Battery Systems Engineering Rahn, Christopher D; Wang, Chao-Yang
2012, 2012., 2013, 2013-01-25, 2012-12-06
eBook
A complete all-in-one reference on the important interdisciplinary topic of Battery Systems EngineeringFocusing on the interdisciplinary area of battery systems engineering, this book provides the ...background, models, solution techniques, and systems theory that are necessary for the development of advanced battery management systems. It covers the topic from the perspective of basic electrochemistry as well as systems engineering topics and provides a basis for battery modeling for system engineering of electric and hybrid electric vehicle platforms.This original approach gives a useful overview for systems engineers in chemical, mechanical, electrical, or aerospace engineering who are interested in learning more about batteries and how to use them effectively. Chemists, material scientists, and mathematical modelers can also benefit from this book by learning how their expertise affects battery management.Approaches a topic which has experienced phenomenal growth in recent yearsTopics covered include: Electrochemistry; Governing Equations; Discretization Methods; System Response and Battery Management SystemsInclude tables, illustrations, photographs, graphs, worked examples, homework problems, and references, to thoroughly illustrate key materialIdeal for engineers working in the mechanical, electrical, and chemical fields as well as graduate students in these areasA valuable resource for Scientists and Engineers working in the battery or electric vehicle industries, Graduate students in mechanical engineering, electrical engineering, chemical engineering.
Increasing energy density of Li-ion batteries (LiBs) along with fast charging capability are two key approaches to eliminate range anxiety and boost mainstream adoption of electric vehicles (EVs). ...Either the increase of energy density or of charge rate, however, heightens the risk of lithium plating and thus deteriorates cell life. The trilemma of fast charging, energy density and cycle life are studied systematically in this work utilizing a physics-based aging model with incorporation of both lithium plating and solid-electrolyte-interphase (SEI) growth. The model is able to capture the key feature of temperature-dependent aging behavior of LiBs, or more specifically, the existence of an optimal temperature with the longest cycle life. We demonstrate that this optimal temperature is a result of competition between SEI growth and lithium plating. Further, it is revealed that either the increase of charge rate or of energy density accelerates lithium plating induced aging. As such, the optimal temperature for cell life increases from ∼20 °C for a high-power cell at 1C charge to ∼35–45 °C with the increase of charge rate and/or energy density. It would be beneficial to further increase the charge temperature in order to enable robust fast charging of high energy EV cells.
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•Temperature-dependent aging behavior of Li-ion battery is studied numerically.•Overall aging rate depends on the competition of lithium plating and SEI growth.•The optimal temperature for cycle life increases with charge rate & energy density.•Raising charging temperature is an effective method to eliminating lithium plating.
Electric vehicles (EVs) suffer from significant driving range loss in subzero temperature environments due to reduced energy and power capability of Li-ion batteries as well as severe battery ...degradation due to Li plating. Preheating batteries to room temperature is an essential function of an effective battery management system. The present study employs an electrochemical–thermal coupled model to simulate, for the first time, the process of heating Li-ion batteries from subzero temperatures. Three heating strategies are proposed and compared using battery power, namely self-internal heating, convective heating and mutual pulse heating, as well as one strategy (AC heating) using external power. Their advantages and disadvantages are discussed in terms of capacity loss, heating time, system durability, and cost. For heating using battery power, model predictions reveal that Li-ion batteries can be heated from −20°C to 20°C at the expense of only 5% battery capacity loss using mutual pulse heating with high-efficiency dc–dc converter, implying considerable potential for improved driving range of EVs in cold weather conditions. Moreover, the heating time can be reduced to within 2min by increasing cell output power using convective heating and mutual pulse heating. For external power heating, high frequency AC signal with large amplitude is a preferred choice, offering both high heating power and improved battery cycle life.
•Ultrasound can enhance the decontamination effect of chemical disinfectants, and effectively remove the biofilm of bacteria.•Ultrasound-assisted thermal technology can effectively reduce the number ...of food-borne pathogens in ready-to-eat foods.•Ultrasound can enhance the mass transfer process, increase the penetration rate, and shorten the dehydration and curing time.•Ultrasonic cooking promotes the oxidation of proteins and lipids to enrich the flavor of meat products.•Ultrasound and ultrasound-assisted traditional tenderization technology can effectively improve the tenderness of meat.
With the increase in food standardization and the pace of modern life, the demand for ready-to-eat foods is growing. The strong processing conditions of traditional technology often accelerate the rate of deterioration of quality, and microbes are the safety hazard of ready-to-eat foods. Ultrasound technology is an environmentally friendly technology that hardly causes thermal damage to raw materials. In this paper, the ultrasound technology is used in the disinfection, sterilization, enzyme inactivation, desensitization, dehydration, curing, tenderization and cooking process of fresh food from the perspective of microbial safety and quality of fresh food. The cavitation effect of ultrasound can improve the mass transfer rate of infiltration processes such as dehydration and curing, promote the oxidation of lipids and proteins for enrich the flavor of meat products, improve the microbiological safety and reduce the sensitization by destroying the integrity of the microbial cells and the conformation of the protein. In addition, ultrasound as an auxiliary processing technology can reduce the damage of traditional production technology to reserve the quality and nutritional value of food. Ultrasound has proved to be an efficient and green processing technology for ready-to-eat food.
The streaming instability is a promising mechanism to drive the formation of planetesimals in protoplanetary disks. To trigger this process, it has been argued that sedimentation of solids onto the ...mid-plane needs to be efficient, and therefore that a quiescent gaseous environment is required. It is often suggested that dead-zone or disk-wind structure created by non-ideal magnetohydrodynamical (MHD) effects meets this requirement. However, simulations have shown that the mid-plane of a dead zone is not completely quiescent. In order to examine the concentration of solids in such an environment, we use the local-shearing-box approximation to simulate a particle-gas system with an Ohmic dead zone including mutual drag force between the gas and the solids. We systematically compare the evolution of the system with ideal or non-ideal MHD, with or without backreaction drag force from particles on gas, and with varying solid abundances. Similar to previous investigations of dead-zone dynamics, we find that particles of dimensionless stopping time do not sediment appreciably more than those in ideal magnetorotational turbulence, resulting in a vertical scale height an order of magnitude larger than in a laminar disk. Contrary to the expectation that this should curb the formation of planetesimals, we nevertheless find that strong clumping of solids still occurs in the dead zone when solid abundances are similar to the critical value for a laminar environment. This can be explained by the weak radial diffusion of particles near the mid-plane. The results imply that the sedimentation of particles to the mid-plane is not a necessary criterion for the formation of planetesimals by the streaming instability.
3D fine-mesh flow-fields recently developed by Toyota Mirai improved water management and mass transport in proton exchange membrane (PEM) fuel cell stacks, suggesting their potential value for ...robust and high-power PEM fuel cell stack performance. In such complex flow-fields, Forchheimer's inertial effect is dominant at high current density. In this work, a two-phase flow model of 3D complex flow-fields of PEMFCs is developed by accounting for Forchheimer's inertial effect, for the first time, to elucidate the underlying mechanism of liquid water behavior and mass transport inside 3D complex flow-fields and their adjacent gas diffusion layers (GDL). It is found that Forchheimer's inertial effect enhances liquid water removal from flow-fields and adds additional flow resistance around baffles, which improves interfacial liquid water and mass transport. As a result, substantial improvements in high current density cell performance and operational stability are expected in PEMFCs with 3D complex flow-fields, compared to PEMFCs with conventional flow-fields. Higher current density operation required to further reduce PEMFC stack cost per kW in the future will necessitate optimizing complex flow-field designs using the present model, in order to efficiently remove a large amount of product water and hence minimize the mass transport voltage loss.
•Forchheimer's inertial effect is dominant in PEMFCs with 3D complex flow-fields.•Forchheimer's inertial effect enhances liquid water removal and mass transport.•PEMFCs with 3D complex flow-fields are robust and efficient at high current density.
Fast charging is a key enabler of mainstream adoption of electric vehicles (EVs). None of today’s EVs can withstand fast charging in cold or even cool temperatures due to the risk of lithium plating. ...Efforts to enable fast charging are hampered by the trade-off nature of a lithium-ion battery: Improving low-temperature fast charging capability usually comes with sacrificing cell durability. Here, we present a controllable cell structure to break this trade-off and enable lithium plating-free (LPF) fast charging. Further, the LPF cell gives rise to a unified charging practice independent of ambient temperature, offering a platform for the development of battery materials without temperature restrictions. We demonstrate a 9.5 Ah 170 Wh/kg LPF cell that can be charged to 80% state of charge in 15 min even at −50 °C (beyond cell operation limit). Further, the LPF cell sustains 4,500 cycles of 3.5-C charging in 0 °C with <20% capacity loss, which is a 90× boost of life compared with a baseline conventional cell, and equivalent to >12 y and >280,000 miles of EV lifetime under this extreme usage condition, i.e., 3.5-C or 15-min fast charging at freezing temperatures.
A physics-based Li-ion battery (LIB) aging model accounting for both lithium plating and solid electrolyte interphase (SEI) growth is presented, and is applied to study the aging behavior of a cell ...undergoing prolonged cycling at moderate operating conditions. Cell aging is found to be linear in the early stage of cycling but highly nonlinear in the end with rapid capacity drop and resistance rise. The linear aging stage is found to be dominated by SEI growth, while the transition from linear to nonlinear aging is attributed to the sharp rise of lithium plating rate. Lithium plating starts to occur in a narrow portion of the anode near the separator after a certain number of cycles. The onset of lithium plating is attributed to the drop of anode porosity associated with SEI growth, which aggravates the local electrolyte potential gradient in the anode. The presence of lithium metal accelerates the porosity reduction, further promoting lithium plating. This positive feedback leads to exponential increase of lithium plating rate in the late stage of cycling, as well as local pore clogging near the anode/separator interface which in turn leads to a sharp resistance rise.
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•We present a Li-ion battery model capable of predicting Li plating induced aging.•The model is able to capture the transition from linear to nonlinear aging.•Nonlinear aging is attributed to exponential increase of Li plating rate.•Anode porosity drop due to SEI growth is response for onset of Li plating.•There is positive feedback btw porosity drop and Li plating rate increase.
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