Rechargeable Lithium Air Research Articles

CO2- tolerant CuFe2O4 as Bifunctional Electrocatalyst for Transition from Rechargeable Li-O2 to Li-CO2 Batteries

CO2-tolerant rechargeable Lithium-Air batteries are seen as a high-performing alternative to Li-ion batteries. They utilize O2 from the air, reducing it at the cathode to form lithium peroxide (Li2O2) during discharge which is then oxidized to form lithium-metal and freeing O2 during charging. Most of the present studies involve pure O2 as the cathode material instead of aerial O2, which has a stiff-challenge due to atmospheric CO2 which produces Li2CO3 during discharge, posing a resistive load on the battery if not re-oxidized on charging. Ideally, presence of CO2 should enhance the charge-storage capacity if it is cycled reversibly. Thus, present research aims at taking advantage of both O2 and CO2 by employing metallic Cu on CuFe2O4 catalyst, synthesized from a one-step auto-combustion route. The Cu metal present in the catalyst leads to a low surface-area, yet the catalyst demonstrates excellent oxygen reduction reaction and moderate oxygen evolution reaction activity. excellent CO2 reduction reaction activity, oxidizing both the Li2O2 and the Li2CO3 during charge in both 10% CO2 and 100% CO2 atmospheres. The fabricated Li-CO2 battery operates for practical application, suggesting the suitability of the catalyst for the transition from practical Li-O2 battery to Li-Air battery.

Operando detection and suppression of spurious singlet oxygen in Li-O2 batteries.

The rechargeable lithium air (oxygen) battery (Li-O2) has very high energy density, comparable to that of fossil fuels (∼3600 W h kg-1). However, the parasitic reactions of the O2 reduction products with solvent and electrolyte lead to capacity fading and poor cyclability. During the oxygen reduction reaction (ORR) in aprotic solvents, the superoxide radical anion (O2˙-) is the main one-electron reaction product, which in the presence of Li+ ions undergoes disproportionation to yield Li2O2 and O2, a fraction of which results in singlet oxygen (1O2). The very reactive 1O2 is responsible for the spurious reactions that lead to high charging overpotential and short cycle life due to solvent and electrolyte degradation. Several techniques have been used for the detection and suppression of 1O2 inside a Li-O2 battery under operation and to test the efficiency and electrochemical stability of different physical quenchers of 1O2: azide anions, 1,4-diazabicyclo[2.2.2]octane (DABCO) and triphenylamine (TPA) in different solvents (dimethyl sulfoxide (DMSO), diglyme and tetraglyme). Operando detection of 1O2 inside the battery was accomplished by following dimethylanthracene fluorescence quenching using a bifurcated optical fiber in front-face mode through a quartz window in the battery. Differential oxygen-pressure measurements during charge-discharge cycles vs. charge during battery operation showed that the number of electrons per oxygen molecule was n > 2 in the absence of physical quenchers of 1O2, due to spurious reactions, and n = 2 in the presence of physical quenchers of 1O2, proving the suppression of spurious reactions. Battery cycling at a limited specific capacity of 500 mA h gC-1 for the MWCNT cathode and 250 mA gC-1 current density, in the absence and presence of a physical quencher or a physical quencher plus the redox mediator I3-/I- (with a lithiated Nafion® membrane), showed increasing cyclability according to coulombic efficiency and cell voltage data over 100 cycles. Operando Raman studies with a quartz window at the bottom of the battery allowed detection of Li2O2 and excess I3- redox mediator during discharge and charge, respectively.

Biomass-derived metal-free heteroatom doped nanostructured carbon electrocatalysts for high-performance rechargeable lithium–air batteries

Biomass-derived metal-free heteroatom doped nanostructured carbon electrocatalysts for high-performance rechargeable lithium–air batteries

Enhancement of catalytic centres by RuO2 addition to CuFe2O4 cathode catalyst for rechargeable lithium–air batteries: influence of CO2 on Li–O2 battery performances

Herein, the oxygen reduction reaction and oxygen evolution reaction (ORR/OER) kinetics of the inverse-spinel CuFe2O4 catalyst was enhanced via the addition of a very low quantity of RuO2, which powers an LED when used in Li–air and Li–CO2 batteries.

Rechargeable Lithium-Air Batteries with Practically High Energy Density

Rechargeable Lithium-Air Batteries with Practically High Energy Density

Bifunctional Electrocatalysts Materials for Non-Aqueous Li–Air Batteries

Rechargeable lithium–air batteries (LABs), particularly the nonaqueous form, are demonstrated as the next-generation energy conversion and storage equipment for many applications. The air cathode has been certified as one of the critical aspects to affect the full performance of the LABs. At present, the main challenge for the commercial application of air cathode is to exploit some new cathode catalysts with lower prices, higher efficiency, and better stability. In the last decade, tremendous efforts have been dedicated to developing new structure design and fabrication processes of the cathode materials to promote the full capability of the LABs. The recent research progress of bifunctional cathode catalysts for LABs, including the main improvement strategies and performance of cathode materials, is introduced in this paper. Besides, related technical challenges are analyzed, and possible resolving strategies for the challenges to develop the nonaqueous Li–air battery catalytic cathodes are elaborated on in this review.

Chemical Challenges that the Peroxide Dianion Presents to Rechargeable Lithium–Air Batteries

Chemical Challenges that the Peroxide Dianion Presents to Rechargeable Lithium–Air Batteries

A Rechargeable Aqueous Lithium-Air Battery with an Acetic Acid Catholyte Operated at High Pressure

Acidic aqueous lithium-air batteries are attractive candidates for use as energy sources in electric vehicles because of their high energy and power densities and ability to operate under ambient conditions. An aqueous lithium-air battery with an acetic acid catholyte has a high theoretical energy density of 1,478 Wh kg–1, and the reaction product is soluble in the catholyte. In this study, we have studied the cell performance of a Li/interlayer electrolyte/NASICON-type solid lithium-ion conductor/acetic acid catholyte/air electrode cell at high pressure and room temperature under air. The cell was successfully operated at 0.5 mA cm–2 and 0.2 MPa.

Coupling Water-Proof Li Anodes with LiOH-Based Cathodes Enables Highly Rechargeable Lithium-Air Batteries Operating in Ambient Air.

Realizing an energy‐dense, highly rechargeable nonaqueous lithium–oxygen battery in ambient air remains a big challenge because the active materials of the typical high‐capacity cathode (Li2O2) and anode (Li metal) are unstable in air. Herein, a novel lithium–oxygen full cell coupling a lithium anode protected by a composite layer of polyethylene oxide (PEO)/lithium aluminum titanium phosphate (LATP)/wax to a LiOH‐based cathode is constructed. The protected lithium is stable in air and water, and permits reversible, dendrite‐free lithium stripping/plating in a wet nonaqueous electrolyte under ambient air. The LiOH‐based full cell reaction is immune to moisture (up to 99% humidity) in air and exhibits a much better resistance to CO2 contamination than Li2O2, resulting in a more consistent electrochemistry in the long term. The current approach of coupling a protected lithium anode with a LiOH‐based cathode holds promise for developing a long‐life, high‐energy lithium–air battery capable of operating in the ambient atmosphere.

Cover Feature: Porous Carbon Networks Decorated with Cobalt on CoFe2O4 as an Air‐Breathing Electrode for High‐Capacity Rechargeable Lithium‐Air Batteries: Role of Metallic Cobalt Nanoparticles (ChemElectroChem 20/2020)

The Cover Feature illustrates use of a Co/CoFe2O4-decorated porous carbon network as an air-breathing electrode for high-capacity rechargeable lithium–air batteries. More information can be found in the Article by M. Athika and P. Elumalai.

Experimental Performance Evaluation of a Hyper-Branched Polymer Electrolyte for Rechargeable Li-Air Batteries

A hyper-branched polymer (HBP) electrolyte is synthesized for rechargeable lithium-air (Li-air) battery cell and experimentally evaluated its performance in actual battery cell environment. Several real-world battery cells were fabricated with synthesized HBP electrolyte, pure lithium metal as anode and an oxygen permeable air cathode to evaluate reproducibility of the rechargeable Li-air battery cell. The effect of various conditions such as various HBP based electrolytes, discharge current - 0.1mA~0.5mA, cathode preparation processes and carbon contents on the battery cell performance were experimentally evaluated using the fabricated battery cells under dry air condition. Detailed HBP electrolyte synthesis procedures and experimental performance evaluation of Li-air battery cell for various conditions are presented. The experimental results showed that different conditions and processes significantly affect the Li-air battery performance. Upon taking into account the effect of different conditions and processes, optimized HBP electrolyte materials, cathode process and conditions were determined. Several Li-air battery cells were fabricated with optimized conditions and optimized battery cell materials to determine the reproducibility and performance consistency. Experimental results showed that over 55~65 hours of discharge occurred over 2.5V terminal cell voltage with all three optimized Li-air battery cells. It implied that the optimized Li-air battery cells were reproducible and were able to hold charge over 2.5V for more than two days. Experimental results of the Li-air battery cell with further refined optimized materials revealed that the battery cell can discharge more than 10 days (i.e. more than 250 hours) at or above 2.0V. The experimental results also showed that the Li-air battery discharge time got shorter as the discharge-charge cycle increases due to increase in internal resistances of battery cell materials. The experimental results confirmed that the lithium-air battery cell can be reproduced without loss of performance and can hold charge more than 10 days at or over 2.0V. The investigation results obtained may usher a pathway to manufacture a long-life rechargeable Li-air battery cell in the near future.

Ambient Air Operation Rechargeable Lithium-Air Battery with Acetic Acid Catholyte

Lithium-air batteries are expected as next-generation secondary batteries for electric vehicles because of their high energy density. In particular, an aqueous lithium-air battery that uses an aqueous electrolyte has advantages such as a high power density and availability of operation under an air atmosphere. Here, we show the feasibility of an acidic aqueous lithium-air battery that consists of a lithium anode, a lithium-ion conducting liquid interlayer, a solid lithium-ion conductor separator of Li1.4Al0.4Ge0.2Ti1.4(PO4)3, an acetic acid catholyte, and a fuel cell-analogous air electrode. The theoretical energy density of this system based on the masses of the lithium anode, oxygen, and acetic acid is 1340 Wh kg−1. This system was successfully cycled at 0.2 mA cm−2 for 5 h polarization and room temperature under an air atmosphere for 30 cycles.

Superior efficient rechargeable lithium–air batteries using a bifunctional biological enzyme catalyst

A biological enzyme – Laccase – exhibited highly efficient bifunctional catalytic activity in a Li–air battery whose intrinsic pH change during discharge/charge can regulate thein situfunction/recovery of Laccase.

Electrolytes for Rechargeable Lithium-Air Batteries.

Lithium-air batteries are promising devices for electrochemical energy storage because of their ultrahigh energy density. However, it is still challenging to achieve practical Li-air batteries because of their severe capacity fading and poor rate capability. Electrolytes are the prime suspects for cell failure. In this Review, we focus on the opportunities and challenges of electrolytes for rechargeable Li-air batteries. A detailed summary of the reaction mechanisms, internal compositions, instability factors, selection criteria, and design ideas of the considered electrolytes is provided to obtain appropriate strategies to meet the battery requirements. In particular, ionic liquid (IL) electrolytes and solid-state electrolytes show exciting opportunities to control both the high energy density and safety.

Nanocrystalline Metal–Organic Frameworks/Carbon Nanotubes Composites As Catalytic Cathode Materials for Lithium–Oxygen Batteries with Long Cycle Life

To meet the needs of emerging technologies such as all-electric vehicles with a long drive range, there are now strong motivations for the development of rechargeable batteries with high specific energy, so called “beyond Li-ion batteries.” Among these beyond Li-ion batteries, lithium–air (Li–O2) batteries have received much attention owing to their five times higher theoretic energy density (ca. 3500 W h/kg) than that of lithium-ion batteries. However, Li–O2 batteries still suffer from several challenges that hinder their practical applications, including low energy efficiency, short cycle life, and poor rate capability. These problems are mainly caused by the sluggish oxygen reduction/evolution reaction (ORR/OER), low stability of electrolyte against O2 −•, and the poor conductivity of discharge product (Li2O2).1 To improve the performance of Li–O2 batteries, much effort has been devoted to searching for new catalytic cathode materials to promote ORR/OER kinetics, which is crucial to lowering overpotential and improving the reversibility.2 Metal–organic frameworks (MOFs), a novel type of crystalline porous materials, are built with metal nodes or clusters (secondary building units) and organic linkers. For the last two decades, MOFs have received considerable attentions for gas storage, catalysis, and energy storage, due to their high surface area and chemically unsaturated metal sites.3 It has been also demonstrated that bulk MOFs could be good electrocatalysts for Li–O2 batteries.4 However, most of MOFs have poor electrical conductivity, which limits their applications in electrocatalysis. Herein, we report nanocrystalline MOFs/CNTs composites as catalytic cathode materials for Li–O2 batteries to further enhance the catalytic performance of MOFs. The direct growth of MOFs on CNTs (MOFs@CNTs) can not only enhance the electronic conductivity but also mitigate the agglomeration issues of MOFs nanoparticles, making them suitable in the applications of electrocatalysis. The as-prepared MOF-74@CNTs hybrid cathodes showed the improved cycling performance of Li-O2 batteries. We have also investigated the effects of chemically unsaturated and various redox-active metal sites on the catalytic performance in Li–O2 batteries. The fundamental mechanism of how MOFs enhance the performance of Li-O2 batteries will also be discussed. Reference 1 Aurbach, D., McCloskey, B. D., Nazar, L. F. & Bruce, P. G. Advances in understanding mechanisms underpinning lithium–air batteries. Nature Energy 1, 16128, doi:10.1038/nenergy.2016.128 (2016). 2 Ma, Z. et al. A review of cathode materials and structures for rechargeable lithium–air batteries. Energy & Environmental Science 8, 2144-2198 (2015). 3 Furukawa, H., Cordova, K. E., O’Keeffe, M. & Yaghi, O. M. The chemistry and applications of metal-organic frameworks. Science 341, 1230444 (2013). 4 Wu, D. et al. Metal–organic frameworks as cathode materials for Li–O2 batteries. Adv Mater 26, 3258-3262, doi:10.1002/adma.201305492 (2014).

Characterization of Charge Reactions of Li-Air Battery Cathodes Studied with Field Ionization Methods

In recent years, lithium-air batteries have attracted significant interest due to increased energy density compared to currently available technologies such as lithium-ion batteries. The discharge process involves oxygen reduction to form LiO2, followed by further reduction to Li2O2 1. Meanwhile, oxygen evolution from the discharge deposits occurs during charge. The poor conductivity of Li2O2 2 requires the use of high overpotentials during charge, leading to side reactions that hinder battery performance1. A significant amount of work has been devoted at improving battery performance via cathode3 and electrolyte engineering4. In addition, several experimental and computational studies have attempted to understand the nature of the charge and discharge reactions through the use of electrochemical cells2,4-5. However, the complexity of electrochemical cells makes it difficult to gain fundamental insight of these processes. An alternative involves the use of ultrahigh vacuum (UHV) studies, where the ability to examine the influence of electrode potential on surface reactions is limited. This issue can be resolved by focusing on the effect of electric field on surface reactions since electric field is directly related to electrode potential. An example of a UHV technique is field ionization microscopy (FIM). In FIM, a Pt field emitter tip of approximately 350 Å radius is used as the substrate. The electric field on the surface is easily controllable by biasing the tip at moderate voltages (around 5 kV), to produce fields of up to 5 V/Å6. Reactions are carried out by adsorption of the species of interest (Li, O2, and a solvent representative of the electrolyte) followed by application of a baseline field. Adsorbed reaction products and their morphology can be monitored by FIM and field electron microscopy (FEM). Reaction intermediates and products can be detected by pulsed field desorption time of flight mass spectrometry (PFD-MS). In PFD, reactions products are formed under a base field, followed by desorption when a field pulse is applied. By varying the base field magnitude, pulse repetition frequency, and reaction temperature, it is possible to obtain information such as activation energies and possible reaction steps7. In this work, the kinetics of LiOx consumption in acetonitrile, a low DN solvent, will be studied using PFD and FIM. Namely, the focus of this work will be to characterize the effect of electric field, temperature, and reaction time on the rate of Li2O2 consumption during charge, as well as characterizing the lifetime of the LiO2 intermediate during charge. References Girishkumar, G; McCloskey, B; Luntz, A. C; Swanson, S; Wilcke, W. “Lithium-air battery: Promise and challenges”. Phys. Chem. Lett. 2010, 1, 2193–2203Viswanathan, V; Thygesen, K. S; Hummelshøj, S; Nørskov, J. K; Girishkumar, G; McCloskey, B. D; Luntz, A. C. “Electrical Conductivity in Li2O2 and its role in determining capacity limitations in non-aqueous Li-O2 batteries”. J Chem. Phys. 2011, 135, 214704Kwak, W. J; Lau, K. C; Shin, C. D; Amine, K; Curtiss, L. A; Sun, Y. K. “AMo2C/Carbon Nanotube Composite Cathode for Lithium-Oxygen Batteries with High Energy Efficiency and Long Cycle Life”. ACS Nano. 2015, 9, 4129–4137Laoire, C. O; Mukerjee, S; Abraham, K. M; Plichta, E. J; Hendrickson, M. A. “Influence of Nonaqueous Solvents on the Electrochemistry of Oxygen in the Rechargeable Lithium-Air Battery”. Phys. Chem. C. 2010, 114, 9178–9186Laoire, C. O; Mukerjee, S; Abraham, K. M; Plichta, E. J; Hendrickson, M. A. “Elucidating the Mechanism of Oxygen Reduction for Lithium-Air Battery Applications”. Commun. 2011 , 47, 9438-9440Rothfuss, C. J; Medvedev, V. K; Stuve, E. M. “The influence of the surface electric field on water ionization: a two-step dissociative ionization and desorption mechanism for water ion cluster emission from a platinum field emitter tip”. Surface Science. 2003, 554-555, 133-143Kruse, N. “Surface reaction kinetics on the atomic scale: studies by means of pulsed field desorption mass spectrometry”. Materials Science and Engineering A. 1999, 270, 75-82

One-Step Synthesis of Co3O4 Thin Film by Reactive Spray Deposition Technology for Efficient Electrochemical Water Splitting

ABSTRACTEfficient catalysts for the oxygen evolution reaction (OER) are widely applied in fuel cells and rechargeable lithium air batteries. It is desirable but challenging to achieve comparable activity to that of the noble-metal catalyst with non-precious metal catalyst. Highly active Co3O4 thin film electrodes have been successfully synthesized by a rapid one-step flame combustion synthesis method called Reactive Spray Deposition Technology. X-ray diffraction confirms the absence of any impurity phase with this synthesis process. The detailed morphology of the Co3O4 thin film is investigated with scanning electron microscopy and transmission electron microscopy. Cyclic voltammetry is used to investigate the redox activity of Co3+ to Co4+ which is crucial for the OER performance. The as-prepared Co3O4 catalyst demonstrates promising activity for OER, with an overpotential of 399 mV (at 10 mA cm-2) for OER.

Perovskite oxides La0.4Sr0.6CoxMn1-xO3 (x = 0, 0.2, 0.4) as an effective electrocatalyst for lithium—air batteries

Co-doped perovskite oxide La0.4Sr0.6CoxMn1-xO3 (x = 0, 0.2, 0.4) composites are prepared by sol–gel method utilizing citric acid as chelating agent. These composites show good catalytic activities when tested as catalysts rechargeable lithium—air batteries. In particular, the La0.4Sr0.6Co0.4Mn0.6O3 shows a lower potential gap. When these samples are tested as catalysts for Li—air batteries at a current density of 100 mA g−1, the discharge capacities with different La0.4Sr0.6CoxMn1-xO3 (x = 0, 0.2, 0.4) catalysts are 5819, 6420, and 7227 mA h g−1, respectively. In addition, under a capacity limitation of 1000 mA h g−1, the cell using La0.4Sr0.6Co0.4Mn0.6O3 as catalyst shows good cycling stability up to 46 cycles. The good electrochemical performance suggests that suitable doping of Co in Mn site of La0.4Sr0.6MnO3 could be a promising route to improve the catalytic activity.

An Investigation of the Electrochemical Properties and Performance of Electrospun Carbon Nanofibers for Rechargeable Lithium-Air Batteries

An Investigation of the Electrochemical Properties and Performance of Electrospun Carbon Nanofibers for Rechargeable Lithium-Air Batteries

Novel Architecture of Air Cathode for Rechargeable Lithium-Air Batteries

As the increased demand of eco-friendly rechargeable batteries in recent years, aqueous/non-aqueous lithium-air batteries have been attached more and more attention because of their high specific energy density, 3-5 times higher than that of lithium-ion batteries1-2. As the key component, the structure of the air cathode should been optimized to improve the cycle performance during discharge and charge process3-4. In this work, polyaniline-assisted polyvinylidene fluoride film was synthesized coated on graphene sponge as flexible cathode for lithium air batteries. With the 3D inter-connected structure of the graphene sponge for the guidance of oxygen flows, the assisted polyaniline for enhanced electron transfer, as well as the polyvinylidene fluoride film for the prevention of electrolyte flooding, the reaction zone can be reserved extremely during oxygen reduction reaction and oxygen evolution reaction, which can then promote charge transfer, and result to the lower overpotential for both discharge and charge process. The detailed electrochemical performance will be analyzed in the following presentation.