Automotive Science and Engineering

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This paper mainly discusses the thermal behavior and performance of Lithium-ion batteries utilized in hybrid electric vehicles (HEVs), battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) based on numerical simulations. In this work, the battery’s thermal behavior is investigated at different C-rates and also contour plots of phase potential for both tabs and volume-monitored plot of maximum temperature inside the computational domain is illustrated. The numerical simulation is done via ANSYS Fluent traditional software package which utilizes the dual potential multi-scale multi-dimensional (MSMD) battery model to analyze the cell discharge behavior and investigate the thermal performance and potential variation(s). The results show that the maximum temperature of battery surface is proportional to the battery discharge rate, i.e., the higher the C-rate, the greater cell surface temperature. Moreover, an increasing symmetric pattern is noticed for volume monitor of maximum temperature over the simulation period. Finally, it is worth noting that the battery tab potential varies more quickly if the C-rate becomes greater. In fact, the lowest and highest rate of changes are observed for 1C and 4C, respectively.

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As electric vehicles become more popular, we need to keep improving the lithium-ion batteries that power them. Electrochemical impedance spectroscopy (EIS) is used based on a discrete random binary sequence (DRBS) to reduce excitation time in the low-frequency region and excite the input of the battery. In this paper, voltage and current signals are processed with wavelet transform for impedance evaluation. In using wavelet transform, choosing the most optimal mother wavelet is crucial for impedance evaluation since different mother wavelets can produce different results. We aim to compare three types of continuous Morse mother wavelet, continuous Morlet, and continuous lognormal wavelet, which are among the most important mother wavelets, to determine the best method for impedance evaluation. We used the dynamic time-warping algorithm to quantify the difference between the initial values obtained from standard laboratory equipment and the impedance evaluation through three different continuous wavelets. Our proposed method (lognormal wavelet) has the lowest difference (3.4086) from the initial values compared to the Morlet (3.5504), and Morse (3.5457) methods. As a result, our simulation shows that the lognormal wavelet transform is the best method for impedance evaluation compared to Morlet and Morse wavelets.

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The global transition towards renewable energy necessitates efficient energy storage solutions to address the intermittency of renewable sources. Lithium-ion batteries (LIBs), widely utilized in electric vehicles (EVs) for their high energy density and efficiency, yet their performance at low temperatures remains a challenge. This study investigates the influence of electrolyte solvent composition on LIB performance under low-temperature conditions. Three electrolytes were studied: a standard electrolyte (STDE) comprising 1 M LiPF₆ in ethylene carbonate (EC) and diethyl carbonate (DEC), a low-temperature electrolyte (LTE) consisting of 1 M LiPF₆ in EC, ethyl methyl carbonate (EMC), and ethyl acetate (EA), and a long-cycle-life electrolyte (LCLE) containing 1 M LiPF₆ in EC/EMC. The EIS results revealed significant differences in resistance values among the electrolytes at varying temperatures. Specifically, at 0 °C, the STDE exhibited a charge transfer resistance (R_ct) of 1055.3 Ω and a solid electrolyte interface resistance (R_SEI) of 803.4 Ω, whereas the LTE showed a substantially lower R_ct of 507.4 Ω and R_SEI of 64.2 Ω, indicating superior low-temperature performance. Similarly, at -20 °C, the R_ct values for STDE, LTE, and LCLE were 8878.6 Ω, 854.2 Ω, and 15622 Ω, respectively, with corresponding R_SEI values of 172.1 Ω, 92.4 Ω, and 2364 Ω. Notably, the addition of EA in the LTE formulation contributed to enhanced low-temperature performance, likely by lowering the overall viscosity of the electrolyte mixture and improving ionic mobility. This study demonstrates the critical role of solvent composition, particularly EA, in optimizing LIB performance for cold climate applications.
 

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High-entropy oxides (HEOs) are single-phase crystal structures composed of multiple metal elements that provide great potential for energy storage applications due to the synergistic effect of various metal species. They are considered effective anode materials for high-performance lithium-ion batteries (LIBs) because of their structural stability, high electronic conductivity, and ability to create anode materials with novel structures using several elemental compounds. Because the effects of different types of electrochemically active elements on the properties of anode materials are unknown, it is necessary to develop HEOs and investigate their properties. Herein, to explore the electrochemical properties of HEOs by changing the content of cations with various mechanisms for storing lithium, we prepared three samples of HEOs with spinel structure using the solid-state method, one of which is equimolar ((MgNiTiFeZn)_0.6O₄) and two numbers are near-equimolar ((Mg_0.6Ni_0.6Ti_0.3Fe_0.9Zn_0.6)O₄ and (Mg_0.6Ni_0.6Ti_0.3Zn_0.9Fe_0.6)O₄)). For structural properties determination, X-ray diffraction analysis was used. The results confirmed the formation of three single-phase high-entropy oxides.
Electrochemical tests indicated the structural stability of three compounds of high entropy oxides, and the composition of (MgNiTiFeZn)_0.6O₄, relative to the others, has better rate capability (163 mAhg⁻¹ at 1000 mAg^–1) and higher discharge capacity (220 mAhg⁻¹ at 200 mAg^–1) after 200 cycles.

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A novel liquid cooling system for pouch-type lithium-ion batteries (LIBs) is proposed by focousing on uniform temperatue disturbution and effective heat dissipation. The system utilizes a michrochannel cold plate with an innovative coolant disturbution design. This study proposes a novel microchannel disturbution path design with each microchannel dimensioning 1 mm² and embeded in the battery's ciritical region to enhance the thermal contact among the LIB and the microchannels. This study aims to simulate and evaluate the performance of cooling system under varius Iranian environmental conditions (Tehran, Shiraz, Isfahan, and Bandar Abbas) and operational parametrs (channel pattern, flow rate) to achieve optimal battery temperature and reduce energy consumption.

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Today, the utilization of lithium-ion batteries (LIBs) has significantly increased as an energy storage technology. In recent years, the high demand for lithium for LIB has resulted in a significant increase in the consumption of lithium-containing materials. It is anticipated that the reduction of lithium due to the limited reserves of lithium will be one of the major challenges in the future. The primary component of the lithium-ion battery industry is lithium, which is extracted from natural minerals and saline water. However, the extraction of lithium from natural minerals and saline water is a complex process that requires a significant amount of energy. Conversely, the quantity of batteries that are approaching the end of their lifespan is unavoidably increasing at an alarming rate. In order to address the obstacles that the lithium battery supply chain encounters, it is imperative that a variety of recycling technologies and methodologies be further developed. This article concentrates on technologies that can recycle lithium compounds from LIB through distinct processes and procedures. These stages are further divided into two pre-treatment phases and a lithium extraction stage. The lithium extraction stage is further divided into three primary methods: pyrometallurgy, hydrometallurgy, Direct. This review article quantitatively compares and analyzes the processes, advantages, disadvantages, efficiency, price, environmental contamination, and degree of commercialization of each recycling method. This review can offer a suitable perspective to enhance this path.

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Lithium-ion batteries hold great promise for addressing environmental and energy challenges, driving their increased adoption in electric vehicles. Their advantages include stability, high energy density, low self-discharge, and long lifespan. However, both high and low temperatures pose significant challenges. High temperatures can lead to thermal runaway and safety hazards such as short circuits and explosions, while low temperatures can promote the formation of lithium dendrites, resulting in degradation and performance issues. To mitigate these thermal challenges, phase change materials (PCMs) have emerged as a promising solution for battery thermal management systems (BTMS). This review provides a comprehensive overview of PCMs and their application in BTMS. We categorize PCMs used in BTMS based on their modified filler materials and functionalities, including carbon-based (carbon fiber-PCM composites, carbon nanotube-PCM composites, and expanded graphite-PCM composites), metal foam, metal mesh, and organic and inorganic materials. Both inorganic and carbon-based materials can serve as highly thermally conductive encapsulants and fillers for PCMs. Finally, we present a thorough review of recent research on the thermal properties of modified PCMs and their impact on BTMS performance, including a detailed discussion of PCM performance metrics and selection criteria.