Li-air Batteries Research Articles

Aprotic Lithium-Carbon Dioxide Batteries: Reaction Mechanism and Catalyst Design.

In recent years, the combustion of fossil fuels leads to the release of a large amount of CO2 gas, which induces the greenhouse effect and the energy crisis. To solve these problems, researchers have turned their focus to a novel Li-CO2 battery (LCB). LCB has received much attention because of its high theoretical energy density and reversible CO2 reduction/evolution process. So far, the emerging LCB still faces many challenges derived from the slow reaction kinetics of discharge products. In this review, the latest status and progress of LCB, especially the influence of the structure design of cathode catalysts on the battery performance, are systematically elaborated. This review summarizes in detail the existing issues and possible solutions of LCB, which is of high research value for further promoting the development of Li-Air battery.

Thermal safety and thermal management of batteries

AbstractElectrochemical energy storage is one of the critical technologies for energy storage, which is important for high‐efficiency utilization of renewable energy and reducing carbon emissions. In addition to the higher energy density requirements, safety is also an essential factor for developing electrochemical energy storage technologies. Lithium‐ion batteries (Li‐ion batteries) are commercialized as power batteries in electric vehicles (EVs) because of their advantages (such as high energy density, long life span, etc.), while for future electrochemical energy storage markets, lithium–sulfur (Li–S) and lithium–air (Li–air) batteries can be promising candidates for high energy density requirements. Therefore, this paper summarizes the present or potential thermal hazard issues of lithium batteries (Li‐ion, Li–S, and Li–air batteries). Moreover, the corresponding solutions are proposed to further improve the thermal safety performance of electrochemical energy storage technologies.

Unprecedented Multifunctionality in 1D Nb1‐xTaxS3 Transition Metal Trichalcogenide Alloy

Abstract1D materials, such as nanofibers or nanoribbons are considered as the future ultimate limit of downscaling for modern electrical and electrochemical devices. Here, for the first time, nanofibers of a solid solution transition metal trichalcogenide (TMTC), Nb1‐xTaxS3, are successfully synthesized with outstanding electrical, thermal, and electrochemical characteristics rivaling the performance of the‐state‐of‐the art materials for each application. This material shows nearly unchanged sheet resistance (≈740 Ω sq−1) versus bending cycles tested up to 90 cycles, stable sheet resistance in ambient conditions tested up to 60 days, remarkably high electrical breakdown current density of ≈30 MA cm−2, strong evidence of successive charge density wave transitions, and outstanding thermal stability up to ≈800 K. Additionally, this material demonstrates excellent activity and selectivity for CO2 conversion to CO reaching ≈350 mA cm−2 at −0.8 V versus RHE with a turnover frequency number of 25. It also exhibits an excellent performance in a high‐rate Li–air battery with the specific capacity of 3000 mAh g−1 at a current density of 0.3 mA cm−2. This study uncovers the multifunctionality in 1D TMTC alloys for a wide range of applications and opens a new direction for the design of the next generation low‐dimensional materials.

Spatial Variations of Cathode Reaction and Discharge Precipitate in Li-Air Batteries: Analysis and Experimental Measurement

In this study, we investigate the spatial variations of discharge precipitate and cathode reaction rate in lithium (Li)-air battery both theoretically and experimentally: (1) the reaction variation of local oxygen reduction reaction (ORR) rate is theoretically analyzed, with analytical solutions as a function of the Damköhler (Da) number; (2) a novel experimental method is proposed to probe local ORR rate by designing a multi-layer cathode which consists of three identical Toray® carbon clothes that have a porosity of 0.8 and a thickness of about 0.4 mm. The morphology of insoluble Li compounds at different thickness locations is uncovered by SEM images. An overall very small volume fraction of precipitates was observed in the air cathode. It is found that the local ORR rate decreases from the air side of cathode to the separator side in the case of study, which is consistent with our model predictions for two orders of the cathode reaction. The theoretical analysis and experimental method can be applied to design and optimize materials for the air cathode of Li-air batteries.

The potential of hydrophobic membranes in enabling the operation of lithium-air batteries with ambient air

Lithium-air batteries are presented in the literature as a candidate for electrochemical energy storage because of their potentially high energy density. Part of this high energy density comes from the fact that one of its components – oxygen – can be sourced from the air. However, when operating with ambient air, these batteries are exposed to contamination with water, a component that may damage the Li electrode. Bearing this in mind, this work analyzes the potential of hydrophobic membranes in allowing lithium-air batteries to work with ambient air containing moisture. For this investigation, a model that includes the influence of water concentration in the electrolyte (LiClO4 in dimethyl sulfoxide) on the morphology of the discharge product was developed based on experimental data. Results demonstrate that membrane permeability should be lower than currently available technologies to satisfactorily reduce the increase in water concentration over time. According to simulation results, membrane permeability for water should be below 0.2 mg m−2 d−1 for a current density of 0.25 A m−2 or 1.6 mg m−2 d−1 for a current density of 0.75 A m−2 to allow a water concentration increase of only 1 ppm after each discharge. This severe limitation in membrane permeability requirement indicates that a moisture-controlled O2 source for Li-air or Li-O2 batteries in a closed system might be preferred to preserve electrolyte properties.

Ru clusters anchored on Magnéli phase Ti4O7 nanofibers enables flexible and highly efficient Li–O2 batteries

Lithium–oxygen (Li–O2) batteries have attracted tremendous attention due to their high specific energy density. However, their sluggish conversion kinetics and detrimental parasitic reactions would deteriorate the lifespan of batteries. Herein, a combined density functional theory (DFT) calculation and experimental approach is carried out to design an efficient cathode electrocatalyst for Li–O2 batteries. A self-supporting film of Ru clusters anchored on Magnéli phase Ti4O7 enriched with oxygen vacancy (Ru/Ti4O7) is fabricated upon electrospinning and carbothermal reduction. In such a synergistic configuration of Ru/Ti4O7 hybrid film, the strong metal-support interaction (SMSI) between Ru and Ti4O7 can improve the charge transfer at the interface and enhance the adsorption energy of intermediates, accelerating the reaction kinetics of the formation/decomposition of Li2O2. Benefitting from this SMSI, the electrochemical stability of Ru/Ti4O7 over cycling is also enhanced. As a result, as-prepared Ru/Ti4O7 cathodes could realize excellent electrochemical performance, including high specific capacity (11000 mAh g–1), low discharge/charge polarization (0.36 V), long lifespan (> 100 cycles) and superior rate capability. Furthermore, a flexible Li–O2 pouch cell, constructed with as-fabricated Ru/Ti4O7 film cathode, lithium foil anode and GPE, can exert an impressive areal capacity of 5 mAh cm–2 with a low voltage gap of 0.82 V in ambient air. This work suggests that the activity of catalysts can be significantly enhanced with interfacial modification, offering an efficient approach for rational designing of electrocatalysts for use in Li–air batteries and beyond.

Lithium-Ion Conductive Film Membrane of Li 0.3La 0.57TiO 2 Perovskite Structure and its Application in Li-Air Batteries

Lithium-Ion Conductive Film Membrane of Li 0.3La 0.57TiO 2 Perovskite Structure and its Application in Li-Air Batteries

Effect of Surface Modification for Carbon Cathode Materials on Charge-Discharge Performance of Li-Air Batteries.

Li-air batteries have attracted considerable attention as rechargeable secondary batteries with a high theoretical energy density of 11,400 kWh/g. However, the commercial application of Li-air batteries is hindered by issues such as low energy efficiency and a short lifetime (cycle numbers). To overcome these issues, it is important to select appropriate cathode materials that facilitate high battery performance. Carbon materials are expected to be ideal materials for cathodes due to their high electrical conductivity and porosity. The physicochemical properties of carbon materials are known to affect the performance of Li-air batteries because the redox reaction of oxygen, which is an important reaction for determining the performance of Li-air batteries, occurs on the carbon materials. In this study, we evaluated the effect of the surface modification of carbon cathode materials on the charge–discharge performance of Li-air batteries using commercial Ketjenblack (KB) and KB subjected to vacuum ultraviolet (VUV) irradiation as cathodes. The surface wettability of KB changed from hydrophobic to hydrophilic as a result of the VUV irradiation. The ratio of COOH and OH groups on the KB surface increased after VUV irradiation. Raman spectra demonstrated that no structural change in the KB before and after VUV irradiation was observed. The charge and discharge capacities of a Li-air battery using VUV-irradiated KB as the cathode decreased compared to original KB, whereas the cycling performance of the Li-air battery improved considerably. The sizes and shapes of the discharge products formed on the cathodes changed considerably due to the VUV irradiation. The difference in the cycling performance of the Li-air battery was discussed from the viewpoint of the chemical properties of KB and VUV-irradiated KB.

Water-stable high lithium-ion conducting Li1.4Al0.4Ge0.2Ti1.4(PO4)3-TiO2-LiCl•H2O–epoxy resin composite film with high mechanical strength as separator for Li-air batteries

Water-stable high lithium-ion conducting Li1.4Al0.4Ge0.2Ti1.4(PO4)3-TiO2-LiCl•H2O–epoxy resin composite film with high mechanical strength as separator for Li-air batteries

Size-Dependent Effects in Fullerene-Based Catalysts for Nonaqueous Li–Air Battery Applications

Size-Dependent Effects in Fullerene-Based Catalysts for Nonaqueous Li–Air Battery Applications

Theoretical Insights into Impact of Electrode and Electrolyte Over Li-Air Battery

The lithium-air battery is getting attention as a good technology for energy storage. Nevertheless, the design of such a device still faces some crucial limitations. The most challenging one concerns the selection of electrodes and solvents to provide good performance during the cell operation. Based on literature evidence, we have selected three system configurations of electrode/electrolyte to be evaluated via molecular dynamics simulation: gold/DMSO (dimethyl sulfoxide), graphene/DMSO, and graphene/TEGDME (tetraethylene glycol dimethyl ether) using lithium hexafluorophosphate—LiPF6. We show that the local concentration distributions for DMSO and Li+ are highly influenced by the electrode material. Furthermore, the Li+ solvation shell presents a more complex arrangement when in composition with TEGDME. Additionally, the electrical double layer capacitance in this solvent shows high impedance to the electrode surface. This investigation noticed that the electric field plays a role over the system, contributing to the solvent organization and the electrical double layer formation. Overall, this study strengthens the idea that theoretical findings may contribute to a complementary investigation, leading some light over experimental Li-air battery data reported in the literature.

The effect of removing the native passivation film on the electrochemical performance of lithium metal electrodes

Lithium metal is accepted as the promising anode for next-generation Li batteries such as solid-state, Li–S, and Li-air batteries, etc. Besides, it is commonly employed as the reference electrodes for evaluating the electrode materials of Li-ion batteries (LIBs) in a half-cell. However, native passivation film (NPF), which is inevitable on the surface, can change the topography and surface composition distribution, and thus deteriorate the performance stability of lithium metal electrodes. Unfortunately, these effects are always neglected during the evaluation of anode or cathode materials of LIBs. Here, we conduct a comprehensive study on the effects of NPF on the electrochemical performance of lithium metal electrodes. After the removal of NPF by polishing, both the interfacial impedance and electrode overpotential are significantly decreased, with a more homogeneous lithium deposition during the charge/discharge process. When it is employed as the reference electrode for characterizing the commercial LiFePO4 or graphite materials in a coin cell, the consistency of the results is remarkably improved. This work not only provides an insight for the interfacial electrochemistry of lithium metal electrodes, but also helps characterize electrode materials in a reliable way.

Numerical simulation of gas-liquid transport in porous media using 3D color-gradient lattice Boltzmann method: trapped air and oxygen diffusion coefficient analysis

ABSTRACT In non-aqueous Li–air batteries, the liquid electrolytes penetrate the porous media such as carbon nanotube (CNT) paper structure, transport dissolved substances such as oxygen, and play a role in generating reactants on the surface of the porous media. Although the trapped air generated during the electrolyte penetration process could affect the oxygen transport and performance of the battery, this issue has not been sufficiently investigated. Therefore, in this study, the patterns of electrolyte penetration and air entrapment in porous media were investigated through numerical analysis. A multi-relaxation time color-gradient lattice Boltzmann method was employed for modeling. Based on a two-phase flow simulation in porous media, electrolyte penetration and trapped-air saturation were analyzed in terms of porosity, wettability, and viscosity ratio. The porosity and viscosity ratio did not considerably affect the trapped-air saturation, whereas wettability had a significant effect on the aforementioned parameter. In addition, for each variable, an increase in the effective diffusive coefficient corresponded to increased porosity and hydrophilicity, as well as an improved viscosity ratio.

Carbon-supported single-atom catalysts for advanced rechargeable metal-air batteries

To address the fossil energy crisis and environmental problems, the urgent demand for clean energy has promoted the rapid development of advanced rechargeable metal-air batteries based on the redox reaction couples of gases, such as the oxygen reduction, oxygen evolution, carbon dioxide reduction and carbon dioxide evolution reactions. High-efficiency electrocatalysts are highly desirable to enhance the conversion efficiency of these reactions for enhancing battery performance. Significant advances in single-atom catalysts (SACs) on carbon matrices have been witnessed in recent years as attractive and unique systems to improve the electrocatalytic activities for high-performance rechargeable Zn- and Li-air batteries. This review summarizes the latest achievements in the applications of carbon-supported SACs in metal-air batteries, with a particular focus on the rational design of SACs and their fundamental electrocatalytic mechanism at the atomic level. The future development and perspectives of SACs in the field of metal-air batteries are also discussed.

Performance evaluation of metal-air batteries for sustainable agricultural equipment

The present work proposes to carry out a performance evaluation of metal-air batteries and hence identify the best battery that can be employed to develop sustainable agricultural equipment. However, a scientific and systematic tool is required since there are several available alternatives for metal-air batteries and numerous conflicting performance measures under which the evaluations can be made. To this end, the present work employs a versatile decision-making tool known as TODIM (an acronym in Portuguese for Interactive Multi-criteria Decision Making) to appraise the available metal-air battery alternatives and select the best metal-air battery to aid in the development of sustainable agricultural equipment. A total of five alternatives have been appraised under the influence of the following five performance measures: Theoretical cell voltage (C1), Practical operation voltage (C2), Theoretical specific energy density (C3), Practical specific energy density (C4), and cost (C5). From the application of the TODIM methodology, it has been revealed that Li-air batteries are the best alternatives among the considered metal-air batteries that may be employed to develop sustainable agricultural equipment. Theoretical specific energy density has been attached to the highest importance while arriving at the appraisal results. The sensitivity analysis regarding the risk appetite reveals the robustness of the obtained appraisal results and the significance of the risk appetite of the experts while they make evaluations.

Designing porous and stable Au-coated Ni nanosheets on Ni foam for quasi-symmetrical polymer Li–air batteries

Au-coated Ni nanosheets on Ni foam (Au/NNS-NF) and Li-based Au/NNS-NF were prepared and further applied as air cathode and anode of quasi-symmetrical polymer Li–air batteries, respectively, which showed good electrochemical performances.

Defect-rich boron doped carbon nanotubes as an electrocatalyst for hybrid Li–air batteries

BC3NTs with topological defects improve the performance of hybrid lithium–air batteries, conducive to the ORR and OER.

The key to improving the performance of Li–air batteries: recent progress and challenges of the catalysts

Li-air batteries are considered to be one of the most promising energy storage devices due to their high energy density and large specific capacity. But the high overpotential, the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics, and the poor cycling stability critically restrict their practical applications. To overcome these problems, various catalysts and electrolyte mediators have been used and studied. However, for practical application, these catalysts still have some challenges and scientific problems that need to be solved. Specifically, the performance of lithium-air batteries faces three major problems of capacity, overpotential, and cycle life that need to be solved. Solid-phase catalysts and liquid-phase redox mediators have their own advantages and disadvantages in the performance and reaction mechanism of lithium-air batteries. This review comprehensively analyzes and summarizes the catalytic materials and electrolyte additives of different systems and discusses in depth the corresponding reaction mechanism and performance (including technical characteristics and application difficulty). Finally, according to the characteristics of catalysts and practical application difficulties, the development direction of lithium-air batteries is proposed. Li-air batteries need to exploit the advantages of catalysts and redox mediators in terms of stability and overpotential to improve the electrochemical performance of the battery. In the future, anode protection and air purification systems will be combined to achieve large-scale, long-cycle applications of lithium-air batteries.

Mass transfer analysis of boron-doped carbon nanotube cathodes for dual-electrolyte lithium-air batteries.

Dual-electrolyte Li-air batteries (LABs) have the advantages of high specific energy density and low overpotential, but the mass transfer mechanism is still unclear. Mass transfer is essential to battery performance. To improve the mass transfer capability of the positive electrode, this research studied the effect of boron (B)-doped carbon nanotubes (BC3NTs) with different amounts of defects as positive electrodes. Deep discharge results showed that the discharge voltage platform of BC3NTs was higher than that of CNTs, and the more defects, the higher the discharge voltage platform. The electrochemical impedance spectroscopy (EIS) results also showed that the more defects, the smaller the charge transfer resistance. As the discharge current density increased, the discharge voltage platform decreased gradually. Traditional molecular dynamics calculation results showed that the topological defects caused by BC3NTs reduced the Li+ and O2 diffusion energy barriers from the sidewalls from 4.5 eV to 1.65 eV and 4.94 eV to 0.11 eV, respectively. The diffusion capabilities of Li+ and O2 in BC3NTs were improved, and at the same concentration, the diffusion coefficients of Li+ and O2 increase to 3.0 × 10-9 m2 s-1 and 0.415 × 10-9 m2 s-1, respectively. The radial distribution function results showed that the larger the topological defect ring was, the greater the probability of finding Li+ and O2 near the electrode. In summary, the defects produced by BC3NTs were conducive to mass transfer, which could reduce polarization and impedance, and improve battery performance.

Liquid Metal-Based Cathode for Flexible Ambient Li-Air Batteries and its Regeneration by Water

Liquid Metal-Based Cathode for Flexible Ambient Li-Air Batteries and its Regeneration by Water