Zinc-air Research Articles

Promoting Reaction Kinetics of the Air Cathode for Neutral Zinc–Air Batteries by the Photothermal Effect

Promoting Reaction Kinetics of the Air Cathode for Neutral Zinc–Air Batteries by the Photothermal Effect

Bamboo-derived aerogel with atomically dispersed Co as a high-performance bifunctional electrocatalyst for durable zinc-air batteries

The development of highly efficient and durable bifunctional electrocatalysts is crucial for rechargeable zinc-air batteries, which have garnered significant attention as a promising sustainable energy storage technology. Herein, a novel Co-N-C-1050 catalyst is synthesized using a high-temperature gas transport method, where high purity cobalt powder and bamboo biomass aerogel are treated with ammonia gas at 1050 °C. The resulting catalyst exhibits a 3D interconnected porous network composed of dense carbon fibers, which atomically dispersed Co, N, and C elements are uniformly distributed. The synergistic integration of highly active Co single atoms and N-doped 3D carbon fiber aerogel enables Co-N-C-1050 to demonstrate excellent bifunctional electrocatalytic performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), comparable to commercial Pt/C and RuO2 catalysts. This catalyst has a half-wave potential of 0.842 V for ORR and a potential of 1.472 V at 10 mA cm−2 for OER, outperforming N-C-1050 and benchmark catalysts. A zinc-air battery is driven by Co-N-C-1050 achieves a high power density of 135 mW/cm2 and exceptional stability over 138 h of charge/discharge cycling, surpassing the higher-cost Pt/C + RuO2 catalyst. This biomass aerogel based single-site Co-N-C catalyst offers a promising approach for developing high-efficiency and long-cycle-life zinc-air batteries.

Anion-induced optimization of non-aqueous zinc-air battery performance: Insights into OTF− selection

Rechargeable non-alkaline zinc-air batteries (ZABs) address the CO₂ incompatibility and instability issues of conventional alkaline batteries. However, the impact of solid discharge products like zinc oxide on discharge capacity at the air cathode remains unexplored. In this study, we investigate how anions influence ion pair solvation structures using Zinc trifluoromethanesulfonate (Zn(OTF)₂)-N, N-dimethylformamide (DMF) and Zinc acetate (Zn(Ac)₂)-DMF electrolytes, and how these structures affect the distribution of discharge product. Our finding shows that anions with lower donor numbers (DNs), like the weaker ligand OTF- (20.5), enhance the zinc ion activity and promote rapid Zn2⁺ reactions with oxygen during discharge, leading to a more than tenfold increase in discharge capacity. In contrast, acetate anions with higher DNs (43.3) form stable complexes, inhibiting zinc ion activity and causing the formation of film-like discharge products, which reduces ZAB performance. The Zn(OTF)₂-DMF electrolyte also enables a battery lifespan of over 200 h, more than fivefold compared to the acetate-based system.

Consolidating the Oxygen Reduction with Sub-Polarized Graphitic Fe–N4 Atomic Sites for an Efficient Flexible Zinc–Air Battery

Consolidating the Oxygen Reduction with Sub-Polarized Graphitic Fe–N₄ Atomic Sites for an Efficient Flexible Zinc–Air Battery

Comparative study of the performance of α-MnO2 and amorphous manganese dioxide air electrodes for zinc-air batteries

Comparative study of the performance of α-MnO2 and amorphous manganese dioxide air electrodes for zinc-air batteries

DFT-guided synthesis of N, B dual-doped porous carbon from saccharina japonica for enhanced oxygen reduction catalysis

IntroductionThe oxygen reduction reaction (ORR) is a crucial determinant of the energy transformation capacity of fuel cells. This study investigates the performance of N and B dual-doped carbon in ORR.MethodsSix models using density functional theory (DFT) are developed to compare the performance of different doping strategies. A highly efficient dual-doped carbon ORR catalyst (S-850-1) is synthesized from Saccharina japonica, containing 4.54 at% N and 1.05 at% B atom.ResultsElectrochemical analysis reveals that S-850-1 significantly outperforms the nitrogen mono-doped carbon S-850, exhibiting a higher half-wave potential of 0.861 V and a greater limited current density of −5.60 mA cm⁻2, compared to S-850’s 0.838 V and −5.24 mA cm⁻2. Furthermore, S-850-1 surpasses the performance of 20% Pt/C, demonstrating enhanced durability and exceptional resistance to CO and methanol. The 1.40 V open circuit voltage produced by S-850-1 when integrated into a Zn-air battery can power an LED light.DiscussionBoth theoretical and practical evaluations validate the excellent ORR performance of nitrogen and boron dual-doped carbon, as evidenced by the agreement between the electrochemical results and DFT calculations. This work not only extends the range of ORR catalysts derived from biomass but also provides guidance on creating and producing affordable, effective catalysts that utilize natural resources.

Manipulation in the In Situ Growth Design Parameters of Aqueous Zinc‐Based Electrodes for Batteries: The Fundamentals and Perspectives

ABSTRACTPrecise exploitation of the growth of Zn metal anode in a power converter system has re‐emerged as one of the technological interests that have surged globally in the past 5 years, specifically to improve the practical use of deep cycling metal batteries. In this review, the in situ architectures of aqueous Zn metal‐based batteries focusing on the intrinsic geometrical building block and their respective mode of assembly classifying the deposition morphologies are scrutinised and discussed. The fundamental electrochemical kinetic principles and the associated critical issues, especially associated with the metal plague deposition that influences the morphology of deposited Zn, are considered. Also, the growing interest in the interphase system, which has an intense influence in characterising the types of Zn deposition morphology, is included. Consideration of the fundamental crystal features of Zn, endowing the predominant key for its growth assembly, is provided. Last, the review offers perspectives on the current progress of Zn–Air batteries in the application of electric vehicles.

An Efficient Cathode Catalyst for Rechargeable Zinc-air Batteries based on the Derivatives of MXene@ZIFs.

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial processes at the cathode of zinc-air batteries. Developing highly efficient and durable electrocatalysts at the air cathode is significant for the practical application of rechargeable zinc-air batteries. Herein, N-doped layered MX containing Co2P/Ni2P nanoparticles is synthesized by growing CoNi-ZIF on the surface and interlayers of the two-dimensional material MXene (Ti2C3) followed by phosphating calcination. The growth of CoNi-ZIF on the surface of MXene results in the attenuation of high-temperature structural damage of MXene, which in turn leads to the formation of Co2P/Ni2P@MX with a hierarchical configuration, higher electron conductivity, and abundant active sites. The optimized Co2P/Ni2P@MX achieves a half-wave potential of 0.85 V for the ORR and an overpotential of 345 mV for the OER. In addition, DFT calculations were adopted to investigate the mechanism at the atomic and molecular levels. The liquid zinc-air battery with Co2P/Ni2P@MX as the cathode exhibits a specific capacity of 783.7 mAh g-1 and exceeds 280 h (840 cycles) cycle stability, superior to zinc-air batteries constructed by the cathode of commercial Pt/C+RuO2 and other previous works. Furthermore, a solid-state battery synthesized with Co2P/Ni2P@MX as the cathode exhibits stable cycle performance (154 h/462 cycles).

Tailored Self-Supported Co,Ni/MnO2 Nanorods@Hierarchical Carbon Spheres Chains as Advanced Electrocatalysts for Rechargeable Zn-Air battery and Self-Driven Water Splitting

Tailored Self-Supported Co,Ni/MnO₂ Nanorods@Hierarchical Carbon Spheres Chains as Advanced Electrocatalysts for Rechargeable Zn-Air battery and Self-Driven Water Splitting

High-Entropy Prussian Blue Analogue Derived Heterostructure Nanoparticles as Bifunctional Oxygen Conversion Electrocatalysts for the Rechargeable Zinc-Air Battery.

In response to energy challenges, rechargeable zinc-air batteries (RZABs) serve as an ideal platform for energy storage with a high energy density and safety. Nevertheless, addressing the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in RZAB requires highly active and robust electrocatalysts. High-entropy Prussian blue analogues (HEPBAs), formed by mixing diverse metals within a single lattice, exhibit enhanced stability due to their increased mixing entropy, which lowers the Gibbs free energy. HEPBAs innately enable sacrificial templating, an effective way to synthesize complex structures. Impressively, in this study, we successfully transform HEPBAs into exquisite multiphase (multimetallic alloy, metal carbide, and metal oxide) heterostructure nanoparticles through a controlled synthesis process. The elusive multiphase heterostructure nanoparticles manifested two active sites for selective ORR and OER. By integrating CNT into HEPBA-derived nanoparticles (HEPBA/CNT-800), the HEPBA/CNT-800 demonstrates superior activity toward both ORR (E1/2 = 0.77 V) in a 0.1 M KOH solution and the OER (η = 330 mV at 50 mA cm-2) in a 1 M KOH solution. The RZAB with a HEPBA/CNT-based air electrode demonstrated an open-circuit voltage of 1.39 V and provided a significant energy density of 71 mW cm-2. Moreover, the charge and discharge cycles lasting up to 40 h at a current density of 5 mA cm-2 demonstrate its excellent stability. This work provides an alternative avenue for the rational design of HEPBA's derivative for a sustainable rechargeable metal-air battery platform.

I3--Mediated Oxygen Evolution Activities to Boost Rechargeable Zinc-Air Battery Performance with Low Charging Voltage and Long Cycling Life.

An effective strategy to facilitate oxygen redox chemistry in metal-air batteries is to introduce a redox mediator into the liquid electrolyte. The rational utilization of redox mediators to accelerate the charging kinetics while ensuring the long lifetime of alkaline Zn-air batteries is challenging. Here, we apply commercial acetylene black catalysts to achieve an I3--mediated Zn-air battery by using ZnI2 additives that provide I3- to accelerate the cathodic redox chemistry and regulate the uniform deposition of Zn2+ on the anode. The Zn-air battery performs an ultra-long cycle life of over 600 h at 5 mA cm-2 with a final charge voltage of 1.87 V. We demonstrate that I- mainly generates I3- on the surface of carbon catalysts during the electrochemically charging process, which can further chemically react with OH- to generate oxygen and further revert to I-, thus obtaining a stable electrochemical system. This work offers a strategy to simultaneously improve the cycling life and reduce the charging voltage of Zn-air batteries through redox mediator methods.

Deep Eutectic Solvent and Molten Salt-Assisted Construction of Wheat Straw-Derived N/O Co-Doped Porous Carbon for Flexible Zinc-Air Batteries.

As a common biomass resource, wheat straw is gradually being derived as carbon materials for oxygen reduction reaction (ORR) in zinc-air batteries (ZABs). Herein, the wheat straw-derived carbon was prepared by ball milling and pyrolysis using deep eutectic solvent (DES) as the medium, which avoided the cumbersome procedures. The hydrogen bond of DES was utilized to reconstructed into a hydrogen bond network structure between DES and lignin/cellulose/hemicellulose of wheat straw. The hydrogen bond network structure was converted into N/O co-doped porous carbon (N/O-WSPC) with abundant N/O co-doped sites after high-temperature pyrolysis. Meanwhile, KHCO3 was employed to further generate hierarchical pore structures and increase the specific surface area of the N/O-WSPC. The N/O co-doped sites provided intrinsic ORR activity, while the porous structure facilitates the mass transfer effect. Therefore, the N/O-WSPC exhibited a half-wave potential of 0.87 V (vs. RHE) and a limiting current density of 5.98 mA cm-2 for ORR. The N/O-WSPC-based flexible ZAB displayed an energy density of 652.23 Wh kg-1 and a charging-discharging cycle duration for over 19 h. The DES-assisted strategy facilitates the sustainable and efficient application of wheat straw-derived carbon materials in energy storage and conversion devices.

Carbon-coated ZnS as a high-performance ORR/OER bifunctional cathode catalyst for zinc-air batteries

The commercial application of zinc-air batteries (ZABs) is hindered by the high cost and scarcity of precious metal catalysts. In this paper, we prepared high-performance ORR/OER bifunctional catalysts with a carbon-coated ZnS spherical structure (ZnS@C) through a hydrothermal method followed by a carbonization process. Characterized by their unique spherical coated pore structure, exhibit impressive electrocatalytic activity. Specifically, ZnS@C-2, produced by a secondary carbonization process demonstrates an ORR half-wave potential of 0.82 V (relative to RHE) and an OER overpotential of 377 mV at 10 mA cm−2. When employed in a ZAB, it achieves a maximum power density of 120.4 mW cm−2, a specific capacity of 836 mAh gZn−1, and maintains cycle stabilization for up to 165 h at 10 mA cm−2. The research results demonstrate that the unique carbon-coated internal porous structure not only significantly enhances the stability of the catalyst but also increases the number of active sites, thereby providing more abundant activation energy for the catalytic reaction and facilitating its efficient progress. This underscores the catalyst's excellent ORR and OER properties, suggesting promising practical application potential.

High Energy Conversion Efficiency and Cycle Durability of Solar-Powered Self-Sustaining Light-Assisted Rechargeable Zinc–Air Batteries System

The issue of energy supply in outdoor and remote areas has become a significant challenge. Solar-powered self-sustaining rechargeable zinc-air batteries (RZABs) offer a viable energy solution for off-grid regions. However, there has been no specific study on the technical compatibility and adaptability of the solar power generation system and RZABs system, as well as the efficiency of energy conversion and storage in such solar-powered RZABs systems. To address these challenges, this study developed a solar-powered self-sustaining photo-assisted RZABs system based on a photo-responsive polyterthiophene (pTTh) cathode. This system employs pTTh with photo-responsive properties as the cathode catalyst for RZABs, which not only significantly reduces the overpotential of the cathode but also enhances the performance of the RZABs and the overall energy conversion efficiency (reaching 16.2%). In practical applications, the system exhibits excellent stability, operating continuously within a wide temperature range of -15 to 40°C, and demonstrating a stable cycling operation capability of up to 33 days. It provides reliable, low-cost power support for electronic devices such as mobile phones, flashlights, GPS units, and small pollutant detection systems, greatly improving the practicality of these devices in off-grid areas.

Enhanced bifunctional electrocatalysis of Co5.47N nanocrystals in porous carbon nanofibers for high-efficiency zinc-air batteries

As a promising energy conversion and storage device, recently, rechargeable zinc-air batteries (ZABs) have developed rapidly, and the exploitation of excellent electrode catalysts to improve the energy efficiency and long-term performance of ZABs has become a focus of current research. Herein, the Co5.47N nanocrystals embedded in porous carbon nanofibers (Co5.47N PCNFs) were designed to act as a bifunctional electrocatalyst for the oxygen reduction reaction (ORR) and iodide oxidation reaction (IOR), which occur on the electrode in the charging-discharging process of ZABs. The electrochemistry results showed that the ORR activity of Co5.47N PCNFs is comparable to the commercial Pt/C electrocatalyst, and the IOR activity and stability are higher than those of the Pt/C electrocatalyst. Importantly, Co5.47N PCNFs electrocatalyst endows ZABs with a low charge–discharge voltage difference (0.49 V), a high round-trip energy efficiency (72.1 %), as well as a large specific capacity (791.5 mAh gZn−1), surpassing the performance of Pt/C electrocatalyst. Density functional theory calculation demonstrates that Co5.47N PCNFs have lower Gibbs free energy for the formation of IOR intermediate species, thereby displaying outstanding IOR catalytic performance compared to that of Pt/C electrocatalyst. These findings offer crucial insights into the rational design of cobalt nitride-based electrocatalysts for application in ZABs with high energy efficiency.

Effect of plant extract additives on the parasitic reaction in alkaline Zn-air batteries

The battery's high energy density, economical price, and ecological sustainability of the Zn-air battery make it a bright future battery technology. However, parasitic reactions, which can diminish the battery's life cycle and efficacy, are the key challenges for potential development of Zn-air batteries. Glycyrrhiza glabra roots extract (GGRE) has been investigated as an alternative hydrogen gas evolution and corrosion inhibitor for Zn-air batteries in order to mitigate the parasitic reaction. The results obtained reveal that the inhibition capacity of the GGRE extract increases with concentration and reaches its highest level (75.6%) around 350 mg L-1 of GGRE extract. GGRE extract is a mixed type inhibitor with a predominately cathodic effect based on the polarization data. The GGRE extract adsorption on the Zn surface complies with Freundlich isotherm. In comparison to the blank Zn-KOH (354 mAh g-1), the battery containing 350 mg L-1 GGRE extract has the highest discharge capacity (533 mAh g-1) and the best cyclability (92.9% retention after 500 cycles). Overall, GGRE extract can significantly optimize the performance of Zn-air batteries.

Atomic modulation of FeN4 sites on hollow carbon nanospheres by neighboring Mn atoms for ultra-stable Zn-air batteries

The sluggish oxygen reduction/evolution reaction (ORR/OER) at the oxygen electrode has significantly hindered the development of Zn-air batteries. Modulating single-atom active sites with neighboring atoms is an effective strategy to enhance ORR/OER activity. Herein, an ordered assembly strategy is employed to anchor FeN4 sites onto hollow carbon nanospheres and then Mn atoms are introduced to modulate the FeN4 sites to construct a electrocatalyst (Fe,Mn-HCNS). Theoretical simulations reveal that neighboring Mn atoms induces a negative shift in the d-band center of Fe, thereby optimizing the adsorption–desorption of key oxygenated intermediates and accelerating ORR/OER kinetics. In addition, the introduction of Mn atoms optimizes the energy barrier for Fe dissolution, which inhibits the demetalation of the FeN4 site. The assembled aqueous Zn-air battery demonstrates ultrahigh open-circuit voltage (1.55 V) and outstanding durability (2000 h at 10 mA cm−2). This work provides an insightful prospect for neighboring Mn atoms in enhancing oxygen electrocatalytic activity at FeN4 sites, thereby advancing the development of superior electrocatalysts.

Pd-Co₃O₄/Acetylene Black Nanocomposite as an Efficient and Robust Bifunctional ORR/OER Electrocatalyst for Rechargeable Zinc-Air Batteries

Developing cost-effective and high-performing bifunctional electrocatalysts is pivotal for advancing rechargeable zinc-air batteries (ZABs). In this study, a Pd-Co₃O₄ loaded on acetylene black (Pd-Co₃O₄/C) electrocatalyst was developed with excellent properties for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) using reduced H₂PdCl₄ to modify Co₃O₄/C. The experimental findings indicate that the Pd-Co₃O₄/C electrocatalyst exhibits a favorable half-wave potential for ORR at 0.91 V, a feasible potential for OER at 1.48 V (measured at 10 mA/cm2), also minor Tafel slopes for both ORR (44.65 mV/dec) and OER (58.41 mV/dec). Additionally, it evidences a power density of 186 mW/cm2 in ZABs and good durability during galvanostatic charge-discharge cycling. The impressive performance of Pd-Co₃O₄/C can be ascribed primarily to the beneficial synergistic effect resulting from the composition of Co₃O₄ and Pd embedded within graphite carbon. This research lays the groundwork for the expansion of additional cost-effective and highly effective electrocatalysts in the coming years.

Modifying d–p orbital hybridization of Ni/Fe[sbnd]O species by high-valence ruthenium doping to enhance oxygen evolution performance

The electron distribution of catalysts can be modulated by high-valence metal doping, thus enhancing the intrinsic activity. Herein, we adopt Ru modification to adjust the d–p orbital hybridization of Ni-Fe oxyhydroxides, significantly increasing the oxygen evolution reaction (OER) activity. The amorphous NiFe0.5Ru0.1OxHy catalyst synthesized by sol–gel method exhibits excellent OER activity, far superior to commercial RuO2. In situ Raman and XPS results confirm that the NiOOH/FeOOH active species gradually form with increasing applied voltage. Density functional theory (DFT) calculations reveal that high-valence Ru dopants can effectively regulate the hybridization of d–p orbital of Ni/FeO, significantly increase the electron density around Fermi level, promote charge transfer, make them have more anti-bonding orbitals, enhance the binding ability of active sites to intermediates, reduce the reaction energy barrier of the rate-determining step (H2O → *OH), and thus improve the OER activity. In addition, NiFeRuOxHy as a cathode catalyst in a rechargeable zinc-air battery shows an outstanding cycle life of 600 h. This study provides a promising hybrid orbital method for designing high-performance OER catalysts for water splitting and rechargeable zinc-air batteries.

Amorphous CoFePOx hollow nanocubes decorated with g-C3N4 quantum dots to achieve efficient electrocatalytic performance in the oxygen evolution reaction.

Simultaneously enriching active sites and enhancing intrinsic activity in a simple way is of great importance for the design of highly active electrocatalysts for the oxygen evolution reaction (OER), but it still faces challenges. Herein, g-C3N4 quantum dot decorated amorphous hollow CoFe bimetallic phosphate nanocubes (a-CoFePOx@CNQD) are prepared as an efficient OER electrocatalyst by a simple in situ etching-phosphating process. Research shows that their unique hollow architecture and amorphous structure can help provide generous exposed active sites for OER, and the incorporation of g-C3N4 quantum dots can effectively adjust the electronic structure to improve the intrinsic activity. Therefore, a-CoFePOx@CNQD exhibits excellent OER performance with a low overpotential (239 mV) at 10 mA cm-2 and a small Tafel slope (58.4 mV dec-1), surpassing the commercial RuO2. Furthermore, a-CoFePOx@CNQD as an electrode catalyst for a water electrolyzer and zinc-air battery also shows higher performance and stability than RuO2 + Pt/C catalysts. This study provides a feasible strategy for preparing efficient and stable amorphous hollow heterostructure OER electrocatalysts.