Zinc-air Research Articles

Defective carbon-bridged Cu sites to boost oxygen reduction reaction in neutral zinc-air batteries

Novel carbon nanomaterials containing N-coordinated metal centers present an advantage in promoting the oxygen reduction reaction (ORR). Despite considerable progress, substantial challenges persist with the advancement of neutral Zinc-air batteries (ZABs), particularly in optimizing the trade-off between the catalytic activity and stability. Herein, employing nanoporous carbon impregnated with Cu(II)-phenanthroline complexes to prepare Cu-ONCs catalysts rich in Cu-Nx sites. Controllable carbon defects to capture Cu2+ enable the enrichment of metal sites on the porous carbon surface, and simultaneously effectively suppress the aggregation of active centers. The metal moieties, specifically Cu-Nx, are incorporated into the porous N-doped carbon, thereby introducing accessible active sites within the partially graphitized carbon framework. Furthermore, the abundant mesopores inside the carbon nanofibers promote the exposure of accessible active sites to substantially augment the electrochemically active electrochemically active area area. Given the unique structure and composition, Cu-ONCs show outstanding ORR activity in neutral and alkaline media, alone with negligible decay observed after 3000 cycles. Moreover, Cu-ONCs based neutral ZABs demonstrate a peak power density of 48.28 mW cm−2 and impressive rate performance. This work provides defects/vacancies insight on transition metal (TM)-based carbon support to facilitate the advancement of cutting-edge neutral ZABs.

A Photo-Assisted Zinc-Air Battery with MoS2/Oxygen Vacancies Rich TiO2 Heterojunction Photocathode.

Converting solar energy into electrochemical energy is a sustainable strategy, but the design of photo-assisted zinc-air battery (ZAB) with efficient utilization of sunlight faces huge challenges. Herein, a photo-assisted ZAB of a three-electrode system using MoS2/oxygen vacancies-rich TiO2 heterojunction as charge cathode and Fe, N-doped carbon matrix (FeNC) as discharge cathode is constructed, where MoS2 is chosen as solar light-responsive catalytic material and TiO2 acts as electron transport layer and hole blocking layer, arising from a train of thought for efficient charging under sunlight irradiation and light-independent discharging. The introduction of oxygen vacancies in TiO2 facilitates the temporary trapping of carriers and triggers rapid carrier transfer at the interface of the heterojunction, which hinders the recombination of photogenerated holes, thereby facilitating their further participation in the oxygen evolution reaction. Moreover, FeNC exhibits superior oxygen reduction reaction performance due to strong d-π interactions. As a result, the well-built ZABs deliver a low charge voltage (0.71 V) under illumination at 0.1 mA cm-2, and a high power density (167.6mW cm-2) in dark. This work paves a special way for the development of ZABs by directly harvesting solar energy in charging and efficiently discharging regardless of lighting conditions.

Pumping Electrons from Oxygen-Bridged Cobalt for Low-Charging-Voltage Zn-Air Batteries.

Reducing the charging voltage is a prerequisite for improving the chargeability and energy efficiency of Zn-air batteries (ZABs). Herein, Fe3+ pumps electrons from oxygen-bridged cobalt (Fe-O-Co) and induces the accelerated charging kinetics. For the liquid ZABs, a charging voltage of around 1.94 V at 10 mA cm-2 was displayed, which slightly increased 2% after continuous cycles for 180 h. A steady charging voltage of around 1.87 V at 10 mA cm-2 was also exhibited for quasi-solid-state ZABs. Control experiments and characterization show that the interactions between the O2- and Fe3+ sites are relatively weaker than those between the O2- and Co3+ sites. Compared with Mn3+, Zn2+, and Cu2+, Fe3+ effectively pumps electrons from Co sites to generate the active species for the oxygen evolution reaction. Thus, the deprotonation behavior and *OH conversion were improved. This work demonstrates the oxygen electron bridge modulated electron transfer between dual metal sites, contributing to the improvement of low-charging-voltage ZABs.

Environmentally Friendly Biological Activated Carbon Derived from Sugarcane Waste as a Promising Carbon Source for Efficient and Robust Rechargeable Zinc–Air Battery

China is one of the largest sugarcane industrial countries in the world, and the annual output of bagasse waste is abundant. Classical incineration, landfill, and other treatment methods are inefficient and seriously harmful to the environment, so it is urgent to develop a new comprehensive utilization of agricultural waste. In this work, the sugarcane waste residue is converted to biological activated carbon (BAC) through a simple pre-carbonization and KOH activation process, which is then mixed with perovskite oxide BaCo0.5Fe0.5O3−δ (BCF) to form BAC/BCF composite air electrode. BAC/BCF assembled rechargeable zinc–air battery (ZAB) exhibits a relatively good output maximum power density of 96 mW·cm−2 and considerable long-term charge–discharge cycle stability over 250 h operation. These results indicate that the BAC derived from sugarcane waste is a promising potential carbon material candidate for ZAB application, which can realize the high-value utilization of agricultural waste in the field of efficient and durable energy storage and conversion devices.

Boosting Zn-air battery performance: Fe single-atom anchored on F, N co-doped carbon nanosheets for efficient oxygen reduction

Sluggish oxygen reduction reaction (ORR) kinetics limit the development of metal-air batteries and fuel cells, hindering overall energy conversion efficiency. Therefore, significant research has focused on cost-effective, highly active, and exceptionally stable non-precious metal ORR electrocatalysts. This study presents the synthesis of a nanohybrid material called Fe SAs/FN-CNs. It is made up of single iron atoms embedded in ultrathin porous carbon nanosheets that are co-doped with F and N. The synthesis process involves an easy one-step pyrolysis technique without additional post-treatment. The Fe SAs/FN-CNs material is designed to function as an effective zinc-air battery ORR electrocatalyst. Based on their distinctive components and structure, the optimal Fe SAs/FN-CNs exhibit outstanding catalytic efficiency and long-lasting performance in the alkaline ORR. They have an onset potential (Eonset) of 0.95 V, a half-wave potential (E0.5) of 0.85 V, a kinetic current density (JK) of 20.49 mA cm−2 at 0.8 V, and a diffusion-limited current (Jd) of 6.2 mA cm−2. In addition, a Zn-air battery made using homemade Fe SAs/FN-CNs demonstrated a power density of 197 mW cm−2, a specific capacitance of 813.5 mAh g−1, and exceptional stability. It outperformed the commercial Pt/C by operating continuously for over 147 hours at 10 mA/cm² (discharge-charge). The Fe SAs/FN-CNs nanohybrid electrocatalyst shows great potential as an electrocatalyst for various metal-air batteries.

Investigating the bifunctional electrocatalytic activity of nickel oxide/nitrogen-doped reduced graphene oxide nanocomposite for zinc-air battery application

Investigating the bifunctional electrocatalytic activity of nickel oxide/nitrogen-doped reduced graphene oxide nanocomposite for zinc-air battery application

Gel polymer electrolytes containing SiO2 spheres with tuned sizes to increase rechargeability of quasi-solid-state Zn-air batteries

Rechargeable zinc–air batteries (RZABs) with high energy densities and low costs have attracted tremendous interest for meeting the ever-growing demand for flexible and portable applications. In these batteries, the quasi-solid/solid-state electrolyte plays a critical role in the battery performance, such as the cycling performance rate and power output. In this study, porous poly (vinyl alcohol) (PVA) and poly (acrylic acid) (PAA) composite gel polymer electrolytes (GPEs) were modified by incorporating SiO2 as a water retainer. For this reason, SiO2 spheres of different sizes were synthesized by varying the temperature (5, 20, 60, and 80 °C) and reaction time (2, 6, 18, and 24 h). According to the SEM micrographs, the average size ranged from 107 to 710 nm depending on the conditions. The porous PVA/PAA–SiO2 GPEs obtained by selecting three SiO2 sizes (107, 425, and 630 nm) exhibited higher water retention capability than the unmodified GPE. Among them, the GPE with SiO2–630 nm displayed the highest battery performance (1.46 V, 85 mWcm−2 @ 0.8 V). This was achieved using CoMn2O4 spinel as a bifunctional electrocatalyst, with a catalyst loading of 2 mg cm−2. The quasi-solid-state RZAB displayed twice the rechargeability of the RZAB assembled with Pt/C+IrO2/C (120 vs. 62 cycles). According to post-mortem tests, this can be related to the improved water retention, the decrease in the size of the formed Zn dendrites, and the stability of the bifunctional material. Thus, fine-tuning of the electrocatalyst/electrolyte interface strongly affects the rechargeability.

Spatially Immobilized PtPdFeCoNi as an Excellent Bifunctional Oxygen Electrocatalyst for Zinc–Air Battery

AbstractDeveloping efficient oxygen electrocatalysts with low cost, high catalytic activity, and robust stability remains a formidable challenge for rechargeable zinc–air batteries (ZABs). Herein, highly dispersed ultrasmall PtPdFeCoNi high‐entropy alloy nanoparticles with a size of ≈ 2 nm and randomly distributed multimetallic single atoms spatially immobilized on the 3D hierarchically ordered porous nitrogen‐doped carbon skeleton (denoted as PtPdFeCoNi/HOPNC) are successfully synthesized via ultra‐rapid Joule heating process. The spatial immobilization on 3D HOPNC skeleton is the key to the high dispersion of multi‐active sites of oxygen electrocatalysts, and the formed hierarchical pore structure is conducive to the successful construction of the rapid mass transfer channel. As a result, the as‐prepared PtPdFeCoNi/HOPNC exhibits a positive half‐wave potential of 0.866 V versus RHE for oxygen reduction reaction (ORR), a low overpotential of 310 mV at 10 mA cm−2 for oxygen evolution reaction (OER), and low Tafel slopes for both ORR and OER. Furthermore, ZAB using PtPdFeCoNi/HOPNC as bifunctional oxygen catalysts exhibits excellent rate performances and superior cycling stability, surpassing that of a commercial Pt/C‐RuO2 mixture. The spatial immobilization strategy of HOPNC provides a new idea for the design and synthesis of efficient catalysts for various applications.

CoFe2O4 with the In-Situ Formed Oxygen Vacancies and Co Particles as an Efficient Bifunctional Catalyst for Rechargeable Zinc-Air Batteries.

Rechargeable zinc-air batteries (RZABs) are considered as one of the most promising clean energy device due to their abundant resources, low cost and environmental friendliness. However, their energy efficiency and cycle life are far from satisfactory due to the poor activity and stability of bi-functional electrocatalyst in air cathode. In this work, an efficient bi-functional catalyst (rGO-CoFe2O4/Co) was derived from its precursor (rGO-CoFe2O4) through a simple annealing process. Electrochemical measurements prove that rGO-CoFe2O4/Co with the in-situ formed Co nano particles and rich oxygen vacancies appears excellent oxygen reduction reaction and oxygen evolution reaction catalytic activity compared to its counterpart. Its half-wave potential is 0.81 V (vs RHE) and the OER overpotential is only 310 mV (vs RHE). In addition, rechargeable zinc-air batteries assembled with rGO-CoFe2O4/Co show the highest peak power density (128.9 mW cm-2) and cycling stability compared to rGO-CoFe2O4 and commercial Pt/C-RuO2 catalysts. This work provides a simple strategy for the design of advanced bifunctional catalysts.

Hybrid Nanoalloy‐Cluster‐Single Atom Sites Based Aerophilic Carbon Fiber Membranes as Binder‐Free Cathodes for Ultra‐Long‐Life Zn‐air Batteries

AbstractHigh‐efficient and durable electrocatalysts for oxygen reduction and oxygen evolution reaction (ORR/OER) are desirable to Zn‐air batteries (ZABs). However, most of catalysts in powder form with sole active sites remain challenging in achieving the satisfactory bifunctional catalysis and suffer from peeling off during the long‐term operation. Herein, hybrid CoFe active sites are constructed containing nanoalloys (≈10 nm), clusters (< 2 nm), and single atoms on aerophilic carbon fiber membranes as binder‐free air cathodes for ultra‐long‐life ZABs. In particular, the high air‐permeability of membranes (0.2 s) can prevent the active sites from blocking by O2 bubbles and promote the mass transfer. The theoretical and experimental results confirm that the hydrophilic CoFe2O4/CoFeOOH sites reconstructed on the surface of CoFe nanoalloys are mainly responsible for OER. While for single atoms and clusters on nitrogen (N)‐doped carbon matrix, they play a synergetic role in optimizing the adsorption energy to enhance ORR activity. Thus, the as‐prepared catalysts exhibit an ultra‐low ORR/OER potential gap (0.64 V). When further assembled as freestanding air‐electrodes, it exhibits an outstanding cycling lifespan of 1200 and 155 h in liquid‐ and quasi‐solid‐state ZABs respectively, which are fivefold and twofold higher than those of powder‐based cathodes (240/67 h).

Novel design of hollow carbon nanocage modified with nanotubes as a bifunctional electrocatalyst for high performance Zn–air batteries

Microcavities play a crucial role as microreactors in the transport of molecular/ionic guests and the exposure of active sites, thus significantly influencing the electrocatalytic performance. This study prepares Co/N-codoped hollow carbon (HT-CoN/C) with surface-distributed carbon nanotubes by pyrolysis of PDA-coated Zn/Co bimetallic ZIF (BM-ZIF@PDA). Benefiting from the hierarchical porous structure, high specific surface area (307.17 m2 g−1) and abundant Co clusters, the HT-CoN/C exhibits remarkable bifunctional oxygen electrocatalytic activity with an overpotential of the ORR/OER processes (ΔE = 0.703 V). The density functional theory (DFT) calculations also verify that the configuration of C-coated N-coordinated Co clusters (Co4-Nx) affect the electrocatalytic activity of ORR and OER, illustrating the source of the excellent oxygen electrocatalytic activity of HT-CoN/C. The aqueous rechargeable zinc-air battery (RZAB) using HT-CoN/C as the air electrode is characterized by a superior peak power density (175 mW cm−2), a prolonged cycle life (1230 cycles/410 h at 5.0 mA cm−2) and a high open-circuit voltage (1.47 V). Meanwhile, the flexible solid-state RZAB assembled by the HT-CoN/C also exhibits a higher peak power density (117 mW cm−2) and an excellent bending performance. This work is extremely valuable for the design and synthesis of Co/N co-doped carbon electrocatalysts.

CuFe Cooperativity at the Membrane-Electrode Interface Elicits a Tandem 2e-+2e- Mechanism for Exclusive O2-To-H2O Electroreduction.

High O2 reduction reaction (ORR) kinetics and exclusive 4e- pathway selectivity are keys to realizing a sustainable society. However, nonprecious electrocatalysts at present cannot enhance the ORR turnover frequency and H2O Faradaic efficiency (FE) concurrently. To address these two challenges, hybrid bilayer membrane (HBM) electrodes with earth-abundant metal centers are developed to control proton-coupled electron transfer (PCET) in ORR. Here, an oxidase-inspired CuFe active site is supported on a tris(2-pyridylmethyl)amine HBM and explored as a unique interface for efficient ORR. This bimetallic HBM displayed an ORR activity 1.4 times higher than the monometallic systems and exhibited the highest FE for H2O (∼94%) among Cu-, Fe-, Ni-, and Co-based HBMs. Contrary to previous studies where the ORR current decreases upon embedding the metal center in a hydrophobic lipid environment, here, the incorporation of a nitrile-terminated proton carrier at the HBM interface boosts the ORR current by 1.7 folds relative to the case where the catalytic site is directly exposed to protons in solution. This intriguing dual improvement is supported by density function theory calculations where an additional 2e-+2e- mechanism occurs in parallel to the direct 4e- pathway, highlighting the synergistic effect of the CuFe HBM for facilitating high-performance ORR. A Zn-air battery is constructed using this CuFe HBM for the first time, further demonstrating that the knowledge gained from this HBM technology holds practical values in real-life applications. These findings on interfacial PCET are envisioned to spark new design principles for future catalysts with optimal electrochemical properties for advanced energy conversion schemes.

Fluorine‐Lodged High‐Valent High‐Entropy Layered Double Hydroxide for Efficient, Long‐Lasting Zinc‐Air Batteries

AbstractEfficient and stable bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts are urgently needed to unlock the full potential of zinc‐air batteries (ZABs). High‐valence oxides (HVOs) and high entropy oxides (HEOs) are suitable candidates for their optimal electronic structures and stability but suffer from demanding synthesis. Here, a low‐cost fluorine‐lodged high‐valent high‐entropy layered double hydroxide (HV‐HE‐LDH) (FeCoNi2F4(OH)4) is conveniently prepared through multi‐ions co‐precipitation, where F− are firmly embedded into the individual hydroxide layers. Spectroscopic detections and theoretical simulations reveal high valent metal cations are obtained in FeCoNi2F4(OH)4, which enlarge the energy band overlap between metal 3d and O 2p, enhancing the electronic conductivity and charge transfer, thus affording high intrinsic OER catalytic activity. More importantly, the strengthened metal‐oxygen (M−O) bonds and stable octahedral geometry (M−O(F)6) in FeCoNi2F4(OH)4 prevent structural reorganization, rendering long‐term catalytic stability. Furthermore, an efficient three‐phase reaction interface with fast oxygen transportation was constructed, significantly improving the ORR activity. ZABs assembled with FeCoNi2F4(OH)4@HCC (hydrophobic carbon cloth) cathodes deliver a top performance with high round‐trip energy efficiency (61.3 % at 10 mA cm−2) and long‐term stability (efficiency remains at 58.8 % after 1050 charge–discharge cycles).

Fluorine-Lodged High-Valent High-Entropy Layered Double Hydroxide for Efficient, Long-Lasting Zinc-Air Batteries.

Efficient and stable bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts are urgently needed to unlock the full potential of zinc-air batteries (ZABs). High-valence oxides (HVOs) and high entropy oxides (HEOs) are suitable candidates for their optimal electronic structures and stability but suffer from demanding synthesis. Here, a low-cost fluorine-lodged high-valent high-entropy layered double hydroxide (HV-HE-LDH) (FeCoNi2F4(OH)4) is conveniently prepared through multi-ions co-precipitation, where F- are firmly embedded into the individual hydroxide layers. Spectroscopic detections and theoretical simulations reveal high valent metal cations are obtained in FeCoNi2F4(OH)4, which enlarge the energy band overlap between metal 3d and O 2p, enhancing the electronic conductivity and charge transfer, thus affording high intrinsic OER catalytic activity. More importantly, the strengthened metal-oxygen (M-O) bonds and stable octahedral geometry (M-O(F)6) in FeCoNi2F4(OH)4 prevent structural reorganization, rendering long-term catalytic stability. Furthermore, an efficient three-phase reaction interface with fast oxygen transportation was constructed, significantly improving the ORR activity. ZABs assembled with FeCoNi2F4(OH)4@HCC (hydrophobic carbon cloth) cathodes deliver a top performance with high round-trip energy efficiency (61.3 % at 10 mA cm-2) and long-term stability (efficiency remains at 58.8 % after 1050 charge-discharge cycles).

Innovative Air Cathode with Ni-Doped Cobalt Sulfide in Highly Ordered Macroporous Carbon Matrix for Rechargeable Zn-Air Battery.

To realize the practical application of rechargeable Zn-Air batteries (ZABs), it is imperative to develop a non-noble metal-based electrocatalyst with high electrochemical performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, Ni-doped Co9S8 nanoparticles dispersed on an inverse opal-structured N, S co-doped carbon matrix (IO─NixCo9-xS8@NSC) as a bifunctional electrocatalyst is presented. The unique 3D porous structure, arranged in an inverse opal pattern, provides a large active surface area. Also, the conductive carbon substrate ensures the homogeneous dispersion of NixCo9-xS8 nanocrystals, preventing aggregation and increasing the exposure of active sites. The introduction of heteroatom dopants into the Co9S8 structure generates defect sites and enhances surface polarity, thereby improving electrocatalytic performance in alkaline solutions. Consequently, the IO─NixCo9-xS8@NSC shows excellent bifunctional activity with a high half-wave potential of 0.926V for ORR and a low overpotential of 289mV at 10mA cm-2 for OER. Moreover, the rechargeable ZAB assembled with prepared electrocatalyst exhibits a higher specific capacity (768 mAh gZn -1), peak power density (180.2mW cm-2), and outstanding stability (over 160h) compared to precious metal-based electrocatalyst.

Boosted electron accumulation around Fe atom by asymmetry coordinated FeN3S1 for efficient oxygen reduction reaction

Catalysts with atomically dispersed Fe–N4 active sites have emerged as promising alternatives for noble-metal catalysts in oxygen reduction reaction (ORR). However, the sluggish reaction kinetics limit their further utilization. Herein, asymmetry active sites FeN3S1 located on mesoporous carbon matrix (Fe–N3S1/Cmeso) are constructed and verified as efficient ORR catalysts with fast reaction kinetics. The synthesized Fe–N3S1/Cmeso catalysts exhibit a half-wave potential of 0.92 V in alkaline electrolyte, a higher power density (178 mW cm−2) and a long-term durability (350 h) in Zn-Air battery. Mechanism study demonstrates that the specific structure induces accumulated electronic density and decreased d band center of Fe atoms which optimize the adsorption energy with OH∗ intermediates thus boosting the intrinsic activity. Moreover, the uniform mesoporous structure significantly increases the accessibility of active sites. This work offers a new perspective to optimize the adsorption strength of reaction intermediates for enhanced ORR.

Bionic Leaf: Ultrahigh energy efficiency in a defect Engineered MoS2 based photo induced charging of flexible Zn-Air battery

Introducing solar energy directly into flexible energy storage systems is an environmentally friendly, efficient, and low-cost strategy. Herein, we constructed a photoelectrode based on flexible carbon cloth (CC) to promote the oxygen evolution reaction (OER) and effectively reduce the charging voltage of flexible zinc-air batteries (ZABs), inspired by the photosynthesis process in leaves. The implementation of sulfur vacancies (VS) and oxygen doping in nanoscale molybdenum disulfide (MoS2) effectively enhances the separation efficiency of photo-generated electron-hole pairs, and adjusts its band structure to improve the oxidation capability. The constructed photocathode with defect-rich MoS2 (D-MoS2) exhibits a low overpotential of 235 mV at 10 mA cm−2 for OER. The sandwich flexible ZABs based on D-MoS2 achieve a low charge voltage around 1.3 V and an ultra-high energy efficiency greater than 90 % under illumination at 0.1 mA cm−2. This strategy provides a new insight for the application of light energy in smart wearable energy storage devices.

Dual Fe/I Single-Atom Electrocatalyst for High-Performance Oxygen Reduction and Wide-Temperature Quasi-Solid-State Zn-Air Batteries.

Oxygen reduction reaction (ORR) electrocatalysts are essential for widespread application of quasi-solid-state Zn-air batteries (ZABs), but the well-known Fe-N-C single-atom catalysts (SACs) suffer from low activity and stability because of unfavorable strong adsorption of oxygenated intermediates. Herein, the study synthesizes dual Fe/I single atoms anchored on N-doped carbon nanorods (Fe/I-N-CR) via a metal-organic framework (MOF)-mediated two-step tandem-pyrolysis method. Atomic-level I doping modulates the electronic structure of Fe-Nx centers via the long-range electron delocalization effect. Benefitting from the synergistic effect of dual Fe/I single-atom sites and the structural merits of 1D nanorods, the Fe/I-N-CR catalyst shows excellent ORR activity and stability, superior to Pt/C and Fe or I SACs. When the Fe/I-N-CR is employed as cathode for quasi-solid-state ZABs, a high power density of 197.9mW cm-2 and an ultralong cycling lifespan of 280h at 20mA cm-2 are both achieved, greatly exceeding those of commercial Pt/C+IrO2 (119.1mW cm-2 and 47h). In addition, wide-temperature adaptability and superior stability from -40 to 60 °C are realized for the Fe/I-N-CR-based quasi-solid-state ZABs. This work provides a MOF-mediated two-step tandem-pyrolysis strategy to engineer high-performance dual SACs with metal/nonmetal centers for ORR and sustainable ZABs.

Synergistic Vertical Graphene‐Exsolved Perovskite to Boost Reaction Kinetics for Flexible Zinc–Air Batteries

AbstractZinc–air batteries (ZABs) hold significant promise for flexible electronics due to their high energy density and low cost. However, their practical application is hindered by the sluggish kinetics of the oxygen evolution and oxygen reduction reactions (OER/ORR). This study highlights a novel design of vertical graphene arrays (VGs) anchored on PrBa0.5Sr0.5Co1.8Ru0.2O5+δ (PBSCRu) perovskite nanofibers, fabricated via plasma‐enhanced chemical vapor deposition. Notably, the VG growth induces the exsolution of Co nanoparticles from the PBSCRu perovskite, resulting in a unique PBSCRu‐Co‐VG heterostructure. Theoretical calculations demonstrate that constructing PBSCRu‐Co‐VG heterojunction regulates interfacial electronic redistribution, thereby lowering energy barriers for both OER and ORR. As a result, the PBSCRu@VG‐5 electrocatalyst exhibits superior stability and higher peak power density in both liquid and flexible solid‐state ZABs compared to the pristine PBSCRu electrocatalyst. This protocol advances the integration of synergetic perovskite/metal/graphene composites, offering considerable potential for next‐generation energy conversion technologies.

Construction of One-Dimensional Covalent-Organic Framework Coordinated with Main Group Metals for Selective Electrochemical Synthesis of H2O2.

Covalent-organic frameworks (COFs) are promising electrocatalysts for the selective synthesis of H2O2 through the two-electron oxygen reduction reaction (2e- ORR). However, the design and synthesis of efficient and stable COF-based electrocatalysts is still challenging. In this work, a predesigned 1,10-phenanthroline-based one-dimensional COF (PYTA-PTDE-COF) was constructed to anchor main group metal (In, Sn, and Sb) as electrocatalysts toward 2e- ORR. The catalysts are featured with fully exposed metalated side chains. Structural characterization revealed that PYTA-PTDE-M's (M = In, Sn, and Sb) are all quite similar, except for the coordinated metal ions with the maintenance of good crystallinity. They all exhibited satisfying activity and selectivity toward 2e- ORR under alkaline conditions. Among them, PYTA-PTDE-Sb exhibited the best performance (Eonset is 0.765 V, the H2O2 selectivity is 96%, and the yield rate is 209.2 mmol gcat-1 h-1). Moreover, it also delivered superior stability with almost no attenuation of current density during the long-time test. Theoretical calculations revealed that the Sb metal site in the COFs has the lowest adsorption strength of *OOH, which could be the main reason for its superior selectivity. The PYTA-PTDE-Sb assembled zinc-air battery realizes not only the supply of clean energy but also the production of green chemicals, showing it is highly promising in practical applications. This work offers an example for designing main group metal-coordinated 1D COFs and reveals fundamental structure-activity relationship toward 2e- ORR.