Search Results (138)

After reviewing the state of the art of the fluorination of inorganic solid electrolytes, an application of gas/solid fluorination is given and how it can be processed. Garnet-type oxide has been chosen. These oxides with an ideal structure of chemical formula A₃B₂(XO₄)₃ are mainly known for their magnetic and dielectric properties. Certain garnets may have a high enough Li⁺ ionic conductivity to be used as solid electrolyte of lithium ion battery. The surface of LLZO may be changed in contact with the moisture and CO₂ present in the atmosphere that results in a change of the conductivity at the interface of the solid. LiOH and/or lithium carbonate are formed at the surface of the garnet particles. In order to allow for handling and storage under normal conditions of this solid electrolyte, surface fluorination was performed using elemental fluorine. When controlled using mild conditions (temperature lower or equal to 200 °C, either in static or dynamic mode), the addition of fluorine atoms to LLZO with Li_6,4Al_0,2La₃Zr₂O₁₂ composition is limited to the surface, forming a covering layer of lithium fluoride LiF. The effect of the fluorination was evidenced by IR, Raman, and NMR spectroscopies. If present in the pristine LLZO powder, then the carbonate groups disappear. More interestingly, contrary to the pristine LLZO, the contents of these groups are drastically reduced even after storage in air up to 45 days when the powder is covered with the LiF layer. Surface fluorination could be applied to other solid electrolytes that are air sensitive. Full article

In this study, we investigate the environmental stability of the sulfide-based argyrodite solid electrolyte Li₆PS₅Cl₀.₅Br₀.₅, a promising candidate for all-solid-state lithium batteries due to its high ionic conductivity and favorable mechanical properties. Despite its potential, the material’s sensitivity to ambient air humidity presents challenges for large-scale battery manufacturing. Moisture exposure leads to performance degradation and the release of toxic hydrogen sulfide (H₂S) gas, raising concerns for workplace safety. The objectives of this study are to validate the electrolyte synthesis process, evaluate the effects of air humidity exposure on its reactivity and ionic conductivity, and establish a standardized protocol for assessing environmental stability. We report a synthesis method based on ball milling and heat treatment that achieves an ionic conductivity of 2.11 mS/cm, along with a fundamental study incorporating modeling and formulation approaches to evaluate the electrolyte’s environmental stability. Furthermore, we introduce a simplified testing method for assessing environmental stability, which may serve as a benchmark protocol for the broader class of argyrodite solid electrolytes. Full article

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

Solid-state electrolytes (SSEs) have emerged as the most promising alternative to liquid electrolytes in batteries due to their enhanced stability and safety. Among these, the garnet-type Li₇La₃Zr₂O₁₂ (LLZO) solid electrolyte has attracted significant research interest due to its wide electrochemical stability window and good air stability. However, the ionic conductivity of LLZO is lower due to its high sintering temperature and unstable phase structure. In this study, Li_6.4+xFe_0.2La₃Zr_2−xBi_xO₁₂ (x = 0, 0.05, 0.1, 0.15) solid electrolytes were synthesized using a conventional solid-state reaction method by co-doping LLZO with Fe³⁺ and Bi³⁺ ions. Compared with pure LLZO, doping with Fe³⁺ effectively stabilizes the cubic phase, thereby enhancing the ionic conductivity. Moreover, Bi³⁺ doping significantly lowers the sintering temperature of the electrolyte, which in turn reduces energy consumption during the processing. The co-doping of Fe³⁺ and Bi³⁺ not only improves the density of the LLZO electrolyte, achieving a relative density of up to 95%, but also increases the ionic conductivity, with a maximum value of 7.57 × 10⁻⁴ S·cm⁻¹ observed at the optimal composition (Li_6.4+xFe_0.2La₃Zr_2-xBi_xO₁₂, x = 0.1). Full article

In order to effectively recover Li from cathode active materials of lithium-ion batteries, model samples of LiCoO₂ mixed with polyvinylidene fluoride (PVDF) were calcined at temperatures of 350–700 °C under an Ar or air atmosphere. Complete Li recovery was achieved by calcining the model sample at 400 °C under an Ar atmosphere, followed by water leaching. Additionally, to immobilize PVDF-derived F, an impurity in Li purification, we explored the use of calcium compounds (Ca(OH)₂ and CaCO₃) and a layered double hydroxide in both dry and wet processing methods. In the wet process, F was fixed by adding Ca(OH)₂ to an aqueous LiF solution containing 1000 ppm of F. We confirmed that 98.6% of F was successfully removed from the solution after repeated fixation procedures. Furthermore, the unreacted Ca in the solution was separated and removed as CaCO₃ by concentrating the solution. 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

Reducing carbon dioxide emissions in transportation has become a priority for achieving emission targets. Transitioning to electric vehicles significantly decreases global CO₂ emissions and reduces urban noise and air pollution. The selection of efficient charging strategies for electric bus fleets substantially influences their environmental impact. This study analyzes the charging strategy for electric bus fleets based on real operational data from Győr, Hungary. It evaluates the impact of different charging times and strategies on CO₂ emissions, considering the energy mixes of Hungary, Poland, Germany, and Sweden. A methodology has been developed for defining sustainable and environmentally friendly charging strategies by incorporating operational conditions as well as daily, monthly, and seasonal fluctuations in emission factors. Results indicate substantial potential for emission reduction through the recommended alternative charging strategies, although further studies regarding battery lifespan and economic feasibility of infrastructure investments are recommended. The novelty of this work lies in integrating real charging data with hourly country-specific emission intensity values to assess environmental impacts dynamically. A comparative framework of four charging strategies provides quantifiable insights into emission reduction potential under diverse national energy mixes. Full article

The rational design of high-performance catalysts for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is essential for the development of clean and renewable energy technologies, particularly in fuel cells and metal-air batteries. Two-dimensional (2D) covalent organic frameworks (COFs) possess numerous hollow sites, which contribute to the stable anchoring of transition metal (TM) atoms and become promising supports for single atom catalysts (SACs). Herein, the OER and ORR catalytic performance of a series of SACs based on TQBQ-COFs were systematically investigated through density functional theory (DFT) calculations, with particular emphasis on the role of the coordination environment in modulating catalytic activity. The results reveal that Rh/TQBQ exhibits the most effective OER catalytic performance, with an overpotential of 0.34 V, while Au/TQBQ demonstrates superior ORR catalytic performance with an overpotential of 0.50 V. A critical mechanistic insight lies in the distinct role of boundary oxygen atoms in TQBQ, which perturb the adsorption energetics of reaction intermediates, thereby circumventing conventional scaling relationships governing OER and ORR pathways. Furthermore, we established the adsorption energy of TM atoms (Ead) as a robust descriptor for predicting catalytic activity, enabling a streamlined screening strategy for SAC design. This study emphasizes the significance of the coordination environment in determining the performance of catalysts and offers a new perspective on the design of novel and effective OER/ORR COFs-based SACs. Full article

Temperature is a crucial parameter for ensuring the long lifespan and safe operation of lithium-ion batteries (LiBs). An efficient battery thermal management system (BTMS) tries to maintain temperature in between optimum limits. Despite some disadvantages, air-cooled BTMSs are still preferred due to their advantages such as light weight, simple design, low cost, and ease of maintenance. This study experimentally evaluated a fan-assisted BTMS for the purpose of cooling a 4S2P battery module that includes 18650 type cells. The battery module was initially tested with no cooling system to observe the temperature characteristics of the module, followed by testing with forced air cooling using a fan. Experiments were also conducted with perforated plates installed between the fan and the module to see their effects on the thermal behaviors. Tests were initiated when the ambient temperature was approximately 25 °C and the discharges were carried out by drawing constant currents of 4 A, 8 A, 12 A, and 16 A from the module via an electronic load. The results of this study highlighted the importance of an effective BTMS in ensuring battery safety and performance across different operational conditions. While all tested cooling configurations maintained acceptable temperature levels at lower discharge currents (4 A and 8 A), they struggled to do so at higher currents (12 A and 16 A). Among them, the Fan–HC mode demonstrated the highest efficiency, reducing the maximum temperature (T_max) by 38.82% at 12 A and 28.89% at 16 A compared to the no-cooling scenario. Moreover, it ensured a more uniform temperature distribution within the module. These findings emphasize the necessity of optimized cooling strategies, particularly for high-power applications. Full article

This paper presents a review of the main trends in the urban air mobility (UAM) sector. After an initial introduction to the key aspects driving the design of aircraft for this type of application and the main characteristics of each type of aircraft developed so far, the focus shifts to the description of the main regulatory frameworks, highlighting the essential requirements that the aircraft must meet at each stage of flight. To translate the aircraft or propeller requirements into design specifications for electric motors, an aerodynamic model is presented. Subsequently, a series of aircraft developed by major industry players is described. In the following section, the key characteristics sought in motors for UAM are outlined, along with various examples of motors developed by leading companies. Additionally, specific design considerations and recommendations are discussed, emphasizing critical aspects such as the adoption of advanced conductors and high-performance cooling systems to enhance power density and efficiency. In conclusion, this review highlights the diverse UAM designs shaping a technological shift in aviation. As prototypes evolve, greater standardization will drive industry growth and support the broader ecosystem, including vertiport providers. Full article

The transition to renewable energy sources from fossil fuels requires that the harvested energy be stored because of the intermittent nature of renewable sources. Thus, lithium-ion batteries have become a widely utilized power source in both daily life and industrial applications due to their high power output and long lifetime. In order to ensure the safe operation of these batteries at their desired power and capacities, it is crucial to implement a thermal management system (TMS) that effectively controls battery temperature. In this study, the thermal performance of a 1S14P lithium-ion battery module composed of cylindrical 18650 cells was compared for distinct cases of natural convection (no cooling), forced air convection, and phase change material (PCM) cooling. During the tests, the greatest temperatures were reached at a 2C discharge rate; the maximum module temperature reached was 55.4 °C under the natural convection condition, whereas forced air convection and PCM cooling reduced the maximum module temperature to 46.1 °C and 52.3 °C, respectively. In addition, contacting the battery module with an aluminum mass without using an active cooling element reduced the temperature to 53.4 °C. The polyamide battery housing (holder) used in the module limited the cooling performance. Thus, simulations on alternative materials document how the cooling efficiency can be increased. Full article

This review presents a comprehensive analysis of battery thermal management systems (BTMSs) for prismatic lithium-ion cells, focusing on air and liquid cooling, heat pipes, phase change materials (PCMs), and hybrid solutions. Prismatic cells are increasingly favored in electric vehicles and energy storage applications due to their high energy content, efficient space utilization, and improved thermal management capabilities. We evaluate the effectiveness, advantages, and challenges of each thermal management technique, emphasizing their impact on performance, safety, and the lifespan of prismatic Li-ion batteries. The analysis reveals that while traditional air and liquid cooling methods remain widely used, 80% of the 21 real-world BTMS samples mentioned in this review employ liquid cooling. However, emerging technologies such as PCM and hybrid systems offer superior thermal regulation, particularly in high-power applications. However, both PCM and hybrid systems come with significant challenges; PCM systems are limited by their low thermal conductivity and material melting points. While hybrid systems face complexity, cost, and potential reliability concerns due to their multiple components nature. This review underscores the need for continued research into advanced BTMSs to optimize energy efficiency, safety, and longevity for prismatic cells in electric vehicle applications and beyond. Full article

Lithium-conducting NASICON materials have emerged as a promising alternative to organic liquid electrolytes for high-energy-density Li-metal batteries, owing to their superior ionic conductivity and excellent air stability. However, their practical application is hindered by poor sintering characteristics and high grain boundary resistance. In this investigation, Li_1.3Al_0.3−xY_xTi_1.7(PO₄)₃ (LAYTP-x, x = 0.00, 0.01, 0.03, 0.05, and 0.07) were successfully synthesized via conventional solid-state reaction to explore the impact of Y³⁺ on both ionic conductivity and chemical stability. The structural, morphological, and transport properties of the samples were comprehensively characterized in order to identify the optimal doping concentration. All samples exhibited a NASICON structure with a uniform distribution of Y elements within the electrolyte. Due to its highest relative density (95.8%), the LAYTP-0.03 electrolyte demonstrated the highest total conductivity of 2.03 × 10⁻⁴ S cm⁻¹ with a relatively low activation energy of 0.33 eV, making it suitable for solid-state batteries. When paired with the NCM811 cathode, the Li/LAYTP-0.03/NCM811 cell exhibited outstanding electrochemical performance: a high capacity of 155 mAh/g was achieved at 0.2C after 50 cycles with a Coulombic efficiency of approximately 100%, indicating highly reversible lithium plating/stripping facilitated by the LAYTP-0.03 electrolyte. These results suggest that the LAYTP-0.03 ceramic electrolyte could be a promising alternative for developing safe solid-state Li-metal batteries. Full article

With the rapid growth of the lithium-ion battery (LIBs) market, recycling and re-using end-of-life LIBs to reclaim the critical Li, Co, Ni, and Mn has become an urgent task. Presently, high temperature, strong acid, and alkali conditions are required to extract blended critical metals (CM) from the typical battery cathode. Hence, there is a need for more effective recycling processes for recycling blended Li, Co, Ni, and their direct regeneration for re-use in LIBs. The goal of the offered paper is the development of recycling technology for degraded battery cathode-active materials based on the thermal decomposition of polyvinylidene fluoride (PVDF) using calcination and air-jet stripping of active materials. The proposed air-jet erosion method of calcined cathode material stripping from Al foil allows for the flexible industry-applicable separation process, which is damage-free for both particles and substrate. The CaO calcination air-jet separation process and equipment can significantly improve the PVDF decomposition and the separation efficiency of the cathode materials. It is demonstrated that low-temperature CaO calcination at 350–450 °C associated with air-jet separation of active material is characterized by low environmental impact, high purity of the recycled material, and low cost as compared to pyro- and hydrometallurgical methods. Full article

Mild conditioned, second-life ternary nickel–cobalt–manganese (NCM) black powder regeneration from spent lithium-ion batteries’ (LIBs) black powder mixture was demonstrated after mild conditioned p-toluenesulphuric acid (PTA)-assisted wet leaching. The NCM ratio was tailored to several combinations (333, 523, 532, and 622) by adding a suitable amount of metal (Ni, Co, Mn)-sulphate salt to the leachate. Regenerated NCM was obtained by co-precipitation with sodium hydroxide pellets and ammonia pH buffering solution, followed by lithium (Li) sintering under ambient air and size sieving. The obtained regenerated NCM powder was used for the energy storage materials (ESM) in coin cell (Li half-cell, CR2032) evaluation. Systematic characterization of regenerated NCM showed that the NCM ratio was close to the target value as assigned in the tailored process, and regenerated 622 (R622) exhibited strong activity in CR2032 coin cell testing among all four ratios with a maximum discharge capacity of 196.6 mAh/g. Full article