Rechargeable Zn-air Batteries Research Articles

P-Block metal atom-induced spin state transition of Fe-N-C catalysts for efficient oxygen reduction.

A deep understanding of the role of spin configurations of Fe-N-C catalysts in the adsorption and desorption of oxygen intermediates during ORRs is critical for the development of new catalysts for the ORR. Herein, we successfully implanted p-block metal single sites (SnN4, SbN4) into the Fe-N-C system to vary the spin states of Fe species and investigated the ORR performance of active metal centers with varying effective magnetic moments. Through a combination of zero-field cooling (ZFC) temperature-dependent magnetic susceptibility measurements and DFT calculations, we successfully established correlations between the spin state and ORR activity. Magnetic analysis reveals that the p-block metal catalytic sites can effectively induce a low-to-high (or medium) spin state transition of Fe centers. Consequently, the 3d orbital electrons in Fe,M-N-C catalysts penetrate the antibonding π-orbitals of oxygen more easily, thus optimizing the adsorption/desorption of key oxygen intermediates on Fe-N-C catalysts. As a result, the optimized Fe,M-N-C catalyst exhibits a half-wave potential of 0.97 V in a 0.1 M KOH electrolyte, as well as higher durability than conventional Pt/C catalysts. Moreover, the Fe,M-N-C catalysts show encouraging performance in a rechargeable Zn-air battery with high power density and long-term cyclability, indicating the practical applicability of these Fe,M-N-C catalysts.

Molecularly engineered potential of d-orbital modulated iron-bridged delaminated MBene for rechargeable Zn–air batteries

An air cathode with high catalytic activity and reversibility toward the OER and ORR is designed by the typical coordinations of iron phthalocyanine molecule crystals on delaminated MoAl1−xB MBene sheets.

Zeolitic imidazolite framework derived bifunctional N,P-codoped hollow carbon sphere electrocatalysts decorated with Co2P/Fe for rechargeable Zn–air batteries

Co2P nanoparticles and Fe–Nx species were anchored on N,P codoped hollow carbonized spheres by structural and active site engineering. This work provides a facile strategy for the construction of bifunctional electrocatalysts for Zn–air batteries.

Versatile electrochemical manufacturing of mixed metal sulfide/N-doped rGO composites as bifunctional catalysts for high power rechargeable Zn–air batteries

Electrodeposition was used for direct synthesis of nitrogen-dopged reduced graphene oxide (NrGO) and mixed transition metal sulfides (NCMS). The resulting NCMS/NrGO composite exhibits excellent OER/ORR peroformance as Zn–air battery cathode.

Chemical fabrication and synergistic mechanism of N-doped carbon modified with FeP as catalysts for flexible rechargeable Zn–air batteries

A 3D porous N-doping Paulownia-derived carbon modified with FeP nanoparticles (FeP@NPW) was used as an air cathode for flexible rechargeable Zn–air batteries. The flexible rechargeable ZAB based on FeP@NPW exhibits outstanding cycle stability and durability.

Selenium-doped mixed metal oxide nanoparticles decorated on g-C3N4 and MXene sheets as promising bifunctional oxygen electrocatalysts for rechargeable Zn–air batteries

The design of bifunctional electrocatalysts to conduct an appropriate oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for high-performance zinc–air batteries is one of the most important challenges for sustainable energy storage devices.

Carbon-based electrocatalysts for rechargeable Zn–air batteries: design concepts, recent progress and future perspectives

This review provides an in-depth discussion of the carbon-based electrocatalysts for rechargeable Zn–air batteries from design strategies, research progress, and future perspectives.

Boosting the electrocatalytic activity of single atom iron catalysts through sulfur-doping engineering for liquid and flexible rechargeable Zn–air batteries

A practical strategy is reported to design single-Fe atom decorated S/N-doped C (Fe SAs@S/N–C) catalysts with a high Fe loading of 5.45 wt%. The prepared catalysts exhibit excellent performances for liquid and all-solid-state Zn–air batteries.

ZIF-67-derived Se-doped CoSe2 grown on carbon nanofibers as oxygen electrocatalysts for rechargeable Zn–air batteries

Se-doping can reduce the charge transfer resistance and enhance the OER kinetics. CNFs significantly improved the electrical conductivity of the materials. The ZIF-67-derived carbon skeleton provides an electron transport channel.

Redox mediators optimize reaction pathways of rechargeable Zn-air batteries

Redox mediators optimize reaction pathways of rechargeable Zn-air batteries

Brush-like Co/CoSe nanoheterostructures embedded in N-doped carbon for rechargeable Zn-air batteries.

Rational design and preparation of high-performance bifunctional oxygen electrocatalysts with effective sites and excellent mass/electron transfer structures are in demand for Zn-air batteries to overcome the sluggish oxygen reduction/evolution kinetics. Herein, a scalable and facile strategy is proposed to obtain brush-like Co/CoSe nanoheterostructures embedded in N-doped carbon catalysts with optimized active sites and hierarchical nanostructures. Systematic investigation indicates that nanoheterogeneous interfaces with appropriate composition deliver significantly improved electrochemical activity. As a result, a zinc-air battery assembled with the obtained Co/CoSe nanoheterostructures embedded in the N-doped carbon (CoSe/Co@NC-1) catalyst exhibits outstanding electrochemical performance with a peak power density of 215 mW cm-2 and excellent stability for 475 hours (2850 cycles). These results indicate that this strategy is an effective method for fabricating multicomponent and hierarchically nanostructured materials with enhanced catalytic efficiency for advanced energy devices.

A seed-like structured Mo@ZrS2 catalyst on graphene nanosheets for boosting the performance of rechargeable Zn-air batteries.

Novel composite materials are being studied by researchers for energy storage and renewable energy applications. Here, a seed-like Mo-doped ZrS2 catalyst was developed on a reduced graphene oxide (rGO) surface by an annealing and hydrothermal method. Using photoelectron spectroscopy, scanning microscopy, and X-ray diffraction analyses, the structure of Mo@ZrS2/rGO and the impact of heteroatoms are demonstrated, providing insight into the catalyst. Furthermore, it is demonstrated that Mo@ZrS2/rGO has been utilized as an efficient energy storage electrocatalyst by offering a very low half-wave potential of 0.80 V for the oxygen reduction reaction in an alkaline solution. Furthermore, Zn-air batteries with a high-power density of 128.6 mW cm-2 and exceptional cycling stability are demonstrated by the developed array electrocatalyst. Ultimately, the research findings suggest novel perspectives on the structure of ZrS2 nanoseeds created by Mo surface doping, promote the usage of Zn-air batteries in practical scenarios, and offer a fascinating idea for creating a redox electrocatalyst.

Movable-type printing method to fabricate ternary FeCoNi alloys confined in porous carbon towards oxygen electrocatalysts for rechargeable Zn-air batteries.

Transition metal-based carbon catalysts are a promising class of electrocatalysts to enhance the efficiency of energy conversion and storage devices. However, it remains a challenging task to develop multi-metal alloy catalysts. Herein, ternary FeCoNi alloy nanoparticles (NPs) confined in nitrogen-doped carbon (NC) catalysts were fabricated via a facile movable-type printing method, where a range of transition metals confined in NC catalysts was prepared using the same technique except for the adjustment of the metal precursors. Due to the unique electronic structure and significant active sites of the medium-entropy alloy, the FeCoNi-NC catalysts demonstrated highly efficient bifunctional electrocatalytic activities for the oxygen reduction (E1/2 = 0.838 V) and evolution (Eoverpotential = 330 mV, 10 mA cm-2) reactions, which were comparable to those of Pt/C and RuO2. Moreover, the FeCoNi-NC-based liquid rechargeable ZABs displayed a substantial power density of 231.2 mW cm-2, and the homemade flexible ZABs also exhibited outstanding activity and cycling durability. Thus, this movable-type printing method is suitable for constructing a variety of multi-metal-based catalysts for metal air batteries.

Potassium ferrite nanosheets with tin doping for enhanced large-current-density H2 production and ultra-long life rechargeable Zn–air batteries

Self-supported Sn-KFO exhibits high-efficiency trifunctional activities in stable Zn–air batteries and large-current-density H2 production, of which, the enhanced electrochemical properties mainly attribute to the introduced tin.

Durable bifunctional electrocatalyst for cathode of zinc-air battery: surface pre-reconstruction of La0.7Sr0.3MnO3 perovskite by iron ions

The utilization of manganese-based perovskite in rechargeable Zn-air batteries encounters challenges related to low catalytic activity and inadequate stability. In this study, we have employed a surface pre-reconstruction technique to produce La0.7Sr0.3MnO3 nanoparticles adorned with iron ions (LSM/Fe-1.5). The optimized LSM/Fe-1.5 catalyst demonstrates an increase in ORR and OER intrinsic activities by 1.8 and 4.9 times, respectively, exhibiting ORR/OER bifunctional activity comparable to that of commercial Pt/C and RuO2. The Zn-air battery employing the LSM/Fe-1.5 catalyst exhibits a charge-discharge voltage difference of 0.89 V after 1500 cycles (500 h). The improved activity of ORR can be attributed to the selective dissolution of A-site cations, optimization of B-site electronic structure and oxygen vacancy concentration. The enhanced OER activity can be ascribed to the augmentation of adsorption energy of iron ions on the surface of perovskite, along with the synergistic influence of iron ions and surface oxygen vacancies. This study not only presents an effective approach for developing efficient and durable bifunctional catalysts for broader application in Zn-air batteries, but also broadens the influence of iron ions in the OER process to include manganese-based perovskite oxide.

Facile hydrothermal synthesis of NiMoO4·xH2O nanorods-like structures as bifunctional oxygen electrocatalysts for rechargeable zinc-air batteries

Developing highly active and low-cost bifunctional catalyst materials to replace precious metal species is of utmost importance for the commercialization of clean and sustainable energy systems. In this report, homogenous NiMoO4·xH2O nanorods (NRs)-like structured materials were synthesized by an annealing-free hydrothermal method. The synthesized electrode electrochemical properties were determined by linear sweep voltammetry using a rotating ring disk electrode to determine the characteristics of oxygen reduction reaction in an O2-saturated electrolyte solution. For the oxygen evolution reaction, the NiMoO4·xH2O NRs electrocatalyst showed lower overpotential of 185 mV to obtain 10 mA cm−2. Furthermore, the NiMoO4·xH2O NRs electrocatalyst-based zinc (Zn)-air battery exhibited lower voltage gaps and smaller electrochemical impedance spectroscopy values than the Pt/C catalyst. Importantly, the NiMoO4·xH2O NRs-based battery (60 cycles (∼1100 min)) revealed excellent cycling stability results when compared with the Pt/C-based battery (30 cycles (∼550 min)). The NR structured electrode provided good steady potential after being subjected to a fixed current density of 10 mA cm−2 for 100 h. Therefore, these results demonstrate that the synthesized NiMoO4·xH2O NRs material is promising as a bifunctional electrocatalyst for rechargeable Zn-air batteries.

Supporting Critical Raw Material Circularity – Graphite from Waste LIBS to Zn-Air Batteries

The use of Li-ion batteries (LIBs) in electrical vehicles and consumer electronics is continuously on the rise which means that the amount of spent LIB (SLIB) is on the rise as well. The sustainable recycling of SLIB for production of secondary resources will prevent the loss of valuable materials and ensures safe and economical management of used batteries. During industrial black mass recycling process only Co and Ni from SLIBs is currently recycled, though LIBs contain many other valuable materials too. Graphite, which is used as an anode active material in LIBs, is discarded as a waste during industrial recycling process. Repurposing inexpensive waste graphite has a huge potential to be alternative for pristine graphite.In this research a novel way to prepare bifunctional oxygen electrocatalyst from industrially produced and hydrometallurgically leached black mass leach residue is shown. The recycling leach residue is utilized as a valuable raw material, graphite and transition metal (Co, Mn, Ni) source, with N-precursor for the synthesis of N-Me-C graphite-based electrocatalyst. For the first time the battery metal residues, left into SLIBs recycling waste, are strategically exploited to achieve metal co-doping of graphite-based material. Battery derived electrocatalysts demonstrated promising electrocatalytic activity towards ORR and OER in alkaline media. Moreover, the novel bifunctional oxygen electrocatalysts were used in a rechargeable Zn-air battery as an air cathode catalyst and achieved a high-power density of 104 mW·cm-2 (Figure 1). The advantageous electrochemical activity of the catalyst materials was linked with its surface morphology, structure, porosity, and elemental composition.This research shows the great potential of SLIBs black mass leach residue as a resource for the more sustainable production of high performance and low-cost bifunctional oxygen electrocatalyst appliable in Zn-air battery. Figure 1

Ni-Fe-S Supported on Mo-Based Mxene (Mo2CTx) As a High-Performance Bifunctional Electrocatalyst for Rechargeable Zinc–Air Batteries

Rechargeable Zn-air batteries are a promising alternative to lithium-ion batteries due to their high theoretical energy density (1350 Wh kg−1), low cost, and environmental benefits. To meet the growing demand on renewable power for electric vehicles and sustainable goals, inexpensive and efficient bifunctional catalysts with both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities have recently garnered a great interest in energy conversion fields. MXene, a rising family of two-dimensional (2D) materials, particularly Mo2CTx, has been identified as a promising electrocatalyst supporter. The tunable surface chemistry, atomic thickness, and high surface area of the MXene architecture reduce the reaction barrier by enhancing the conductivity, exposing active sites and increasing the reaction rate in charge transfer and gas/ion diffusion process. Therefore, with coexistence of MXene platform, favorable reaction conditions can be created to facilitate the catalyst's performance.In this study, a novel bifunctional electrocatalyst of Ni-Fe sulfide uniformly embedded in a Mo-based MXene (Mo2CTx) sheet structure is designed for Zn-air battery applicaiton. Surface characterization shows that 2-D Mo2CTx nanosheets can be successfully fabricated by hydrothermal etching method. The deposition of Ni-Fe sulfide nanocatalysts onto Mo2CTx MXene nanosheets exhibits excellent electrochemical performance, which is attributed to the enhanced intrinsic activity due to rapid electron transfer from MXene, abundant functional groups on the surface to lower the reaction activity energy. In addition, the architecture of MXene support provides a large specific surface area, high porosity, good conductivity and highly exposed active sites. When using MXene supported Ni-Fe-S nanocatalysts as the electrode materials for Zn-air battery application, a high peak power density at 107.24 mW cm−2 with superior cycle stability within 200h is obtained. Moreover, the possible mechanisms on energy storage is also proposed. These results clearly indicates the successfully development of an exciting bifunctional electrocatalyst for electrochemical energy conversion applications.

Longevous Cycling of Rechargeable Zn-Air Battery Enabled by "Raisin-Bread" Cobalt Oxynitride/Porous Carbon Hybrid Electrocatalysts.

Developing commercially viable electrocatalyst lies at the research hotspot of rechargeable Zn-air batteries, but it is still challenging to meet the requirements of energy efficiency and durability in realistic applications. Strategic material design is critical to addressing its drawbacks in terms of sluggish kinetics of oxygen reactions and limited battery lifespan. Herein, a "raisin-bread" architecture is designed for a hybrid catalyst constituting cobalt nitride as the core nanoparticle with thin oxidized coverings, which is further deposited within porous carbon aerogel. Based on synchrotron-based characterizations, this hybrid provides oxygen vacancies and Co-Nx -C sites as the active sites, resulting from a strong coupling between CoOx Ny nanoparticles and 3D conductive carbon scaffolds. Compared to the oxide reference, it performs enhanced stability in harsh electrocatalytic environments, highlighting the benefits of the oxynitride. Furthermore, the 3D conductive scaffolds improve charge/mass transportation and boost durability of these active sites. Density functional theory calculations reveal that the introduced N species into hybrid can synergistically tune the d-band center of cobalt and improve its bifunctional activity. As a result, the obtained air cathode exhibits bifunctional overpotential of 0.65V and a battery lifetime exceeding 1350 h, which sets a new record for rechargeable Zn-air battery reported so far.

Fe-Nx sites coupled with core-shell FeS@C nanoparticles to boost the oxygen catalysis for rechargeable Zn-air batteries

The development of efficient single-atom catalysts (SACs) for the oxygen reduction reaction (ORR) remains a formidable challenge, primarily due to the symmetric charge distribution of metal single-atom sites (M-N4). To address such issue, herein, Fe-Nx sites coupled synergistic catalysts fabrication strategy is presented to break the uniform electronic distribution, thus enhancing the intrinsic catalytic activity. Precisely, atomically dispersed Fe-Nx sites supported on N/S-doped mesoporous carbon (NSC) coupled with FeS@C core-shell nanoparticles (FAS-NSC@950) is synthesized by a facile hydrothermal reaction and subsequent pyrolysis. Due to the presence of an in situ-grown conductive graphitic layer (shell), the FeS nanoparticles (core) effectively adjust the electronic structure of single-atom Fe sites and facilitate the ORR kinetics via short/long-range coupling interactions. Consequently, FAS-NSC@950 displays a more positive half-wave potential (E1/2) of 0.871 V with a significantly boosted ORR kinetics (Tafel slope = 52.2 mV dec−1), outpacing the commercial Pt/C (E1/2 = 0.84 V and Tafel slope = 54.6 mV dec−1). As a bifunctional electrocatalyst, it displays a smaller bifunctional activity parameter (ΔE) of 0.673 V, surpassing the Pt/C-RuO2 combination (ΔE = 0.724 V). Besides, the FAS-NSC@950-based zinc-air battery (ZAB) displays superior power density, specific capacity, and long-term cycling performance to the Pt/C-Ir/C-based ZAB. This work significantly contributes to the field by offering a promising strategy to enhance the catalytic activity of SACs for ORR, with potential implications for energy conversion and storage technologies.