Electric Transition Research Articles

A resilient battery electric bus transit system configuration

Electric mobility is fundamental to combat climate change and attaining the United Nations Sustainable Development Goals (SDG-11). However, electric mobility necessitates a seamless integration between power and transportation systems, as the resiliency of both systems is becoming far more interdependent. Here, we focus on disruption to Battery Electric Bus (BEB) transit system charging infrastructure and offer a resilient BEB transit system planning model. The proposed model optimizes the BEB system costs while ensuring the system’s robustness against simultaneous charging station failures. In our case study, a single charging station failure would lead to up to 34.03% service reduction, and two simultaneous failures would reduce the service by up to 58.18%. Our proposed two-stage robust model addresses this issue with a relatively small added cost (3.26% and 8.12% higher than the base model). This cost enables uninterrupted BEB system operation during disruption, ensuring personal mobility, social interaction, and economic productivity.

Strong Substrate Influence on Atomic Structure and Properties of Epitaxial VO2 Thin Films

AbstractThe metal–insulator transition (MIT) observed in vanadium dioxide has been a topic of great research interest for past decades, with the underlying physics yet not fully understood due to the complex electron interactions and structures involved. The ability to understand and tune the MIT behavior is of vital importance from the perspective of both underlying fundamental science as well as potential applications. In this work, scanning transmission electron microscopy (STEM) is used to investigate cross‐section lamella of the VO2 films deposited using pulsed laser deposition on three substrates: c‐cut sapphire, TiO2(101) and TiO2(001). Advanced STEM imaging is performed in which also the oxygen atom columns are resolved. The overall film quality and structures on atomic and nanoscale are linked to the electrical transition characteristics. Relatively poor MIT characteristics are observed on c‐sapphire due to the presence of very small domains with six orientation variants, and on TiO2 (001) due to the presence of cracks induced by stress relaxation. However, the MIT on TiO2 (101) behaves favorably, despite similar stress relaxation which, however, only leads to domain boundaries but no cracks.

Sustainable Growth through Green Electricity Transition and Environmental Regulations: Do Risks Associated with Corruption and Bureaucracy Matter?

Sustainable Growth through Green Electricity Transition and Environmental Regulations: Do Risks Associated with Corruption and Bureaucracy Matter?

Robust Service and Charging Plan for Dynamic Electric Demand-Responsive Transit Systems

Robust Service and Charging Plan for Dynamic Electric Demand-Responsive Transit Systems

Research on energy management and control for six-wheel-drive electric bus rapid transit with photovoltaic-battery-supercapacitor

Electric Bus Rapid Transit is an effective solution to traffic congestion and environmental pollution. At present, Electric Bus Rapid Transit needs to be equipped with a large number of power batteries, which brings the key problems of long charging time, short driving range, and high comprehensive utilization cost. To solve the above problems, a novel six in-wheel motors driving Electric Bus Rapid Transit scheme with photovoltaic cells, lithium-ion batteries and supercapacitors (SWEBRT-PBS) is studied, constrained by the cost and comprehensive energy efficiency of vehicle. First, the system architecture for hybrid energy storage system composed of photovoltaic cells, lithium-ion batteries and supercapacitors (PBS) is analyzed. The life cycle cost function for PBS based on the degradation cost of lithium-ion batteries and the electricity cost of each energy source is proposed. The dynamic programming algorithm is employed to optimize the life cycle cost function of PBS, and then to obtain the optimal size of matches for supercapacitors. Second, the fixed step disturbance observation method is adopted to ensure stable power output in the maximum power point tracking controller of photovoltaic cells based on the vehicle application environment. Third, the power control rules are extracted based on the optimization results of dynamic programming algorithm, and the power allocation strategy for PBS with dynamic programming algorithm joint rules is formulated. Fourth, the overall efficiency function for driving system is established and optimized based on the sequential quadratic programming algorithm. The collaborative optimization strategy for SWEBRT-PBS is developed based on the corresponding optimization results, PBS operating modes and vehicle operating modes. The results show that the SWEBRT-PBS can reduce the number of lithium-ion batteries, thereby reducing the vehicle mass by 1.27 % and increasing the vehicle space utilization by 1.81 %. In addition, the comprehensive energy efficiency of vehicle can be improved by 28.79 %.

High-performance van der Waals antiferroelectric CuCrP2S6-based memristors

Layered thio- and seleno-phosphate ferroelectrics, such as CuInP2S6, are promising building blocks for next-generation nonvolatile memory devices. However, because of the low Curie point, the CuInP2S6-based memory devices suffer from poor thermal stability (<42 °C). Here, exploiting the electric field-driven phase transition in the rarely studied antiferroelectric CuCrP2S6 crystals, we develop a nonvolatile memristor showing a sizable resistive-switching ratio of ~ 1000, high switching endurance up to 20,000 cycles, low cycle-to-cycle variation, and robust thermal stability up to 120 °C. The resistive switching is attributed to the ferroelectric polarization-modulated thermal emission accompanied by the Fowler–Nordheim tunneling across the interfaces. First-principles calculations reveal that the good device performances are associated with the exceptionally strong ferroelectric polarization in CuCrP2S6 crystal. Furthermore, the typical biological synaptic learning rules, such as long-term potentiation/depression and spike amplitude/spike time-dependent plasticity, are also demonstrated. The results highlight the great application potential of van der Waals antiferroelectrics in high-performance synaptic devices for neuromorphic computing.

The vortex light induced electric dipole and electric quadru-pole transition in Ca atom

The Laguerre–Gaussian beam induced electric transition model is presented. The major mechanism of angular momentum exchange between the light and the atomic system is discussed. The influence of the topological charge on the transition probability and selection rules is obtained. Our results show that the Ca(4s2 1S0–4s3d 1D2) electric quadrupole transition selection rules are sensitive to the sign of l, and the center of mass transition selection rules are governed by the topological charge l of the light. The electric dipole transition is possible in a field with topological charge l > 0, and the quadrupole transition is no longer forbidden. The overall transition probability difference between dipole transition and quadrupole transition can be decreased by the joint action of the light angular momentum exchange with the external and the internal motion.

Chiral Benzene Triimide (BTI) Radical Anions for Probing the Interplay of Unpaired Electron Spin and Chirality.

Herein a series of chiral BTI radical anions bearing different chiral substituents were efficiently prepared by chemical reduction. X-ray crystallography revealed finely-tuned packing and helix assemblies of the radicals by the size of chiral substituents in crystalline state. In accordance with the crystalline-state packing, the powder ESR spectra indicate that 4 a- ⋅CoCp2 + and 4 c- ⋅CoCp2 + π-dimers exhibit thermally excited triplet states arising from strong spin-spin interactions, while discrete 4 b- ⋅CoCp2 + shows a broad doublet-state signal reflecting weak spin-spin interactions. The interplay between the unpaired electron spin and chiral substituents was studied by UV-Vis-NIR spectra, electronic circular dichroism (ECD) and TD DFT calculations. Different NIR absorptions of the radicals attributing to isolated SOMO→LUMO+1 (~889 nm) transitions were recorded. The emergence of Cotton effects (CEs) at the NIR region for 4 c- ⋅CoCp2 + radical enantiomers suggest the interplay between chirality and unpaired electron spin. The origin of the different circularly polarized light absorptions regarding SOMO derived transitions (around 880 nm) was attributed to chiral substitutes regulated electric and magnetic transition dipole moments of the unpaired electron participated transition.

Have climate policies accelerated energy transitions? Historical evolution of electricity mix in the G7 and the EU compared to net-zero targets

Climate policies are often assumed to have significant impacts on the nature and speed of energy transitions. To investigate this hypothesis, we develop an approach to categorise, trace, and compare energy transitions across countries and time periods. We apply this approach to analyse electricity transitions in the G7 and the EU between 1960 and 2022, specifically examining whether and how climate policies altered the transitions beyond historical trends. Additionally, we conduct a feasibility analysis of the required transition in these countries by 2035 to keep the global temperature increase below 1.5°C. We find that climate policies have so far had limited impacts: while they may have influenced the choice of deployed technologies and the type of transitions, they have not accelerated the growth of low-carbon technologies or hastened the decline of fossil fuels. Instead, electricity transitions in the G7 and the EU have strongly correlated with the changes in electricity demand throughout the last six decades. In contrast, meeting the 1.5°C target requires unprecedented supply-centred transitions by 2035 where all G7 countries and the EU must expand low-carbon electricity five times faster and reduce fossil fuels two times faster on average compared to the rates in 2015–2020. This highlights the insufficiency of incremental changes and the need for a radically stronger effort to meet the climate target.

Political economy of low-carbon electricity: Governance effects across 198 countries

Which countries best foster low-carbon electricity transitions – authoritarian regimes or democratic societies? Crucial for understanding how transitions unfold is identifying contextual factors conditioning propensity to adopt specific forms of energy production. This research assesses the relationship between quality of governance within 198 countries and domestic electricity production from all major energy sources, across the years 2002–2020. Governance quality is measured via a range of comprehensive, internationally recognised metrics, focusing predominantly on the World Bank's worldwide governance indicators. The data reveal that a future, decarbonised electricity system via wind, solar, and/or nuclear appears most likely in countries where the traditions and institutions by which authority is exercised support good governance. Over the last two decades, the association between electricity from solar and wind and good governance has progressively strengthened globally. Beyond governance, national measures of economic (in)equality are strongly related to electricity production from nuclear and hydropower. These findings offer a point of departure for assessing how governance systems might predispose countries to particular energy choices.

Electrical energy harvesting by connected form stable phase change material composites

Over the years, thermoelectric energy harvesting has been becoming a topic of intensive research and thermoelectric power generator has been utilized in various energy harvesting applications. However, a thermoelectric device is required to harvest energy, which has relatively low efficiency and high cost. To overcome such a common problem, the objective of this study is to generate electrical energy without using thermoelectric devices. To this end, an advanced energy harvester composed of two different phase change material composites was explored. It was hypothesized that based on the well-known Seebeck effect, stable electrical energy output would be feasible without a thermoelectric device, by directly connecting two types of phase change materials with different electrical conductivities and different phase transition temperatures. In this study, polydimethylsiloxane open-cell foam embedded with single walled carbon nanotubes was prepared and utilized as a supporting material to fabricate form stable phase change material composites. Two types of polydimethylsiloxane open-cell foams were prepared by embedding single walled carbon nanotubes, which had a weight fraction of 0.33 % and 0.1 %, respectively, leading to different electrical conductivities. The different electrical conductivities of the supporting foams are vital to cause electron motion. Two types of phase change materials with different phase change temperatures were selected as working materials by filling them into the polydimethylsiloxane open-cell foams. Based on the test results, it is found that direct connection of 1-tetradecanol and polyethylene glycol composites can produce stable electrical voltage and current under different thermal energy inputs: through the change of external temperature from 25 °C to 80 °C, through the light-on/-off process, and through heat flow treatment. The maximum output voltage was up to 1.18 mV with a 50 % energy harvesting efficiency and the harvesting time was maintained for 50 min. To confirm the temperature profiles of the phase change material composites, numerical simulation was conducted and the thermal properties during the phase transition process were estimated, with good agreement. This research would create a new concept of thermoelectric energy harvesting for further development in practical applications.

Exploring the structural and electrical trends in Mo2+ substituted Ba0.7Gd0.3MoxF12-xO19 Hexaferrite

The investigation of structural and electrical properties of Ba0.7Gd0.3MoxF12-xO19 for x = 0.02, 0.04, 0.06, and 0.08 were synthesized using a solid-state reaction method. Dielectric study and different impedance parameters were measured at temperature ranging from room temperature (RT) to 500 °C and frequencies ranging from 20Hz to 20 MHz. XRD study confirms the presence of hexagonal P63/mmc phases. Average crystallite size of Ba0.7Gd0.3MoxF12-xO19 for x = 0.02, 0.04, 0.06, and 0.08 were found as 42.177 nm, 42.550 nm, 48.026 nm, and 55.057 nm respectively. Dielectric constant of the sample decreases (at a specific frequency) when the Mo2+ concentration increases. Two transition peaks were observed in the dielectric plot with the temperature variation, indicating multiple electrical transitions in Mo2+ substituted barium hexaferrite. The existence of one semicircle in the Nyquist plot indicates the presence of grain effect in all ceramic samples.

Path creation for an electricity transition in South African tourism

Transitions to low-carbon energy are central to sustainability transitions, with electricity being a pressing current concern both in South Africa and globally. Economic, social, institutional, and political factors often make transitioning to renewable electricity particularly complex. In this article, we examine electricity transitions in tourism from a global South context, combining evolutionary economic geography (EEG) concepts with the multi-level perspective (MLP). Our findings point to strong exogenous lock-in factors working against an electricity transition in South African tourism. A historic dependence on coal, along with complex place-based factors lock the country into a carbon-intensive electricity path at the national electricity infrastructure level. In turn, these complexities adversely affect an electricity transition in the tourism sector. However, energy policy change along with innovation by tourism actors is emergent stimuli for creating low-carbon electricity paths. More specifically, recent climate change mitigation policies, the increasing unreliability of grid electricity, and legislative reforms are significant factors encouraging the renewal of the electricity system. At the same time, it is becoming more cost-effective for businesses, including tourism establishments, to install renewables. The South African case contributes to the emerging body of literature on sustainability transitions in tourism. It does this by showing that to achieve a just energy transition, proper appraisal of path-dependent structural challenges is needed to understand the nature and levels of change required.

High-quality VO2 films synthesized on polymer substrates using room-temperature pulsed laser deposition and annealing

With the growing trend towards portable and adaptable devices in various fields, the demand for flexible electronics and coatings utilizing phase transition materials like VO2 as a functional layer is rising. However, depositing high-quality crystalline VO2 films directly onto polymer substrates remains challenging due to the thermosensitivity of such materials being barely compatible with usual VO2 deposition methods. In this study, we present a simple method for directly growing VO2 on Kapton substrates. VOx films were first deposited onto the Kapton substrate at room temperature using pulsed laser deposition and subsequently annealed in an oxygen atmosphere at 390 °C. The electrical and optical properties of the VO2/Kapton samples with different film thicknesses were investigated. The 200 nm-thick vanadium dioxide films exhibit the best resistivity contrast with 3.1 orders of magnitude (OOM), while the 50 nm-thick films show the best transmittance change of 54 % at 2500 nm. The switching performances are comparable or even superior to those achieved previously using more complicated synthesis processes such as film transfer, introduction of buffer layers, and ink injection. Additionally, by coupling W elemental doping and thin film strain, we successfully tuned the VO2 transition temperature to room temperature with a dopant concentration of only 1.1 at.% while maintaining a high electrical contrast (2 OOM). The impressive electrical and optical transition performance of the VO2/Kapton samples, combined with their tunable transition temperature, makes them promising candidates for flexible electronic devices and thermochromic smart coatings.

Demonstration and scale‐up of high‐temperature electrolysis systems

AbstractHigh‐temperature electrolysis (HTE) is a key to link the electricity sector with other industries and to evolve the electricity transition into a full energy transition. After years of development, HTE is now on the threshold to reach market readiness. The present work shows the latest achievements of Sunfire's development based on the results of the project GrInHy2.0 demonstrating hydrogen production (solid oxide electrolysis cell [SOEC]) in an industrial environment and the project SynLink demonstrating co‐electrolysis (Co‐SOEC) for renewable synthesis gas production. The GrInHy2.0 system is a 720 kWAC electrolyzer operating in the iron‐and‐steel works Salzgitter (Germany). It is now in operation for approx. 14,500 h and achieved a mean degradation rate below 23 mOhm cm2 kh−1 and an electrical efficiency of up to 84%LHV. It also proved that HTE now reached industrial‐relevant availability of over 90%. While the HTE system in Salzgitter consists of eight modules, a single module was tested in co‐electrolysis mode within the project SynLink. It demonstrated synthesis gas generation via Co‐SOEC with a flexible H2/CO ratio between 1 and 4. The work provides insight into how HTE will play a major role in the near future to efficiently produce renewable feedstock for an economy with a drastically reduced carbon footprint.

Study on the electrical breakdown failure mode transition of TSV-RDL

This study investigates the electrical breakdown failure modes and mechanisms of TSV-RDL (Through-Silicon Via with Redistribution Layer) structures through experiments and finite element simulation analysis. By employing a Taguchi method-based finite element simulation, the impact of structural parameters on the electrical breakdown failure modes of TSV-RDLs has been explored. The study reveals two electrically induced breakdown failure modes for TSV-RDLs. One case involves failures occurring at the RDL_pad/SiO2 interface, while the other involves failures within the SiO2 layer along the TSV sidewall interface. The design of TSV-RDLs can influence the distribution of electric field strength and subsequently lead to different electrical breakdown failure modes. In the case of double-blind solid TSV-RDLs, double-through solid TSV-RDLs, and double-blind hollow TSV-RDLs, the pad pitch is identified as a crucial parameter that affects their failure modes. As the pad pitch increases, the location of electrical breakdown failure shifts from the RDL_pad/SiO2 interface to the SiO2 layer along the TSV sidewall interface. Conversely, for the double-through hollow TSV-RDL structure, the structural parameters of TSV, including TSV height, TSV pitch, and SiO2 layer thickness, are the principal factors influencing its failure modes. As these parameters decrease, the position of electrical breakdown failure transitions from the RDL_pad/SiO2 interface to the SiO2 layer along the TSV interface.

Induced photoelectron circular dichroism onto an achiral chromophore

An achiral chromophore can acquire a chiral spectroscopic signature when interacting with a chiral environment. This so-called induced chirality is documented in electronic or vibrational circular dichroism, which arises from the coupling between electric and magnetic transition dipoles. Here, we demonstrate that a chiroptical response is also induced within the electric dipole approximation by observing the asymmetric scattering of a photoelectron ejected from an achiral chromophore in interaction with a chiral host. In a phenol–methyloxirane complex, removing an electron from an achiral aromatic π orbital localised on the phenol moiety results in an intense and opposite photoelectron circular dichroism (PECD) for the two enantiomeric complexes with (R) and (S) methyloxirane, evidencing the long-range effect (~5 Å) of the scattering chiral potential. This induced chirality has important structural and analytical implications, discussed here in the context of growing interest in laser-based PECD, for in situ, real time enantiomer determination.

Quantum imaging of the reconfigurable VO2 synaptic electronics for neuromorphic computing.

Neuromorphic computing has shown remarkable capabilities in silicon-based artificial intelligence, which can be optimized by using Mott materials for functional synaptic connections. However, the research efforts focus on two-terminal artificial synapses and envisioned the networks controlled by silicon-based circuits, which is difficult to develop and integrate. Here, we propose a dynamic network with laser-controlled conducting filaments based on electric field-induced local insulator-metal transition of vanadium dioxide. Quantum sensing is used to realize conductivity-sensitive imaging of conducting filament. We find that the location of filament formation is manipulated by focused laser, which is applicable to simulate the dynamical synaptic connections between the neurons. The ability to process signals with both long-term and short-term potentiation is further demonstrated with ~60 times on/off ratio while switching the pathways. This study opens the door to the development of dynamic network structures depending on easily controlled conduction pathways, mimicking the biological nervous systems.

Electrocaloric effect in pure and NaNbO3-modified Na0.5Bi0.5TiO3–BaTiO3 solid solutions near the morphotropic phase boundary

Morphotropic phase boundary of ferroelectric solid solutions attracts interest with respect to not only improved piezoelectric properties but also the electrocaloric effect, which is attractive to build new-generation cooling devices. In the present study, the electrocaloric effect in (1 − x − y)Na0.5Bi0.5TiO3–xBaTiO3–yNaNbO3 near its morphotropic phase boundary is studied by direct measurements of temperature change ΔT. ΔT maximum is observed in the region of depolarization temperature, where the major contribution comes from an entropy jump at the electric field-induced phase transition. Differences between ΔT values measured when an electric field pulse is applied and removed are explained by slow domain rearrangement in the ferroelectric phase and metastability of phases close to the depolarization temperature. Among studied compositions, the highest value of ΔT is obtained for the compositions 0.94Na0.5Bi0.5TiO3–0.06BaTiO3 and 0.93Na0.5Bi0.5TiO3–0.06BaTiO3–0.01NaNbO3 in the region of depolarization temperature. Examples of the comparison of the directly measured values of ΔT and the values calculated using the Maxwell relation revealing inconsistency between the two methods in the ferroelectric and the nonferroelectric phase are presented.

Multi-Criteria Design of Electric Transit Bus Based on Wireless Charging Infrastructure: A Case Study of Real Road Map in Wakefield

In this paper, a new design strategy is developed for the Wireless Charging Electric Transit Bus (WCETB). The technology is innovative in that the battery in the bus is charged while it is moving over the charging infrastructure. In particular, an improved version of the Whale Optimization Algorithm (IWOA) is adopted for the WCETB system in the road map of Wakefield City, located in the United Kingdom. The main challenge in the WCETB is to select the power transmitter and battery size efficiently from an economical point of view. For this purpose, both factors are considered in the objective function to achieve the benefits of WCETBs from an energy perspective. Two analytical economic design optimization models are developed in this work. The first model is the real- environment model, which considers a WCETB system operating under typical traffic conditions characterized by vehicle interactions and inherent uncertainties. In this scenario, vehicle speeds vary with time, and specific traffic routes may encounter congestion. The second model concentrates on a WCETB system operating in a traffic-free environment with minimal vehicle interactions and uncertainties. The IWOA is implemented for the WCETB to operate in the real environment. Under traffic-free environment conditions, we utilize mathematical procedures and General Algebraic Modeling System (GAMS) software to solve the optimization problem. This approach not only allows us to comprehensively analyze the WCETB system’s behavior but also examine the interactions among different components of the objective function and constraints. Finally, a comprehensive numerical analysis under various conditions, including changes in the number of buses and increases in the length of routes, is conducted.