Search Results (25)

Lithium–air batteries (LABs) possess the highest energy density among all energy storage systems, and have drawn widespread interest in academia and industry. However, many arduous challenges are still to be conquered, one of them is Li₂CO₃, which is a ubiquitous product in LABs. It is inevitably produced but difficult to decompose; therefore, Li₂CO₃ is perceived as the “Achilles’ heel of LABs”. Among various approaches to addressing the Li₂CO₃ issue, developing Li₂CO₃-decomposing redox mediators (RMs) is one of the most convenient and versatile, because they can be electrochemically oxidized at the gas cathode surface, then they diffuse to the solid-state products and chemically oxidize them, recovering the RMs to a pristine state and avoiding solid-state catalysts’ contact instability with Li₂CO₃. Furthermore, because of their function mechanism, they can double as catalysts for Li₂O₂/LiOH decomposition, which are needed in LABs/LOBs anyway regardless of Li₂CO₃ incorporation due to the sluggish kinetics of oxygen reduction/evolution reactions. This review summarizes the progress in Li₂CO₃-decomposing RMs, including halides, metal–chelate complexes, and metal-free organic compounds. The insights into and discrepancies in the mechanisms of Li₂CO₃ decomposition and corresponding catalysis processes are also discussed. Full article

Li-ion batteries (LIBs) are one of the most deployed energy storage technologies worldwide, providing power for a wide range of applications—from portable electronic devices to electric vehicles (EVs). The growing demand for LIBs, coupled with a shortage of critical battery materials, has prompted the scientific community to seek ways to improve material utilization through the recycling of end-of-life LIBs. While valuable battery metals are already being recycled on an industrial scale, graphite—a material classified as a critical resource—continues to be discarded. In this study, graphite waste recovered from the recycling of LIBs was successfully upcycled into an active graphite/rGO (reduced graphene oxide) composite oxygen electrocatalyst. The precursor graphite for rGO synthesis was also extracted from LIBs. Incorporating rGO into the graphite significantly enhanced the specific surface area and porosity of the resulting composite, facilitating effective doping with residual metals during subsequent nitrogen doping via pyrolysis. These composite catalysts enhanced both the oxygen reduction and oxygen evolution reactions, enabling their use as air electrode catalyst materials in zinc–air batteries (ZABs). The best-performing composite catalyst demonstrated an impressive power density of 100 mW cm⁻² and exceptional cycling stability for 137 h. This research further demonstrates the utilization of waste fractions from LIB recycling to drive advancements in energy conversion technologies. Full article

As modern society continues to advance, the depletion of non-renewable energy sources (such as natural gas and petroleum) exacerbates environmental and energy issues. The development of green, environmentally friendly energy storage and conversion systems is imperative. The energy density of commercial lithium-ion batteries is approaching its theoretical limit, and even so, it struggles to meet the rapidly growing market demand. Lithium–oxygen batteries have garnered significant attention from researchers due to their exceptionally high theoretical energy density. However, challenges such as poor electrolyte stability, short cycle life, low discharge capacity, and high overpotential arise from the sluggish kinetics of the oxygen reduction reaction (ORR) during discharge and the oxygen evolution reaction (OER) during charging. This article elucidates the fundamental principles of lithium–oxygen batteries, analyzes the primary issues currently faced, and summarizes recent research advancements in air cathodes and anodes. Additionally, it proposes future directions and efforts for the development of lithium–air batteries. Full article

Ni-rich layered cathodes are deemed as a potential candidate for high-energy-density lithium-ion batteries, but their high sensitivity to air during storage and poor thermal stability are a vital challenge for large-scale applications. In this paper, distinguished from the conventional surface modification and ion doping, an effective solid-solution strategy was proposed to strengthen the surface and structural stability of Ni-rich layered cathodes by introducing Li₂MnO₃. The structural analysis results indicate that the formation of Li₂CO₃ inert layers on Ni-rich layered cathodes during storage in air is responsible for the increased electrode interfacial impedance, thereby leading to the severe deterioration of electrochemical performance. The introduction of Li₂MnO₃ can reduce the surface reactivity of Ni-rich cathode materials, playing a certain suppression effect on the formation of surface Li₂CO₃ layer and the deterioration of electrochemical performances. Additionally, the thermal analysis results show that the heat release of Ni-rich cathodes strongly depends on the charge of states, and Li₂MnO₃ can suppress oxygen release and significantly enhance the thermal stability of Ni-rich layered cathodes. This work provides a method to improving the storage performance and thermal stability of Ni-rich cathode materials. Full article

Lithium-ion batteries (LIBs) are fundamental for the energetic transition necessary to contrast climate change. The characteristics of cathode active materials (CAMs) strongly influence the cell performance, so improved CAMs need to be developed. Currently, Li(Ni_0.8Mn_0.1Co_0.1)O₂ (NMC811) is state-of-the-art among the cathodic active materials. The aim of this work is the optimization of the procedure to produce NMC811: two different syntheses were investigated, the co-precipitation and the self-combustion methods. For a better understanding of the synthesis conditions, three different types of atmospheres were tested during the calcination phase: air (partially oxidizing), oxygen (totally oxidizing), and nitrogen (non-oxidizing). The synthesized oxides were characterized by X-ray Powder Diffraction (XRPD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Inductively Coupled Plasma (ICP), and Particle Size Distribution (PSD). The most promising materials were tested in a half-cell set up to verify the electrochemical performances. The procedure followed during this study is depicted in the graphical abstract. The oxidizing atmospheric conditions turned out to be the most appropriate to produce NMC811 with good electrochemical properties. Full article

Lithium–air batteries (LABs) have a theoretically high energy density. However, LABs have some issues, such as low energy efficiency, short life cycle, and high overpotential in charge–discharge cycles. To solve these issues electrocatalytic materials were developed for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which significantly affect battery performance. In this study, we aimed to synthesize electrocatalytic N-doped carbon-based composite materials with solution plasma (SP) using Co or Ni as electrodes from organic solvents containing cup-stacked carbon nanotubes (CSCNTs), iron (II) phthalocyanine (FePc), and N-nethyl-2-pyrrolidinone (NMP). The synthesized N-doped carbon-based composite materials were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). TEM observation and XPS measurements revealed that the synthesized carbon materials contained elemental N, Fe, and electrode-derived Co or Ni, leading to the successful synthesis of N-doped carbon-based composite materials. The electrocatalytic activity for ORR of the synthesized carbon-based composite materials was also evaluated using electrochemical measurements. The electrochemical measurements demonstrated that the electrocatalytic performance for ORR of N-doped carbon-based composite material including Fe and Co showed superiority to that of N-doped carbon-based composite material including Fe and Ni. The difference in the electrocatalytic performance for ORR is discussed regarding the difference in the specific surface area and the presence ratio of chemical bonding species. Full article

One of the most popular solutions for electrochemical energy storage is metal–air batteries, which could be employed in electric vehicles or grid energy storage. Metal–air batteries have a higher theoretical energy density than lithium-ion batteries. The crucial components for the best performance of batteries are the air cathode electrocatalysts and corresponding electrolytes. Herein, we present several of the latest studies on electrocatalysts for air cathodes and bifunctional oxygen electrocatalysts for aqueous zinc–air and aluminium–air batteries. Full article

Traditional lithium–air batteries (LABs) have been seriously affected by cycle performance and safety issues due to many problems such as the volatility and leakage of liquid organic electrolyte, the generation of interface byproducts, and short circuits caused by the penetration of anode lithium dendrite, which has hindered its commercial application and development. In recent years, the emergence of solid-state electrolytes (SSEs) for LABs well alleviated the above problems. SSEs can prevent moisture, oxygen, and other contaminants from reaching the lithium metal anode, and their inherent performance can solve the generation of lithium dendrites, making them potential candidates for the development of high energy density and safety LABs. This paper mainly reviews the research progress of SSEs for LABs, the challenges and opportunities for synthesis and characterization, and future strategies are addressed. Full article

Efficient oxygen reduction reaction (ORR) electrocatalysts are the key to advancement of solid-state alkaline zinc–air batteries (ZAB). We demonstrate an electrocatalyst, spinel lithium-manganese oxide LiMn₂O₄ (LMO) by a simple hydrothermal method. Scanning electron microscope (SEM), X-ray diffraction (XRD), and Raman spectra indicate that the as-synthesized LiMn₂O₄ presents nanoscale irregular-shaped particles with the well-known spinel structure. The polarization curve, chronoamperometery curve, and linear scanning voltammograms of rotating disk electrode (RDE) results reveal that the as-synthesized LiMn₂O₄ possesses a higher electrocatalytic activity than that of electrolytic manganese dioxide for the ORR. A solid-state zinc–air cell with LiMn₂O₄ as the air electrode catalyst has a long voltage plateau of discharge and a discharge capacity of 188.4 mAh at a constant discharge current density of 10 mA·cm⁻². In summary, spinel LiMn₂O₄ in which the JT effect enables electron hoping between Mn³⁺ and Mn⁴⁺ can be regarded as an effective robust oxygen reduction catalyst. Full article

Lithium–oxygen (Li-O₂) batteries have captured worldwide attention owing to their highest theoretical specific energy density. However, this promising system still suffers from huge discharge/charge overpotentials and poor cycling stability, which are related to the leakage/volatilization of organic liquid electrolytes and the inefficiency of solid catalysts. A mixing ionic liquid-based gel polymer electrolyte (IL-GPE)-based Li-O₂ battery, consisting of a 20 mM 2,5-di-tert-butyl-1,4-benzoquinone (DBBQ) 40 mM N-methylphenothiazine (MPT)-containing IL-GPE and a single-walled carbon nanotube cathode, is designed for the first time here. This unique dual redox mediators-based GPE, which contains a polymer matrix immersed with mixed ionic liquid electrolyte, provides a proper ionic conductivity (0.48 mS cm⁻¹) and effective protection for lithium anode. In addition, DBBQ, as the catalyst for an oxygen reduction reaction, can support the growth of discharge products through the solution–phase pathway. Simultaneously, MPT, as the catalyst for an oxygen evolution reaction, can decompose Li₂O₂ at low charge overpotentials. Hence, the DBBQ-MPT-IL-GPE-based Li-O₂ battery can operate for 100 cycles with lower charge/discharge overpotentials. This investigation may offer a promising method to realize high-efficiency Li-O₂/air batteries. Full article

Lithium-air batteries (LABs) have attracted extensive attention due to their ultra-high energy density. At present, most LABs are operated in pure oxygen (O₂) since carbon dioxide (CO₂) under ambient air will participate in the battery reaction and generate an irreversible by-product of lithium carbonate (Li₂CO₃), which will seriously affect the performance of the battery. Here, to solve this problem, we propose to prepare a CO₂ capture membrane (CCM) by loading activated carbon encapsulated with lithium hydroxide (LiOH@AC) onto activated carbon fiber felt (ACFF). The effect of the LiOH@AC loading amount on ACFF has been carefully investigated, and CCM has an ultra-high CO₂ adsorption performance (137 cm³ g⁻¹) and excellent O₂ transmission performance by loading 80 wt% LiOH@AC onto ACFF. The optimized CCM is further applied as a paster on the outside of the LAB. As a result, the specific capacity performance of LAB displays a sharp increase from 27,948 to 36,252 mAh g⁻¹, and the cycle time is extended from 220 h to 310 h operating in a 4% CO₂ concentration environment. The concept of carbon capture paster opens a simple and direct way for LABs operating in the atmosphere. Full article

Lithium–air batteries have become a desirable research direction in the field of green energy due to their large specific capacity and high energy density. The current research mainly focuses on an open system continuously supplying high-purity oxygen or air. However, factors such as water and CO₂ in the open system and liquid electrolytes’ evaporation will decrease battery performance. To improve the practical application of lithium–air batteries, developing a lithium–oxygen battery that does not need a gaseous oxygen supply is desirable. In this study, we designed a closed lithium–oxygen battery model based on the conversion of lithium superoxide and lithium peroxide (LiO₂ + e⁻ + Li⁺ ↔ Li₂O₂). Herein, the Pd-rGO as a catalyst will produce the LiO₂ in the pre-discharge process, and the closed battery can cycle over 57 cycles stably. In addition to in situ Raman spectra, electrochemical quartz crystal microbalance (EQCM) and differential electrochemical mass spectrometry (DEMS) have been applied to explanation the conversion between LiO₂ and Li₂O₂ during the charge–discharge process. This work paves the way to introduce a new closed “lithium–oxygen” battery system for developing large-capacity green energy. Full article

Reduced global warming is the goal of carbon neutrality. Therefore, batteries are considered to be the best alternatives to current fossil fuels and an icon of the emerging energy industry. Voltaic cells are one of the power sources more frequently employed than photovoltaic cells in vehicles, consumer electronics, energy storage systems, and medical equipment. The most adaptable voltaic cells are lithium-ion batteries, which have the potential to meet the eagerly anticipated demands of the power sector. Working to increase their power generating and storage capability is therefore a challenging area of scientific focus. Apart from typical Li-ion batteries, Li-Air (Li-O₂) batteries are expected to produce high theoretical power densities (3505 W h kg⁻¹), which are ten times greater than that of Li-ion batteries (387 W h kg⁻¹). On the other hand, there are many challenges to reaching their maximum power capacity. Due to the oxygen reduction reaction (ORR) and oxygen evolution reaction (OES), the cathode usually faces many problems. Designing robust structured catalytic electrode materials and optimizing the electrolytes to improve their ability is highly challenging. Graphene is a 2D material with a stable hexagonal carbon network with high surface area, electrical, thermal conductivity, and flexibility with excellent chemical stability that could be a robust electrode material for Li-O₂ batteries. In this review, we covered graphene-based Li-O₂ batteries along with their existing problems and updated advantages, with conclusions and future perspectives. Full article

In this paper, the saturation of electrolytes on the mass transfer property of porous electrodes in non-aqueous lithium air batteries has been studied based on digital twin. Herein, we reconstruct the porous cathode based on X-ray micro-computed tomography (μct) and quantitatively analyze the pore size distribution, specific surface area, triple-phase interface area, conductivity and diffusion coefficient of reactants at varying filling degrees of the electrolyte. The results derived from digital twin provide insight into the gas–liquid two-phase mass transfer performance in the porous cathode with various degrees of electrolyte saturation and demonstrate that the optimum electrolyte saturation is 60%. Full article

Although research in the field of lithium-oxygen (air) batteries (LOB) is rapidly developing, few comprehensive studies on the dependence of the catalytic properties of positive electrode materials on LOB test conditions are present. In this paper, the influence of the current density, the type of oxidizer (pure oxygen or air), and a solvent in the electrolyte (DMSO or tetraglyme) on the electrocatalytic properties of PtM/CNT systems (M = Ru, Co, Cr) used as a positive electrode is investigated. It is shown that at a current density of 500 mA/g, more pronounced catalytic effects are observed during the LOB operation than that at 200 mA/g. The obtained results may be explained by the reduced adverse impact of surface passivation with lithium peroxide in the presence of catalysts compared to a similar effect when using unmodified carbon nanotubes (CNT). It is established that the influence of the current density on the catalytic properties continues upon the transition from oxygen to air as an oxidizer. When studying the effect of electrolytes on the catalytic properties of materials subjected to long-term LOB cycling, it is shown that the catalytic effects are most prominent when charged in a tetraglyme medium. Although using a catalyst has practically no effect on the number of cycles for both electrolytes, LOB having tetraglyme exceeds the cyclability of LOB having DMSO. Full article