An Investigation into the Viability of Battery Technologies for Electric Buses in the UK

This study explores the feasibility of integrating battery technology into electric buses, addressing the imperative to reduce carbon emissions within the transport sector. A comprehensive review and analysis of diverse literature sources establish the present and prospective landscape of battery electric buses within the public transportation domain. Existing battery technology and infrastructure constraints hinder the comprehensive deployment of electric buses across all routes currently served by internal combustion engine counterparts. However, forward-looking insights indicate a promising trajectory with the potential for substantial advancements in battery technology coupled with significant investments in charging infrastructure. Such developments hold promise for electric buses to fulfill a considerable portion of a nation’s public transit requirements. Significant findings emphasize that electric buses showcase considerably lower emissions than fossil-fuel-driven counterparts, especially when operated with zero-carbon electricity sources, thereby significantly mitigating the perils of climate change

Unlocking the Potential of Fluoride-based Solid Electrolytes for Solid-State Lithium Batteries

The development of high energy density and sustainable all-solid-state lithium batteries relies on the development of suitable Li+ transporting solid electrolytes with high chemical and electrochemical stability, good interfacial compatibility, and high ionic conductivity. Ceramic-based electrolytes show high bulk Li+ conductivity and stability but exhibit poor mechanical properties. In contrast, few sulfide-based electrolytes show high total Li+ conductivity and better mechanical properties but poor chemical and electrochemical stability. Moreover, both types of electrolytes exhibit interfacial compatibility issues with several electrode materials. Here, we reveal the potential of Li-containing metal fluorides as Li+ conducting solid electrolytes for solid-state lithium batteries, demonstrating their viability with a case study on β-Li3AlF6. We have synthesized β-Li3AlF6 by mechanical milling and investigated its properties as a solid electrolyte. Ionic conductivity of 3.9x10-6 S cm-1 was observed at 100 °C, which was increased to 1.8x10-5 S cm-1 by compositing with nanocrystalline alumina (γ-Al2O3). Furthermore, the performance of β-Li3AlF6 as a solid electrolyte was successfully tested in an all-solid-state lithium battery using LiMn2O4 as cathode and Li metal as an anode. Finally, we have used density functional theory to shed light on the Li diffusion pathways and associated activation barriers in β-Li3AlF6. Overall, our studies reveal the hidden potential of Li-containing metal fluorides as solid electrolytes for all-solid-state lithium batteries

Improving Wildlife Monitoring using a Multi-criteria Cooperative Target Observation Approach

Wildlife Monitoring is very important for maintaining sustainability of environment. In this paper we pose Wildlife Monitoring as Cooperative Target Observation (CTO) problem and propose a Multi Criteria Decision Analysis (MCDA) based algorithm named MCDA-CTO, to maximize the observation of different animal species by Unmanned Aerial Vehicles (UAVs) and to effectively handle multiple target types and the multiple criteria that arise due to targets and environmental factors, during decision making. UAVs have uncertainty in observation of targets which makes it challenging to develop a high-quality monitoring strategy. We therefore develop monitoring techniques that explicitly take actions to improve belief about the true type of targets being observed. In wildlife monitoring, it is often reasonable to assume that the observers may themselves be a subject of observation by unknown adversaries (poachers). Randomizing the observer’s actions can therefore help to make the target observation strategy less predictable. We then provide experimental validation that shows that the techniques we develop provide a higher (true positive/true negative) ratio along with better randomization than state of the art approaches

Greener, Safer and Better Performing Aqueous Binder for Positive Electrode Manufacturing of Sodium Ion Batteries

P2-type cobalt-free MnNi-based layered oxides are promising cathode materials for sodium-ion batteries (SIBs) due to their high reversible capacity and well chemical stability. However, the phase transformations during repeated (dis)charge steps lead to rapid capacity decay and deteriorated Na+ diffusion kinetics. Moreover, the electrode manufacturing based on polyvinylidene difluoride (PVDF) binder system has been reported with severely defluorination issue as well as the energy intensive and expensive process due to the use of toxic and volatile N-methyl-2-pyrrolidone (NMP) solvent. It calls for designing a sustainable, better performing, and cost-effective binder for positive electrode manufacturing. In this work, we investigated inorganic sodium metasilicate (SMS) as a viable binder in conjunction with P2-Na0.67Mn0.55Ni0.25Fe0.1Ti0.1O2 (NMNFT) cathode material for SIBs. The NMNFT-SMS electrode delivered a superior electrochemical performance compared to carboxy methylcellulose (CMC) and PVDF based electrodes with a reversible capacity of ~161 mAh/g and retaining ~83 % after 200 cycles. Lower cell impedance and faster Na+ diffusion was also observed in this binder system. Meanwhile, with the assistance of TEM technique, SMS is suggested to form a uniform and stable nanoscale layer over the cathode particle surface, protecting the particle from exfoliation/cracking due to electrolyte attack. It effectively maintained the electrode connectivity and suppressed early phase transitions during cycling as confirmed by operando XRD study. With these findings, SMS binder can be proposed as a powerful multifunctional binder to enable positive electrode manufacturing of SIBs and to overall reduce battery manufacturing costs

Alkali metal insertion into hard carbon – the full picture

Carbon-based anodes are technologically highly relevant for Li and post-Li ion batteries. While the storage mechanism of Li in graphite is essentially understood, the alkali metal intercalation into carbon derivatives has been strongly debated. Here, we present a combined computational and experimental study on the intercalation of Li and Na into hard carbon, elaborating on the impact of different alkali metals on the storage mechanism. Our results give strong evidence that the intercalation of Li and Na into hard carbon follows the same route and moreover, shows that in operando Raman scattering is a sensitive and powerful tool for characterizing the intercalation mechanism in carbon based materials. In fact, by exploiting the so-called double resonance, even information on the electronic structure can be obtained. Finally, theoretical predictions for the insertion mechanism of K are presented

New insights into the electrochemistry of magnesium molybdate hierarchical architectures for high performance sodium devices

Magnesium molybdate (MgMoO4), which possesses synergistic features combining both hierarchical plate-like nanomaterials and porous architectures, has been successfully synthesized through a facile combustion synthesis at a low temperature. The hierarchical architecture is characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) analyses. The as-obtained MgMoO4 nanoplates showed a porous structure with a pore-size distribution ranging from 50 to 70 nm. This porosity provides an electron transport pathway and enhanced surface reaction kinetics. The binding energies measured for Mg 2p, Mo 3d, 3p and O 1s are consistent with the literature, and with the metal ions being present as M(II) and M(VI) states, respectively. This indicates that the oxidation states of the metal cations are as expected. The electrochemical behaviour of MgMoO4 was investigated using aqueous (NaOH) and non-aqueous solvents (NaClO4 in EC : DMC : FEC) for supercapacitor and battery applications. The sodium-ion capacitor involves ion absorption and insertion into the MgMoO4 electrodes resulting in superior power and energy densities. However, the cycling stability was found to be stable only for an aqueous system. The formation of a solid electrolyte surface layer restricted the reversible capacity of the MgMoO4 in the sodium-battery. Nevertheless, it does offer some promise as an anode material for storing energy with high rate performance and excellent capacity retention. Detailed comparative analyses of various electrolytes in storage devices such as hybrid sodium-ion capacitors and sodium-ion batteries are vital for the integration of hierarchical structured materials into practical applications. The reaction mechanisms are postulated

Insight into Sulfur Confined in Ultramicroporous Carbon

Here, we provide a deeper insight into the state of sulfur confined in ultramicroporous carbon (UMC) and clarify its electrochemical reaction mechanism with lithium by corroborating the results obtained using various experimental techniques, such as X-ray photoelectron spectroscopy, electron energy loss spectroscopy, in situ Raman spectroscopy, and in situ electrochemical impedance spectroscopy. In combination, these results indicate that sulfur in UMC exists as linear polymeric sulfur rather than smaller allotropes. The electrochemical reactivity of lithium with sulfur confined in UMC (pore size ≤0.7 nm) is different from that of sulfur confined in microporous carbon (≤2 nm, or ultramicroporous carbon containing significant amount of micropores) and mesoporous carbon (>2 nm). The observed quasi-solid-state reaction of lithium with sulfur in UMC with a single voltage plateau during the discharge/charge process is due to the effective separation of solvent molecules from the active material. The size of carbon pores plays a vital role in determining the reaction path of lithium with sulfur confined in UMC

Penicillin induced toxic epidermal necrolysis with secondary impetiginization: a rare case

Drug induced allergic reactions can be categorized into IgE-mediated and non-IgE mediated hypersensitivity reactions. Symptoms of IgE-mediated reactions are angioedema, bronchospasm, anaphylaxis, and urticaria that appears within 72 hours and those which are Non-IgE mediated hypersensitivity reactions include morbilliform eruptions, interstitial nephritis, hemolytic anemia, serum sickness, thrombocytopenia, and erythema multiforme, after 72 hours. TEN is defined as an extensive detachment of full-thickness epidermis most often related to an adverse drug reaction. We report a rare case of penicillin induced toxic epidermal necrolysis with Secondary Impetigination in a 38-year-old male patient with complaints of rashes all over the body, chest pain and dry tongue since seven days. Based on history and clinical examination patient was diagnosed as of penicillin induced toxic epidermal necrolysis with secondary impetigination and was successfully treated with antihistamines, parenteral antibiotics and corticosteroids.

Reinvestigation of Na₅GdSi₄O₁₂: A Potentially Better Solid Electrolyte than Sodium β Alumina for Solid-State Sodium Batteries

Developing high-performing solid electrolytes that could replace flammable organic liquid electrolytes is vital in designing safer solid-state batteries. Among the sodium-ion (Na+) conducting solid electrolytes, Na-β″-alumina (BASE) is highly regarded for its employment in solid-state battery applications due to its high ionic conductivity and electrochemical stability. BASE has long been employed in commercial Na–NiCl2 and Na–S batteries. However, the synthesis of highly conductive BASE is energy-intensive, involving elevated temperatures for sintering and the incorporation of stabilizing additives. Additionally, BASE is highly sensitive to humidity, which limits its applications. Hence, there is an intense search to identify suitable high-performing solid electrolytes that could replace BASE. In this context, we reinvestigated Na5GdSi4O12 (NGS) and demonstrated that phase pure NGS could be synthesized by a simple solid-state reaction. Beyond a high ionic conductivity of 1.9 × 10–3 S cm–1 at 30 °C (1.5 × 10–3 S cm–1 for BASE), NGS exhibited high chemical as well as electrochemical stability, lower interfacial resistance, lower deposition and stripping potential, and higher short-circuiting current, designating NGS as a better solid electrolyte than BASE

Fabrication and Testing of Apparatus for Electrochemical Mechanical Polishing (ECMP) of Copper for Semiconductor Applications

Electrochemical mechanical polishing (ECMP) is a process wherein the surface layer of a substrate is smoothened using a combination of electrochemical reactions, chemical reactions and mechanical forces. It is an alternative technology to chemical mechanical polishing (CMP) to prevent delamination in the porous low-k dielectric films in advanced IC devices. Copper is widely used in the metallization of these device structures. ECMP is excellent for bulk copper planarization because it has higher material removal rates and better planarization efficiency at low down-force. Also, ECMP has proven to be better than electrochemical polishing (ECP) as it is not pattern sensitive. In the present study, a face-up ECMP apparatus with planetary motion was fabricated and tested to polish 4-inch copper wafers. A ball bearing arrangement was used to provide a positive charge to the rotating wafer in the wafer carrier. Five different slurry compositions were prepared to polish the copper wafers. Multi-stage polishing was adopted to achieve a good surface finish on the wafer. Surface characterization was studied by optical microscope and MicroXAM, an optical laser interference microscope. The slurry composition for ECMP should be such that it forms a passivation layer on the surface of the copper wafer which is subsequently removed by the polishing pad. The necessary components of the slurry, in order to produce a good surface finish are an acid-based electrolyte, a corrosion inhibitor, a leveling agent, an oxidizer, a pH adjusting agent, and abrasive particles. The slurries with pH of 6 or above produced a smooth uniform surface. This was validated using Pourbaix diagram of copper. Phosphoric acid-based slurry with a pH of 6 and Buehler alumina-based slurry with a pH of 9 produced a good surface finish. The surface roughness obtained with the phosphoric acid-based slurry was 12.05 nm. Process parameters, such as polishing time, voltage applied, pad and wafer carrier speed were studied as a function of material removal rate and surface roughness. Material removal rates increased with increase in polishing time and applied voltage. Good surface finish was obtained with a polishing time of 10 minutes at a voltage range of 9.5 to 10.5 V with a wafer carrier speed of 15 rpm and a pad speed of 325 rpm.Mechanical & Aerospace Engineerin