE film reaches up to 6.3 × 10⁻³ S cm⁻¹ at room temperature, enabling rapid lithium-ion transportation. The self-limited SSE thin films are evaluated in various ASS LMBs with different types of cathode (sulfur and lithium titanate) and anode materials (lithium and lithium-indium alloy) at both mold-cell and pouch-cell levels, demonstrating a stable performance and high-rate capability. This study provides a general strategy for the rational design of an SSE thin film towards high-energy-density ASS batteries.     

Reassembly of MXene Hydrogels into Flexible Films towards Compact and Ultrafast Supercapacitors

The freestanding MXene films are promising for compact energy storage ascribing to their high pseudocapacitance and density, yet the sluggish ion transport caused by the most densely packed structure severely hinders their rate capability. Here, a reassembly strategy for constructing freestanding and flexible MXene-based film electrodes with a tunable porous structure is proposed, where the Ti₃C₂T_x microgels disassembled from 3D structured hydrogel are reassembled together with individual Ti₃C₂T_x nanosheets in different mass ratios to form a densely packed 3D network in microscale and a film morphology in macroscale. The space utilization of produced film can be maximized by a good balance of the density and porosity, resulting in a high volumetric capacitance of 736 F cm⁻³ at an ultrahigh scan rate of 2000 mV s⁻¹. The fabricated supercapacitor yields a superior energy density of 40 Wh L⁻¹ at a power density of 0.83 kW L⁻¹, and an energy density of 21 Wh L⁻¹ can be still maintained even when the power density reaches 41.5 kW L⁻¹, which are the highest values reported to date for symmetric supercapacitors in aqueous electrolytes. More promisingly, the reassembled films can be used as electrodes of flexible supercapacitors, showing excellent flexibility and integrability.     

Triboelectric Polymer with High Thermal Charge Stability for Harvesting Energy from 200 °C Flowing Air

Due to the thermionic emission effect, the electron transferred to dielectric surface can be released into vacuum after the contact electrification (CE). Therefore, triboelectric nanogenerator (TENG) cannot maintain effective electrical output under high temperature conditions. In order to obtain high thermal charge stability, polyimide is modified with strong electron withdrawing groups like trifluoromethyl ( CF₃) and sulfone group ( SO₂ ) in backbone. The fluorinated polyimides (F-PI) with a big band gap can provide a tribocharge density of 170 µC m⁻² (4 times of common Kapton film) and become more negative than polytetrafluoroethylene in triboelectric series. In addition, BaTiO₃ nanoparticles are doped in F-PI film for inducing deep traps and interfacial polarizations for CE, which can further enhance the charge density (200 µC m⁻²) and thermal charge stability. Finally, a flutter-driven TENG (FD-TENG) is designed based on this BaTiO₃-doped F-PI film to harvest wind energy and sense wind velocity. This FD-TENG can maintain 32% of its output performance at 200 °C in comparison with room temperature, which is the highest thermal charge stability reported for triboelectric polymers. Therefore, this BaTiO₃-doped F-PI has great application prospects for energy generation and motion detection in hot wind tunnel and many other harsh environments.     

Anode/Cathode Dual-Purpose Aluminum Current Collectors for Aqueous Zinc-Ion Batteries

Rechargeable aqueous zinc (Zn)-ion batteries (RAZIBs), which use non-flammable aqueous electrolytes and low-cost electrode materials, show great potential to boost the development of safe, cost-effective, and highly efficient energy storage systems. The adoption of lightweight and inexpensive aluminum (Al) as current collectors seems to be a good vision, but Al exhibits an easily-corroded nature and a high impedance in aqueous electrolytes, making it a challenge to realize the utilization of Al current collector in RAZIBs. In this study, through the direct current magnetron sputtering, niobium (Nb) coated Al (Al-Nb) foils are prepared, which shows superior corrosion-resistance in an aqueous solution, while maintaining a satisfying electronic conductivity. Moreover, the Al-Nb foils can be adopted to both anode and cathode current collectors while exhibiting high coulombic efficiency and good cycling stability even when they are tested under a condition that can meet the real-world application demands, e.g., the Zn||Al-Nb half-cell shows an average coulombic efficiency of 99.17% in 320 cycles under a current density of 25 mA cm⁻² and a galvanizing capacity of 6.25 mAh cm⁻². The superior performance of the modified Al current collectors may mark a significant step toward the development of high-energy-density aqueous batteries.     

High-Performance Quasi-Solid-State Na-Air Battery via Gel Cathode by Confining Moisture

Rechargeable Na-air batteries are the subject of great interest because of their high theoretical specific energy density, lower cost, and lower charge potential compared with Li-air batteries. However, high purity O₂ as a working environment is required to achieve high-performance Na-air batteries, which obstructs their application as a high-energy-density battery. Although aqueous Na-air batteries can operate in ambient air, long cycle and high safety remain challenges for aqueous Na-air batteries because the aqueous electrolyte is volatile. Here, a quasi-solid-state Na-air battery is reported by utilizing a gel cathode, which is composed of single-walled carbon nanotubes and room-temperature ionic liquids, achieving high safety and long cycling life of 125 cycles (528 h) at a current density of 0.1 mA cm⁻², which is surprisingly better than that of quasi-solid-state Na O₂ batteries. In situ XRD characterizations reveal that water in ambient air is gradually deposited on the surface of the gel cathode to form a water layer, which facilitates the generation of soluble discharge product of NaOH thermodynamically with high conductivity. This work shall be critical to develop and promote the practical application of Na-air batteries, opening a new way to the design of solid-state metal-air batteries.     

Regulating Oxygen Substituents with Optimized Redox Activity in Chemically Reduced Graphene Oxide for Aqueous Zn-Ion Hybrid Capacitor

Functionalizing carbon cathode surfaces with oxygen functional groups is an effective way to simultaneously tailor the fundamental properties and customize the electrochemical properties of aqueous Zn-ion hybrid capacitors. In this work, the oxygen functional groups of chemically reduced graphene oxide (rGO) are systematically regulated via a series of reductants and varied experimental conductions. Carboxyl and carbonyl have been proven to significantly enhance the aqueous electrolyte wettability, Zn-ion chemical adsorption, and pseudocapacitive redox activity by experimental study and computational analysis. The rGO cathode produced through hydrogen peroxide assisted hydrothermal reduction exhibits a specific capacitance of 277 F g⁻¹ in 1 m ZnSO₄ after optimization of surface oxygen functional groups. In addition, a quasi-solid-state flexible Zn-ion hybrid capacitor (ZHC) with a polyacrylamide gel electrolyte and a high loading mass of 5.1 mg cm⁻² are assembled. The as-prepared quasi-solid state ZHC can offer a superior areal capacitance of 1257 mF cm⁻² and distinguished areal energy density of 342 µW h cm⁻². The significant enhancement of redox activity and Zn-ion storage capability by regulating the oxygen functional groups can shed light on the promotion of electrochemical charge storage properties even beyond protic electrolyte systems.     

High-Energy-Density All-Organic Dielectric Film via a Continuous Preparation Processing

Dielectric polymers with high power density and breakdown strength (E_b) are indispensably used in electrostatic energy-storing systems and devices. However, the discharged energy density (U_e) of dielectric polymers is severely limited due to the relatively low dielectric constant (K). Although current polymer composites improve K, this approach usually faces challenges in enhancing U_e due to the trade-off relation between K and E_b and difficulties in scalable production of dielectric films. Here, a fully melt-extrudable, meter-scale, and high-U_e ferroelectric polymer-based all organic composite film comprising a poly(p-phenylene terephthalamide)-based fluxible polymer (denoted as f-PPTA) is reported. The polymer composite with only 2 wt% of f-PPTA presents a productivity of 12 m² h⁻¹ and an ultrahigh U_e of 20.7 J cm⁻³, which outperforms other extruded dielectric polymers reported in the literatures. Such enhancements of dielectric and capacitive properties have been comprehensively investigated and attributed to the crystallization behavior modulations and conformation changes induced by f-PPTA. As a demonstration of real applications, the dielectric capacitors established based on the extruded films enable tens of times higher efficacy on powering electronic devices than biaxially oriented polypropylene capacitors, in addition to long-term cyclic stability. This study opens up new avenue for the design and fabrication of high-U_e polymer dielectrics that are totally compatible with industrial production.     

High Durable Rotary Triboelectric Nanogenerator Enabled by Ferromagnetic Metal Particles as a Friction Material

Rotary sliding mode triboelectric nanogenerator (TENG) provides high efficiency, a continuous and high output strategy for harvesting low-frequency mechanical energy. However, poor durability owing to material abrasion during sliding restricts its practical application. Here, a novel ferromagnetic metal particle-based triboelectric nanogenerator (FMP-TENG) is proposed, which couples the unlimited point contact rolling motion of particles instead of planar contact of film to improve durability of TENG. Besides, due to the extensively enhanced contact area by ferromagnetic metal particles, FMP-TENG improves its electric output, achieving a charge density of 103 µC m⁻² and a peak power density of 400 mW m⁻² Hz⁻¹. After 10 000 cycle running-in, FMP-TENG exhibits excellent durability, which retains 97% of the output charge for 110 000 cycles. In addition, a metal powder mass sensor based on FMP-TENG is also designed, which can effectively detect mass change in ferromagnetic metal powder in a dynamic mechanical platform. A novel strategy is proposed here to solve the problem of durability of sliding TENG in practical applications.     

Diamond-Based Supercapacitors with Ultrahigh Cyclic Stability Through Dual-Phase MnO2-Graphitic Transformation Induced by High-Dose Mn-Ion Implantation

While occasionally being able to charge and discharge more quickly than batteries, carbon-based electrochemical supercapacitors (SCs) are nevertheless limited by their simplicity of processing, adjustable porosity, and lack of electrocatalytic active sites for a range of redox reactions. Even SCs based on the most stable form of carbon (sp³ carbon/diamond) have a poor energy density and inadequate capacitance retention during long charge/discharge cycles, limiting their practical applications. To construct a SC with improved cycling stability/energy density Mn-ion implanted (high-dose; 10¹⁵–10¹⁷ ions cm⁻²) boron doped diamond (Mn-BDD) films have been prepared. Mn ion implantation and post-annealing process results in an in situ graphitization (sp² phase) and growth of MnO₂ phase with roundish granular grains on the BDD film, which is favorable for ion transport. The dual advantage of both sp² (graphitic phase) and sp³ (diamond phase) carbons with an additional pseudocapacitor (MnO₂) component provides a unique and critical function in achieving high-energy SC performance. The capacitance of Mn-BDD electrode in a redox active aqueous electrolyte (0.05 M Fe(CN)₆^3-/4− + 1 M Na₂SO₄) is as high as 51 mF cm⁻² at 10 mV s⁻¹ with exceptional cyclic stability (≈100% capacitance even after 10 000 charge/discharge cycles) placing it among the best-performing SCs. Furthermore, the ultrahigh capacitance retention (≈80% retention after 88 000 charge/discharge cycles) in a gel electrolyte containing a two-electrode configuration shows a promising prospect for high-rate electrochemical capacitive energy storage applications.     

Defect Modulation in Cobalt Manganese Oxide Sheets for Stable and High-Energy Aqueous Aluminum-Ion Batteries

Rechargeable aqueous Al-ion batteries (AIBs) are promising low-cost, safe, and high energy density systems for large-scale energy storage. However, the strong electrostatic interaction between the Al³⁺ and the host material, usually leads to sluggish Al³⁺ diffusion kinetics and severe structure collapse of the cathode material. Consequently, aqueous AIBs currently suffer from low energy density as well as inferior rate capability and cycling stability. Here, defective cobalt manganese oxide nanosheets are reported as cathode material for aqueous AIBs to improve both reaction kinetics and stability, delivering a record high energy density of 685 Wh kg⁻¹ (based on the masses of the cathode and anode) and a reversible capacity of 585 mAh g⁻¹ at 100 mA g⁻¹ with a retention of 78% after 300 cycles. The impressive energy density and cycling stability are due to a synergistic effect between the substituted cobalt atoms and the manganese vacancies, which improve the structural stability and promote both electron conductivity and ion diffusion. When applied in aqueous Zn-ion batteries, a high specific energy of 390 Wh kg⁻¹ at 100 mA g⁻¹ is realized while retaining 84% initial capacity over 1000 cycles. The study offers a new pathway to building next-generation high-energy aqueous rechargeable metal batteries.