Thermal Runaway Of Lithium-ion Batteries Research Articles

Experimental investigation on the cooling effect of fully submerged fine water mist on lithium-ion batteries in confined space

Due to insufficient heat dissipation, the severity of thermal runaway of lithium-ion batteries in confined space tends to get aggravated which may lead to significant loss. Therefore, effective countermeasures are urgently needed. This study aims to investigate its cooling control capability of fine water mist on suppressing the thermal runaway induced by overheating in confined space, and determine its key interfering factors. The results show that the occurrence of thermal runaway accelerated accompany by a more intense thermal process in confined space, and the average mass loss of lithium-ion batteries at 100 % state of charge increases by 14.6 %. Fine water mist exhibited an excellent control effect on thermal runaway even in confined space as long as it was released before the critical temperature of 172 °C with concentration around 0.9 kg m−3. In addition, even if the suppression fails, the thermal runaway triggering can still be delayed for around 25 s and its severity be mitigated. This work may be helpful for further analysis of cooling effectiveness of thermal runaway control with fine water mist in confined space, as well as provide guidance for practical applications in such real cases.

Thermal runaway aspect of ultrahigh-nickel cathode-based lithium-ion batteries at increasing charge states

High-nickel cathode-based lithium-ion batteries (LIBs) are the core of sustainable innovation in electric vehicles (EV). However, there exists a fire hazard associated with thermal runaway (TR) during charging due to chemical instability of the abundant nickel oxides produced. While the subject of TR in LIBs has been considered in the past, research on the ultrahigh-nickel (Ni content >90 wt%) cathode materials subjected to a wide range of state of charge (SOC) is limited. The LIB is transforming towards going ultrahigh in Ni content to improve the performance of EVs, and ultimately resolving safety issues associated with TR related fire accidents is an immediate goal. The current study presents a correlation amongst the LIB components, SOCs, and Ni contents on two classes of cathodes, namely high-Ni at 88 % and ultrahigh-Ni at 91 % Ni. The exothermic reaction involving anode and electrolyte in a full cell was intensified at SOCs >75 %, leading to the dissociation of cathode materials and a significant self-heating via repeated reactions. When self-heating rate exceeded 1000 °C/min, the reaction developed into a TR, elucidating that a 3 % increase from 88 % to 91 % Ni content brought forward the likelihood of TR with a much shorter delay time.

Modelling and simulation of thermal runaway phenomenon in lithium‐ion batteries

AbstractTo improve the operational time of electronic devices and the driving spectra of electric cars, multiple investigation missions regarding batteries are focussed on refining the energy capacity of batteries. However, this pursuit of better performance introduces potential risks, such as fire incidents, due to the use of dynamic materials in lithium‐ion batteries (LIBs) to enhance their electrochemical performance. These fire incidents have resulted in financial losses and raised safety concerns. One common type of battery failure, called thermal runaway (TR), takes place when the rate of heat discharge from internal chain reactions accelerates the level of external cooling. This study aims to model and comprehensively analyse the phenomenon of TR in LIBs by investigating its underlying physics.To conduct this research systematically, a mathematical framework of heat transfer from existing literature has been employed as a foundation to come up with a novel framework specifically for LIBs built on the ideas of Semenov's equation. The established model associates both thermal and mass balance aspects, with the consideration of response kinetics including other heat transfer modes (convective and radiation). Range–Kutta technique is used to unravel the model's equations instantaneously using MATLAB. Consequently, the impact of model factors on the thermal performance of LIBs has been evaluated. The outcomes of the study reveal that when an increase in activation temperature occurs, a decrease in peak temperature is followed whilst constant circumstances are ensured. This implies that more time is needed in order for the temperature to reach its maximum. Furthermore, the simulation demonstrated that any growth in the body capacity of the battery for absorbing heat during the reaction results in a higher maximum temperature. Heat convection is found to have a greater impact on the occurrence of TR in LIBs compared to heat radiation. For improved accuracy in calculating LIBs TR, an accurate kinetic model could be utilised in future research endeavours.

A smart membrane with negative thermo-responsiveness in battery electrolyte solution

The challenge of thermal runaway in lithium-ion batteries necessitates innovative solutions to enhance their safety. In this work, a negatively thermo-responsive membrane is proposed with grafting poly (N-isopropylacrylamide) onto polydopamine-modified polypropylene (PP) membrane via the Michael addition reaction. The implementation of such smart membrane is achieved based on the upper critical solution temperature (UCST) of the PNIPAM in the electrolyte solution containing 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]), ethylene carbonate/diethyl carbonate (EC/DEC), and lithium tetrafluoroborate (LiBF4). The conformational transition of the PNIPAM in the electrolyte solution is intricately influenced by the competing salting-out effect of [EMIM][BF4] and salting-in effect of LiBF4. By maintaining a constant 1.0 M LiBF4 concentration in the electrolyte solution, the UCST of the PNIPAM that is precisely adjusted according to the 45.5 wt%-50 wt% of [EMIM][BF4] in the mixed EC/DEC solution provides the gating temperature. When below the gating temperature, the PNIPAM gating polymer grafted on the PP membrane remains in a shrinkable state to let the electrolyte ions shuttle feely between the electrodes. Conversely, in the event of overheating stemming from inadvertent Li-ion battery mismanagement, the PNIPAM gating polymer becomes extensible above the gating temperatures, resulting in the closure of the separator membrane. This mechanism effectively arrests the mobility of electrolyte ions, thereby contributing to the enhanced safety and security of lithium-ion batteries. The finding in this work offers valuable insights into the design and development of smart battery membranes with enhanced safety features to advance the progress of lithium-ion battery technology.

Overview of the Thermal Runaway in Lithium-Ion Batteries with Application in Electric Vehicles: Working Principles, Early Warning, and Future Outlooks

Overview of the Thermal Runaway in Lithium-Ion Batteries with Application in Electric Vehicles: Working Principles, Early Warning, and Future Outlooks

Development of equivalent circuit model for thermal runaway in lithium-ion batteries

An integrated equivalent circuit model was developed to analyze thermal runaway in lithium-ion batteries under different conditions. The thermal runaway model was developed by adding various circuit components to a second-order resistor–capacitor circuit, whose values were obtained based on previous experimental studies. First, the characteristics of thermal runaway by electrical abuse were analyzed. When the charge rate was high, the maximum temperature during thermal runaway was high, and the thermal runaway ended fast. At charge rate of 3C, the maximum temperature was 209.4 °C, since a high current generates large heat, and the thermal runaway duration was 1200 s. Next, thermal runaway by mechanical abuse was analyzed by examining the state of charge effect on the maximum temperature. When the state of charge increased from 0.5 to 1, the temperature increased to 470 °C during thermal runaway because a high potential difference arises when the state of charge is high. Lastly, an integrated equivalent circuit model was developed by adding a series of resistors and capacitors in parallel to the conventional battery model. The model showed an accuracy of 87 % compared to previous experimental results. The proposed model can enable the analysis of thermal runaway during fast charge caused by combined abuse factors.

Organic and Inorganic Hybrid Composite Phase Change Material for Inhibiting the Thermal Runaway of Lithium-Ion Batteries

To deal with the flammability of PA (paraffin), this paper proposes a CPCM (composite phase change material) with a high heat-absorbing capacity for mitigating the thermal runaway of lithium-ion batteries. Two heating power levels were used to trigger thermal runaway in order to investigate the influence of heating power on thermal runaway characteristics and the mitigation effect of the PCM (phase change material). Thermal runaway processes and temperature changes were recorded. The results showed that heating results in a violent reaction of the battery, generating a high temperature and a bright flame, and the burning of PA increases the duration of a steady flame, indicating an increased threat. SA (sodium acetate trihydrate) effectively inhibited PA combustion, and the combustion time was reduced by 40.5%. PA/SA effectively retarded the rise in temperature of the battery, and the temperature rise rate was reduced by 87.3%. Increased heating power caused faster thermal runaway, and the thermal runaway mitigation effect of the CPCM was dramatically reduced. This study may provide a reference for the safe design and improvement of thermal management systems.

Research on internal short circuit detection method for lithium-ion batteries based on battery expansion characteristics

Short circuits are a major contributor to thermal runaway in lithium-ion batteries, but present detection techniques cannot distinguish different forms of short circuits. Therefore, the paper provides a detection method for internal short circuits (ISCs) based on coupled mechanical stress that can determine the type of short circuit. Firstly, cathode-anode (Ca-An) short-circuit batteries with a controllable triggering time and measurable internal temperature and electrode potential are designed. Secondly, the performance evolution of fault batteries under coupled mechanical stress conditions is investigated, along with the impact of faults on the battery's safety performance. Additionally, the influence of battery expansion characteristics on the contact pressure at the short circuit location and the correlation between short circuit resistance and mechanical stress are analyzed. The results show, except for self-discharge, no significant differences between Ca-An short-circuit and normal batteries, and there are no mutable features observed, but the faults can exacerbate internal-external temperature differences during charging. The different reasons for thermal runaway during sustained pressurization between short-circuit and normal batteries are revealed. Finally, a method for detecting ISC based on the differences in short-circuit resistance at different states of charge is proposed. Overall, the paper provides a basis for fault classification in lithium-ion batteries.

Efficiency of dodecafluoro-2-methylpentan-3-one microemulsion to inhibit thermal runaway in lithium-ion batteries

Efficiency of dodecafluoro-2-methylpentan-3-one microemulsion to inhibit thermal runaway in lithium-ion batteries

Influencing factors of lithium-ion battery thermal runaway in confined space

Lithium-ion batteries with high state of charge (SOC), low state of health (SOH) and at summer are prone to fire accidents. The influence of these factors on thermal runaway triggered by external heating in confined space is studied in this manuscript. Based on the results of temperature, voltage changes and video, gas explosion occurs before thermal runaway in confined space. The results of heat calculation indicate that radiation and conduction contribute the most to thermal runaway. Thermal runaway of lithium-ion battery triggered by external heating is determined by the accumulated exothermic side reactions, remaining reactants and surface temperature of battery. Accumulated exothermic side reactions increase with higher SOC and lower SOH. Remaining reactants increase with the increase of SOC and SOH. Surface temperature of lithium-ion battery increases to high temperature at a shorter time for battery at higher initial temperature. Thermal runaway time interval decreases with the increase of SOC and ambient temperature, and the decrease of SOH. High SOC and ambient temperature and low SOH increase hazardous risk of lithium-ion battery to some extent. The results can explain why batteries with high SOC, low SOH and at high ambient temperature are prone to fire accidents. This is important for battery safety control.

Understanding the combustion characteristics and establishing a safety evaluation technique based on the overcharged thermal runaway of lithium-ion batteries

As an abusive method to trigger thermal runaway (TR), the overcharge method has been widely used to evaluate the safety status of lithium-ion batteries (LIBs). In this study, the combustion characteristics of LIBs were systematically studied by overcharging batteries at different charging rates (C-rates). The results indicated that a high C-rate could cause jet flames with temperatures as high as 1350 °C at a relatively low state of charge. Furthermore, certain maximum heat release rate (HRR) and mass loss rate (MLR) values of 192 kW and 1785 g/s were obtained at 1C, respectively. X-ray photoelectron spectroscopy results for sulfur showed that the valence of sulfur was related to the peak HRR. Moreover, a novel safety evaluation technique denoted as the relative overcharge safety status (OCSS) was presented to highlight the safety status of the overcharging battery. We found that the OCSS at different C-rates presented a linear relationship with the dimensionless time and obtained the safety threshold, safety boundary, and safety level to easily evaluate the TR risk. Therefore, the OCSS method may provide timely, real-time evidence for battery management systems when batteries are overcharged.

Model-free quantitative diagnosis of internal short circuit for lithium-ion battery packs under diverse operating conditions

The internal short circuit (ISC) serves as a primary source of thermal runaway in lithium-ion batteries, thereby posing a potential safety risk. The early identification of ISC faults is crucial for mitigating risks associated with fire or explosion, but quantitatively diagnosing minor energy leakage in the initial stage of ISC can be a considerable challenge in the absence of battery modeling or preliminary experiments. In light of these constraints, this study puts forth a quantitative diagnosis technique underpinned by an innovative model-free approach tailored for battery pack systems. Our method hinges on the analysis of voltage characteristics and certain premises, wherein the variance in the quantity of electrical charge retained in a cell is estimated solely through measured voltage data. The ISC current is determined through measured current data while maintaining cell balance within the packs. In addition, we propose an ISC current compensation scheme to accommodate fluctuations in ambient temperatures over time. Consequently, the ISC resistances of all cells within the packs can be computed as an index of fault to assess the degree of ISC severity. To ascertain the feasibility of our proposed method, we undertook ISC pack experiments under a wide range of conditions, encompassing aspects such as cell inconsistency, cell balancing, subzero and varying ambient temperatures, and diverse charge/discharge protocols. The results of our experiments demonstrate that the proposed model-free method exhibits considerable applicability for real-world battery operational circumstances while also maintaining a high degree of accuracy in ISC resistance estimation.

Study on the suppression of thermal runaway of lithium-ion battery by water mist with different additives

ABSTRACT Water mist with additives is a promising emergency control technology for the lithium-ion battery’s thermal runaway. Developing efficient, green, and environmental-friendly additive is a key issue to the technology. Here, using 18,650 batteries as the experimental object, three different suppression mechanism additives, i.e. sodium dodecyl benzene sulfonate (SDBS), sodium chloride (NaCl), and soy protein, were studied and discussed after optimizing the condition of water mist generated with different Here, using 18,650 batteries as the experimental object, three different suppression mechanism additives, i.e. sodium dodecyl benzene sulfonate (SDBS), sodium chloride (NaCl), and soy protein, were studied and discussed after optimizing the condition of water mist generated with different compressed air. The battery thermal runaway process concluded four stages, and the initial stage of explosion, i.e. the safety valve broke through companying with some noise and gases spilling out, was a typical phenomenon that suggested the beginning of thermal runaway. The water mist generated with optimized air pressure of 0.2 to 0.25 MPa, the droplet SMD size was 71–89 μm, could effectively suppress the battery thermal runaway, decrease T2 quickly from about 700°C to no more than 413°C, and reduce the cooling time from above 1000 s to no more than 203 s. Although the mechanism of the three additives was different, all of them could evidently enhance the suppression effect of water mist on the lithium-ion battery’s thermal runaway. Especially, the addition of 1.5% soy protein to water mist could decrease greatly both the flame temperature and the battery’s surface temperature, and shorten 63% cooling time comparing to the pure water mist. The results showed that soy protein was an efficient and environmental-friendly additive for water mist to inhibit the thermal runaway of lithium-ion battery and had good potential practical application value. The in-depth research and analysis of SDBS and NaCl would provide basis data for the development of compound additive.

Multiphysics-informed DeepONet of a lithium-ion battery to predict thermal runaway

This study proposes a multiphysics-informed deep operator network (MPI-DeepONet) to predict the thermal runaway of lithium-ion batteries (LIBs) under a variety of thermal operational and abuse conditions. Specifically, this study aims to address the functional mapping from a heating curve to predict the evolution of the temperature of a LIB and dimensionless concentration of dominant components of the LIB including an anode, cathode, electrolyte, and solid electrolyte interphase. The proposed method has two key characteristics. First, the MPI-DeepONet is supervised by using ordinary and partial differential equations, which govern highly complex and nonlinear phenomena of thermal runaway of a LIB, including the chemical reaction degradation of the dominant four components and thermodynamics. This feature enables to train of the proposed neural network with a small amount of data available, suggesting that the proposed neural network is accurate and robust even though the proposed method is trained even with limited data. Second, the proposed neural network is trained with the data that is generated from high-fidelity finite element analysis under a variety of thermal operational and abuse conditions because measurements for the thermal runaway of a LIB are limitedly available. Hence, the MPIDeepONet does not require actual measurements, which is extremely difficult in field experiments. Finally, the accuracy and robustness of the proposed architecture are verified through actual measurements and other scenarios, which are different from the data trained. The analysis of results reveals that the MPI-DeepONet secures higher accuracy and robustness than purely data-driven DeepONet. The proposed surrogate model, which is faster than existing surrogate models, suggesting that this model contributes to developing a digital twin model of a LIB, which can be deployed on a battery thermal management system and provides sufficient information for effective power and energy management.

Experimental study of explosion parameters of hybrid mixture caused by thermal runaway of lithium-ion battery

The explosion characteristics of the runaway battery vented gas (BVG) was studied using an 8 L column type device. The effects of ambient temperature, turbulence condition, and graphite dusts-ejected along with the BVG on the explosion process-were investigated. At 25 ℃, the explosion limits of pure BVG, the maximum explosion pressure (Pmax), and the maximum rate of explosion pressure rise (dP/dt)max is 10.8–45.8% by volume, 0.62 MPa, and 37.6 MPa/s, respectively. At 80 ℃, the three parameters changed to 10.4%− 46.5%, 0.49 MPa and 35.5 MPa/s. Moreover, these three parameters changed to 10.2–47.5%, 0.45 MPa and 33.3 MPa/s at 120 ℃. The increase in temperature reduced Pmax of BVG. While turbulence had little effect on the explosion pressure of BVG, it has significantly affected the dP/dt value. Adding graphite dusts helps BVG get to Pmax at a much lower volume concentration. As temperature increased, this effect became greater. Also, the graphite dusts can reduce the time of BVG to attain the Pmax value after igniting – the maximum reduction is from 325 ms to 158 ms. As ambient temperature increased, the combustible gas molecules were reduced, resulting in a lower Pmax value. The heat released from the BVG explosion drives the graphite involving dust explosion when oxygen is excessive. The above findings can provide a reference for the prevention of environmental explosions caused by the thermal runaway of lithium-ion batteries in process industry.

Experimental study on suppression of thermal runaway in lithium-ion battery by mixed particle size water mist

With the implementation of the green energy development strategy, new energy vehicles and related industries have been experiencing rapid growth, leading to an expansion in the market scale of the lithium-ion battery (LIB) industry. While the high energy density of LIB is being pursued, the risk of thermal runaway (TR) cannot be underestimated. Water mist (WM) is currently considered an efficient and environmentally friendly fire extinguishing agent, highly favored for its exceptional cooling capabilities. In this study, an alternative WM control strategy is proposed that capitalizes on the distinct advantages of varying particle sizes of WM during different cooling stages and integrates them to enhance overall cooling effectiveness. The experimental results demonstrate that the utilization of WM with mixed particle sizes not only reduces the peak temperature of TR, but also significantly shortens the cooling time. Compared to using WM with a single particle size, this method greatly reduces water consumption and enhances its utilization rate. This finding can offer valuable suggestions for the future implementation of WM in battery fire suppression systems design.

Experimental study on thermal runaway characteristic and residue of Li(Ni0.8Co0.1Mn0.1)O2 lithium-ion batteries induced by overcharge

Overcharge is one of the most common triggers of thermal runaway in lithium-ion batteries. The process and mechanism of overcharging are not clarified. In particular, little research has been done on thermal runaway residues. Accident investigators require a method to identify thermal runaway residue. In this study, the thermal runaway induced by 1C (12 A) current overcharge in 12 Ah pouch Li(Ni0.8Co0.1Mn0.1)O2 lithium-ion batteries was investigated. The battery residue was disassembled. Scanning electron microscopy, X-ray diffractometry, and other analysis methods were used to investigate macro characteristics, micromorphology, and phase composition of the residue. The analysis of the residues revealed that the layered electrode adhesion was severe, the current collectors at the rupture were damaged and ejected, and copper molten beads were observed in the ejecta. Numerous fracture and breaking were observed in the residue cathode material particles, and the explanatory hypothesis was proposed. New phase C, Li2CO3, LiF, MnO, NiO, Co and Ni were found. Also, the mechanisms of the phenomena and characteristics were discussed. Accident investigators would be helped if these overcharge characteristics were widely validated.

Reducing lithium-ion battery thermal runaway risk based on an integrated cooling strategy for electric vehicles

Nowadays, thermal runaway of lithium-ion battery is widely considered to be a serious hazard to the safety of electric vehicles. In order to effectively prevent thermal runaway, an integrated thermal management solution is proposed. Firstly, a few models of battery, air conditioning system, phase change cooling and liquid cooling are established, respectively. The temperature and heat are used to coupling each model. Then the effectiveness of models is validated by experiment. Finally, the cooling performances of this system are discussed. Under the circumstance of thermal runaway, the battery thermal management system can inhibit thermal runaway, and the battery temperature is reduced from 1208.17 to 304.82 K. In addition, the influences of the convective heat transfer coefficient and flow channel number on the cooling effect are also studied, and in order to ensure that the batteries have an appropriate temperature and reduce energy consumption, their values should be 20 W∙m−2∙K−1 and 5, respectively. When the vehicle is normally driving, the influences of different driving speeds, pump speeds and compressor speeds on the battery temperature are discussed, meanwhile, combined with the cooling effect of air conditioning, a reasonable and economic scheme is determined, that is, the pump speed is 2250 r∙min−1 and the compressor speed is 2500 r∙min−1, and under this scheme, the maximum battery temperature is only 35 °C, and the cab temperature can be reduced to the target temperature within 112 s.

Short-Circuit Fault Detection and Quantitative Analysis Based on Mean-Difference Model With Variational Modal Decomposition

Abstract Short-circuit failure is one of the triggers for thermal runaway of lithium-ion batteries, which can lead to serious safety issues. This paper attempts to estimate the short-circuit resistance of the cell using the mean difference model and relies on the estimated results to make a quantitative analysis of short-circuit fault. To achieve this goal, a combination of forgetting factor recursive least squares and extended Kalman filter is used to estimate the average open-circuit voltage within the battery pack. Subsequently, since both the open-circuit voltage (OCV) and intrinsic mode function (IMF0) components reflect the low-frequency characteristics of the battery voltage, we propose a new method based on the variational modal decomposition to extract the differential open-circuit voltage of the battery and finally make an estimate of the short-circuit resistance after obtaining OCV of the battery using the idea of the mean difference model (MDM). In addition, the effectiveness of the proposed method is verified under different degrees of short-circuit faults by connecting different resistors to the series battery pack.

Review of Thermal Runaway Monitoring, Warning and Protection Technologies for Lithium-Ion Batteries

Due to their high energy density, long calendar life, and environmental protection, lithium-ion batteries have found widespread use in a variety of areas of human life, including portable electronic devices, electric vehicles, and electric ships, among others. However, there are safety issues with lithium-ion batteries themselves that must be emphasized. The safety of lithium-ion batteries is receiving increasing amounts of attention as incidents such as fires and explosions caused by thermal runaway have caused significant property damage and fatalities. Thermal runaway can easily occur when lithium-ion batteries experience issues such as electrical abuse and thermal abuse. This study compares various monitoring, warning, and protection techniques, summarizes the current safety warning techniques for thermal runaway of lithium-ion batteries, and combines the knowledge related to thermal runaway. It also analyzes and forecasts the future trends of battery thermal runaway monitoring, warning, and protection.