Lithium-ion Battery Fires Research Articles

Investigation into the Lithium-Ion Battery Fire Resistance Testing Procedure for Commercial Use

Lithium-ion batteries (LIBs) have many advantages (e.g., high voltage and long-life cycle) in comparison to other energy storage technologies (e.g., lead acid), resulting in their applicability in a wide variety of structures. Simultaneously, the thermal stability of LIBs is relatively poor and can be damaged by exposure to fire. This paper presents an investigation into a fire resistance safety test for LIBs and the use of thermal sensors to evaluate exposure conditions and estimate the temperatures to which cells are subjected. Temperature distribution data and statistical analysis show significant differences of over 200 ∘C, indicating the stochastic nature of the heating curve despite following the testing procedure requirements. We concluded that the current testing procedure is inadequate for the reliable testing of LIBs, leaving an alarming loophole in the fire safety evaluation. The observed instability is mostly related to wind speed and direction, and fire source size.

Thermal stability of modified lithium-ion battery electrolyte by flame retardant, tris (2,2,2-trifluoroethyl) phosphite

With the increasing awareness of green energy, electric vehicles have become the future trend, with lithium-ion batteries (LIBs) regarded as the most suitable energy storage carrier. Therefore, more and more research topics are focused on LIBs, and all parties are working hard to improve the performance of LIBs. Yet, the safety concerns caused by the failure of LIBs cannot be ignored. LIBs themselves are energetic materials, and the causes of accidents often go through multistage irreversible reactions. Several studies have also pointed out that the electrolyte has a significant correlation with the response characteristics because, in the process of LIBs thermal runaway, the electrolyte participating in the oxidation of the entire battery leads to a considerable amount of heat and even runaway reaction as well. Accordingly, it is necessary to obtain a safer electrolyte by modification. In this study, a significant flame retardant (FR) additive, tris (2,2,2-trifluoroethyl) phosphite (TTFP), is used to suppress lithium-ion battery fires or even explosions and maintain typical battery performance. The performance of the electrolyte was tested by differential scanning calorimetry and thermogravimetric analyzer, and the electrolysis was examined on liquid flash point (FP), self-extinguishing time (SET), and conductivity. During the heating process, adding TTFP to the electrolyte effectively delayed the exothermic peak, reduced the amount of heat, improved the FP, and curtailed the SET. The hazard degree of the electrolyte under high-temperature environment was much lower than before adding the additives, and the additives were finally obtained. It can conclusively prove the safety of lithium batteries without lessening the practical performance of the batteries.

Test and research on suppressing fire of lithium-ion battery with water mist containing additive

In order to improve the fire extinguishing effect on lithium-ion battery fires, the paper experimented with compound solution of sodium dodecylbenzenesulfonate-dodecanol-sodium carbonate at a ratio of 3:2:2, polyfiouroalkyll betaine-alkylglycoside-potassium carbonate at a ratio of 2: 3: 3 and monoalkyl ether phosphate potassium-fatty acid ester polyoxyethylene etherurea at a ratio of 3:2: 3. The fire of the lithium-ion battery was extinguished with water mist containing additive compound solution by building lithium-ion battery fire extinguishing experimental platform. The experiment selected four different concentrations of 0.5%, 1%, 1.5%, and 2%. The results showed that the polyfluoroalkyl betaine-alkyl glycoside-potassium carbonate compound solution had better fire extinguishing effect in the early stage of thermal runaway, and the battery did not reignite. The sodium dodecylbenzene sul-fonate-dodecanol-sodium carbonate compound solution took the least time to reduce the battery temperature to below 200 °C. In the later period, the sodium dodecylbenzenesul-fonate-dodecanol-sodium carbonate compound solution has the greatest advantage in cooling rate. In the gas absorption test, the sodium dodecylbenzenesulfonate-dodecanoll-sodium carbonate compound solution has the best absorption effect on methane, and the polyfluoroalkyl betaine-alkyl glycoside-potassium carbonate compound solution releases CO. The concentration of the compound has a more obvious drop than the other two compound solutions.

Analysis of effectiveness of suppression of lithium ion battery fires with a clean agent

A campaign of experiments was conducted in a previously designed bench-scale wind tunnel to determine the effectiveness of suppression of lithium ion battery fires with a clean agent, Novec 1230 (CF3CF2C(O)CF(CF3)2). The experiments were performed on twelve 18650 form factor, fully charged, lithium cobalt oxide cells arranged in a rectangular array without intercell spacing. A set of baseline experiments performed at 640 l min−1 of air flow, 320 l min−1 of air flow, and 186 l min−1 of nitrogen flow indicated that, while flaming combustion had a significant impact on the speed of thermal runaway propagation through the array, fully preventing combustion did not prevent propagation. Addition of gaseous Novec 1230 to 640 l min−1 air flow immediately after the thermal runaway of the first cell produced 8.5 vol% concentration of the agent. At this concentration, which is above that recommended for suppression of traditional fires, the agent failed to suppress flaming combustion and did not prevent propagation of thermal runaway through the array. Increasing the concentration of Novec 1230 to 15.2 vol% by reducing the air flow rate to 320 l min−1 reduced the flaming combustion efficiency below 18% and prevented complete thermal runaway propagation in 67% of tests.

A Review of Experimental and Numerical Studies of Lithium Ion Battery Fires

Lithium-ion batteries (LIBs) are used extensively worldwide in a varied range of applications. However, LIBs present a considerable fire risk due to their flammable and frequently unstable components. This paper reviews experimental and numerical studies to understand parametric factors that have the greatest influence on the fire risks associated with LIBs. The LIB chemistry and the state of charge (SOC) are shown to have the greatest influence on the likelihood of a LIB transitioning into thermal runaway (TR) and releasing heats which can be cascaded to cause TR in adjacent cells. The magnitude of the heat release rate (HRR) is quantified to be used as a numerical model input parameter (source term). LIB chemistry, the SOC, and incident heat flux are proven to influence the magnitude of the HRR in all studies reviewed. Therefore, it may be conjectured that the most critical variables in addressing the overall fire safety and mitigating the probability of TR of LIBs are the chemistry and the SOC. The review of numerical modeling shows that it is quite challenging to reproduce experimental results with numerical simulations. Appropriate boundary conditions and fire properties as input parameters are required to model the onset of TR and heat transfer from thereon.

Inhibition Effect of Thermally-Induced Fire in 21,700 Lithium-Ion Battery With Low-Pressure Twin-Fluid Water Mist

Abstract The fire hazard of lithium-ion batteries (LIBs) poses a serious threat to their transportation and use. The purpose of this study is to investigate the efficiency of low-pressure twin-fluid water mist (TFWM) on suppressing lithium-ion battery fires. Experiments were executed to research the effect of working pressures and release stages on extinguishing the fire. Aqueous vermiculite dispersion (AVD), a commercial agent that was specifically designed to extinguish battery fires, was chosen to compare with the fire suppression performance of TFWM under the same conditions. The results indicate that the type 21,700 LIB fires could be controlled by applying the water mist within 10 s. The cooling ability at various working pressures (0.4, 0.8, 1.0, and 1.2 MPa) demonstrated an increase in inhibitory effects as the working pressure increased, and the optimal pressure was 1.2 MPa. The results further show that the extinguishing ability of the TFWM was better than the AVD agent. When the water mist was applied at the optimal working pressure, the surface temperature, flame temperature and concentration of CO reduced more significantly, compared with the AVD agent. Therefore, the TFWM shows considerable merit as a candidate to fight LIB fires.

Fabrication of a microcapsule extinguishing agent with a core–shell structure for lithium-ion battery fire safety

Microcapsule technology was used to encapsulate the prepared fire extinguishing agent and attach it to the surface of lithium-ion batteries. This work creates a new lithium-ion battery security protection strategy, and can be extended to the safety design of other batteries.

Experimental and modeling analysis of jet flow and fire dynamics of 18650-type lithium-ion battery

The lithium-ion battery (LIB) is widely used in modern society, while the fire accidents caused by battery thermal runaway (TR) also happen frequently. However, the gas generation, jet flow, and fire dynamics of LIB TR are still unclear. In this paper, a lumped model for the characteristics of the 18650-type LIB jet flow and fire dynamics is set up and validated by experiments. The gas generation rate is described by the Arrhenius equation, and the peak generation rate is 2.724 g s−1. The isentropic flow equations are used to simulate the gas venting process. The gas flow is choked when the safety valve opens, then returns to subsonic levels until the onset of TR. When the cell falls into TR, the peak speed of the gas flow at the orifice is 162.0 m s−1, and the corresponding peak mass flow rate is 2.6 g s−1. The trend and peak value of the simulated flame height agree with the experimental results. This feasible model describes the LIB fire dynamics, and the knowledge gap over the gas generation rate and jet flow speed during TR is filled. The reveal of the fire dynamics of LIB provides guidance for the design of safety precaution measures on LIB packs in electric vehicle and energy storage system. Furthermore, the cause of error is analyzed, and some future modifications on the model of LIB fire are proposed.

Research and Development of Fire Alarm Detection Device for Lithium Ion Battery Based on Strain Measurement

In order to realize the fire alarm of lithium ion battery, a fire alarm detection device is developed based on the principle of strain measurement. This paper makes a study of the detection principle and application circuit. Firstly, according to characteristic rule of thermal runaway process of lithium ion battery, the correlation between battery deformation, temperature and released gas is analyzed and a battery fire warning method based on strain measurement is proposed. Then, the strain measuring circuit is designed and circuit working principle is analyzed. In the end, the application effect of the battery fire warning method based on strain measurement is verified through thermal runaway experiment of lithium ion battery. The experimental results show that the method based on strain measurement can identify fire risks at the early stage when the lithium ion battery thermal is out of control, preventing fire from spreading. Basically it can meet the needs of lithium-ion battery fire warning.

A Review of Lithium-Ion Battery Fire Suppression

Lithium-ion batteries (LiBs) are a proven technology for energy storage systems, mobile electronics, power tools, aerospace, automotive and maritime applications. LiBs have attracted interest from academia and industry due to their high power and energy densities compared to other battery technologies. Despite the extensive usage of LiBs, there is a substantial fire risk associated with their use which is a concern, especially when utilised in electric vehicles, aeroplanes, and submarines. This review presents LiB hazards, techniques for mitigating risks, the suppression of LiB fires and identification of shortcomings for future improvement. Water is identified as an efficient cooling and suppressing agent and water mist is considered the most promising technique to extinguish LiB fires. In the initial stages, the present review covers some relevant information regarding the material constitution and configuration of the cell assemblies, and phenomenological evolution of the thermal runaway reactions, which in turn can potentially lead to flaming combustion of cells and battery assemblies. This is followed by short descriptions of various active fire control agents to suppress fires involving LiBs in general, and water as a superior extinguishing medium in particular. In the latter parts of the review, the phenomena associated with water mist suppression of LiB fires are comprehensively reviewed.

ESS의 안정성 증대를 위한 Li-ion 배터리의 충전 알고리즘에 대한 특성 검토

This paper examines methods for Li-ion battery charging algorithm used in ESS(Energy Storage System). Recently, it is necessary to study how to restore the stability and reliability of ESS because of the lithium ion battery fires. Therefore, in this paper, the battery charging algorithm studied to date has been simulated with respect to CC-CV method, MCC-CV method, BC and PC methods, etc. In addition, comparison and analysis were performed for the charging time for each algorithm. As a result, the charging algorithm of the BC method using a high C-rate charged the battery fastest. it is considered that the consideration of C-rate is essential for stable charging of ESS.

Handling Lithium-Ion Batteries in Electric Vehicles: Preventing and Recovering from Hazardous Events

The demand for lithium-ion battery powered road vehicles continues to increase around the world. As more of these become operational across the globe, their involvement in traffic accidents and incidents is likely to rise. This can damage the lithium-ion battery and subsequently pose a threat to occupants and responders as well as those involved in vehicle recovery and salvage operations. The project this paper is based on aimed to alleviate such concerns. To provide a basis for fire safety systems to be applied to damaged EVs, hazards have been identified and means for preventing and controlling lithium-ion battery fires, including preventive measures during workshop and salvage activities were studied. Tests were also performed with fixed fire suppression systems applying suppressant inside traction batteries which showed to improve their safety.

Experimental study on the synergistic effect of gas extinguishing agents and water mist on suppressing lithium-ion battery fires

Abstract Currently, effective suppression methods are still required to deal with lithium-ion battery (LIB) fires. In this paper, a novel synergistic fire extinguishing method of gas extinguishing agent (C6F12O, CO2 and HFC-227ea) and water mist is designed to evaluate the effect of their combination. A 243 Ah large-scale LIB with LiFePO4 as cathode is used in this work. Several cell parameters are measured to evaluate the suppression effect of fire extinguishing method, such as extinguishing time, maximum temperature, mass loss and heat release rate. Meanwhile, the cooling effect, fire extinguishing effect and economic benefit of different fire extinguishing methods are all considered. Results show that the suppression effect of synergistic fire extinguishing method is better than that of the single agent. Single application of water mist can hardly extinguish the flame, while the combination of gas extinguishing agents and water mist can extinguish the flame finally. However, the C6F12O extinguishes the flame immediately, while CO2 has a longer extinguishing time, and HFC-227ea cannot extinguish the flame. So in these experiments, the C6F12O combined with water mist exhibits the best extinguishing and cooling effect. The CO2 combined with water mist has good economic benefit, better fire extinguishing effect and cooling effect in these experiments, which can also be considered in suppressing LiFePO4 LIB fires.

Experimental investigation of water spray on suppressing lithium-ion battery fires

This work investigated the effects of water spray on lithium-ion battery (LIB) fires. Experiments were conducted on single cell and multi-cell batteries to study the effect of water volume and spray pressure on the fire extinguishing and the effectiveness of preventing propagation of thermal runaway in LIB's. Meanwhile, the potential hazard of water spray as a fire extinguishing method was assessed by investigating the influence of water on combustion gas production during extinguishing. It was found from these experiments that water spray can effectively extinguish 21700 LIB fires and reduce the maximum surface temperature of LIB. But the water spray has no significant difference in cooling rate after temperature recovery. The contact efficiency between the water spray and batteries decreased with the increase in water pressure. With sufficient volume of water spray and high contact efficiency, water spray can inhibit the thermal runaway propagation. With insufficient volume of water spray or low contact efficiency, the time to onset of thermal runaway was delayed. Water affects combustion gas production during thermal runaway. When water was applied, the concentration of CO, H2 and HF increased, while CO2 decreased.

Effect of Different Arrangement on Thermal Runaway Characteristics of 18650 Lithium Ion Batteries Under the Typical Pressure in Civil Aviation Transportation

In order to investigate the thermal runaway mechanism of 18650 lithium ion batteries and the related hazards, an experimental platform for lithium ion battery fire and explosion is designed and built. The effects of different arrangements, including vertical 2 × 2 and vertical 4 × 1, and initial pressure (96 kPa and 61 kPa) on lithium ion battery thermal runaway are studied in this paper. Compared with the results of thermal runaway characteristics with two arrangements, a higher explosion pressure, a larger mass loss, more O2 consumption and more CO and CO2 production are observed of vertical 2 × 2 batteries due to the larger contact area between batteries. The explosion pressure of vertical 4 × 1 batteries decreases gradually with thermal runaway propagation. For vertical 2 × 2 batteries, the explosion pressure of battery C, D is about twice as large as battery A. The intensity of chemical reaction is more violent under 96 kPa which cause a lower onset temperature and a shorter onset time than that under 61 kPa. The thermal runaway propagation hazard can be reduced by decreasing the contact area between batteries. The results could provide useful guidance for the safety of lithium ion battery transportation in civil aviation.

CFD-analysis of the Sensible Enthalpy Rise Approach to determine the heat release rate of electric-vehicle-scale lithium-ion battery fires

• Concept of large-scale calorimeter with cement board walls. • Heat release rate of Li-ion battery determinable with Sensible Enthalpy Rise Approach. • Increased accuracy when using modified wall temperature determination. • Power 4 approach for ambient heat flow more accurate than linear approach. • Presented Fit calibration method is suitable for constants.

Experimental study of the effectiveness of three kinds of extinguishing agents on suppressing lithium-ion battery fires

The thermal runaway of a lithium-ion battery (LIB) often results in fires or even explosions. Thus, finding a proper, effective and clean extinguishing agent is imperative. In this paper, fire and extinguishing tests on commercially available large-scale LIBs with LiNixCoyMnzO2 (NCM)/graphite electrodes are investigated. Three different extinguishing agents including CO2, HFC-227ea and water mist were adopted. The results show that each agent can inhibit the combustion of the combustible gases and jet fire of the cell. However, a flame is observed during the release of CO2 and HFC-227ea, while no flame is observed in the case with water mist, which means that water mist shows a better suppressive effect than the other two extinguishing agents. The absence of these extinguishing agents was often accompanied with black smoke and violent jet fire. Moreover, the peak average temperatures before the extinguishing agents were depleted were 43, 75 and 133 °C lower, respectively, than that in the situation without an extinguishing agent. These results indicate that water mist has the best cooling effect comparing with CO2 and HFC-227ea, which has significant implications for the design of a LIB fire protection system.

Experimental study on a novel safety strategy of lithium-ion battery integrating fire suppression and rapid cooling

The prompt and effective suppression of lithium-ion battery (LIB) fires presently remains a challenge. In the present work, apparatus is constructed to investigate the extinguishment and cooling effectiveness of a single LIB dodecafluoro-2-methylpentan-3-one (C6F12O) suppression and rapid water mist cooling system. Tests indicated effective cooling by combining of the C6F12O and water mist, with significant reductions in the cell's peak temperature and high-temperature duration compared to C6F12O only and without suppression. The cooling rate was influenced by the delay period between application of C6F12O and water mist, with a longer delay period giving a reduced cooling effect. Water mist cooling at various working pressures (1, 2, and 3 MPa) demonstrated a reduction in peak battery temperature with increased working pressure. The cooling and suppression effects were also improved by using water mist containing KHCO3 and K2C2O4•H2O. These results have implications in the design of LIB fire suppression systems.

The Burning Issue

High-profile coverage of lithium-ion battery fires is generating cautious policies around handling and use–but are the risks being overplayed?

Quantitative identification of emissions from abused prismatic Ni-rich lithium-ion batteries

Abstract The emissions from lithium-ion batteries in the process of thermal runaway are one of the important sources of electric vehicle fire hazards. The purpose of this study is to reveal the gaseous and solid emission characteristics of lithium-ion batteries after thermal runaway. A 50 Ah commercial prismatic cell with Li(Ni0.6Mn0.2Co0.2)O2 cathode was triggered to thermal runaway by external heating in a sealed chamber with nitrogen atmosphere. Elements of settleable particles were detected, and size distributions were analyzed. The gaseous emissions were detected and their compositions were classified by boiling temperatures. The results show that the total emissions accounted for 28.53% of the cell mass. The settleable particles accounted for 17.00% of the emission mass, and 30 elements were found in them. Near 90% of the particle mass were those with a size less than 0.5 mm in diameter, and the median size of these particles was approximately 397 μm. A total of 31 compositions were found in the gaseous emissions, of which 17 were compositions with boiling temperatures below 25 °C, 8 compositions between 25 °C and 90 °C, and 6 compositions between 90 °C and 185 °C. The gases with boiling temperatures below 90 °C accounted for 32.75% of the emission mass, while the remaining gases and undetected particles accounted for 50.25%. These results further clarified the sources of lithium-ion battery fire hazards.