bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Multi-Physical Simulation Models for Quasi-Static Load Analysis to Predict the Behavior of Li-Ion and Na-Ion Batteries Under Different Mechanical Abuse Loadings
Authors: Cabello Moreno Noelia , Vicente Lopez Ana Maria 
Published: February 2024

There are lot of studies on understanding the short-circuit phenomena at cell component level and how to address the thermal management at module and pack level to avoid overheating. However, it is also very important, in terms of safety, to evaluate the response and failure of cells during abuse tests as this can promote the thermal runaway event. Safety of metal ion batteries under mechanical loadings is currently one of the most challenging and urgent issues face in the Electric Vehicle (EV) industry. In the battery manufacturing community, the property of strength and resistance of batteries to external loading has never been a design consideration. However, under local mechanical loading, batteries are prone to developing a internal short circuit (ISC), which may lead to the generation of smoke, fire, and possible explosion.
This work is focused on the metal ion batteries safety studies (lithium and sodium) including the investigation of predictive models to determine the critical parameters that would lead to potential failure and provide critical insights to understand the mechanical and ISC behaviors of cells under mechanical abuse. Having a numerical model that correctly represents the cells and its response under different abuse tests could allow identifying main issues and helping on the cell design and chemistries to be used. To develop these models using LS-Dyna, it has been necessary to carry out studies of mechanical deformation on cell components and the complete cells. These studies have offered a better knowledge of the deformation of the inner components of the battery, being useful to identify the mechanism that initiate short circuits under mechanical misuse conditions. Building numerical models for batteries requires experimental work that provides not only the data for mechanical behavior of individual components (anode, cathode, separator, etc.), but also validation data for simulations of internal short circuit induced by mechanical abuse.

Figure 1
Non-Flammable Ether and Phosphate-Based Liquid Electrolytes for Sodium-Ion Batteries
Authors: van Ekeren Wessel Willem Andries , Mogensen Ronnie , Younesi Reza 
Published: February 2024

The demand on the lithium reserves has been increasing rapidly due to the continuous growth in energy storage devices. Since the lithium reserves are limited and only accessible at certain geographical areas, the costs of lithium precursors are increasing significantly.1 Therefore, alternative battery chemistries need to be investigated. One of the next generation battery solutions is sodium-ion batteries (SIBs).2 However, current commercial electrolytes in SIBs are based on highly flammable carbonate-based solvents, such as ethylene carbonate, propylene carbonate, diethyl carbonate and dimethyl carbonate.3 To enhance the safety of SIBs, it is of utmost importance to develop non-flammable electrolytes. In this work, NaPF6 and NaBF4 salts are used in combination with a solvent mixture of ethers (diglyme, tetraglyme) and phosphates (triethylphosphate, trimethylphosphate) to obtain non-flammable liquid electrolytes. The electrolytes are evaluated in terms of physicochemical properties and electrochemical performance full-cells using high-mass loading Prussian White (12 mg/cm2) and Hard Carbon (7 mg/cm2). Flammability tests have shown that at least 70% of phosphate co-solvents are required to make the glyme based electrolyte non-flammable. In summary, the combination of glymes and phosphates provide promising electrolyte formulations in terms of non-flammability characteristics and ionic conductivities, but still lack long-term cycling stability. This work opens avenues to optimizing non-flammable electrolytes for high-performing and safe SIBs.

References

1 R. Schmuch, R. Wagner, G. Hörpel, T. Placke and M. Winter, Nat. Energy, 2018, 3, 267–278.
2 H. S. Hirsh, Y. Li, D. H. S. Tan, M. Zhang, E. Zhao and Y. S. Meng, Adv. Energy Mater., 2020, 10, 1–8.
3 R. Gond, W. Van Ekeren, R. Mogensen, A. J. Naylor and R. Younesi, Mater. Horizons, 2021, 8, 2913–2928.

Acknowledgement

The authors would like to acknowledge the financial support by the Swedish Energy Agency via project no. 50177-1, VINNOVA via projects no. 2022-01465 and 2019-00064 (Batteries Sweden), and SuSaNa project under M-ERA-Net call 2021 (G.A. no 958174).
(Invited) The Path to Vapour Cloud Explosions and Lithium-Ion Batteries
Authors: Christensen Paul A. 
Published: February 2024

The lecture will cover the research that led to the realisation that vapour cloud explosion was and is the understated hazard of lithium-ion batteries, commencing with work in January and March 2020 and leading up to the present day. The research was initiated with an exploration of the effect of various abuse methods on 1.7 kWh Envision-AESC modules, followed by investigating the effect of State-of-Charge on the manifestation of thermal runaway, the latter leading to the realisation of the vapour cloud and its potential consequences. This was followed by experiments on the larger scale to analyse the vapour cloud composition and to trigger deflagration: these suggested the possibility that arc plasma may have a role in the production of the vapour cloud. Later, experiments on the suppression of thermal runaway clearly showed the risks associated with the suppression of fire without the suppression of thermal runaway, as the hazard flips from fire to explosion. This was a key finding, as was the large volume of vapour cloud produced by lithium-ion batteries (i.e. at least 500 L/kWh and up to 5500 L/kWh), causing the routinely observed rocket-like flames when the cloud ignites immediately, and the fact that even small lithium-ion batteries (e-bikes, e-scooters) are causing vapour cloud explosions.
As well as academic research, the concepts and ideas discussed will be illustrated with information and videos from a wide range of sources including first responder reports from across the world.
Finally, the possible risks and hazards of the use of electric vehicle batteries in 2nd life applications will be addressed
Increasing Battery Safety of Lithium-Ion Batteries by Using Cell-Internal Glass Fiber Sensors for in-Situ Temperature Monitoring
Authors: Burger Alexandra , Krause Florian , Bausch Bruno , Böse Olaf , Ophey Jannes , Wuersig Andreas , Sauer Dirk Uwe , Kapels Holger 
Published: February 2024

Lithium-ion batteries (LIB), featuring high energy density and power density, are used in a wide range of applications. One of the most important requirements for their application is to ensure their safety and continuous performance under different operating conditions. In order to ensure the afore mentioned factors, in-situ monitoring of internal cell parameters, such as temperature, state-of-charge, and state-of-health of LIB is essential. The cell temperature is a critical factor for both the safety and the LIB’s health. Not only the average temperature, but also the temperature distribution within the cell must be considered. However, common battery management systems mostly rely on monitoring the surface temperature of the cells, while neglecting changes of the internal parameters. This is where the integration of optical glass fiber sensors into battery cells, which allow direct monitoring of internal temperature changes during operation, makes a significant contribution.
In this work, different approaches for the integration of optical glass fiber sensors into battery cells have been evaluated. The focus was set on the complete integration of the glass fiber at specific positions within the LIB, while ensuring that both, the glass fiber, and the battery components remain intact. Furthermore, the influence of the integrated glass fibers on the performance of the LIB was investigated. Finally, their functionality as temperature sensors was evaluated.
In a second step, temperature measurements were performed on LIB during operation, using both internal and external sensors. The results obtained clearly reveal an early detection of temperature changes by internal glass fibers compared to external sensors. This not only confirms the efficiency of the internal sensors, but also leads the path to improved battery safety by early detection of critical temperatures within the cell.
Experimental Analysis of Thermal Runaway Energy Release of an Automotive Li-Ion Battery Cell
Authors: Novotny Frederik , Köhler Jürgen , Golubkov Andrey 
Published: February 2024

Thermal runaway (TR) reactions of lithium ion cells pose a particular risk to the safety of battery systems. Beside the energy remaining in the cell body, particles and gases exiting the cell during the venting process cause major thermal load for adjacent cells and further system components [1]. In addition, high energy particles can act as an ignition source in the presence of ignitable venting gases and oxygen [2]. Therefore, measurements minimizing the risk of thermal propagation (TP) caused by venting ejecta material and the ignition of combustible gases are introduced on system level. For the dimensioning of the measures, the energy transported by venting particles and gases is identified as a crucial parameter. Depending on the amount of transported energy, the gas cooling distance as well as the complexity of the particle separation structure differ. Simulation methods are used to evaluate the effectiveness of such system measures. More information is needed regarding energy release to accurately predict the system behavior in simulations and to use them as a tool for design.
Introducing a novel approach for TR tests enables the determination of the energy remaining in the cell body, separated from the energy transported by venting ejecta. The test setup combines a calorimeter combined with a cyclone separator placed inside an autoclave reactor. The TR energy release of 156 Ah prismatic lithium ion cells have been analyzed using the setup. Venting particles and gases transported a main part of the released energy out of the cell during the TR. Using an analytical approach, the energy transferred to the calorimeter is calculated. The obtained data can be used for validating simulation models for predicting the impact of venting reactions on TP.

References

[1] W. Walker, J. Darst, D. Finegan, G. Bayles, K. Johnson, E. Darcy, S. Rickman, J. Power Sources 2019, 415, 207-218
[2] H. Wang, H. Xu, Z. Zhao, Q. Wang, C. Jin, Y. Li, J. Sheng, K. Li, Z. Du, C. Xu, X. Feng, Appl. Therm. Eng. 2022, 211, 118418.
Developing an Apparatus to Analyze Volume Changes in a Pouch Battery Cell
Authors: Kim Dongchan , Choi Sung Hwan , Sim Gyu Jang , You Jehyun , Choi In-Suk 
Published: February 2024

Recently, there has been a significant increase in demand for lithium-ion batteries due to the growing demand for eco-friendly mobility. However, to ensure the stability of electric vehicles during operation, research on the structural and material characteristics of batteries is essential. The Battery Management System (BMS), responsible for managing battery degradation and performance, is directly impacted not only by the electrochemical characteristics but also by the structural and material stability of the battery. As the demand for high-density battery modules increases, the volume change of batteries after degradation can generate significant internal stresses, making it crucial to develop the vehicle's BMS in relation to this issue. Therefore, this study aims to measure the characteristics of batteries volume changes during degradation under various pressure conditions from the cell level. Ultimately, we propose a homogenized model that can predict the degradation characteristics of a battery pack subjected to pressure during charging and discharging. An apparatus capable of measuring the volume changes of batteries is developed for the modelling.
Keywords: Battery volume changes, pouch cell, modeling, mechanical properties, compression test, apparatus
Three-Dimensional Modeling of Dendrite Formation during Automotive Relevant Cycling
Authors: Teel Hunter , Lopata Joseph Steven , Garrick Taylor R. , Shimpalee Sirivatch 
Published: February 2024

Dendrites commonly form during rapid charging of lithium-ion batteries when plating is favored over intercalation. If not mitigated, the potential exists for dendrites to growth through the separator and short the anode and cathode. One metric for diagnosing plating conditions in a computational model is the minimum local potential at the anode, where plating is seen to be thermodynamically favorable below 0.0 V with respect to Li metal.1, 2 Three-dimensional (3D) models can offer insight to predict the possibility of local lithium plating and can be used as a tool to detect possible global lithium plating onset, so it follows that 3D microstructure models can be used to predict dendrite formation and propagation as well. The moving boundary technique with mesh motion can be utilized to separate the electrolyte region into a liquid phase and a dendrite phase.3

This strategy is implemented in a 3D microstructure model of a lithium-ion battery to observe the growth of dendrites at the anode during rapid charging. Under onset conditions at the solid/electrolyte interface (SEI), the solid metal phase is deposited at the SEI. Upon growth, the overall electrolyte resistance at the tip of the metal phase is reduced, leading to dendrite growth. The 3D model provides valuable insight into various conditions that may cause plating, if dendrites are formed due to plating, and whether the dendrites formed may proceed to a shorting effect.
References

T. R. Garrick, J. Gao, X. Yang and B. J. Koch, J Electrochem Soc, 168, 010530 (2021).

U. Janakiraman, T. R. Garrick and M. E. Fortier, J Electrochem Soc, 167, 160552 (2020).

T. Jang, L. Mishra, S. A. Roberts, B. Planden, A. Subramaniam, M. Uppaluri, D. Linder, M. P. Gururajan, J.-G. Zhang and V. R. Subramanian, J Electrochem Soc, 169, 080516 (2022).
(Invited) Effect of Oxygen on Activation Annealing of Mg-Doped GaN
Authors: Kumar Ashutosh , Wang Qin , Ramvall Peter 
Published: February 2024

The effects of N2 and O2:N2 (1:1) as ambient gases during activation annealing of Mg as p-type doping of GaN grown by MOCVD are investigated. The purpose is to understand the mechanisms involved and especially the impact of O2 on the resulting free hole concentration and hole mobility. The addition of O2 to the ambient gas during annealing is very effective in reducing the H level of the Mg-doped GaN layer, especially at lower activation temperatures, but the maximum achievable hole concentration and mobility, as determined by Hall characterization, is still higher with pure N2.
The difference between activation in pure N2 or O2:N2 (1:1) ambient a is explained by an in-diffusion of O to the GaN layer acting as n-dopant and thus giving rise to a compensation effect. It is found that to a large degree only the Mg-H complexes at substitutional (MgGa), i.e., the electrically active acceptor sites that provide free holes, are activated by annealing with N2 only as ambient gas, while annealing with O2:N2 (1:1) also dissociates electrically inactive Mg-H complexes resulting in much less residual H. Thus, the residual H level in relation to the Mg level after activation annealing with N2 only may provide a representative measure of the resulting free hole concentration of the Mg-doped GaN layer.
An additional factor to be taken into account for in order to maximize the hole concentration is the growth pressure. At the lower growth pressure of 150 mbar compared to higher growth pressure of 300 mbar, an increasing carbon incorporation leads to a compensation effect drastically reducing the free hole concentration while the mobility is unaffected.

Conclusions

Addition of O2 during RTP is very effective in reducing the H level however, the maximum hole concentration and mobility are still higher with pure N2.
Mg-H complexes at substitutional (MgGa) electrically active acceptor are preferentially dissociated by annealing with N2 as ambient gas.
By employing a higher growth pressure, carbon incorporation that leads to a compensation effect drastically reducing the free hole concentration can be minimized.
By activation annealing with N2 the residual H level provides a measure of the free hole concentration.

Figure 1
(Invited) Selective Area Growth, Etching, and Doping of GaN By MOCVD for Power Electronics
Authors: Li Bingjun , Han Jung 
Published: February 2024

Gallium Nitride (GaN) possesses a wide band gap and excellent transport properties, making it a highly promising material for high-power and high-frequency applications. Microwave power amplification for commercial and military purposes has already benefited from GaN-based high electron mobility transistors (HEMTs). However, currently available GaN optoelectronic and electronic devices use planar junctions and heterostructures prepared by epitaxy, typically via metalorganic chemical vapor deposition (MOCVD). To enable more sophisticated device configurations, in-plane lateral junctions are necessary. The most effective method for achieving this is through selective area etching (SAE) followed by selective area growth (SAG). In this talk, we will discuss the progress made at Yale in the selective-area etching, growth, and doping of GaN.
Selective-area etching of GaN is the most challenging and critical step in this process. Instead of using conventional ICP etching, we have employed tertiarybutylchloride (TBCl) as an in-situ chemical etchant of GaN in MOCVD to create smooth trenches and remove plasma etching-generated damages on the surface. With electrical and material characterizations, we have confirmed that TBCl etching is a low-damage and clean etching process. We will also describe our recent efforts to bypass the constraint of dielectric masking during in-situ etching and perform maskless selective area etching (SAE) to create low-defect lateral p-n junctions for GaN power electronics. Additionally, we will discuss non-planar selective-area growth and doping, including the principles of growth evolution, non-uniform Mg distribution, and parasitic impurities.
This work is supported by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. DOE, under DE-AR0000871 as part of the PNDIODES program managed by Dr. Isik Kizilyalli.
(Invited) Growth and Characterization of 200 mm SiC Crystals and Substrates
Authors: Carria Egidio , Sörman Erik , Thörnberg Jimmy , Ellison Alexandre , Magnusson Bjorn , Riva Carlo 
Published: February 2024

SiC power device technology has over the past years continued to gain massive interest in automotive and industrial applications. The majority of devices is today fabricated on 150 mm diameter substrates while the 200 mm diameter substrates still is at early stage in both development and in terms of mass production. An increase of 50 mm in the wafer diameter corresponds to a 78% larger area and then a corresponding increase of the number of devices per wafer. This change impacts on the productivity of a production line and therefore the cost of the final device can be reduced. Higher production volume and lower cost will lead to a further massive implementation of SiC based power devices in the automotive industry that today is rushing on the path of electrification.
At STMicroelectronics we are an early adopter of 200 mm substrates since the first substrate was demonstrated in 2021. Development of 200 mm device quality substrates have progressed well and defect density are today in same range as for 150 mm substrates. The ramp up of production is now made in the new STMicroelectronics plant in Catania while R&D unit in Norrköping Sweden continue to further push the limits of the technology.
In this paper, we report the latest progress on STMicroelectronics 200 mm diameter crystals and substrates. We will discuss the most suitable characterization routes available and how we can detect device affecting defects at an early stage. In particular we will start by describing the mechanism that is behind the crystal growth process together with the characterization methods that allow to control the quality of the ingot by monitoring the relevant properties (i.e. bulk defectivity, polytype composition, internal stress). We will then describe the main key parameters to be controlled on the substrate to be sure it is suitable for device making (i.e. mechanical behavior, resistivity, surface roughness, effectiveness of the surface preparation). We will also describe the CVD process that is used to grow on top of the substrate an epitaxial layer with proper resistivity and thickness tailored on the device we need to produce for specific applications. In conclusion we will show some data about the correspondence in between device failure and defectivity on both substrate and epitaxial layer. A comparison of the results collected on both 6” and 8” substrates will be reported to show the excellent job performed in our R&D department in Norrköping to increase the wafer size maintaining the same level of quality. On the other side, our production line in Catania is going to be the first of this kind in Europe with a vertical integration that guarantee process control from the SiC powder to the design and characterization of the final power device.