Search

Lithium-ion batteries are expected to operate within a narrow temperature window around room temperature for optimal performance and lifetime. Therefore, in cold environments, electric vehicle battery packs must be extensively preheated prior to charge or discharge. However, conventional preheating is accomplished externally, which is slow and thus significantly increases charging times. Recently, internal heating has been demonstrated as a potential solution to quickly and uniformly preheat a lithium-ion pouch cell. However, internal heating has not been evaluated in other battery formats such as cylindrical batteries. In this work, we present a numerical model of a 4680 battery with internal heaters for fast preheating in cold environments. The effects that the number of heater layers, heating duration, resting duration, environmental temperature, and boundary heat transfer coefficient have on the temperature heterogeneity of the battery were investigated. The results show that internal heating alone reduces the temperature variation within the battery by a factor of 5 compared to external heating, and by a factor of 20 when combining internal and external heating. This study further proves that internal preheating of lithium-ion batteries is a promising thermal management strategy, and provides guidance on potential design considerations and heating protocols to implement internal heating. [ABSTRACT FROM AUTHOR]

To protect the environment and reduce dependence on fossil fuels, the world is shifting towards electric vehicles (EVs) as a sustainable solution. The development of fast charging technologies for EVs to reduce charging time and increase operating range is essential to replace traditional internal combustion engine (ICE) vehicles. Lithium-ion batteries (LIBs) are efficient energy storage systems in EVs. However, the efficiency of LIBs depends significantly on their working temperature range. However, the huge amount of heat generated during fast charging increases battery temperature uncontrollably and may lead to thermal runaway, which poses serious hazards during the operation of EVs. In addition, fast charging with high current accelerates battery aging and seriously reduces battery capacity. Therefore, an effective and advanced battery thermal management system (BTMS) is essential to ensure the performance, lifetime, and safety of LIBs, particularly under extreme charging conditions. In this perspective, the current review presents the state-of-the-art thermal management strategies for LIBs during fast charging. The serious thermal problems owing to heat generated during fast charging and its impacts on LIBs are discussed. The core part of this review presents advanced cooling strategies such as indirect liquid cooling, immersion cooling, and hybrid cooling for the thermal management of batteries during fast charging based on recently published research studies in the period of 2019–2024 (5 years). Finally, the key findings and potential directions for next-generation BTMSs toward fast charging are proposed. This review offers an in-depth analysis by providing recommendations and potential solutions to develop reliable and efficient BTMSs for LIBs during fast charging. [ABSTRACT FROM AUTHOR]

After an introductory reminder of safety concerns pertaining to early rechargeable battery technologies, this review discusses current understandings and challenges of advanced sodium-ion batteries. Sodium-ion technology is now being marketed by industrial promoters who are advocating its workable capacity, as well as its use of readily accessible and cheaper key cell components. Often claimed to be safer than lithium-ion cells, currently only limited scientifically sound safety assessments of sodium-ion cells have been performed. However, the predicted sodium-ion development roadmap reveals that significant variants of sodium-ion batteries have entered or will potentially enter the market soon. With recent experiences of lithium-ion battery failures, sodium-ion battery safety management will constitute a key aspect of successful market penetration. As such, this review discusses the safety issues of sodium-ion batteries, presenting a twofold innovative perspective: (i) in terms of comparison with the parent lithium-ion technology making use of the same working principle and similar flammable non-aqueous solvent basis, and (ii) anticipating the arrival of innovative sub-chemistries at least partially inspired from successive generations of lithium-ion cells. The authors hope that the analysis provided will assist concerned stakeholders in the quest for safe marketing of sodium-ion batteries. [ABSTRACT FROM AUTHOR]

Fault diagnosis is crucial to guarantee safe operation and extend the operating time while preventing the thermal runaway of the lithium-ion battery. This study presents a data-driven thermal runaway diagnosis framework where Bayesian optimization techniques are applied to optimize the hyperparameter of various machine learning techniques. We use different machine learning models such as support vector machine, naive Bayes, decision tree ensemble, and multi-layer perceptron to estimate a high likelihood of causes of thermal runaway by using the experimental measurements of open-source battery failure data. We analyze different evaluation metrics, including the prediction accuracy, confusion metrics, and receiver operating characteristic curves of different models. An experimental evaluation shows that the classification accuracy of the decision tree ensemble outperforms that of other models. Furthermore, the decision tree ensemble provides robust prediction accuracy even with the strictly limited dataset. [ABSTRACT FROM AUTHOR]

The fast charge and discharge of a battery will significantly increase the overall temperature and thermal difference of the battery, which will further affect the working performance and safety of the battery. Therefore, a heat–fluid coupling topology optimization pipeline for developing radiation performance of the cooling plate is presented to ensure the thermal homogeneity of the battery in this paper. First, the Brinkman penalty model is utilized to construct the solid and fluid structures. Then, a local volume constraint is introduced to create the lattice structure to reduce the temperature difference of the cooling plate. Furthermore, a functionally graded lattice structure via a variable influence radius is presented to improve the radiation performance of the cooling plate when the thermal load is uneven. Numerical experiments are carried out to evaluate the performance of the presented methods on the optimization of the cooling plate, which indicates that the designed cooling plate by the proposed method improves the radiation performance when compared against a traditional straight channel and a SIMP-based optimal design. [ABSTRACT FROM AUTHOR]

One of the key issues confronting modern greenhouses is the need to supply the necessary energy in an environmentally friendly manner to facilitate heating and cooling processes within greenhouses. Solar radiation entering the greenhouse during the day can sometimes be more than the energy demand of the greenhouse. In contrast, there are cases where the greenhouse must dissipate a significant amount of heat, absorbed over a long period, either naturally or forcibly, during the cooling process. Moreover, the system's efficiency could be enhanced if there is a mechanism capable of capturing heat expelled during greenhouse cooling and redistributing it on demand. Employing thermal energy storage is critical for maintaining stable temperatures, assuring energy efficiency, encouraging sustainability, and enabling year-round production. This technique ensures a safe environment for crops and eliminates temperature fluctuations inside the greenhouse. Nocturnal thermal energy storage, storing thermal energy during the daytime for later use at night, is essential to managing a contemporary greenhouse because it promotes consistent crop growth, sustainability, and profitability, particularly in areas with severe winters and significant day-to-night temperature variations. This work reviews various types of thermal energy storage systems employed in previous works focusing on greenhouse applications by researchers and categorizes them based on efficient factors. [ABSTRACT FROM AUTHOR]

Hydrogen is increasingly recognized as a clean and reliable energy vector for decarbonization in the future. In the marine sector, marine solid oxide fuel cells (SOFCs) that employ hydrogen as an energy source have already been developed. In this study, a multi-channel plate-anode-loaded SOFC was taken as the research object. A three-dimensional steady-state computational fluid dynamics (CFD) model for anode-supported SOFC was established, which is based on the mass conservation, energy conservation, momentum conservation, electrochemical reactions, and charge transport equations, including detailed geometric shapes, model boundary condition settings, and the numerical methods employed. The polarization curves calculated from the numerical simulation were compared with experimental results from the literature to verify the model's accuracy. The curved model was applied by enlarging the flow channels or adding blocks. Numerical calculations were employed to obtain the current density, temperature distribution, and component concentration distribution under the operating conditions of the SOFC. Subsequently, the distribution patterns of various physical parameters during the SOFC operation were analyzed. Compared to the classical model, the temperature of the curved model was reduced by 1.3%, and the velocities of the cathode and anode were increased by 4.9% and 5.0%, respectively, with a 2.42% enhancement in performance. The findings of this study provide robust support for research into and the application of marine SOFCs, and offer they insights into how we may achieving "dual carbon" goals. [ABSTRACT FROM AUTHOR]

The catalytic activity and thermomechanical stability of electrode materials are crucial for the efficient operation of reversible solid oxide cell (rSOC). However, these two traits often impose limitations on one another. In this work, a unique quintuple perovskite Sm2Ba3Co2Fe3O15‐δ (SBCF‐5L), comprising of A‐site ordered double perovskite layers and disordered simple perovskite layers, is reported as a high‐performance air electrode material for rSOC. The designed SBCF‐5L material exhibits a highly symmetrical tetragonal structure (pseudo‐cubic) with an isotropic thermal expansion and a limited chemical expansion. The formation barriers for oxygen vacancies are comparable between A‐site ordered layers and disordered simple perovskite layers, resulting in a high concentration of oxygen vacancies and 3D‐like bulk mobility of oxygen ions. Perpendicularly twinned nanodomains are developed in the particles, providing more active sites for surface electrode reaction. When applied in electrolyte‐supported cells, the SBCF‐5L electrode exhibits excellent electrochemical performance with low polarization resistance of 0.017 Ω cm−2, high power density of 1.01 W cm−2 and high electrolysis current density of 1.08 A cm−2 at 1.3 V at 800 °C in fuel cell and electrolysis modes, respectively. This study introduces a new approach of atomic‐scale engineering to rationally design a new generation of air electrodes for rSOC. [ABSTRACT FROM AUTHOR]

Micrometer‐sized silicon monoxide (SiO) is regarded as a high‐capacity anode material with great potential for lithium ion batteries (LIBs). However, the problems of low initial Coulombic efficiency (ICE), poor electrical conductivity, and large volume change of SiO inevitably impede further application. Herein, the vacuum thermal reduced SiOx with amorphous AlPO4 and carbon double‐coating layers is used as the ideal anode material in LIBs. The vacuum thermal reduction at low temperature forms fine silicon grains in the internal particles and maintains the external integrity of SiOx particles, contributing to mitigation of the stress intensification and the subsequent design of multifunctional coating. Meanwhile, the innovative introduction of the multifunctional amorphous AlPO4 layer not only improves the ion/electron conduction properties to ensure the fast reversible reaction but also provides a robust protective layer with stable physicochemical characteristics and inhibits the volume expansion effect. The sample of SiOx anode shows an ICE up to 87.6% and a stable cycling of 200 cycles at 1 A g−1 with an initial specific capacity of 1775.8 mAh g−1. In addition, the assembled pouch battery of 1.8 Ah can also ensure a cycling life of over 150 cycles, demonstrating a promising prospect of this optimized micrometer‐sized SiOx anode material for industrial applications. [ABSTRACT FROM AUTHOR]

Semiconductor ion fuel cells (SIFCs) have demonstrated impressive ionic conductivity and efficient power generation at temperatures below 600 °C. However, the lack of understanding of the ionic conduction mechanisms associated with composite electrolytes has impeded the advancement of SIFCs toward lower operating temperatures. In this study, a CeO2/β″‐Al2O3 heterostructure electrolyte is introduced, incorporating β″‐Al2O3 and leveraging the local electric field (LEF) as well as the manipulation of the melting point temperature of carbonate/hydroxide (C/H) by Na+ and Mg2+ from β″‐Al2O3. This design successfully maintains swift interfacial conduction of oxygen ions at 350 °C. Consequently, the fuel cell device achieved an exceptional ionic conductivity of 0.019 S/cm and a power output of 85.9 mW/cm2 at 350 °C. The system attained a peak power density of 1 W/cm2 with an ultra‐high ionic conductivity of 0.197 S/cm at 550 °C. The results indicate that through engineering the LEF and incorporating the lower melting point C/H, there approach effectively observed oxygen ion transport at low temperatures (350 °C), effectively overcoming the issue of cell failure at temperatures below 419 °C. This study presents a promising methodology for further developing high‐performance semiconductor ion fuel cells in the low temperature range of 300–600 °C. [ABSTRACT FROM AUTHOR]

Two new cold plates manufactured via metal 3D printing were experimentally investigated for thermal performance analysis in indirect liquid cooling operations; then they were compared to the traditional cold plates. Experiments were performed with different coolant inlet temperatures (15.7 °C and 24.5 °C) and ambient air velocities (0.5 m/s and 3 m/s) at tropical conditions; hereby, the impact of high dew point temperatures at tropics was also investigated. Body-centered cubic (BCC) and pillar elements were applied in the cooling cavity of the cold plates. The results showed that the target surface temperature in both BCC- and pillar-filled plate designs was maintained below the limits at the lower inlet temperature. However, at the higher inlet temperature, the temperature was only maintained below the limit when the ambient air velocity was 3 m/s. The convective heat transfer coefficient at the inlet temperature of 15.7 °C was found 1.5 and 2.5 times higher than the convective heat transfer coefficient value at the inlet temperature of 24.5 °C for the pillar- and BCC-filled plates, respectively. The performance evaluation criterion values were found in the range of 1.2 − 2.4, which depended on the operating conditions and were already higher than the referenced studies in the literature. [ABSTRACT FROM AUTHOR]

This paper reports on a novel hybrid thermal management strategy. It uses secondary coolants (air and liquid) to withdraw heat simultaneously from the composite phase change material, resulting in increased heat extraction capability of the composite phase change material and improved thermal environment of the battery module. The significance of this strategy is that the fluid used in the liquid cooling stays stationary. Comprehensive experimental and numerical studies are performed, and parametric studies are conducted to reduce the volume of the phase change material, size of the air duct, and airflow Reynolds number. The numerical results showed that the maximum temperature was limited to 27.8°C, and a high‐temperature uniformity of 0.4°C was obtained. Furthermore, the required volume of the composite phase change material is reduced by ~50%. Additionally, beyond a 6 mm height of the air duct, the reduction in maximum pressure drop is not significant enough, and it is considered the optimal height, and a Reynolds number of 1950 is considered the optimal airflow Reynolds number. Therefore, the proposed thermal management concept for the battery module can sustain the thermal environment needed for the effective operation of Lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are alternatives to traditional combustion engine-powered vehicles. This work focuses on a thermal management system for battery EVs using liquid cooling and a machine learning (ML) model to predict their thermal-related health. Real-world data of EV operation, battery and cooling conditions were collected. Key influencing factors on the thermal-related health of batteries were identified. The ML model's effectiveness was evaluated against experimental test data. The ML model proved effective in predicting and analyzing battery thermal health, suggesting its potential for use with the thermal management system. [ABSTRACT FROM AUTHOR]

Batteries, particularly lithium‐ion batteries, are sensitive to temperature changes. Battery thermal management systems (BTMS) are essential in various battery‐powered applications, especially electric vehicles (EVs) and portable electronic devices. This study examines the importance of phase change material (PCM) in battery packs using numerical analysis. An examination is conducted on a battery pack consisting of 18 650 battery cells arranged in a 5 × 5 configuration. A comparative analysis is performed to evaluate the thermal efficiency of the battery pack with and without PCM. The study examines the influence of ambient conditions and charging rates on the selection of PCM for battery packs. A hybrid cooling solution utilizing PCM and a water tube has also been investigated against conventional passive PCM‐based BTMS. Additionally, two types of fins, namely circular and spiral fins, are introduced to improve the heat transfer rate. PCM‐based cooling systems are most effective when the ambient temperature is below the melting temperature of the PCM. However, when the ambient temperature exceeds the melting temperature of the PCM, this cooling system outperforms conventional PCM‐based cooling. The maximum temperature is found as 319, 316.9, and 315.3 K using without fin, circular fin and spriral fina, respectively. The spiral fins are found more effective than circular fins under high ambient temperature. In conclusion, The PCM‐with spiral‐fin system demonstrates notable benefits in high‐temperature environments. [ABSTRACT FROM AUTHOR]

The study investigates the approach to enhance the thermal management of battery cell module by attaching number of inverted triangular cavity to its casing. A sinusoidal heating is considered to battery cell module or a left wall of the cavity. The sinusoidal heated region is considered to be a function of amplitude ratio. The objective is to transfer the heat from module using natural convection process. The enhanced heat transfer is possible by adopting hybrid nanofluid in a triangular cavity due to its improved thermophysical properties. Thus, the investigation on natural convection heat transfer, fluid flow, and irreversibility within an inverted right-angled triangular porous cavity is conducted. Numerical results are obtained through an own-house FORTRAN coding, that uses the streamfunction–vorticity algorithm. The numerical results are derived for various values with Rayleigh number ( 10 3 - 10 6 ), Darcy number ( 10 - 5 - 10 - 1 ) , Hartmann number ( 0 - 50) , amplitude ratio ( 0.0 - 0.9 ) and volume fraction of nanoparticles ( 0.01 - 0.04 ), respectively. The irreversibility and flow results are compared with the various hybrid nanofluids. The study indicates that opting inverted right-angled triangular cavity rather than a square shape leads to an improvement in heat transfer. Accordingly, this inverted right-angled triangular cavity natural convective cooling can be considered as optimum design with the battery cell module for improved thermal management. [ABSTRACT FROM AUTHOR]

As the EV and battery market continues to grow, understanding and mitigating battery thermal runaway remains a critically important area of research. Under controlled experimental conditions, researchers have employed a range of different techniques to initiate battery fires and understand both how and why they occur. These tests give important information about how a battery cell catastrophically fails under abuse conditions. However, recognizing the changes in the internal structure of the cell is vital to understanding the mechanisms of thermal runaway which enables the development of effective mitigation strategies. During the last decade, X-ray imaging has emerged as an important diagnostic tool for battery degradation, electrochemical performance, and safety diagnostics. Researchers use X-ray imaging to directly observe the internal changes in the cell during all stages of thermal runaway. Depending on the initiation method, it can sometimes take minutes, hours, or days for a cell to undergo failure. However, the actual final reactions that cause thermal runaway occur over fractions of a second. High-speed cameras, operating at up to 40,000 frames per second, can capture the interactions between electrodes at the final moments of thermal runaway. In this article, the basics of high-speed X-ray imaging and how this technique has been applied to investigating battery thermal runaway are discussed. [ABSTRACT FROM AUTHOR]

This article discusses the dual challenges of modeling and predicting thermal runaway (TR) in li-ion batteries. It explores the current challenges of TR modeling, the methods for progressing from single cells to battery packs, and future directions involving the use of probabilistic methods and ML/AI to tackle this multifaceted issue. Accurate prediction of TR events remains a major challenge, especially because of the cell-to-cell variability, but also due to parametrization, which requires complex experimentation or exhaustive experimental data for training data-driven ML models. Continued research and innovation in modeling and predictive techniques are essential for ensuring safer and more reliable battery systems. [ABSTRACT FROM AUTHOR]

The thermal performance of a lithium-ion battery pack for an electric vehicle by adding straight rib turbulators in battery cooling plate channels has been numerically investigated in this paper and the numerical model of the battery pack has been validated by experimental data, which exhibits a satisfactory prediction accuracy. The effects of rib shapes, rib angles, rib spacings, and irregular gradient rib arrangement configurations on the flow and heat transfer behaviors of battery pack cooling plates have been thoroughly explored and analyzed in this paper. In addition, the thermal performance of the ribbed battery cooling plates was examined at actual high-speed climbing and low-temperature heating operating conditions. The results indicate that compared to the original smooth cooling plate, the square-ribbed battery cooling plate with a 60° angle and 5 mm spacing reduced the maximum battery temperature by 0.3 °C, but increased the cross-sectional temperature difference by 0.357 °C. To address this issue, a gradient rib arrangement was proposed, which slightly reduced the maximum battery temperature and lowered the cross-sectional temperature difference by 0.445 °C, significantly improving temperature uniformity. The thermal performance of the battery thermal management system with this gradient rib configuration meets the requirements for typical electric vehicle operating conditions, such as high-speed climbing and low-temperature heating conditions. [ABSTRACT FROM AUTHOR]

As one of the core components of electric vehicles, Li-ion batteries (LIBs) have attracted intensive attention due to their high energy density and good long-term cycling stability. However, some abuse conditions inevitably occur during battery operation, resulting in safety accidents such as the thermal runaway (TR) of LIBs. Therefore, the efficient and appropriate thermal insulation material design is crucial for LIB packs to effectively reduce or even inhibit the spread of TR. Based on it, in this review, we present the principle and influences of TR to provide the necessity of battery thermal management and thermal insulating materials. Then, we deeply discuss and compare the two kinds of representative thermal insulating materials: phase change thermal insulating materials and barrier-type thermal insulating materials. Their properties, synthesis methods, and modification means are investigated to provide some guidance for the future application of high-performance thermal insulating materials in the field of LIBs. [ABSTRACT FROM AUTHOR]

This study examines the thermal behavior of lithium-ion battery modules intended for Urban Air Mobility (UAM), a forthcoming urban transport system designed to facilitate efficient and secure passenger and cargo transport within city centers. UAM applications necessitate batteries with high energy densities capable of sustaining elevated discharge rates during critical phases such as takeoff and landing. The battery module evaluated in this study comprises four cells arranged in series and configured as a submodule for UAM applications. A three-dimensional thermal model was utilized to analyze the impact of external temperature fluctuations and high discharge rates on the performance of the battery module. The numerical findings indicated considerable variations in temperature and internal resistance among the cells, especially under high discharge rates at low temperatures, with a maximum temperature deviation of 32.952 °C observed at an 8 C discharge rate. These thermal non-uniformities were attributed to variations in cell capacity and internal resistance, which were amplified by manufacturing inconsistencies and operational conditions. The study underscores the necessity of robust thermal management strategies to mitigate the risk of thermal runaway and ensure the operational safety and reliability of UAM systems. The results emphasize the critical role of advanced Battery Management Systems (BMS) in monitoring and controlling cell voltage and temperature to achieve consistent performance across the battery module. This research contributes valuable insights into the design of more efficient and reliable battery modules for UAM, highlighting the importance of addressing cell-to-cell performance discrepancies to enhance overall module efficacy and durability. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries (LIBs) play a pivotal role in today's society, with widespread applications in portable electronics, electric vehicles, and smart grids. Commercial LIBs predominantly utilize graphite anodes due to their high energy density and cost‐effectiveness. Graphite anodes face challenges, however, in extreme safety‐demanding situations, such as airplanes and passenger ships. The lithiation of graphite can potentially form lithium dendrites at low temperatures, causing short circuits. Additionally, the dissolution of the solid‐electrolyte‐interphase on graphite surfaces at high temperatures can lead to intense reactions with the electrolyte, initiating thermal runaway. This review introduces two promising high‐safety anode materials, Li4Ti5O12 and TiNb2O7. Both materials exhibit low tendencies towards lithium dendrite formation and have high onset temperatures for reactions with the electrolyte, resulting in reduced heat generation and significantly lower probabilities of thermal runaway. Li4Ti5O12 and TiNb2O7 offer enhanced safety characteristics compared to graphite, making them suitable for applications with stringent safety requirements. This review provides a comprehensive overview of Li4Ti5O12 and TiNb2O7, focusing on their material properties and practical applicability. It aims to contribute to the understanding and development of high‐safety anode materials for advanced LIBs, addressing the challenges and opportunities associated with their implementation in real‐world applications. [ABSTRACT FROM AUTHOR]

The development of high‐performance organic solar cells (OSCs) with high operational stability is essential to accelerate their commercialization. Unfortunately, our understanding of the origin of instabilities in state‐of‐the‐art OSCs based on bulk heterojunction (BHJ) featuring non‐fullerene acceptors (NFAs) remains limited. Herein, we developed NFA‐based OSCs using different charge extraction interlayer materials and studied their storage, thermal, and operational stabilities. Despite the high power conversion efficiency (PCE) of the OSCs (17.54%), we found that cells featuring self‐assembled monolayers (SAMs) as hole‐extraction interlayers exhibited poor stability. The time required for these OSCs to reach 80% of their initial performance (T80) was only 6 h under continuous thermal stress at 85 °C in a nitrogen atmosphere and 1 h under maximum power point tracking (MPPT) in a vacuum. Inserting MoOx between ITO and SAM enhanced the T80 to 50 and ~15 h after the thermal and operational stability tests, respectively, while maintaining a PCE of 16.9%. Replacing the organic PDINN electron transport layer with ZnO NPs further enhances the cells' thermal and operational stability, boosting the T80 to 1000 and 170 h, respectively. Our work reveals the synergistic roles of charge‐selective interlayers and device architecture in developing efficient and stable OSCs. [ABSTRACT FROM AUTHOR]

The design of an efficient thermal management system for a lithium-ion battery pack hinges on a deep understanding of the cells' thermal behavior. This understanding can be gained through theoretical or experimental methods. While the theoretical study of the cells using electrochemical and numerical methods requires expensive computing facilities and time, the Equivalent Circuit Model (ECM) offers a more direct approach. However, upfront experimental cell characterization is needed to determine the ECM parameters. In this study, the behavior of a cell is characterized experimentally, and the results are used to build a second-order equivalent electrical circuit model of the cell. This model is then integrated with the cooling system of the battery pack for effective thermal management. The Equivalent Circuit Model estimates the internal heat generation inside the cell using instantaneous load current, terminal voltage, and temperature data. By extrapolating the heat generation data of a single cell, we can determine the heat generation of the cells in the pack. With the implementation of the ECM in the cooling system, the coolant flow rate can be adjusted to ensure the attainment of a safe operating cell temperature. Our study confirms that 14% of pumping power can be reduced when compared to the conventional constant flow rate cooling system, while still maintaining the temperature of the cells within safe limits. [ABSTRACT FROM AUTHOR]

As the preferred technology in the current energy storage field, lithium-ion batteries cannot completely eliminate the occurrence of thermal runaway (TR) accidents. It is of significant importance to employ real-time monitoring and warning methods to perceive the battery's safety status promptly and address potential safety hazards. Currently, the monitoring and warning of lithium-ion battery TR heavily rely on the judgment of single parameters, leading to a high false alarm rate. The application of multi-parameter early warning methods based on data fusion remains underutilized. To address this issue, the evaluation of lithium-ion battery safety status was conducted using the cloud model to characterize fuzziness and Dempster–Shafer (DS) evidence theory for evidence fusion, comprehensively assessing the TR risk level. The research determined warning threshold ranges and risk levels by monitoring voltage, temperature, and gas indicators during lithium-ion battery overcharge TR experiments. Subsequently, a multi-parameter fusion approach combining cloud model and DS evidence theory was utilized to confirm the risk status of the battery at any given moment. This method takes into account the fuzziness and uncertainty among multiple parameters, enabling an objective assessment of the TR risk level of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are extensively utilized in electric vehicles (EVs), energy storage systems, and related fields due to their superior performance and high energy density. However, battery-related incidents, particularly fires, are increasingly common. This paper aims to first summarize the flame behavior of LIBs and then thoroughly examine the factors influencing this behavior. Based on these factors, methods for suppressing LIB flames are identified. The factors affecting flame behavior are categorized into two groups: internal and external. The paper then reviews the flame behavior within battery modules, particularly in confined spaces, from both experimental and simulation perspectives. Furthermore, methods for suppressing battery flames are classified into active and passive techniques, allowing for a more comprehensive analysis of their effectiveness. The paper concludes with a summary and outlook, offering new insights for future research and contributing to the development of safer and more efficient battery systems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The safety of lithium-ion batteries is critical to the safety of battery electric vehicles (BEVs). The purpose of this work is to develop a method to predict battery thermal runaway in full electric vehicle crash simulation. The thermal–electrical–mechanical-coupled finite element analysis is used to model an individual lithium-ion battery cell, a battery module, a battery pack, and a battery electric vehicle with 24 battery modules in a live circuit connection. The lithium-ion battery is modeled using a representative approach, with each internal battery component individually modeled to represent its geometric shape and realistic thermal, mechanical, and electrical properties. A resistance heating solver and Randles circuit model built with a generalized voltage source are used to simulate the electrical behavior of the battery. The thermal simulation of the battery considers the heat capacity and thermal conductivity of different cell components, as well as heat conduction, radiation, and convection at their interfaces. The mechanical property of battery cell and battery module models is validated using spherical punch tests. The electrical property of the battery cell and battery module models is verified against CircuitLab simulation in an external short-circuit test. The simulation results for the battery module's internal resistance are consistent with both experimental data and literature values. The multi-physics coupling phenomenon is demonstrated with a cylindrical compression simulation on the battery module. The multi-physics BEV model with 24 live battery modules is used to simulate the external short-circuit test and the side pole impact test. The simulation run time is less than 24 h. The results demonstrated the feasibility of using a representative battery model and multi-physics analysis to predict battery thermal runaway in full electric vehicle crash analysis. [ABSTRACT FROM AUTHOR]

Oxides with the same structure as K 2 NiF 4 have received increasing interest in reversible solid oxide cells (RSOCs) because of the unique advantages of low thermal expansion efficient (TEC), fast oxygen exchange kinetics, and high chemical stability. Herein, Fe-doped Nd 0.8 Sr 1.2 Ni 1-x Fe x O 4±δ (x = 0, 0.15, 0.3, 0.45, NSNF) oxygen electrodes with fast oxygen reduction/evolution reactions (ORR/OER) kinetics are reported. The optimal composition of NSNF is found to be NSNF45 (x equals to 0.45) and the best ratio of NSNF45 to GDC is 6:4 by the mass ratio, delivering a low polarization resistance of 0.067 Ω cm2 at 800 °C. The RSOC with Co-free NSNF45-GDC (6:4) composite oxygen electrode achieves a high peak power density of 1.33 W cm−2 and a favorable electrolysis current density of 1.39 A cm−2 at 1.32 V with 50% steam concentration at 800 °C. Additionally, the reversible cycling between fuel cell and electrolysis modes at 700 °C and the thermal cycling between 700 °C and 300 °C show excellent stability over four hundred hours. The results indicate that composite NSNF45-GDC can be utilized as a promising oxygen electrode material for RSOCs. • A series of Nd 0.8 Sr 1.2 Ni 1-x Fe x O 4±δ are synthesized and evaluated. • The optimal NSNF45-GDC composite shows a R p of 0.067 Ω cm2 at 800 °C. • The cell show good electrochemical performance in both FC and EC modes. • High stability is demonstrated after the reversible cycling and thermal cycling test. [ABSTRACT FROM AUTHOR]

Passivation of perovskite crystals is a crucial strategy to improve the efficiency and stability of perovskite solar cells (PSCs). Zwitterions, which contain both positive and negative charges in the molecule, can be used to passivate perovskite crystals. However, these materials strongly interact with each other, resulting in extremely low solubility in common organic solvents. The low solubility of zwitterions hinders the formation of uniform films, which negatively affects perovskite crystal growth. In this study, a liquid‐type zwitterion (LTZ) is synthesized by modulating intermolecular interactions of the zwitterion (3‐(1‐Pyridinio)‐1‐propanesulfonate). By suppressing intermolecular interactions, the solubility and processibility of the zwitterion in common organic solvents are successfully improved. The well‐distributed LTZ‐treated films are obtained, resulting in better electrical properties for the PSCs compared to solid‐type zwitterion‐based devices. With these characteristics, the resulting device achieves a power conversion efficiency of 24.9% with excellent thermal stability (under 60 °C and N2 atmosphere), maintaining over 80% of its initial efficiency for 1968 h. In addition, the PSC module (active area of 32.7 cm2) achieves an improved efficiency of 19.86% with high open‐circuit voltage and fill factor. The results suggest that interface engineering with an LTZ has the potential to fabricate efficient and stable PSCs. [ABSTRACT FROM AUTHOR]

Background: Lipids produced using oleaginous yeast cells are an emerging feedstock to manufacture commercially valuable oleochemicals ranging from pharmaceuticals to lipid-derived biofuels. Production of biofuels using oleaginous yeast is a multistep procedure that requires yeast cultivation and harvesting, lipid recovery, and conversion of the lipids to biofuels. The quantitative recovery of the total intracellular lipid from the yeast cells is a critical step during the development of a bioprocess. Their rigid cell walls often make them resistant to lysis. The existing methods include mechanical, chemical, biological and thermochemical lysis of yeast cell walls followed by solvent extraction. In this study, an aqueous thermal pretreatment was explored as a method for lysing the cell wall of the oleaginous yeast Rhodotorula toruloides for lipid recovery. Results: Hydrothermal pretreatment for 60 min at 121 °C with a dry cell weight of 7% (w/v) in the yeast slurry led to a recovery of 84.6 ± 3.2% (w/w) of the total lipids when extracted with organic solvents. The conventional sonication and acid-assisted thermal cell lysis led to a lipid recovery yield of 99.8 ± 0.03% (w/w) and 109.5 ± 1.9% (w/w), respectively. The fatty acid profiles of the hydrothermally pretreated cells and freeze-dried control were similar, suggesting that the thermal lysis of the cells did not degrade the lipids. Conclusion: This work demonstrates that hydrothermal pretreatment of yeast cell slurry at 121 °C for 60 min is a robust and sustainable method for cell conditioning to extract intracellular microbial lipids for biofuel production and provides a baseline for further scale-up and process integration. Highlights: Hydrothermal pretreatment was evaluated as a method for lysing oleaginous yeast cell walls. Thermal lysis of a yeast slurry (7% w/v, dry cell weight basis) at 121 °C for 60 min. followed by solvent extraction yielded 84.6 ± 3.2% (w/w) of the total lipids. Hydrothermal pretreatment of a yeast slurry (7% (w/v, dry cell weight basis)) at 170 °C for 10 min yielded 35.6 ± 0.6% (w/w) of the total lipids. Conditioning yeast slurry at 121 °C for 60 min is proposed to be a green scalable method for cell lysis. [ABSTRACT FROM AUTHOR]

In the current era of energy conservation and emission reduction, the development of electric and other new energy vehicles is booming. With their various attributes, lithium batteries have become the ideal power source for new energy vehicles. However, lithium-ion batteries are highly sensitive to temperature changes. Excessive temperatures, either high or low, can lead to abnormal operation of the batteries, posing a threat to the safety of the entire vehicle. Therefore, developing a reliable and efficient Battery Thermal Management System (BTMS) that can monitor battery status and prevent thermal runaway is becoming increasingly important. In recent years, deep learning has gradually become widely applied in various fields as an efficient method, and it has also been applied to some extent in the development of BTMS. In this work, we discuss the basic principles of deep learning and related optimization principles and elaborate on the algorithmic principles, frameworks, and applications of various advanced deep learning methods in BTMS. We also discuss several emerging deep learning algorithms proposed in recent years, their principles, and their feasibility in BTMS applications. Finally, we discuss the obstacles faced by various deep learning algorithms in the development of BTMS and potential directions for development, proposing some ideas for progress. This paper aims to analyze the advanced deep learning technologies commonly used in BTMS and some emerging deep learning technologies and provide new insights into the current combination of deep learning technology in new energy trams to assist the development of BTMS. [ABSTRACT FROM AUTHOR]

A three-dimensional organic–inorganic hybrid halide perovskite (CH3NH3PbI2Br) nanoparticle film was synthesized using solution process in one step. Precursors' stoichiometry was used to prepare methylammonium bromide and lead (II) bromide in dimethyl formamide. The synthesized CH3NH3PbI2Br solution was spin coated on cleaned ITO prepatterned glass substrate at 2000 rpm. In addition, the influence of post-thermal treatment on the deposited nanoparticles films was evaluated by studying the structural, optical and morphological properties using X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectrometry, UV–visible spectrophotometry, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The average crystallite sizes were calculated to be ~ 8.0, ~ 9.4, ~ 11.3 and ~ 13.1 nm of as-prepared and annealed films at 400, 500 and 600 °C, respectively. Besides, the bandgaps of 2.22 eV, 1.96 eV, 1.89 eV and 1.63 eV were extrapolated for as-prepared and annealed films at 400 °C, 500 °C and 600 °C, respectively. From J–V curves, the Jsc values of 9.4, 10.6, 11.7 and 12.8 mAcm−2, FF values of 56.99%, 57.25%, 58.94% and 59.26% and PCE values of 2.99%, 3.49%, 3.96% and 4.39% were calculated for as-prepared and annealed CH3NH3PbI2Br films at 400 °C, 500 °C and 600 °C, respectively. The percentage enhancement values of 14.32%, 24.49% and 31.89% compared to as-prepared CH3NH3PbI2Br film. Hence, post-thermal treatment of organic–inorganic halide perovskite material improved its photoconversion efficiency without sacrificing its dimensionality. [ABSTRACT FROM AUTHOR]

Background: Xanthenes and multi-aryl carbon core containing compounds represent different types of complex and condensed architectures that have impressive wide range of pharmacological, industrial and synthetic applications. Moreover, indoles as building blocks were only found in naturally occurring metabolites with di-aryl carbon cores and in chemically synthesized tri-aryl carbon core containing compounds. Up to date, rare xanthenes with indole bearing multicaryl carbon core have been reported in natural or synthetic products. The underlying mechanism of fluorescein-like arthrocolins with tetra-arylmethyl core were synthesized in an engineered Escherichia coli fed with toluquinol remained unclear. Results: In this study, the Keio collection of single gene knockout strains of 3901 mutants of E. coli BW25113, together with 14 distinct E. coli strains, was applied to explore the origins of endogenous building blocks and the biogenesis for arthrocolin assemblage. Deficiency in bacterial respiratory and aromatic compound degradation genes ubiX, cydB, sucA and ssuE inhibited the mutant growth fed with toluquinol. Metabolomics of the cultures of 3897 mutants revealed that only disruption of tnaA involving in transforming tryptophan to indole, resulted in absence of arthrocolins. Further media optimization, thermal cell killing and cell free analysis indicated that a non-enzyme reaction was involved in the arthrocolin biosynthesis in E. coli. Evaluation of redox potentials and free radicals suggested that an oxygen-mediated free radical reaction was responsible for arthrocolins formation in E. coli. Regulation of oxygen combined with distinct phenol derivatives as inducer, 31 arylmethyl core containing metabolites including 13 new and 8 biological active, were isolated and characterized. Among them, novel arthrocolins with p-hydroxylbenzene ring from tyrosine were achieved through large scale of aerobic fermentation and elucidated x-ray diffraction analysis. Moreover, most of the known compounds in this study were for the first time synthesized in a microbe instead of chemical synthesis. Through feeding the rat with toluquinol after colonizing the intestines of rat with E. coli, arthrocolins also appeared in the rat blood. Conclusion: Our findings provide a mechanistic insight into in vivo synthesis of complex and condensed arthrocolins induced by simple phenols and exploits a quinol based method to generate endogenous aromatic building blocks, as well as a methylidene unit, for the bacteria-facilitated synthesis of multiarylmethanes. [ABSTRACT FROM AUTHOR]

To reduce the battery performance attenuation of electric vehicles under high and low temperature conditions, it is necessary to design a battery thermal management system to avoid unnecessary energy consumption, while improving safety and endurance. In this paper, a battery thermal management system is established. Considering the time-delay and nonlinear characteristics of the battery system itself, the control strategy is designed based on multivariate model predictive control (MPC), and the simulation is carried out based on MATLAB. Simulation results show that MPC controller can save energy and improve efficiency, and have a better control effect than PID control. [ABSTRACT FROM AUTHOR]

In this paper, a novel power management strategy (PMS) is proposed for optimal real-time power distribution between battery and supercapacitor hybrid energy storage system in a DC microgrid. The DC-bus voltage regulation and battery life expansion are the main control objectives. Contrary to the previous works that tried to reduce the battery current magnitude and its fluctuation to increase the battery life, the battery thermal considerations, which are a key factor in battery life, are also considered as an objective function in the proposed PMS. Also, the quick charging capability of the battery is another objective in the optimization problem. To solve this multi-objective problem, the Karush–Kuhn–Tucker conditions have been used to make the PMS suitable for real-time operation. In addition, one of the important inputs of conventional PMS is the amount of grid excess/deficiency power. Due to the use of the adaptive Kalman filter estimator, another superior of the proposed PMS is using local data and no need for communication and knowledge of the load or generation power. Using simulation, the performance of the proposed method is compared with three traditional methods filter-based, droop control, and fuzzy logic in terms of controlling the battery current, battery temperature, and battery health, and its superiority has been shown. Finally, the validation of the proposed PMS is experimentally tested on a real setup. [ABSTRACT FROM AUTHOR]

Recent research has focused on applying PEM fuel cell systems to heavy-duty unmanned aerial vehicles (UAVs) as eco-friendly power sources to enhance their mission capabilities. High-altitude operation poses challenges owing to low temperatures, poor oxygen concentrations, and humidity, which affect fuel cell performance. In this study, the thermal stability of a PEM fuel cell system for UAVs was analyzed using an integrated system model in MATLAB/Simulink. Parametric studies were conducted to analyze the thermal parameters of the stack and observe the changes in the cooling load of the system according to the cruising altitude, as well as variations in the optimal operating conditions to ensure the durability of the fuel cell stack. The results of this study are expected to contribute to the selection of optimal operating conditions and the development of thermal management strategies for PEM fuel cell-based UAVs operating at different cruising altitudes. [ABSTRACT FROM AUTHOR]

To suppress the thermal runaway (TR) and its propagation in lithium‑ion batteries, a nitrogen and water mist (NWM) biphasic flow system is constructed. By changing the pressure and duration of the system, comparing the surface temperature and the volume fraction of flue gas emitted from the batteries, and analyzing the cooling power of NWM and the heat accumulation in the battery module, the mechanism and effectiveness of NWM system in suppressing TR propagation in the lithium‑ion battery module are studied. The results show that under the synergistic effect of NWM cooling the battery module surface and the suffocation mechanism, duration of the jet fire of the battery module is significantly reduced. Moreover, higher NWM pressure and longer duration of the system leads to lower peak temperature on the battery surface, and time intervals for TR propagation between adjacent batteries increases, demonstrating a significantly enhanced effectiveness of NWM in suppressing the propagation of TR in lithium‑ion batteries. [ABSTRACT FROM AUTHOR]

With the increasingly widespread application of large-scale energy storage battery systems, the demand for battery safety is rising. Research on how to detect battery anomalies early and reduce the occurrence of thermal runaway (TR) accidents has become particularly important. Existing research on battery TR warning algorithms can be mainly divided into two categories: model-driven and data-driven methods. However, the common model-driven methods are often of high complexity, with poor versatility and low early warning capability; and the common data-driven methods are mostly based on neural networks, requiring substantial training costs, with better early warning capabilities but higher false alarm probabilities. To address the limitations of existing works, this paper proposes a combined data-driven and model-based algorithm for accurate battery TR warnings. Specifically, the K-Means algorithm serves as the data-driven module, capturing outliers in battery data, and the Bernardi equation serves as the model-driven module used to evaluate battery temperature. Ultimately, the outputs of the weighted model-driven module and data-driven module are combined to comprehensively assess whether the battery is abnormal. The proposed algorithm combines the advantages of model-driven and data-driven approaches, achieving a 25 min advance warning for thermal runaway, with a significantly reduced probability of false alarms. [ABSTRACT FROM AUTHOR]

Isocyanates are critical components that affect the crosslinking density and structure of polyurethane (PU) foams. However, due to the cost and hazardous nature of the precursor for isocyanate synthesis, there is growing interest in reducing their usage in polyurethane foam production—especially in rigid PU foams (RPUF) where isocyanate is used in excess of the stoichiometric ratio. In this study, lignin-containing nanocellulose fibrils (LCNF) were explored as mechanical reinforcements for RPUF with the goal of maintaining the mechanical performance of the foam while using less isocyanate. Different amounts of LCNF (0–0.2 wt.%) were added to the RPUF made using isocyanate indices of 1.1, 1.05, 1.0, and 0.95. Results showed that LCNF served as a nucleating agent, significantly reducing cell size and thermal conductivity. LCNF addition increased the crosslinking density of RPUF, leading to enhanced compressive properties at an optimal loading of 0.1 wt.% compared to unreinforced foams at the same isocyanate index. Furthermore, at the optimal loading, LCNF-reinforced foams made at lower isocyanate indices showed comparable stiffness and strength to unreinforced foams made at higher isocyanate indices. These results highlight the reinforcing potential of LCNF in rigid polyurethane foams to improve insulation and mechanical performance with lower isocyanate usage. [ABSTRACT FROM AUTHOR]

To establish battery electric vehicles as an attractive alternative to internal combustion vehicles, charging times of 15 min or less are increasingly demanded. This is especially challenging for lower battery temperatures, as this exacerbates the risk of accelerated battery degradation due to lithium plating. Therefore, active battery heating is utilized in state-of-the-art electric vehicles. To evaluate the impact of such heating strategies at vehicle level, we deployed an electrochemical battery model coupled with a longitudinal vehicle dynamics model. Using anode potential control to prevent lithium plating, we assess the time-saving potential versus the energy cost of different preconditioning and fast-charging strategies. The results reveal substantial energy saving and charge speed increase potential through optimal charge-stop planning, preconditioning timing, cost-adjusted thermal management thresholds, and considering driving behavior. This emphasizes the need for advanced operation strategies, taking into account both battery-level electrical and thermal restrictions, as well as vehicle integration and route planning. [ABSTRACT FROM AUTHOR]

Lithium‐ion batteries are widely used in various industrial and consumer applications. One key point is the thermal stability of these batteries regarding safety. Thermogravimetric analysis and differential scanning calorimetry (DSC) are ideal methods to study the thermal properties of differently charged electrode materials without safety issues associated with thermal runaway tests of the complete cell. This study shows a significant relationship between state of charge (SOC) and power released by the electrode material during the heating process. For the utilized cathode material LixCoO2, a linear relationship is apparent between the decomposition temperature and the decomposition energy, enabling estimation of the SOC. The decomposition temperature of differently charged anode material strongly correlates with the selected heating rate. This study reveals substantial dependencies of the measured power on the utilized crucibles, providing a systematic approach to benchmark the impact of crucible type on observed DSC signals during battery component analysis. [ABSTRACT FROM AUTHOR]

In order to solve the compatibility problem of lithium batteries thermal management and cabin comfort in electric vehicles, a refrigerant direct cooling thermal management system is designed in this article, which is expected to balance the temperature demands of entire vehicle at different driving conditions. A one‐dimensional model is established to investigate the system performance, whose accuracy has been verified by the testing bench of a prototype fixed with a 16‐battery module. By the aid of this model, the thermal characteristics of the battery pack and the passenger cabin are obtained, and the compressor speed as well as the valves are selected as control units by sensitivity analysis of the important components. Subsequently, detailed control strategies around the variable frequency of compress speed and switch regulation for the valves are proposed based on the temperature changes, torque, and operating power consumption of the system in different control modes. Under the test conditions of the global light‐duty vehicle test procedure, it is found that cabin temperature can be quickly stabilized about 26 °C under different ambient temperatures. Additionally, the battery pack can be effectively maintained within the safe operating temperature range of 20–40 °C. [ABSTRACT FROM AUTHOR]

The instability of perovskite solar cells (PSCs) remains a major bottleneck for their commercialization, with thermal instability posing a major concern, given the inevitable presence of heat in photovoltaic devices. Mixed‐cation/halide perovskites demonstrate enhanced stability and efficiency compared to single‐cation/halide perovskites. Identifying the optimal perovskite composition capable of withstanding high temperatures for longer durations is crucial for the development of thermally stable PSCs. This study provides valuable insights into the optimization of mixed‐cation/halide perovskites to enhance the thermal and structural stability of perovskite films. By systematically varying the Cs content in FA1−yCsyPb(I0.85Br0.15)3 (0 < y < 25)‐based perovskite, it is observed that controlling the Cs content allows precise modulation of crystal orientation in perovskite film with 10% Cs obtained as the optimal value. The perovskite film containing 10% Cs not only exhibits reduced microstrain but also demonstrates enhanced thermal stability during testing at 85 °C under controlled humidity. Furthermore, planar PSCs are fabricated using FA0.90Cs0.10Pb(I0.85Br0.15)3 as the absorber layer and TOP‐3 as the hole‐transporting material, achieving a promising power conversion efficiency (PCE) of 17.70%. Impressively, the unencapsulated devices retain 95% of their initial PCE after 1000 h of dark storage under ambient conditions. [ABSTRACT FROM AUTHOR]

Since their invention by Akachi in 1990s, pulsating heat pipes (PHPs) have attracted widespread interest and application in practice, e.g., grinding, chip cooling, the thermal management of batteries, etc., owing to their notable efficiency in heat transfer and their simplicity and flexibility in structure. Key factors influencing the heat transfer efficacy of pulsating heat pipes are mainly attributed to the thermophysical properties of the working fluid, the structural parameters, and the operating conditions. Research on pulsating heat pipes is conducted through theoretical investigations, numerical simulations, and visual experiments. In this paper, the research on PHPs in recent decades is reviewed with the consideration of the heat transfer performance mechanism and application of pulsating heat pipes, especially research under operation conditions such as with "status with motion" and with "inconsistent heat flux". [ABSTRACT FROM AUTHOR]

Ternary lithium batteries have been widely used in transportation and energy storage due to their high energy density and long cycle life. However, safety issues arising from thermal runaway (TR) need urgent resolution. Current research on thermal runaway in large-capacity ternary lithium batteries is limited, making the study of hazard indicators during the thermal runaway ejection process crucial. This study places a commercial 156 Ah prismatic battery (positive electrode material: Li(Ni0.8Mn0.1Co0.1)O2, negative electrode material: graphite) in a nitrogen-filled sealed container, triggering thermal runaway through lateral heating. The experimental results show that the battery's maximum surface temperature can reach 851.8–943.7 °C, exceeding the melting point of aluminum. Temperature surge inflection points at the battery's bottom and near the small side of the negative electrode coincide with the inflection point on the heated surface. The highest jet temperatures at three monitoring points 50 mm, 150 mm, and 250 mm above the safety valve are 356.9 °C, 302.7 °C, and 216.5 °C, respectively. Acoustic signals reveal two ejection events. The average gas production of the battery is 0.089 mol/Ah, and the jet undergoes three stages: ultra-fast ejection (2 s), rapid ejection (32 s), and slow ejection (47 s). Post-thermal runaway remnants indicate that grooves from internal jet impacts are mainly located at ±45° positions. This study provides valuable insights for the safety design of batteries and the suppression of thermal runaway propagation. [ABSTRACT FROM AUTHOR]

With the widespread application of lithium-ion batteries (LIBs) energy storage stations in high-altitude areas, the impact of ambient pressure on battery thermal runaway (TR) behavior and venting flow characteristics have aroused wide research attention. This paper conducts a lateral heating experiment on 280 Ah lithium iron phosphate batteries (LFPs) and proposes a method for testing battery internal pressure using an embedded pressure sensor. This paper analyzes the battery characteristic temperature, internal pressure, chamber pressure, and gas components under different chamber pressures. The experiment is carried out in a N2 atmosphere using a 1000 L insulated chamber. At 40 kPa, the battery experiences two instances of venting, with a corresponding peak in temperature on the battery's side of 136.3 °C and 302.8 °C, and gas generation rates of 0.14 mol/s and 0.09 mol/s, respectively. The research results indicate that changes in chamber pressure significantly affect the center temperature of the battery side (Ts), the center temperature of the chamber (Tc), the opening time of the safety valve (topen), the triggering time of TR (tTR), the time difference (Δt), venting velocity, gas composition, and flammable limits. However, the internal pressure and gas content of the battery are apparently unaffected. Considering the TR characteristics mentioned above, a safety assessment method is proposed to evaluate the TR behavior and gas hazard of the battery. The results indicate that the risk at 40 kPa is much higher than the other three chamber pressures. This study provides theoretical references for the safe use and early warning of energy storage LIBs in high-altitude areas. [ABSTRACT FROM AUTHOR]

With the widespread application of electrochemical energy storage technology, the safety issues of lithium-ion batteries have garnered significant attention. The issue of arc faults resulting from electrical failures is especially critical, as it can lead to catastrophic battery disasters. Therefore, this paper first established an arc testing platform and conducted experiments on top cover and body of prismatic lithium-ion batteries to analyze the thermoelectric characteristics between arc and battery. Under experimental conditions of 300 V and 15 A, it was found that arcs can induce thermal runaway in batteries. Subsequently, based on the experimental conditions, a mathematical model was established to induce thermal runaway in batteries through an equivalent method of arc heat source. By comparing the temperature curves of model and experiment, the RMSE of temperature at the center point of large surface was 5.09 °C (with a maximum temperature of 212 °C), indicating the accuracy of the model. This paper's research on arc faults in battery systems revealed the evolution pattern and realized that arcs can trigger thermal runaway in batteries. The model for arc-triggered thermal runaway in batteries is highly accurate, capable of reducing the number of experiments, accelerating experimental progress, and is of significant importance for guiding the design of arc experiments about batteries. [ABSTRACT FROM AUTHOR]