Large Packing Research Articles

Tacking: Shear fragility and geometry reduces the dissipation for dense suspensions

Dense suspensions tend to shear jam at large packing fractions. However, it has recently been shown that various oscillation protocols can unjam as well as reduce viscosity and dissipation per strain. In this numerical work, we show that alternating shear rotations protocols also reduce the dissipation per strain similar to shear protocols with a steady primary shear and superimposed cross oscillations, even though the latter's viscosity reduction is more considerable. Furthermore, we find that alternating between primary and perpendicular oscillations yields a much higher dissipation than the two protocols mentioned above, yet has similar viscosity as the cross-oscillatory one. While self-organization has been shown to minimize viscosity, our findings challenge the idea that random organization is the underlying mechanism for reducing the dissipation per strain. Instead, we attribute it to shear “fragility” combined with geometry, which explains the counterintuitive decoupling of the minima of viscosity and dissipation for the alternating shear rotation protocol. This work paves the way for a new class of highly energy-efficient flow protocols. Published by the American Physical Society 2024

Meeting the challenge of mitigating Li-ion battery fires for aviation

The aviation industry faces a pressing challenge in reducing its environmental footprint, especially with the projected growth in global passenger traffic. Electrification and more-electric aircraft, particularly through Lithium-ion Battery (LiB) systems, offers a promising pathway to reduce emissions but introduces significant safety concerns, particularly regarding thermal runaway (TR) events. This prospective paper examines the unique challenges posed by aviation environments for developing safe LiB systems. It discusses multifaceted mitigation approaches, integrating fire containment structures with advanced thermal management and fire protection technologies. Various cooling technologies and fire suppression agents are explored for their effectiveness in extinguishing LiB fires and mitigating thermal runaway propagation. Integrated LiB suppression systems are proposed to combine fire containment, suppression, and thermal management functionalities for achieving the demanding specific energy density levels that will be required. Scaling safe LiB pack solutions for commercial aviation requires coordinated efforts among regulators, original equipment manufacturers (OEMs), engineers, and researchers to establish standardized design criteria, develop validated modeling tools, and establish rigorous certification testing requirements. In conclusion, addressing the safety concerns of large LiB packs in aircraft applications requires a holistic, integrated approach. This paper provides insights into current research, identifies key challenges, and outlines future directions for advancing LiB safety in aviation.

Yttria substitution effect of tantalate aluminosilicate glasses with ultra‐high Young's modulus

AbstractWe report novel oxide glasses that are compatible with ultra‐high Young's modulus (∼150 GPa) and a small coefficient of thermal expansion (∼5.0 ppm/K). These glasses were prepared using a conventional melt‐quenching technique. The viscosity–temperature relation provides the reshaping temperature for the stiff and less dilated oxide glasses. The origin of the ultra‐high Young's modulus is the inclusion of Y2O3 as well as five‐ and six‐coordinated alumina oxide and Ta2O5, which has a large ionic packing ratio due to higher oxygen coordination numbers. On the other hand, the small thermal expansion coefficient originates from including Ta2O5 and SiO2 with large dissociation energy due to strong bonds.

Optimization and analysis of chassis for heavy electric truck under different condition

The design of heavy electric truck chassis is a critical aspect of developing sustainable and efficient transportation solutions. Heavy electric trucks, which are powered by electric motors and rely on large battery packs for energy storage. the structural integrity and strength of the chassis are of utmost importance. the integration of the battery pack into the chassis is a critical consideration. The chassis needs to accommodate the size, weight, and distribution of the battery pack while ensuring proper thermal management and protection. the unique challenges posed by these vehicles. By considering factors such as structural integrity, battery integration, lightweight materials, and other relevant design considerations, it is possible to develop efficient and sustainable heavy electric trucks that meet the demands of modern transportation.

Promotion of practical technology of the thermal management system for cylindrical power battery

Amidst the industrial transformation and upgrade, the new energy vehicle industry is at a crucial juncture. Power batteries, a vital component of new energy vehicles, are currently at the forefront of industry competition with a focus on technological innovation and performance enhancement. The operational temperature of a battery significantly impacts its efficiency, making the design of a reliable Thermal Management System (TMS) essential to ensure battery safety and stability. Cylindrical power batteries are widely utilized in the industry. This article outlines the four main structures and their drawbacks of TMS for cylindrical power batteries. Among these structures, air cooling falls short in meeting high heat dissipation requirements. Liquid cooling is expensive, intricate, and adds considerable weight. Phase Change Materials (PCM) are not yet prevalent in practical applications. Similarly, heat pipes are relatively uncommon in large high-power battery packs. To better align with the new energy vehicle industry’s demands for top-notch performance, cost-effectiveness, eco-friendliness, and reliability, this paper strongly recommends delving deeper into composite cooling solutions. The construction of an economically viable and fully optimized composite cooling method is poised to become a significant scientific challenge for future research endeavors.

Two polymorphs of a new AIEgen from transition-metal-free cross-coupling reactions: A combined experimental and crystal structure prediction study

We synthesized a new double aromatic pyrrole [2,5-bis(2,5-dimethoxyphenyl)-1H-pyrrole, abbreviated as BDMP] without using transition metals. This compound exhibits a conjugated skeleton, ideal for aggregation-induced emission luminogens (AIEgens). Two methods, Lewis acid catalysis and photoreaction, were used for synthesis. Different methods produce different crystal structures with the same molecular skeleton. The crystals show different AIE properties. The photocatalytically formed crystal (BDMP-B) is highly luminescent with a 10.4 % fluorescence yield. In contrast, the Lewis acid-catalyzed crystal (BDMP-A) has a lower fluorescence yield of 3.0 %. These differences in emission are due to varying crystal packings, confirmed by quantum calculations.To understand these differences, Crystal Structure Prediction (CSP) studies were conducted. Our goal was to find if more stable crystal packings exist. Several energy ranking approaches were used to identify the most feasible polymorphic forms. These approaches include static lattice energy, lattice binding energy, enthalpy, cohesive enthalpy, Gibbs Free Energy, cohesive Gibbs Free Energy, and high-accurate electronic binding energy from large molecule-cluster crystal packings. Our findings suggest that the most stable crystal forms can be predicted accurately using appropriate theoretical methods.This research improves our understanding of AIEgens. It shows the value of combining experimental work with both cost-effective and highly accurate theoretical methods for crystal structure analysis and prediction.

Solar Based Wireless Power Transmission for Electric vehicle Charging Station

Wireless power transfer (WPT) using magnetic resonance is the technology which could set human free from the annoying wires. In fact, the WPT adopts the same basic theory which has already been developed for at least 30 years with the term inductive power transfer. WPT technology is developing rapidly in recent years. At kilowatts power level, the transfer distance increases from several millimetres to several hundred millimetres with a grid to load efficiency above 90%. The advances make the WPT very attractive to the electric vehicle (EV) charging applications in both stationary and dynamic charging scenarios. For energy, environment, and many other reasons, the electrification for transportation has been carrying out for many years. In railway systems, the electric locomotives have already been well developed for many years. A train runs on a fixed track. It is easy to get electric power from a conductor rail using pantograph sliders. However, for electric vehicles (EVs), the high flexibility makes it not easy to get power in a similar way. Instead, a high power and large capacity battery pack is usually equipped as an energy storage unit to make an EV to operate for a satisfactory distance. The problem for an electric vehicle is nothing else but the electricity storage technology, which requires a battery which is the bottleneck today due to its unsatisfactory energy density, limited lifetime and high cost. Keywords: Wireless Power transfer, Electric Vehicle, Battery

A Review on Cooling Methods of Lithium-Ion Battery Pack for Electric Vehicles Applications

The thermal concerns, such as capacity loss, uneven temperature distribution and thermal runaway of the battery packs made of lithium-ion batteries (LIB) used in electric vehicles (EV), limits its applicability, especially in situations of high-power demand. This article analyses the causes of heat generation in lithium-ion battery packs, focusing on their dominance over total heat generation. It discusses the thermal issues arising from heat generation, their root causes, and influencing parameters. Further, it examines the effect of cooling systems on peak battery temperature and temperature uniformity, as well as their design, operating, and performance parameters. The review suggests that, when designing a cooling system, entropic heating should be considered alongside Joule heating during low discharge rates and high temperatures, which are the conditions that prevail when an EV cruises on highways in hot weather. Capacity fade of battery is caused by temperature-dependent factors such as the growth of the SEI layer, rise in separator resistance, and active material loss. Hence an effective battery cooling system should maintain a temperature range of 15°C to 35°C and ‘ΔTmax’ below 6°C. Out of the reviewed cooling systems, air cooling is found to be simple and cost effective, but inefficient for large battery packs. PCM based cooling technique offers greater temperature uniformity but is sensitive to melting point. Liquid cooling is most efficient but adds cost and complexity. Evaporative cooling can serve as a middle ground between air and liquid cooling with further research to put it into practice. The future research in battery thermal management may focus lowering the energy consumption of the cooling systems by taking into account, the precise cooling needs as per the modes of battery operation.

Size matters: Natural experiments suggest the dear enemy effect is moderated by pack size in African wild dogs.

Remote monitoring of communal marking sites, or latrines, provides a unique opportunity to observe undisturbed scent marking behaviour of African wild dogs (Lycaon pictus). We used remote camera trap observations in a natural experiment to test behavioural scent mark responses to rivals (either familiar neighbours or unfamiliar strangers), to determine whether wild dogs exhibit the "dear enemy" or "nasty neighbour" response. Given that larger groups of wild dogs represent a greater threat to smaller groups, including for established residents, we predicted that the overarching categories "dear enemy" vs. "nasty neighbour" may be confounded by varying social statuses that exists between individual dyads interacting. Using the number of overmarks as a metric, results revealed an interaction between sender and receiver group size irrespective of familiarity consistent with this prediction: in general, individuals from large resident packs overmarked large groups more than they overmarked smaller groups, whereas individuals from smaller packs avoided overmarking larger groups, possibly to avoid detection. Monitoring a natural system highlights variables such as pack size that may be either overlooked or controlled during scent presentation experiments, influencing our ability to gain insights into the factors determining territorial responses to rivals.

Ligand-Assisted Direct Lithography of Upconverting and Avalanching Nanoparticles for Nonlinear Photonics.

Upconverting nanoparticles (UCNPs) exhibit unique nonlinear optical properties that can be harnessed in microscopy, sensing, and photonics. However, forming high-resolution nano- and micropatterns of UCNPs with large packing fractions is still challenging. Additionally, there is limited understanding of how nanoparticle patterning chemistries are affected by the particle size. Here, we explore direct patterning chemistries for 6-18 nm Tm3+-, Yb3+/Tm3+-, and Yb3+/Er3+-based UCNPs using ligands that form either new ionic linkages or covalent bonds between UCNPs under ultraviolet (UV), electron-beam (e-beam), and near-infrared (NIR) exposure. We study the effect of UCNP size on these patterning approaches and find that 6 nm UCNPs can be patterned with compact ionic-based ligands. In contrast, patterning larger UCNPs requires long-chain, cross-linkable ligands that provide sufficient interparticle spacing to prevent irreversible aggregation upon film casting. Compared to approaches that use a cross-linkable liquid monomer, our patterning method limits the cross-linking reaction to the ligands bound on UCNPs deposited as a thin film. This highly localized photo-/electron-initiated chemistry enables the fabrication of densely packed UCNP patterns with high resolutions (∼1 μm with UV and NIR exposure; <100 nm with e-beam). Our upconversion NIR lithography approach demonstrates the potential to use inexpensive continuous-wave lasers for high-resolution 2D and 3D lithography of colloidal materials. The deposited UCNP patterns retain their upconverting, avalanching, and photoswitching behaviors, which can be exploited in patterned optical devices for next-generation UCNP applications.

A study on the quantity, type, economic value and reasons for pharmaceutical waste returned to pharmacies in Finland

IntroductionSome medicines purchased are not used, resulting in pharmaceutical waste. Finland, among many other countries, is seeking to reduce the amount of pharmaceutical waste, but little information on this is currently available. This study aimed to evaluate the quantity, type, economic value, and reasons for returning pharmaceutical waste from households to community pharmacies in Finland. MethodsCommunity pharmacies (n = 82) quantified and qualified the amount of pharmaceutical waste returned to them over three days in May 2022. The data was collected using an electronic form. The reasons for returning medicines were asked from customers who returned medicines using a paper questionnaire. The data was analyzed for frequencies and percentages. To estimate the economic value, we used the Finnish medicines prices at the end of June 2022. The annual economic value was calculated by means of a pharmacy size-weighted average. The confidence intervals were estimated using the non-parametric bootstrap method. Sensitivity analyses were conducted to examine the reliability of the results. ResultsIn total, 5173 medicines were returned to pharmacies, of which 66 % were prescription medicines. The most common medicines group returned were medicines for nervous system (18 %), respiratory system (16 %), and alimentary tract and metabolism (12 %). The estimated annual economic value of the medicines returned was 81 million euros (CI 95 % M€61–M€103), of which the cost to society was 43 million euros (CI 95 % M€30–M€60). 799 customers responded to the questionnaire (Response rate 81.9 %). The limited shelf life of the medicine after opening (36 %), improvement of the medical condition or symptom (25 %), and the unnecessarily large pack size (22 %) were common reasons for returning. ConclusionA considerable amount of pharmaceutical waste is returned to pharmacies, causing unnecessary costs to both individuals and society, indicating the need to reduce waste. The limited shelf life and large pack sizes of medicines account for a large proportion of causes for household pharmaceutical waste. Reducing pharmaceutical waste requires action from all actors in the pharmaceutical chain.

New Method for Designing Robust External Short-Circuit Protection Systems at Different Scales

External short circuit is one of the failure modes of Li-ion and other batteries that potentially leads to serious damage such as, overheating and/or thermal runaway. Therefore in this work we test and analyse the short circuit behaviour of different system sizes from coin cells, 10Ah pouch cells and upto large scale automotive high voltage battery packs. It was found that the complex short circuit behavior can be described by 3 regions independently of the size of the battery. In the first region 274C-rate is observed which is mainly governed by the cell's double and diffusion layer discharge. In the second region, the current drops significantly to 50–60C-rate where mass transport becomes the current limiting factor. The maximum temperature is reached and cell rupture, venting and electrolyte leakage may occur. Then the current stabilizes at the maximum mass transport region independently of the external short circuit. This complex time behavior need to be covered by different fuses, circuit breaker and intelligent battery management system. The protection strategy depends on several factors, which makes the design process complex. We introduce the normalized resistance ratio which allows the comparison of external shorts with different external resistance and cells and with different capacities. We demonstrate that the estimation of the maximum external short circuit current derived in this work is more accurate than other calculations at different levels. Furthermore we developed and present a generalized visualisation of the full time-current window which potentially help scientists and engineers to design more robust external short circuit protection systems. With this method we also demonstrate that the currently used external short circuit design methods may potentially lead to unsafe regions especially in the soft short region. We also propose a testing protocol which can be applied in standards, regulations without jeopardizing the safety of testing personnels and infrastructure.

Detecting Abnormality of Battery Lifetime from First‐Cycle Data Using Few‐Shot Learning

AbstractThe service life of large battery packs can be significantly influenced by only one or two abnormal cells with faster aging rates. However, the early‐stage identification of lifetime abnormality is challenging due to the low abnormal rate and imperceptible initial performance deviations. This work proposes a lifetime abnormality detection method for batteries based on few‐shot learning and using only the first‐cycle aging data. Verified with the largest known dataset with 215 commercial lithium‐ion batteries, the method can identify all abnormal batteries, with a false alarm rate of only 3.8%. It is also found that any capacity and resistance‐based approach can easily fail to screen out a large proportion of the abnormal batteries, which should be given enough attention. This work highlights the opportunities to diagnose lifetime abnormalities via “big data” analysis, without requiring additional experimental effort or battery sensors, thereby leading to extended battery life, increased cost‐benefit, and improved environmental friendliness.

Probabilistic lithium-ion battery state-of-health prediction using convolutional neural networks and Gaussian process regression

As the world accelerates its renewable energy transition, lithium-ion batteries are increasingly being used for large scale energy storage. Due to the high cost of production and replacement of large lithium-ion battery packs, accurate estimation of battery state-of-health (SOH) has become important. Accurate estimation is especially important for microgrid and transportation industries where operational batteries will be charged intermittently and incompletely. Incomplete charging scenarios provide models with inconsistent inputs, hence, cause inconsistent output accuracies, which are important to quantify in the context of dispatch controllers and predictive maintenance. In this paper, we present a model that provides a probabilistic prediction of battery SOH from periodic charging events as would be encountered in real world operations. The proposed model combines the feature recognition and many-to-one mapping abilities of the classic convolutional neural network (CNN) with the probabilistic characteristics of Gaussian Process Regression (GPR) models. The combined CNN-GPR model predicts battery SOH to less than 1% mean absolute error using random partial charge segments as input and displays its confidence in the prediction using the variance from the GPR. Additionally, the CNN-GPR is able to predict battery SOH irrespective of battery usage history; this is demonstrated by validation on dynamic data sets where the model achieves a mean absolute error of less than 1% despite only being trained on standardized degradation cycles.

Constructing a tannic-Fe interlayer via a simple in-situ method to enhance the filtration performance of hollow fiber organic solvent nanofiltration membranes

Hollow fiber (HF) organic solvent nanofiltration (OSN) membranes have the advantage of simple production and large packing density, which make them promising for organic solvent recovery. However, current HF OSN membranes still suffer from poor separation performance. To overcome this problem, in this work, we proposed a simple method to in-situ construct a tannic (TA)-Fe interlayer on the surface of an HF ultrafiltration membrane. In this way, we could effectively manipulate the interfacial polymerization (IP) reaction between m-phenylenediamine (MPD) and trimesoyl chloride (TMC), thus successfully boosting the filtration performance of the polyamide (PA) HF OSN membrane. We highlight that TA molecules were enriched on the surface of the HF ultrafiltration membrane during the phase inversion process, which is beneficial for the in-situ construction of a TA-Fe interlayer via immersing this HF substrate in FeCl3 solution. Consequently, we effectively simplified the fabrication procedure for constructing an interlayer. With the aid of the TA-Fe interlayer, the HF OSN membrane obtained higher crosslinking degree and better filtration performance. The optimized HF OSN membrane achieves an ethanol permeance of 14.7 L m−2 h−1 MPa−1 and a Rhodamine B (RDB, 479 Da) rejection of 98.6 %. Additionally, it displays excellent operation stability performance. It remains an ethanol permeance of 8.6 L m−2 h−1 MPa−1 and an RDB rejection of 99.4 % after a continuous cross-flow filtration for over 1000 min. Also, it shows excellent chemical stability performance, corresponding to an extension of less than 4 % after soaking in ethanol for 8 d. This research shows a simple approach for the fabrication of interlayered thin film composite (iTFC) HF OSN membranes.

Numerical optimization of the cooling effect of a bionic fishbone channel liquid cooling plate for a large prismatic lithium-ion battery pack with high discharge rate

Numerical optimization of the cooling effect of a bionic fishbone channel liquid cooling plate for a large prismatic lithium-ion battery pack with high discharge rate

Polarizability, optical basicity and electrical susceptibility of Nd3+-doped ytterbium–zinc–lithium–calcium–potassiumniobate–phosphate glasses with large oxygen packing density

Polarizability, optical basicity and electrical susceptibility of Nd3+-doped ytterbium–zinc–lithium–calcium–potassiumniobate–phosphate glasses with large oxygen packing density

Effect of thermal gradients on inhomogeneous degradation in lithium-ion batteries

Understanding lithium-ion battery degradation is critical to unlocking their full potential. Poor understanding leads to reduced energy and power density due to over-engineering, or conversely to increased safety risks and failure rates. Thermal management is necessary for all large battery packs, yet experimental studies have shown that the effect of thermal management on degradation is not understood sufficiently. Here we investigated the effect of thermal gradients on inhomogeneous degradation using a validated three-dimensional electro-thermal-degradation model. We have reproduced the effect of thermal gradients on degradation by running a distributed model over hundreds of cycles within hours and reproduced the positive feedback mechanism responsible for the accelerated rate of degradation. Thermal gradients of just 3 °C within the active region of a cell produced sufficient positive feedback to accelerate battery degradation by 300%. Here we show that the effects of inhomogeneous temperature and currents on degradation cannot and should not be ignored. Most attempts to reproduce realistic cell level degradation based upon a lumped model (i.e. no thermal gradients) have suffered from significant overfitting, leading to incorrect conclusions on the rate of degradation.

(Digital Presentation) Experimental Investigation of Thermal Runaway of Single 21700 Li-Ion Cell and Runaway Propagation in a Battery Module

Li-ion battery is an integral part for the electric or hybrid electric vehicles, as they provide high energy density and power density with extended cycle-life compared to their closest rivals, Ni-MH batteries [1]. As the Li-ion batteries gained significant success in the automotive sector, safety issues, pertaining to the fire and explosion accidents caused by thermal runaway (TR) have become a critical issue obstructing their applications. Therefore, the Li-ion battery thermal runaway has attracted an increasing attention of the research community worldwide. Thermal runaway is a self-accelerated degradation process of Li-ion batteries, [2] it can be brought by abuse [3] or internal cell failure due to defects [4]. During the TR, a significant amount of burnable and harmful gas and a large amount of heat are generated, which substantially increase the temperature of batteries [5]. Currently, most of the research work on the TR characteristics are conducted under different triggering modes at the cell level. However, the research on the large lithium battery pack is quite scarce. Therefore, several important issues need to be identified to reveal the critical conditions of the fire propagation, and precisely predict the fire risk of Li-ion battery pack fire.In this work, thermal failure experiments were performed using commercial cylindrical 21700 Li-ion single cell and a module by external heating, to analyze the casing rupture and the TR propagation behaviors in the pack based on the fire test apparatus. The critical parameters including the temperature, and heat release rate will be carefully analyzed to reveal the fire propagation hazards of battery packs.

Longitudinal analysis of cigar use patterns among US youth and adults, 2013–2019

BackgroundCigars are available in a range of pack quantities, which contrasts regulations requiring cigarettes to be sold in packs of 20 or greater. Smaller packages may be associated with increases in initiation while larger packs may lead consumers to smoke more. The purpose of this study was to inform pack quantity regulations by examining whether usual cigar pack quantity purchased was associated with use, initiation, and discontinuation among youth and adults for four cigar types: premium cigars, large cigars, cigarillos, and filtered cigars.MethodsWe analyzed waves 1–5 (2013–2019) of the adult and waves 2–5 (2014–2019) of the youth Population Assessment of Tobacco and Health (PATH) Study. Samples included those responding to the item on pack quantity and providing data at all waves (adults: premium cigars [N = 536], large cigars [N = 1,272], cigarillos [N = 3,504], filtered cigars [N = 1,281]; youth: premium cigars [N = 55], large cigars [N = 217], cigarillos [N = 1514], filtered cigars [N = 266]). Generalized estimating equation models examined the population-averaged effects of pack quantity on cigar use, initiation, and discontinuation.ResultsAdult pack quantity was positively associated with the days used per month for premium cigars (b: 0.23, 95% CI: 0.11, 0.34), large cigars (b: 0.17, 95% CI: 0.08, 0.25), cigarillos (b: 0.12, 95% CI: 0.003, 0.24), and filtered cigars (b: 0.07, 95% CI: 0.04, 0.10), and positively associated with amount smoked per day for all cigar types. Youth pack quantity was positively associated with days used per month for premium cigars (b: 0.88, 95% CI: 0.33, 1.43), large cigars (b: 0.79, 95% CI: 0.43, 1.15), and cigarillos (b: 0.17, 95% CI: 0.01, 0.34). Adult initiation was associated with pack quantity for filtered cigars (b: -2.22, 95% CI: -4.29, -0.13), as those who initiated purchased smaller pack quantities compared to those who did not initiate that wave. Pack quantity was not associated with discontinuation for adults or youth.ConclusionsCigar use increased as usual pack quantity purchased increased across cigar types for youth and adults. Small increases in pack quantity (e.g., one additional cigar) are likely to result in consuming less than one additional day per month, though larger increases (e.g., 10 additional cigars per pack) may result in greater use.