Layered V5 O12 & centerdot;6H2 O is a cathode material with great development potential for aqueous zinc-ion batteries due to its large interlayer spacing ( similar to 1.18 nm), high proportion of V4 + , and abundant interlayer H2 O. However, its low electronic conductivity and poor lattice stability lead to significant capacity degradation. In this regard, we develop a synergistic pre-intercalation & coating engineering, where Ni2 + , Mn2 + , or Zn2 + cations are pre-intercalated by one-step hydrothermal approach, and graphite oxides (GO) are coated by an electrostatic self-assembly strategy. It is found that Zn2 + pre-intercalation shows a better enhancement effect on the Zn2 + /H+ storage reversibility and stability, and the charge and mass transfer kinetics. Meanwhile, the synergistic effect of Zn2 + pre-intercalation and GO coating achieves the enhancement of the cycling performance and rate capacity with the minimal loss of initial capacities, where the discharge capacity of 288.3 and 183.3 mAh/g with the retention of 85.0 % and 61.6 % are achieved at 1 and 3 A/g after 150 and 600 cycles, respectively. The excellent electrochemical performance is attributed to the biggest downward shift of the p-band center of oxygen, the moderate radius of Zn2 + , and the coating of ultrathin GO with high electrical conductivity. (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Prussian blue analogues (PBAs) are highly competitive cathode candidates for sodium-ion batteries (SIBs), yet their practical viability is limited by sluggish reaction kinetics and severe lattice strain during cycling, which originate from intrinsic structural defects and poor electronic conductivity. Herein, an in-situ mechanochemical strategy is developed to construct TeO2@PBAs heterostructures, achieving interfacial electronic structure modulation to simultaneously mitigate the thermodynamic and kinetic barriers of PBAs cathodes. Density functional theory (DFT) and spectroscopic analyses reveal that mechanically induced TeO2@PBAs heterointerface induces spontaneous charge redistribution. This electronic reconstruction modulates the d-band center of transition metals and increases the density of states near the Fermi level, significantly enhancing localized electronic conductivity. Moreover, this strong interfacial coupling enhances the covalency of the Fe-C/N coordination bonds, establishing a structurally rigid network that effectively buffers phase-transition-induced lattice distortions. Simultaneously, the optimized local electronic environment lowers the Na+ migration barrier, accelerating ion diffusion kinetics. Consequently, the TeO2@PBAs delivers a high reversible specific capacity of 142.3 mAh g-1 at 0.02 A g-1 and exhibits superior structural reversibility (78% initial capacity is retained after 1,000 cycles). This work provides insights into heterointerface-driven electronic modulation, offering a viable pathway for engineering robust and kinetically favorable cathodes for large-scale energy storage.

With the continuing demand for clean and sustainable energy storage devices, aqueous magnesium-ion capacitors have gained prominence as a viable electrochemical solution. However, highperformance aqueous magnesium-ion storage devices for energy need to satisfy rigorous requirements due to the large hydrated ionic radius of Mg2+ cations and the structural collapse of host materials during insertion/extraction. Herein, we propose a fluorine-mediated structural regulation strategy to design fluorine-mediated multivalent manganese oxide (F-m-MnOx) as cathode materials. By partially substituting oxygen sites with fluorine atoms, high-strength Mn-F bonds are formed within the MnO2 lattice, which locally enhance the framework stability by reinforcing the tunnel structure and effectively suppressing structural degradation during cycling. Furthermore, the robust Mn-F bond energy enables a unique "pinning effect" anchoring hydrothermally synthesized KMnF3 nanoparticles onto the MnO2 matrix. These KMnF3 nanoparticles act as dynamic bridges during Mg2+ insertion/extraction processes, with their surface-exposed chemically active sites facilitating transient yet reversible interactions with migrating Mg2+ ions. This innovative design significantly enhances Mg2+diffusion kinetics through the bulk phase, offering a groundbreaking mechanism to overcome the inherent sluggish ion transport in multivalent cation systems. The F-m-MnOx cathode delivers exceptional performance metrics: a high specific capacity of 142 mAh/g at 0.1 A/g, outstanding cycling stability (89.6% retention after 1800 cycles), and rapid kinetics. This research not only establishes an innovative design concept for advanced electrode materials through halogen-mediated structural engineering but also elucidates the dual magnesium-ion storage mechanism involving both KMnF3 and MnO2 in F-m-MnOx through ex-situ characterization, enabling new possibilities for future clean energy storage.

Iron-based Prussian blue analogs (PBAs) represent promising, facile-to-prepare, and low-cost positive electrode materials for sodium-ion batteries. However, their practical application is hindered by the markedly irreversible three-phase transitions and severe lattice distortion that occur during sodium ion storage, leading to capacity limitations and diminished cycling stability. Herein, a simple pyrrole-induced phase transition engineering strategy is proposed to successfully transform monoclinic PBAs into cubic polypyrrole-PBAs (PPy-PBAs). In situ X-ray diffraction (XRD) testing and density functional theory (DFT) calculations reveal that the phase transition mechanism transforms from an unfavorable three-phase process to a highly reversible two-phase transition. Compared to complex three-phase transition (PBAs), the efficient two-phase transition (PPy-PBAs) exhibits smaller lattice volume contraction/expansion and less Fe-C/Fe-N bond length stretching/shrinking, demonstrating remarkable structural stability. Moreover, this strategy effectively reduced the energy barrier for sodium-ion (Na+) migration, with the density of states crossing the Fermi level, significantly enhancing electronic conductivity, and thereby facilitating redox reactions and Na+ transport kinetics within the material. The reversible two-phase transition enables sustainable sodium-ion storage through phase-transition engineering. Compared with PBAs that undergo structural distortion and significant lattice strain, the optimized positive electrode material demonstrates a discharge capacity of 136 mAh/g and an ultralong stable cycling lifespan of 1700 cycles, establishing new possibilities for advanced sodium-ion batteries.

Vanadates possess a crystal structure conducive to Zn2+ migration, establishing them as promising cathode materials for aqueous zinc-ion batteries (AZIBs). However, the continuous intercalation/deintercalation of Zn2+ causes repeated expansion and contraction of the vanadate interlayer spacing, potentially leading to structural distortion. This distortion reduces active sites and promotes V dissolution and structural collapse. This work presents a novel approach to constructing low-dimensional AgVO3@Ag2Cu(VO3)4 heterostructure cathodes through atomic-nanoscale synergistic effects for application as cathodes in AZIBs. Distinguished from conventional composite materials, this design strategically constructs a Cu-O-V covalent bonding network that strengthens metal-oxygen interactions and enhances interlayer electrostatic screening effects, thereby significantly improving interlayer stability. Ex-situ XPS and X-ray diffraction analyses verified the charging/discharging mechanism as embedding/dembedding of Zn2+ in Ag@Zn3V2O7(OH)2 & sdot;2(H2O), coupled with a reversible reduction of some Ag+ to Ag0 during the charging/discharging process. Simultaneously, the in-situ phase transformation generates a three-dimensional percolating Ag conductive network, enabling selfreinforcing electrical conductivity. Electrochemical characterization demonstrates that this integrated design allows the material to deliver exceptional performance: a high specific capacity of 135.3 mAh g- 1 at 3.0 A g- 1, retaining over 80% capacity after 1460 cycles. Its power density reaches 732.61 W kg- 1 with an energy density of 168.5 Wh kg- 1. The pioneering implementation of AgVO3@Ag2Cu(VO3)4 composite material as a cathode material establishes a novel approach for the enhancement of AZIB materials.

The development of high-performance aqueous magnesium-ion capacitors (AMICs) critically depends on overcoming the inherent challenges of sluggish Mg2+ diffusion and limited electronic conductivity in cathode materials. This study presents an effective strategy utilizing oxygen defect engineering in MgMn2O4 cathodes to enhance Mg2+ storage performance in aqueous electrolytes. Oxygen defect formation induces significant lattice expansion, increasing the crystal plane spacing from 0.22 nm to 0.36 nm, which substantially reduces steric hindrance for bulky hydrated Mg2+ ions during intercalation. This structural modification accelerates ion diffusion kinetics and mitigates volumetric changes during cycling, thereby minimizing mechanical stress and enhancing the electrode's structural stability. Density functional theory (DFT) calculations demonstrate that oxygen defects reduce the Mg2+ diffusion barrier from 0.97 eV to 0.38 eV, and modify the electronic structure by introducing defect states near the Fermi level, thus improving electronic conductivity and charge transfer efficiency. Furthermore, defect-induced charge redistribution generates energetically favorable adsorption sites with binding energies of-0.44 eV for Mg2+ ions. Ex-situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses confirm the structural and chemical stability of the host lattice during Mg2+ insertion/ extraction, emphasizing the role of oxygen defects in framework stabilization. The optimized oxygen-deficient MgMn2O4 cathode demonstrates a remarkable specific capacity of 230.8 mAh g-1 at 0.1 A g-1 and exceptional cycling stability, maintaining 85 % capacity after 3000 cycles. This research provides valuable insights into defect engineering as a versatile approach for advancing aqueous multivalent ion energy storage and establishes a framework for rational cathode design through electronic structure modification.

Manganese-based oxides, recognized as suitable cathode materials for aqueous zinc-ion batteries (AZIBs), often face challenges in cycling stability and rate performance due to poor electronic conductivity and slow ion migration rates. In this study, we synthesized Co-doped Mn3O4/MnOOH materials using a straightforward magnetic element induction method. The cobalt incorporation significantly alters the microstructure of MnOOH, creating a multiphase manganese oxide system that enhances electron transportation and accelerates charge transfer rates. This improvement not only boosts zinc storage capacity but also mitigates the Jahn-Teller distortion associated with Mn3+ during electrochemical reactions, enhancing both cycling stability and energy storage capacity. The charge storage mechanism of Co-Mn3O4/MnOOH, identified as Zn2+/H+ co-insertion, was confirmed through ex-situ X-ray diffraction and X-ray photoelectron spectroscopy. Impressively, Co-Mn3O4/ MnOOH achieves a specific capacity of 310.45 mAh g- 1 and an energy density of 415.48 Wh kg- 1 at 0.1 A g- 1, maintaining 80 % capacity after 800 cycles at 0.6 A g- 1. This discovery could lead to the development of innovative two-phase or multiphase manganese-based composites for AZIBs.

Adaptive adjustment of layered metal oxide structures is the key to achieving high energy density in reversible zinc-ion batteries. However, as a transition metal oxide, vanadium-based cathode materials often have problems such as poor cycle stability and low energy storage capacity due to their poor conductivity and high solubility. Here, we constructed a covalent polymer network composed of polyaniline (PANI) in the layered structure of V3O7 & sdot;H2O (HVO). Through the construction of a conjugated polymer network, not only expands the layer spacing but also enhances the electron utilization rate in the protonation process of PANI, and the local charge accumulation in the redox process is effectively reduced. In addition, the interaction forces between PANI and HVO, including covalent bonds and hydrogen bonds, effectively inhibited the structural collapse of layered metal oxides and the dissolution of active substances alleviated the stress induced by ion intercalation. Finally, during the protonation process of polyaniline, the unique Zn2+/H+ co-intercalation mechanism is concurrently achieved through synchronized H+ intercalation/deintercalation dynamics, harmonized with the co-embedding of H+ and Zn2+ within the HVO framework. This collaborative energy storage, with PANI serving as an additional cathode material for zinc ion accumulation, achieves good cycle stability and a high specific capacity of 546 mAh g-1 at 0.1 A g-1 current density, significantly improving the battery's energy storage performance. This work is of great significance to elucidate the charge storage mechanism and design organic-inorganic cooperative energy storage materials for high-performance zinc-ion batteries.

Aqueous zinc-ion batteries (ZIBs) represent an emerging energy storage solution that offers significant advantages in terms of safety, cost-effectiveness, and longevity in cycling. Among the various materials available, manganese-based oxides stand out as the most promising options for cathodes due to their impressive theoretical specific capacity, suitable operating voltage, and abundant natural availability. In published reports, pre-embedding is frequently used to modify the layered cathode; however, non-electrochemically active molecular embedding often results in a decrease in battery capacity. In this paper, a hydrothermal method is employed to intercalate poly(o-phenylenediamine) (PoPD) into δ-MnO2 (MO) to produce PoPD-MO cathode materials. Here, PoPD serves a dual role in the cathode: (1) PoPD is inserted into the interlayer of MO, providing support within the intercalation layer, enhancing material stability, increasing ionic storage sites, and creating space for more Zn2+ to be embedded, and (2) inserting PoPD into the interlayer structure of MO effectively expands the space between layers, thus allowing for greater ion storage, which in turn enhances the rate and efficiency of electrochemical reactions. Consequently, PoPD-MO shows remarkable cycling durability and adaptability in ZIBs, achieving a specific capacity of 359 mAh g−1 at a current density of 0.1 A g−1, and even under the strain of a high current density of 3 A g−1, it maintains a respectable capacity of 107 mAh g−1. Based on this, PoPD-MO may emerge as a new cathode material with promising applications in the future.

With the efficient use of sustainable sunlight, the development of the novel photo-assisted supercapacitor electrode is a practical method to improve energy storage performance by sunlight irradiation. Herein, the new type of self-standing NiCo2O4/Cu2O photoelectrode with dual-component pseudocapacitive NiCo2O4 and photosensitive Cu2O are successfully synthesized on copper foam via an ultra-simple approach. Intriguingly, the copper foam substrate is ingeniously designed to serve as the growth skeleton for the formation of NiCo2O4 as well as the light-sensitive copper source, which significantly simplifies the preparation process of the photoelectrode. The NiCo2O4/Cu2O photo-assisted electrode demonstrates markedly high specific capacitance of 7.16F cm(-2) at 1 mA cm(-2) under light irradiation (the light intensity is 100 mW cm(-2)), which far exceeds those of conventional similar active materials. A maximum energy density of 105.38 Wh kg(-2) at power density of 1.86kW kg(-1) is demonstrated by the photo-assisted supercapacitor under light. More importantly, this work builds the energy band structure by DFT calculations and the electron transfer path in NiCo2O4/Cu2O heterojunction, which contributes to a deeper understanding of the mechanism of photo-assisted supercapacitors.

The shuttle effect, arising from the dissolution and migration of polyiodide species, severely hinders the practical application of high‐energy‐density zinc‐iodine (Zn─I 2 ) batteries. Conventional carbon‐based cathode materials, relying on weak physical adsorption, fail to effectively confine iodine species. To address this issue, a synergistic strategy is proposed that combines the targeted capture of I − to form BiOI with the potential responsive release of I − from BiOI during the reduction of Bi 3+ to Bi. This approach enables a dynamic and directional capture‐release process at a potential lower than that required for the reduction of I 2 . This methodology is validated through ex situ spectroscopic analysis and Density functional theory (DFT) calculations. This decoupled mechanism suppresses polyiodide formation and ensures efficient cathode reversibility. The incorporation of Bi 2 O 3 also introduces an additional redox couple, contributing extra capacity to the battery. The battery not only efficiently suppresses the inherent side reaction issues of zinc‐iodine batteries, but also achieves a considerably high capacity level in the field of iodine single‐electron conversion. This work provides a universal design principle for manipulating iodine electrochemistry, paving the way for high‐energy, long‐lifespan halogen‐based batteries.

Zinc-based alkaline batteries (ZABs) have experienced tremendous breakthroughs in the past few years, particularly in the context of new energy storage solutions. Among various cathode materials, cobalt-nickelbased compounds have emerged as highly promising candidates. In this study, we introduce the novel synthesis of NiCo2O4 (NCO) and phase-transition CoNiO2 (PT-CNO) via glucose and hydrothermal methods for the first time in aqueous zinc-based alkaline batteries. The phase transition process effectively regulates the morphology of the material. Specifically, glucose reduction transforms the material's structure from nanoflowers composed of stacked nanowires (NCO) to self-assembled sheet-like formations (PT-CNO). This morphological transformation enhances the electrochemical activity specific surface area of the electrode, increases the number of active sites, and facilitates the electrochemical energy storage process. Furthermore, the phase transition and resulting morphological changes enhance charge transfer and electrolyte penetration, significantly reducing side reactions between the material and the electrolyte and thereby improving electrode stability. The Zn//PT-CNO configuration demonstrated a remarkable capacity retention rate of 70% after 10,000 cycles at a current density of 6 A/ g. The phase transition strategy employed and the cobalt-nickel-based materials developed in this study offer valuable insights for designing advanced cathode materials in the realm of renewable and sustainable energy.

Aqueous zinc-ion batteries (AZIBs) have become a potential energy storage technology due to their inherent safety, environmental compatibility, and cost-effectiveness. Vanadate compounds have demonstrated considerable potential for AZIB applications among various cathode materials. However, their practical implementation is significantly constrained by intrinsic limitations, including sluggish ion diffusion kinetics, structural instability, and vanadium framework collapse during cycling. To address these challenges, we developed a novel strategy involving polyvinylpyrrolidone (PVP) pre-intercalation into CaV6O16·3H2O (CaVO), resulting in a phase transformation to Ca0.24V2O5·H2O (PVP-CaVO). The embedded PVP acts as a "pillar" between the interlayer spaces, stabilizing the structural stability and thereby enhancing cycling performance. Incorporating PVP introduces additional functional advantages through its amide groups, which possess strong polar characteristics. These groups serve as hydrogen bond acceptors, with nitrogen and oxygen atoms acting as coordination sites. This unique configuration facilitates chemical bond rearrangement and promotes partial reduction of vanadium from higher oxidation states (V5+) to lower ones (V4+), establishing a V4+/V5+ hybrid valence system. Such electronic structure modification not only enables multi-step redox reactions but also alleviates the strong polarization effect of Zn2+ ions. Benefiting from these synergistic effects, the PVP-CaVO cathode demonstrates remarkable electrochemical performance in AZIBs, delivering a specific capacity of 323 mA h g-1 at 0.5 A g-1 and maintaining a specific capacity of 169 mA h g-1 at 10 A g-1, coupled with excellent cycling stability. Comprehensive ex situ characterization studies further elucidated the energy storage processes, verifying a reversible Zn2+/H+ co-insertion mechanism. This innovative approach of structural and phase engineering through PVP intercalation provides a valuable approach for optimizing vanadate-based materials.

The advancement of aqueous magnesium ion energy storage devices encounters limitations due to the substantial hydration radius of magnesium ions (Mg2+) and their strong electrostatic interaction with the primary material. Consequently, this study successfully developed a MnS/MnO heterostructure through a straightforward hydrothermal and annealing method, marking its initial application in aqueous magnesium ion capacitors (AMICs). The fabricated MnS/MnO heterostructure, characterized by S defects, also generates Mn defects via in-situ initiation of early electrochemical processes. This unique dual ion defects MnS/MnO heterostructure (DID-MnS/MnO) enables the transformation of MnS and MnO, initially not highly active electrochemically for Mg2+, into cathode materials exhibiting high electrochemical activity and superior performance. Moreover, DID-MnS/MnO enhances conductivity, improves the kinetics of surface redox reactions, and increases the diffusion rate of Mg2+. Furthermore, this study introduces a dual energy storage mechanism for DID-MnS/MnO, which, in conjunction with dual ion defects, offers additional active sites for Mg2+ insertion/deinsertion in the host material, mitigating volume expansion and structural degradation during repeated charge-discharge cycles, thereby significantly enhancing cycling reversibility. As anticipated, using a three-electrode system, the developed DID-MnS/MnO demonstrated a discharge specific capacity of 237.9 mAh/g at a current density of 0.1 A/g. Remarkably, the constructed AMIC maintained a capacity retention rate of 94.3 % after 10000 cycles at a current density of 1.0 A/g, with a specific capacitance of 165.7 F/g. Hence, DID-MnS/MnO offers insightful perspectives for designing alternative clean energy sources and is expected to contribute significantly to the advancement of the clean energy sector.

Zinc–iodine batteries, grounded in halogen-powered static conversion mechanisms, are experiencing significant development. However, clarity regarding their industrialization pathway remains elusive. This review delves into the energy storage mechanism of zinc–iodine batteries, encompassing not only the conventional low-valence transformation mechanism but also spotlighting emerging high-valence transformation mechanisms. Simultaneously, several optimization routes are proposed from the perspective of battery industrialization, mainly covering the optimization direction of cathode and anode materials, including efficient restraints of iodine effect behavior, promotion of iodine conversion reaction, and effective design of zinc anode. Furthermore, starting from promoting practical application, the optimization path of designing zinc–iodine battery prototypes and functionalized devices, focusing on battery design and device development, while also improving relevant industrialization strategies for cost-effective and efficient use are explored. Additionally, considering the future demand of the energy storage industry, the discussion extends from zinc–iodine batteries to encompass extreme temperature conditions, derivative battery product designs, and interdisciplinary integration. With a focus on practical application, this work identifies key challenges in the field and proposes comprehensive optimization strategies, aiming to provide guidance for the design of high-performance, cost-effective zinc–iodine batteries applications.

Rapid ion-electron transport kinetics play a pivotal role in realizing high-efficiency aqueous zinc-ion batteries. However, the sluggish Zn2+ intercalation kinetics in MnO2 crystal lattices and the intrinsically low conductivity of MnO2 have hindered the development of aqueous Zn-MnO2 systems. As an effective modification method, doping has been widely acknowledged for modifying lattices and optimizing electronic structures. Herein, we synthesize a crystalline-amorphous P/C co-doped MnO2 cathode (P/C-MnO2) featuring high-valent P5+-O bonds via dual-ion co-doping. The charge compensation mechanism effectively reduces Mn valence states, facilitating ion diffusion and stabling phase structure. The crystalline phase part ensures an ordered electron transfer path and enhancing redox reaction reversibility, while the introduction of amorphous phase carbon helps improve conductivity. Concurrently, surface carbonyl functional groups and expanded interlayer spacing synergistically accelerate ion capture and transport. The Zn2+/H+ co-intercalation storage mechanism is systematically elucidated through ex-situ characterizations. The optimized P/C-MnO2 delivers an exceptional discharge capacity of 323.52 mA h center dot g-1 at 0.1 A center dot g-1 as well as maintains 80.9 % capacity retention over 700 cycles at 0.8 A center dot g-1, achieving a high energy density of 410.24 W h center dot kg-1. This work demonstrates that synergistic modulation of lattice architecture and charge configuration enables highly efficient electron-ion transport processes in advanced cathode materials.

The performance of aqueous zinc-ion batteries (AZIBs) is often hindered by issues at the electrode/electrolyte interface, such as dendrite growth and unwanted byproducts. In this study, we applied pyridoxine (PN) and used in situ UV-vis spectroscopy to observe its multistep transformation. The pristine protonated pyridoxine (PN+) gradually lost a proton connecting to the N atom and became PN due to the applying voltage bias. Then PN kept lost a proton that connected to the O atom, changing to a higher electronegativity variant named PN-. The final variant maintained its state and possibly coordinated with zinc ion, and bonded to H+. Relying on the continuous multivariate conversion processes, these transformed PN variants can release H+ ions to maintain pH balance at the interface and interact strongly with zinc ions, improving the zinc ion solvation structure and reducing hydrogen evolution reaction (HER). Additionally, as-generated higher electronegativity variants formed an electrostatic shielding layer on the Zn electrode, promoting uniform zinc deposition and enhancing the plating/ stripping process. As proof of continuous multivariate conversion processes, Zn||Zn symmetric batteries operated stably for 7000 h at 1 mA cm-2 and 1 mAh cm-2, and Zn||NH4V4O10 (NVO) full batteries showed excellent stability over 1500 cycles. These results significantly outperformed those using the ZnSO4 (ZS) electrolyte and previously reported systems. This work suggests a promising approach for advancing various metal batteries towards commercialization, not limited to AZIBs.

Inducing the phase transition from Mn2O3 to trace Cs induced Mn3O4 (CMO) by trace Cs can provide more magnesium ion energy storage active sites, enhance the reversibility of ion insertion/deinsertion and result in higher capacity.

The performance of aqueous zinc-ion batteries (AZIBs) at high temperatures (HT) is severely compromised by active water corrosion, parasitic reactions, and dendrite growth. Herein, zinc trifluoroacetate is introduced at a low concentration (0.2 m), dissolved in triethyl phosphate (TEP)and H2O. The active water is suppressed due to the reconstructed original hydrogen bond network, which helps inhibit parasitic reactions and severe corrosion. Meanwhile, a solid electrolyte interphase (SEI) formed on the zinc anode due to the decomposition of the introduced zinc salt. The high-tolerance SEI physically separates the electrolyte and anode, reducing the corrosion caused by active water. Moreover, TEP, as a prevalent fire-retardant cosolvent, can preferentially anchor on the zinc sheet, serving as a shielding buffer layer. TEP is not only reconstructing the structure of the electric double layer (EDL), decreasing the content of active water, but also accelerating the prompt formation of SEI further. As proof of this synergistic effect, the assembled symmetric Zn.

The rapid transport kinetics of divalent magnesium ions are crucial for achieving distinguished performance in aqueous magnesium-ion battery-based energy storage capacitors. However, the strong electrostatic interaction between Mg 2+ with double charges and the host material significantly restricts Mg 2+ diffusivity. In this study, a new composite material, EDA-Mn 2 O 3, with double-energy storage mechanisms comprising an organic phase (ethylenediamine, EDA) and an inorganic phase (manganese sesquioxide) was successfully synthesized via an organic–inorganic coupling strategy. Inorganic-phase Mn 2 O 3 serves as a scaffold structure, enabling the stable and reversible intercalation/deintercalation of magnesium ions. The organic phase EDA adsorbed onto the surface of Mn 2 O 3 as an elastic matrix, works synergistically with Mn 2 O 3 , and utilizes bidentate chelating ligands to capture Mg 2+ . The robust coordination effect of terminal biprotonic amine in EDA enhances the structural diversity and specific capacity characteristics of the composite material, as further corroborated by density functional theory (DFT) calculations, ex situ XRD, XPS, and Raman spectroscopy. As expected, the EDA-Mn 2 O 3 composite achieved an outstanding specific discharge capacity of 188.97 mAh/g at 0.1 A/g. Additionally, an aqueous magnesium ion capacitor with EDA-Mn 2 O 3 serving as the cathode can reach 110.17 Wh/kg, which stands out among the aqueous magnesium ion capacitors that have been reported thus far. The abundant reversible redox sites are ensured by the strategic design concept based on the synergistic structure and composition advantages of organic and inorganic phases. This study aimed to explore the practical application value of organic-inorganic composite electrodes with double-energy storage mechanisms.