Development of Binder for Fast-Charging for Li-Ion Battery

Performance analysis on compression-assisted absorption heat transformer: A new low-temperature heating system with higher heating capacity under lower ambient temperature

The solvation structures of Li+ in electrolytes play prominent roles in determining the fast-charging capabilities of lithium-ion batteries (LIBs), which are in urgent demand for smart electronic devices and electric vehicles. Nevertheless, a comprehensive understanding of how solvation structures affect ion transport through the electrolyte bulk and interfacial charge transfer reactions remains elusive. We report that the charge transfer reaction involving the desolvation process is the rate-determining step of the fast charging when ion conductivity reaches a certain value as determined by investigating electrolytes with eight conventional solvents (linear/cyclic carbonate/ether). The physicochemical characteristics of solvent molecules can result in strong ion-ion, moderate ion-dipole, strong ion-dipole, and weak ion-dipole/ion-ion interactions, respectively, in which the speed of the charge transfer reaction follows the above order of interactions. Among all solvents, dioxolane (DOL) is found to enable strong ion-ion interactions in electrolytes and thus exhibits exceptional fast-charging performance and it can still retain 60% of the initial capacity at 20C (1C = 170 mA g-1) with a polarization of merely 0.35 V. Further experimental characterization and theoretical calculation reveal that the aggregates in DOL electrolytes contribute to hopping assisted ion transport and facilitate the desolvation process of Li+. Our results deepen the fundamental understanding of the behavior of Li+ solvation and provide an effective guiding principle for electrolyte design for fast-charging batteries.

The air conditioning system of a passenger car causes significant power consumption. For hybrid and electric vehicles the power consumption for heating of the cabin and windshield (defrosting, defogging) at low ambient temperatures in particular plays an important role, considering that there is only little or no waste heat available. Electric heating of the cabin air drastically reduces the driving range. Additionally, in case of electric vehicles there may be a demand for cooling of the traction battery at high ambient temperatures while in contrary the waste heat of the power electronics could be used for cabin heating at low ambient temperatures if its temperature level is raised by means of a heat pump. This chapter illustrates strategies for the transition of a conventional heating, ventilation and air conditioning (HVAC) system for fuel based vehicles to a more appropriate one for highly electrified vehicles from the standpoint of an effective reduction of energy consumption. The benefits of implementing heat pump technology into the traditional air conditioning system are shown in contrast to systems utilizing electric air heating and a proposition of a vehicles’ thermal management system is given, integrating the air conditioning system into an overall vehicle cooling and heating system for an even further reduction of energy consumption. The chapter is complemented with a comparison of two HVAC system topologies regarding their overall annual energy demand for air conditioning and highlighting the implication of heat pump technology from this point of view.

Fast charging technology for electric vehicles (EVs), which promises rapid charging times similar to refueling conventional vehicles, holds promise but encounters hurdles due to kinetic issues within lithium-ion batteries (LIBs). These issues include both kinetic and thermodynamic challenges within batteries, resulting in restricted utilization of active materials, Li plating, excessive heat generation, and accelerated capacity degradation.1 Efforts to tackle issues associated with fast charging have predominantly concentrated on modifying the Li salts in the electrolyte or the structure and surface/interface of the anode materials.However, compared to the electrolyte or anode materials, the importance of the cathode in relation to fast charging has not been significantly highlighted. Because properties such as the energy density, thermal stability, and rate performance of LIBs are largely determined by the cathode material, 2 understanding the characteristics of the cathode under high-current-density conditions is essential to comprehensively understand fast charging.In this study, the mechanism responsible for the loss of fast charging capability of Ni-rich cathodes during prolonged cycling is examined via a comparative analysis of Ni-rich cathodes exhibiting different microstructures. The results demonstrate that microcracks and subsequent cathode degradation notably compromise the fast charging capability over extended cycling periods. Formation of thick rocksalt impurity phases throughout the particles due to electrolyte infiltration via microcracks leads to limited kinetics of Li+ ions, resulting in electrochemically inactive regions under high-current conditions, hence leading to the loss of fast charging capability. Therefore, preventing microcrack formation by microstructural modification is imperative to ensure stability in fast charging capability. These findings underscore the need to comprehensively understand the degradation of the cathode during extended cycling, particularly from the perspective of the kinetic loss of utilizable Li+ ions at high currents, rather than just the loss of capacity. Reference s : [1] Y. Liu, Y. Zhu, Y. Cui, Nat. Energy, 2019, 4, 540.[2] H.-J. Noh, S. Youn, C. S. Yoon, Y.-K. Sun, J. Power Sources, 2013, 233, 121.

Some take it cool, some like it hot—A comaprative study of male mate searching tactics in two species of hymenoptera (colletidae and sphecidae)

Low ambient temperature as a novel risk factor of oral diseases: A time-series study

While the idea that fast charging batteries could be utilized in electric vehicles is enticing, current fast charging batteries face significant challenges that must be mitigated before this application is realized. Fast charging batteries currently suffer from capacity loss and degradation over time which not only affects battery life but poses a safety hazard. The current electrolyte, 1.2 M LiPF6 in 3:7 wt.% EC/EMC (Gen2), contains the salt LiPF6 that when exposed to moisture can form dangerous hydrofluoric acid and contains a carbonate-based solvent that when exposed to oxygen can ignite. In addition, batteries experience degradation over many cycles of fast charging which results in capacity fade and poor battery performance. However, previous studies have shown the potential for other electrolyte systems to mitigate these problems, specifically by using highly concentrated electrolytes1. These studies claim that using these electrolytes results in the formation of a solid electrolyte interphase (SEI) that passivates Li ions better than the Gen2 electrolyte. The SEI is a layer that forms on the anode within the battery and serves as a protective layer that allows for Li intercalation into graphite and can therefore protect against degradation. By using different electrolytes, a different SEI is formed, and different degradation mechanisms are observed. In this way, the SEI can be tuned to improve Li passivation and ionic conductivity by changing the electrolyte’s composition and concentration2. This research focuses on such alternative electrolyte systems and aims to characterize the different degradation mechanisms corresponding to each electrolyte. Favorable performance has been observed using 1.2 M LiFSI in 3:7 wt.% EC/EMC as an electrolyte. We are studying LiFSI in acetonitrile (AN) at higher concentrations than traditional Gen2 to quantify the SEI. We expect AN to form an anion derived SEI, a composition of which results in improved passivation of Li ions1. In this study, we characterize degradation of alternative electrolyte systems through x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Through these methods we can observe and quantify both crystalline, amorphous degradation products due to loss of Li inventory and loss of active material. XPS allows quantification of compositional changes in the SEI layer at the surface of the electrode. The SEM provides qualitative information on degradation such as visualizing lithium plating and dendrite formation. We implement quantitative XRD to measure the crystalline phases of the graphite anode, showing the degree of lithium intercalation and further quantifying degradation such as Li plating. Putting the results of these three characterization techniques together in tandem with electrochemical cycling data paints a picture of the degradation that happens on the anode of a fast-charging lithium-ion battery with respect to electrolyte composition.[1] Yamada, Y., Wang, J., Ko, S., Watanabe, E., & Yamada, A. (2019). Advances and issues in developing salt-concentrated battery electrolytes. Nature Energy. [2] Logan, E. R., & Dahn, J. R. (2020). Electrolyte Design for Fast-Charging Li-ion Batteries. Trends in Chemistry.

Electric vehicle (EV) fast charging capabilities, and availability of fast charge infrastructure, are perhaps the greatest remaining obstacles in the future widespread use of EVs. Solving fast charging paradigms and issues will enhance driver and electric utility acceptance of EVs. Potential impact to the grid is one of the perceived issues. The technologies to transform EV fast chargers, a grid load, into a valuable grid asset, exist in the form of components and a system approach that includes: Synchrophasors Active Transformers Grid-Level Energy Storage Demand Response and Time of Use pricing Many of these technologies and strategies are in place or in the advanced stages of development. This would allow this system approach to become commercial as the widespread adoption of EVs unfolds.

The driving range of an electric vehicle depends on the vehicle weight, road load conditions, battery capacity, and battery performance. The battery rated capacity and its characteristics could be heavily affected by the ambient temperature. This paper investigates the effects of ambient temperature on the electric vehicle driving range, equivalent fuel economy, and performance. A production-type battery electric vehicle is modeled and simulated in the AVL-Cruise platform using semi-empirical data. The modeled vehicle battery pack consists of 20Ah Lithium-Nickel-Manganese-Cobalt-Oxide (LiNiMnCoO2) cells. The battery cell characteristics are experimentally measured to build the battery pack model. The simulated driving range and equivalent fuel economy are correlated with the published information as vehicle model validation. Series of simulations on driving cycles (UDDS, HWFET, US06, and WLTP) with across a broad range of ambient temperatures are conducted to investigate the quantified effects of ambient temperature on driving range, equivalent fuel economy, and vehicle performance. Simulation results show that driving range and fuel economy are much reduced to 70% at low ambient temperature. Driving range and fuel economy are almost not affected by high ambient temperature, such as 50 C, since this model does not include accessory load of thermal management. The vehicle performance is almost not affected by the ambient temperature.

The article presents research on the impact of a 359 compression-ignition engine starting at low ambient temperatures. This engine is used in vehicles such as STAR 200, 244, and 226. The purpose of these tests was to determine the amount of wear depending on the ambient temperature and the number of starts, as well as to compare the wear at start-up with the wear occurring during tests on the dynamometer (long-term test for reliability) and wear occurring during the operation of the engine in the vehicle, and the impact of the number of starts and ambient temperature on diesel engine for the life of the vehicle to be repaired. The results of the author’s research showed that a minimum of the number of starts at low ambient temperatures has an impact on the number of kilometers driven by the car during operation to replace the cylinder liners (engine repair). Apart from the Polish armed forces and armies of other countries in which this type of vehicle is still used, the direct recipients of the research results are also other entities from the logistics transport sector for which further use of this power unit especially at low ambient temperatures is of fundamental economic importance.

The article presents research on the impact of a 359 compression-ignition engine starting at low ambient temperatures. This engine is used in vehicles such as STAR 200, 244, and 226. The purpose of these tests was to determine the amount of wear depending on the ambient temperature and the number of starts, as well as to compare the wear at start-up with the wear occurring during tests on the dynamometer (long-term test for reliability) and wear occurring during the operation of the engine in the vehicle, and the impact of the number of starts and ambient temperature on diesel engine for the life of the vehicle to be repaired. The results of the author’s research showed that a minimum of the number of starts at low ambient temperatures has an impact on the number of kilometers driven by the car during operation to replace the cylinder liners (engine repair). Apart from the Polish armed forces and armies of other countries in which this type of vehicle is still used, the direct recipients of the research results are also other entities from the logistics transport sector for which further use of this power unit especially at low ambient temperatures is of fundamental economic importance.

Microbiological Evaluation of Stuffed Mussels

Electric vehicles usage and adoption have expanded rapidly over the last decade, as the global energy demand is shifting away from fossil fuels. The recent development of electric vehicle charging technology, which is a fast charging mode, enables an electric vehicle to be fully charged within 10 minutes. However, the generated harmonics, control complexity, and cost of fast charging are the main challenges that need to be addressed to further expand the electric vehicle fast charging technologies. In this manuscript, a new electric vehicle fast charger was designed by introducing the three-stage converters based on the integration between internal model controller with synchronized decoupled controller algorithms. The proposed charger can provide two types of charging approaches, namely alternating current (AC) fast charging and direct current (DC) fast charging. To verify the effectiveness of the proposed charger, the model is developed and simulated in MATLAB/Simulink 2018a platform. Additionally, experimental verification, which utilizes a digital signal processor (TMS320F28335), is conducted to further support the design concept and the simulation findings. These research results have indicated that the proposed charger is applicable for fast AC and DC charging. Moreover, the total harmonic distortion value for the input current is 1.55%, where it has constantly been maintained within the standard limits, thus showing the effectiveness of proposed charger in performing the charging process without causing any significant impact to the grid.

Some researchers have hypothesised that meteorological factors may have an impact on acute cerebrovascular diseases. The aim of this study was to determine an impact of some meteorological factors on occurrence of acute cerebrovascular events in the middle-aged Kaunas population. Kaunas stroke register data were used. Data on meteorological factors for the time period from 2000 to 2010 were obtained from the Lithuanian Hydrometeorological Service Kaunas Meteorological Station. We analysed 4038 cases with stroke. Ischemic strokes composed 80.4% and haemorrhagic strokes-19.6%. According to Poisson regression analysis, significant negative correlation between ischemic, haemorrhagic and all types of stroke and ambient air temperature was found (β coefficient-0.007, -0.016, -0.009, p<0.001, respectively). Results of ARIMA showed that ambient temperature of the day of stroke onset was associated with the occurrence of ischemic, haemorrhagic and all types of stroke: when temperature was lower, the risk of stroke was higher (-0.006, -0.003, -0.009, p<0.001, respectively). Low temperature on the event day and 1 and 2days before the event was associated with higher incidence of haemorrhagic stroke in women. Low ambient temperature on the event day increased incidence of haemorrhagic stroke in subjects 55-64years. High wind speed on the event day was associated with higher incidence of ischemic stroke in older subjects. Meteorological factors may have some impact on the risk of acute cerebrovascular events. Health care providers should focus on preventive measures, which can reduce these risks.

Laminated Lithium Ion Batteries with improved fast charging capability