Large Capacity Research Articles

Crafting Core-Shell Heterostructures with Enriched Active Centers for High-Energy-Density Symmetric Lithium-Ion Batteries.

Current research strives to create sustainable and ecofriendly organic electrode materials (OEMs) due to the rising concerns about traditional inorganic electrode materials that call for substantial resource consumption in battery manufacturing. However, OEMs often exhibit unbalanced performance, with high capacity conflicting with a long lifespan. Herein, a 2D fully conjugated covalent organic framework featuring abundant C═O and C═N groups (HTPT-COF) was strategically synthesized by coupling 2,3,7,8-tetraamino-1,4,6,9-tetraketone with hexaketocyclohexane octahydrate. It stabilizes the enriched active centers by an extended π-conjugated skeleton, thereby affording a high theoretical capacity in conjunction with potential structure stability. To further unlock the barriers of fast charge, the HTPT-COF was interwoven around highly conductive carbon nanotubes, creating a robust core-sheath heterostructure (HTPT-COF@CNT). Consequently, the crafted HTPT-COF@CNT achieves large reversible capacities of 507.7 mA h g-1, high-rate performance (247.8 mA h g-1 at 20.0 A g-1), and long-term durability (1000 cycles). Aiming to streamline the process and cut the cost of battery manufacturing, all-organic symmetric batteries were well fabricated using HTPT-COF@CNT as both cathode and anode, demonstrating high energy/power density (up to 191.7 W h kg-1 and 3800.3 W kg-1, respectively) and long-term stability over 1000 cycles. Such HTPT-COF@CNT represents a promising sustainable electrode that effectively addresses irreconcilable contradictions encountered by OEMs, boosting the development of advanced organic batteries with high capacity and cycling stability.

The dynamic resistance of muti-layer conductor on round core cables for SMES systems

The conductor on round core (CORC) cables with multi-layer structure show great potential for superconducting magnetic energy storage (SMES) because of their low AC losses and large current carrying capacity. The dynamic resistance is an important electro-magnetic property of CORC cables for SMES. Considering that experimental results of multi-layer CORC cables are usually difficult to obtained, numerical model is an efficient method to demonstrate their electro-magnetic properties. In the work, a numerical model is proposed to illustrate the dynamic resistance of the multi-layer CORC cables. Then, an analytical model using method of rotating magnetic field is proposed to provide mathematical expressions for computing the dynamic resistance, which verifies the numerical model. According to the numerical model, the impacts of DC current and AC magnetic field on dynamic resistances of the multi-layer CORC cables are investigated respectively. The simulation clearly illustrates the dynamic resistance characteristics of CORC cables, showing dynamic resistances and currents in individual layers. This study can serve as a valuable guidance for the implementation of multi-layer CORC cables in SMES systems.

Single-ended protection scheme for three-terminal hybrid DC transmission system based on refractive coefficients

Abstract Three-terminal hybrid DC transmission technology has the advantages of long-distance and large capacity, and there is no phase change failure and other problems, which is an effective means of sending out new energy bases. Correspondingly, the reliability of the existing single-ended traveling wave protection is further degraded by the unknown fault characteristics introduced by the greater variety and combination of converters and add-ons in the three-terminal hybrid DC transmission system. Therefore, a single-ended protection scheme based on the refractive coefficient is proposed. First, an expression for the refraction coefficient of a three-terminal hybrid DC system is derived. Subsequently, the variability of the refraction coefficients for different faults is analyzed. Finally, a single-ended protection scheme using the fault characteristics of the refraction coefficients is proposed and validated by simulation. The program has the advantages of theoretical clarity, reliability, and the ability to recognize near-end faults.

Zinc Dicyanamide: A Potential High-Capacity Negative Electrode for Li-Ion Batteries.

We demonstrate that the β-polymorph of zinc dicyanamide, Zn[N(CN)2]2, can be efficiently used as a negative electrode material for lithium-ion batteries. Zn[N(CN)2]2 exhibits an unconventional increased capacity upon cycling with a maximum capacity of about 650 mAh·g-1 after 250 cycles at 0.5C, an increase of almost 250%, and then maintaining a large reversible capacity of more than 600 mAh·g-1 for 150 cycles. Such an increased capacity is primarily attributed to the increased level of activity in the conversion reaction. A combination of conversion-type and alloy-type mechanisms is revealed in this anode material via advanced characterization studies and theoretical calculations. This mechanism, observed here for the first time in transition-metal dicyanamides, is probably responsible for the outstanding electrochemical performance. We believe that this study guides the development of new high-capacity anode materials.

Tailoring Single‐Atom Coordination Environments in Carbon Nanofibers via Flash Heating for Highly Efficient Bifunctional Oxygen Electrocatalysis

The rational design of carbon‐supported transition metal single‐atom catalysts necessitates precise atomic positioning within the precursor. However, structural collapse during pyrolysis can occlude single atoms, posing significant challenges in controlling both their utilization and coordination environment. Herein, we present a surface atom adsorption‐flash heating (FH) strategy, which ensures that the pre‐designed carbon nanofiber structure remains intact during heating, preventing unforeseen collapse effects and enabling the formation of metal atoms in nano‐environments with either tetra‐nitrogen or penta‐nitrogen coordination at different flash heating temperatures. Theoretical calculations and in situ Raman spectroscopy reveal that penta‐nitrogen coordinated cobalt atoms (Co‐N5) promote a lower energy pathway for oxygen reduction and oxygen evolution reactions compared to the commonly formed Co‐N4 sites. This strategy ensures that Co‐N5 sites are fully exposed on the surface, achieving exceptionally high atomic utilization. The turnover frequency (65.33 s‐1) is 47.4 times higher than that of 20% Pt/C under alkaline conditions. The porous, flexible carbon nanofibers significantly enhance zinc‐air battery performance, with a high peak power density (273.8 mW cm‐2), large specific capacity (784.2 mA h g‐1), and long‐term cycling stability over 600 h. Additionally, the flexible fiber‐shaped zinc‐air battery can power wearable devices, demonstrating significant potential in flexible electronics applications.

Enhancing Rapid Li+/Na+ Storage Performance via Interface Engineering of Reduced Graphene Oxide-Wrapped Bimetallic Sulfide Nanocages.

Transition-metal sulfide is considered to be an admirable transformational electrode material due to low cost, large specific capacity, and good reversibility in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, the reduced graphene oxide-wrapped open bimetallic sulfide (NiS2-Co3S4@rGO) nanocage, derived from nickel-cobalt Prussian blue, was obtained by two-step calcination. There are luxuriant pore structures in the nanocage composite with a specific surface area of 85.28 m2 g-1, which provides plentiful paths for rapid transmission of Li+/Na+ and alleviates the volume stress caused by insertion and extraction of alkali metal ions. The excellent interface combination of bimetallic sulfide wrapped in reduced graphene oxide improves the conductivity and overall performance of the battery. Thanks to the special interface engineering, the open NiS2-Co3S4@rGO nanocage composite displays rapid lithium storage properties with an average diffusion coefficient of 8.5 × 10-13 cm2 s-1. Moreover, after 300 cycles, the reversible capacity of the composite is 1113.2 mAh g-1 at 1 A g-1. In SIBs, the capacity of the open NiS2-Co3S4@rGO composite is 487.9 mAh g-1 when the current density is 5 A g-1. These preeminent performances demonstrate the enormous development prospects of bimetallic sulfide nanocage as anode material in LIBs and SIBs.

Tailoring Single-Atom Coordination Environments in Carbon Nanofibers via Flash Heating for Highly Efficient Bifunctional Oxygen Electrocatalysis.

The rational design of carbon-supported transition metal single-atom catalysts necessitates precise atomic positioning within the precursor. However, structural collapse during pyrolysis can occlude single atoms, posing significant challenges in controlling both their utilization and coordination environment. Herein, we present a surface atom adsorption-flash heating (FH) strategy, which ensures that the pre-designed carbon nanofiber structure remains intact during heating, preventing unforeseen collapse effects and enabling the formation of metal atoms in nano-environments with either tetra-nitrogen or penta-nitrogen coordination at different flash heating temperatures. Theoretical calculations and in situ Raman spectroscopy reveal that penta-nitrogen coordinated cobalt atoms (Co-N5) promote a lower energy pathway for oxygen reduction and oxygen evolution reactions compared to the commonly formed Co-N4 sites. This strategy ensures that Co-N5 sites are fully exposed on the surface, achieving exceptionally high atomic utilization. The turnover frequency (65.33 s-1) is 47.4 times higher than that of 20 % Pt/C under alkaline conditions. The porous, flexible carbon nanofibers significantly enhance zinc-air battery performance, with a high peak power density (273.8 mW cm-2), large specific capacity (784.2 mAh g-1), and long-term cycling stability over 600 h. Additionally, the flexible fiber-shaped zinc-air battery can power wearable devices, demonstrating significant potential in flexible electronics applications.

HoDyGdCoAl high-entropy amorphous alloys working at full temperature range for hydrogen liquefaction with large magnetocaloric effects

Cryogenic magnetic refrigeration materials based on magnetocaloric effect can be used for hydrogen liquefaction. In this work, glass formation ability (GFA), magnetocaloric effect (MCE), refrigeration performance of melt-extracted HoDyGdCoAl amorphous ribbons have been investigated. Amorphous ribbons undergo a second order magnetic phase transition which achieve a table-like behavior broaden the range of magnetic transition temperature in hydrogen liquefaction.The maximum magnetic entropy change (-ΔSmaxM), the δTFWHM and the refrigeration capacity (RC) achieved 10.9 J/ (kg K), 84.2 K and 742.4 J/ kg (x = 5) and 11.2 J/ (kg K), 69.8 K and 643.0 J/ kg (x = 20) under a magnetic field change of 7 T, respectively. Combining wide magnetic transition temperature and large refrigerant capacity, the present amorphous ribbons can be used as potential magnetic refrigerant materials in hydrogen liquefaction temperature region.

Efficient microwave induction to modify surface for high-rate lithium/fluorinated carbon battery with ultra-high power density

The practical application of high-rate lithium/fluorinated carbon (Li/CFx) primary batteries faces challenge of relatively slow electrode reaction kinetics limited by inert C-F bond and strong polarity. Herein, an effective microwave-induction strategy was developed to regulate C-F bond for 80C high-rate Li/CFx battery with suppressed polarization. The as-mentioned microwave method was carried out in the alcohol-based solvent for uniformly modify CFx, including precise defluorination, C-F bond regulation, surface functional groups and carbon quantum dots. Precise defluorination contains the conversion of C-F bond to semi-ionic C-F bond while preserving C-F2 and C-F3. During the process of C-F bond regulation, hydroxyl groups is grafted onto the surface of CFx to increase the wettability and electronegativity of the electrode. Compared with raw CFx, the Li/CFx batteries using microwave-modified CFx achieved high discharge rate of 80C possessing a high power density of 134.091 kW/kg. In addition, the optimal Li/CFx battery possesses a large specific capacity increase ratio of 142.6 % at 50C. This microwave-induction approach for modifying CFx in ethanol-based solvent provides a facile and effective pathway to design high-rate Li/CFx battery.

Amorphous Hydrated Tungsten Oxides with Enhanced Pseudocapacitive Contribution for Aqueous Zinc‐Ion Electrochromic Energy Storage

AbstractTungsten oxides suffer from sluggish ion diffusion kinetics, limited ion storage capacity, and inadequate stability within the aqueous zinc ion electrolyte, thereby constraining their applicability in electrochromic energy storage devices (EESDs). Here, the amorphous hydrated tungsten oxide films with large optical modulation, fast response speed, large capacity, and high cycling stability are reported, enabled by tuning the contents of structural water and adjusting the pH value of aqueous zinc ion electrolyte. The enhancement of the electrochromic and ion storage performance is mainly due to the introduction of structural water which triggers pseudocapacitive behavior dominated by surface redox reaction, resulting in high electrochemical activity and fast electrochemical kinetics. Meanwhile, the relatively low pH value ensures the chemical stability of the hydrated tungsten oxide film, in synergy with surface redox that avoids ion trapping, leading to extraordinary cycling stability of up to 13000 cycles, marking the state‐of‐the‐art stability for tungsten oxide‐based materials in aqueous electrolyte. Based on the hydrated tungsten oxide films, high‐capacity and stable large‐size EESDs are constructed with the capability of visually monitoring energy status, recovering energy, and regulating light. This work provides a simple yet effective strategy for enhancing the performance of tungsten oxide‐based aqueous zinc ion EESDs.

Green Phytic Acid-Assisted Synthesis of LiMn1-xFexPO4/C Cathodes for High-Performance Lithium-Ion Batteries.

As a promising cathode material, olivine-structured LiMnPO4 holds enormous potential for lithium-ion batteries. Herein, we demonstrate a green biomass-derived phytic-acid-assisted method to synthesize a series of LiMn1-xFexPO4/C composites. The effect of Fe doping on the crystal structure and morphology of LiMnPO4 particles is investigated. It is revealed that the optimal Fe doping amount of x = 0.2 enables a substantial enhancement of interfacial charge transfer ability and Li+ ion diffusion kinetics. Consequently, a large reversible capacity output of 146 mAh g-1 at 0.05 C and a high rate capacity of 77 mAh g-1 at 2 C were acquired by the as-optimized LiMn0.8Fe0.2PO4/C cathode. Moreover, the LiMn0.8Fe0.2PO4/C delivered a specific capacity of 68 mAh g-1 at 2 C after 500 cycles, with a capacity retention of 88.4%. This work will unveil a green synthesis route for advancing phosphate cathode materials toward practical implementation.

Copper substituted manganese Prussian blue analogue composite nanostructures for efficient aqueous zinc-ion batteries

Aqueous zinc (Zn)-ion batteries (AZIBs) are considered a promising green energy storage alternative due to their large capacity, low cost, and exceptional safety. Prussian blue analogues (PBAs) with a robust three-dimensional structure and extensive ion channels are highly favorable for Zn2+ insertion/extraction, surpassing manganese (Mn) and vanadium oxides. Herein, copper (Cu) substituted Mn PBA (CuMn PBA) composite nanostructures are synthesized via a simple water-based co-precipitation technique using different concentrations of Cu and Mn sources. The partial substitution of Cu and the formation of Mn vacancies prevent Jahn-Teller distortions of MnN6 octahedra, extending the lifespan. The CuMn PBA-2 electrode exhibits a high discharge capacity of 175.14 mA h g−1 at 0.5 A g−1, superior rate capability of 89.08 mA h g−1 at 2.4 A g−1, and robust cycling stability, maintaining 73.15 mA h g−1 over 2000 cycles at 3 A g−1. Furthermore, the distinct structure provides numerous active sites and reduces volume volatility during cycling. The presence of Cu enhances electrode conductivity, thereby promoting a higher rate of Zn-ion diffusion between electrodes. The reversible intercalation and deintercalation of Zn2+ ions in the CuMn PBA-2 cathode are substantiated by ex-situ analysis methods. This work presents a novel approach for producing high-performance and stable PBA cathode materials for AZIBs.

Carbon-Coated MOF-Derived Porous SnPS3 Core-Shell Structure as Superior Anode for Sodium-Ion Batteries.

Metal thiophosphites have recently emerged as a hot electrode material system for sodium-ion batteries because of their large theoretical capacity. Nevertheless, the sluggish electrochemical reaction kinetics and drastic volume expansion induced by the low conductivity and inherent conversion-alloying reaction mechanism, require urgent resolution. Herein, a distinctive porous core-shell structure, denoted as SnPS3@C, is controllably synthesized by synchronously phosphor-sulfurizing resorcinol-formaldehyde-coated tin metal-organic framework cubes. Thanks to the 3Dporous structure, the ion diffusion kinetics are accelerated. In addition, SnPS3@C features a tough protective carbon layer, which improves the electrochemical activity and reduces the polarization. As expected, the as-prepared SnPS3@C electrode exhibits superior electrochemical performance compared to pure SnPS3, including excellent rate capability (1342.4 and 731.1mAhg-1 at 0.1 and 4Ag-1, respectively), and impressive long-term cycling stability (97.9% capacity retention after 1000 cycles at 1Ag-1). Moreover, the sodium storage mechanism is thoroughly studied by in-situ and ex-situ characterizations. This work offers an innovative approach to enhance the energy storage performance of metal thiophosphite materials through meticulous structural design, including the introduction of porous characteristics and core-shell structures.

Analisis Keterlambatan Clearance in dan Clearance out Kapal Asing di PT. Pertamina Trans Kontinental Cabang Balikpapan

Sea transportation is in high demand in Indonesia due to the geographical conditions of the archipelago, low cost, and large carrying capacity. However, the development of international regulations has created a bureaucratic process that causes ship delays. Non-technical impacts also contribute to these delays. This study analyzes these factors to provide a basis for reducing ship delays that can lead to material losses, time, and opportunities. The research was conducted at PT. Pertamina Trans Continental Cab. Balikpapan during the author's job training from July 2022 to July 2023. Data were obtained through observations, interviews with staff, and secondary sources related to the thesis title. Using qualitative methods, this study focuses on delaying the clearance in and clearance out of foreign ships. Descriptive techniques include interviews, field observations, images, photographs, and video recordings. The results of the study revealed the main factors affecting the delays, such as bureaucratic and regulatory challenges, document availability, technical issues, and non-technical conditions such as weather and the COVID-19 pandemic. Recommendations include increased coordination between relevant authorities, development of integrated information systems, increased staff training, and infrastructure improvements.

Effect of sucrose fatty acid ester on crystal growth of carbon dioxide hydrate in aqueous fructose solution

CO2 hydrate is a remarkable candidate for novel solid carbonated foods because of its large gas capacity. This paper reports the effect of surfactants, essential additives in food production, on hydrate crystal growth by visually observing the CO2 hydrate crystal growth in aqueous fructose + sucrose fatty acid ester solution + gaseous CO2 system. Under all thermodynamic conditions, the surfactants affected the crystal growth of CO2 hydrates at liquid/gas interface, while not influencing growth in the liquid bulk phase. Porous hydrate crystals were formed at the liquid/CO2 interface and grew continuously along the reactor wall. The hydrate crystal morphology in liquid bulk phase was not affected by surfactants, changing from polyhedral and polygonal to dendritic shapes as temperature decreased. Discussion is provided on how the observation results can be specifically applied to intensification of hydrate formation process design and evaluation of hydrated food texture.

High-Performance Optimised Porosity Iron Electrode for Hybrid Battery Electrolyzer

The growing demand for efficient, cost-effective and sustainable energy systems has prompted significant research into the development of advanced electrochemical devices. Hybrid battery electrolyzer, integrating the capabilities of both battery and electrolyzer, is a groundbreaking technology aiming to enhance both energy conversion efficiency and storage capacity. [1] Iron with large earth-abundance, low-cost, robustness, and high capacity is a promising electrode material for such hybrid energy systems. [2-4]This study focuses on the design, fabrication, and performance evaluation of a novel porous iron electrode tailored for use in a hybrid battery electrolyzer system. The proposed electrode exhibits superior electrocatalytic activity, enhanced mass transport properties, and increased surface area, contributing to improved overall performance. The electrode's porosity and pore structure are tuned to facilitate efficient mass transport and electrolyte penetration, addressing common challenges associated with conventional electrodes. The electrochemical performance of the optimised porosity iron electrode is investigated through comprehensive characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and charge-discharge cycling tests. Results indicate superior electrochemical properties, showcasing enhanced specific capacity, faster charge/discharge kinetics, and prolonged cycle life compared to conventional electrodes. The incorporation of conducting nanocarbon and sintering at optimized temperature of 800 ℃ led to the achievement of a stable and elevated capacity exceeding 500 mAh/g for these advanced iron electrodes. The iron electrodes exhibit outstanding porosity (65 - 70%), along with a pore size of 5-10 µm. This configuration results in exceptional current rate performance, achieving a discharge capacity of 350 mAh/cm2 at a current density of 35 mA/cm2 and 245 mAh/cm2 at 50 mA/cm2. Furthermore, the iron electrodes exhibit superior performance in high-current electrolysis, showcasing an HER potential of -1.25, -1.34, and -1.50 V (vs Hg/HgO) at a current density of 200, 500 and 1000 mA/cm2 respectively.These findings highlight the potential of optimised porosity iron electrodes as a key component in the development of high-performance and cost-effective hybrid battery electrolyzer systems. The integration of such advanced materials holds promise for unlocking new frontiers in energy storage and green hydrogen technology, contributing to the realization of efficient and sustainable energy systems.

Prelithiated Silicon Anodes for High-Energy and High-Power Lithium-Ion Batteries

Lithium-ion batteries (LIBs) are pivotal in powering modern electronic devices and next-generation land and air electric vehicles. Silicon-based anodes are considered the next technology to replace traditional graphite anodes due to their high theoretical capacity. However, the inherent challenges associated with their large volume expansion and high irreversible capacity loss (IRCL) limit their practical application. This abstract explores our patented strategy of prelithiation as a viable approach to mitigate the IRCL limitations of SiOx dominant anodes. Prelithiation involves the precise addition of supplemental lithium into the anode, mitigating the adverse effects of initial lithiation and enhancing overall cyclability, energy, power, and extreme fast charge capability for silicon oxide dominant LIBs. Various prelithiation techniques, including Li powder, Li slurry, Li-foil, and the chemical doping of SiOx are examined to evaluate their effectiveness in providing supplemental lithium. The effectiveness of the prelithiation process is assessed by examining the impact on the structural stability, cycling performance, power capability, and rate capability of SiOx dominant anodes integrated into high-capacity (~30 Ah) pouch cells. Our focus is to emphasize prelithiation as a practical and scalable solution to enhance the electrochemical performance of SiOx dominant anodes, contributing to the development of high-energy and high-power LIBs enabling advanced air mobility and high-performance electric vehicles. The findings presented in this abstract contribute to the growing body of knowledge aimed at advancing the fundamental understanding and practical implementation of prelithiation as an enabler for SiOx-based anodes in LIBs. Figure 1

Advancing Aqueous Batteries: Harnessing Trivalent Indium for Superior Capacity, Efficiency, and Extended Cycle Life

Trivalent indium is distinguished by its unique three-electron In3+/In redox system and has a large capacity of approximately 700 mAh g−1, similar to that of metallic zinc. In addition, indium has a good redox potential (-0.34 V compared to standard hydrogen electrode) and no dendrite growth during the plating/stripping process, which allows In||Ti asymmetric cells to achieve 99.3% to 99.8% High Coulombic efficiency. Remarkably, its polarization in symmetric cells is only 1 mV, 1 to 2 orders of magnitude superior to reported metals. The effectiveness of trivalent indium extends to full-battery applications. Taking the In-MnO2 system as an example, the battery voltage reaches about 1.2 V, the capacity reaches about 330 mAh g−1, and the cycle life is extended to 680 cycles. This study highlights the potential of trivalent indium as an anode material characterized by high capacity, efficiency, low polarization, and extended cycle life, thereby providing a compelling trajectory for the advancement of aqueous battery technology.

(Invited) Recycling Zn for Rechargeable Zinc-Ion Batteries

Aqueous energy storage devices require highly reversible Zn electrodes, but this has been impeded by challenges including dendrite growth, low efficiency, hydrogen evolution, and metal corrosion. Here, we have successfully fabricated a reversible Zn powder electrode via engineering the growth of zinc crystals in different solvents from spent Zn foils. Theoretical calculations demonstrate that the adsorption energy gap of different solvents on the (002) or (100) facet of Zn metal varies and that a larger energy gap favors a higher orientation of Zn (002) plane. Highly oriented Zn (002) powder exhibits horizontal deposition, corrosion resistance, faster kinetics, and longer life under deep discharge (60%) in symmetric cells compared with less-oriented Zn. Under practical conditions including low N/P ratios (1–3), high-loading cathodes (10–18 mg cm−2), and lean electrolyte (5–9 μL mg−1), highly (002)-oriented Zn powder-based batteries and supercapacitors demonstrate large capacity (∼3 mAh cm−2) and energy/power density (108 Wh kg−1/2,317 W kg−1), holding promise for applications. And for the first time, we have also upcycled spent alkaline batteries into rechargeable Zn metal batteries through a simple thermal treatment of electrode waste. The regenerated Zn powder anode shows super-zincophilicity and low overpotentials even under fast rates (8 mA cm−2) and high depth-of-discharge (50 %), which can be ascribed to coating of hydroxyl-rich organic layer with abundant nucleation sites as well as high orientation of favorable (002) plane and induced horizontal plating behavior. The regenerated cathode composed of MnO2 and MnOOH manifests enhanced capacity in comparison to pristine ones. Under a low negative-to-positive capacity ratio of 3.8 and high loading of ~10 mg cm−2, the regenerated electrodes are paired to fabricate zinc metal batteries which demonstrate high energy and power densities (94 Wh kg−1, 1349 W kg−1), holding potential for practical applications. Given the sustainable, low-cost, environmental-friendly, and value-added features, the strategy proposed here will open a new pathway toward battery recycling/upcycling.

A Redox-Active Iron-Organic Framework Cathodes for Sustainable Magnesium Metal Batteries.

Rechargeable magnesium metal batteries (RMBs) have shown promising prospects in sustainable energy storage due to the high crustal abundance, safety, and potentially large specific capacity of magnesium. However, their development is constrained by the lack of effective cathode materials that can achieve high capacity and stable magnesium storage at a practically reasonable rate. Herein, we construct a three-dimensional (3D) iron(III)-dihydroxy-benzoquinone (Fe2(DHBQ)3) metal-organic framework (MOF) material with dual redox centers of Fe3+ cations and DHBQ2- anions for reversible storage of Mg2+ in RMBs. Spectroscopic analysis and density functional theory (DFT) calculations reveal the redox chemistry of both Fe3+ ions and carbonyls from DHBQ ligands during electrochemical processes. Benefiting from the rational structure, the Fe2(DHBQ)3∥Mg cells exhibit a high reversible capacity of 395.3 mAh/g, large energy density of 463.5 Wh/kg, and high power density of 2456.0 W/kg. Moreover, the high electronic conductivity (8.35 × 10-5 S/cm) and favorable diffusion path of Mg2+ in Fe2(DHBQ)3 endow the cells with exceptional cycling stability and rate capability with a long life of 5000 cycles at 2000 mA/g. The dual redox-active MOF demonstrates a category of advanced cathode materials for high-performance RMBs.