The Experts below are selected from a list of 28014 Experts worldwide ranked by ideXlab platform
Chi-min Shu - One of the best experts on this subject based on the ideXlab platform.
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dynamic hazard evaluation of explosion severity for premixed hydrogen air mixtures in a spherical Pressure vessel
Fuel, 2020Co-Authors: Yun Zhang, Chi-min Shu, Weiguo Cao, Mengke Zhao, Zhaobian Xie, Jinhu Liang, Zhiqiang Song, Xiong CaoAbstract:Abstract To evaluate dynamic explosion severity levels of premixed hydrogen–air mixtures, Pressure sensors were used to test explosion Pressure in a spherical Pressure vessel (inner diameter: 0.34 m). ANSYS Fluent 19.0 three-dimensional software was used to simulate the explosion process. The results revealed that when the hydrogen volume fraction was 30 vol%, the explosion Pressure and Pressure Rise Rate reached maximum values at 1.0 atm. As the initial Pressure increased, the explosion Pressure, and Pressure Rise Rate increased gradually. At initial Pressures of 1.0, 1.2, 1.5, and 2.0 atm, the peak Pressure levels were 0.85, 0.87, 0.92, and 0.99 MPa and the Pressure Rise Rates were approximately 198, 241, 302, and 558 MPa/s, respectively. The initial Pressure exerted greater effects on the Pressure Rise Rate than did the explosion Pressure. The simulation results were consistent with the experimental findings. Moreover, the simulation yielded multi-dimensional transient explosion parameters—such as turbulent kinetic energy distribution—that are difficult to obtain in experiments. The findings pertaining to the physical experiments, numerous simulations, and influence of initial Pressure on the explosion reaction mechanism of premixed hydrogen–air mixtures were discussed.
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Thermal stability evaluation of lithium-ion polymer batteries
Journal of Thermal Analysis and Calorimetry, 2015Co-Authors: Wun-cheng Jhang, Wei-chun Chen, Yih-wen Wang, Ron-hsin Chang, Chi-min ShuAbstract:Lithium-ion polymer battery (LIPB) is a thin and high-aspect-ratio fabrication, which provides the high specific energy; it is widely used in consumer electronics. The calorimetry method was conducted by using an adiabatic calorimeter, vent sizing package 2, to identify the thermal runaway hazards of various state-of-charges (SOCs) on LIPB. The relationships between temperature, Pressure, and time under adiabatic condition for LIPB could evaluate the safe performance characteristics. Furthermore, the measurements of thermokinetic parameters, such as apparent onset temperature ( T _0), maximum temperature ( T _max), maximum Pressure ( P _max), maximum self-heating Rate [(d T d t ^−1)_max], and maximum Pressure Rise Rate [(d P d t ^−1)_max], would rank the thermal hazards for various SOC LIPB and design the safer protective devices. The higher self-heating Rate and Pressure Rise Rate of 600 mAh LIPB at 100 % SOC were determined as approximately 7200 °C min^−1 and 12,600 psig min^−1, respectively. In addition, the experimental results are distinguished the thermal response from SOC levels and the loss prevention considerations provided a reference for the applications of LIPB.
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Study on thermal hazards for isoprene monomer (IPM) mixed with aluminum oxide
Journal of Thermal Analysis and Calorimetry, 2014Co-Authors: Mei-li You, Can-yong Jhu, Sheng-yi Weng, Min-siou Liao, Yun-ting Tsai, Quentin Lineberry, Chi-min ShuAbstract:Isoprene monomer (IPM) is a colorless, volatile liquid obtained from petroleum or coal tar that occurs naturally in many process plants. It is used chiefly to make synthetic rubber. Our study used calorimetric approaches to conduct thermal analysis and hazard assessment of aluminum oxide (Al_2O_3) and IPM relevant studies. Differential scanning calorimetry, thermal activity monitor III, thermogravimetry, and vent sizing package 2 were used to discuss thermal instability reaction of Al_2O_3, which adsorbed IPM, and find every possible reason for cases of fire to prevent any future recurrence of the package store and transport related hazards. By means of calorimetric analysis technology, we can observe thermal decomposition or mass loss for different adsorbed concentrations of IPM and Al_2O_3 to discuss the related thermal stability parameters, such as exothermic onset temperature ( T _0), heat of decomposition (Δ H _d), self-accelerating exothermic Rate (d T d t ^−1), Pressure Rise Rate, and maximum reaction temperature ( T _max). Then, we can understand the potential hazard factors that contribute to disasters related to processing, transport, and storage of security controls and reaction process design.
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Evaluation of thermal hazard for lauroyl peroxide by VSP2 and TAM III
Journal of Thermal Analysis and Calorimetry, 2012Co-Authors: Jian-ming Wei, Mei-li You, Yung-chuan Chu, Chi-min ShuAbstract:When above certain temperature limits, lauroyl peroxide is an unstable material. If the thermal source cannot be properly governed during any stage in the preparation, manufacturing process, storage or transport, runaway reactions may inevitably be induced immediately. In this study, the influence of runaway reactions on its basic thermal characteristic was assessed by evaluating thermokinetic parameters, such as activation energy ( E _a) and frequency factor ( A ) by thermal activity monitor III (TAM III). This was achieved under five isothermal conditions of 50, 60, 70, 80, and 90 °C. Vent sizing package 2 (VSP2) was employed to determine the maximum Pressure ( P _max), maximum temperature ( T _ma x ), maximum self-heating Rate ((d T d t ^−1)_max), maximum Pressure Rise Rate ((d P d t ^−1)_max), and isothermal time to maximum Rate (( TMR )_iso) under the worst case. Results of this study will be provided to relevant plants for adopting best practices in emergency response or accident control.
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Evaluation of adiabatic runaway reaction of methyl ethyl ketone peroxide by DSC and VSP2
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: Yu-chuan Liang, Can-yong Jhu, Sun-ju Shen, Chi-min ShuAbstract:Methyl ethyl ketone peroxide (MEKPO) is generally applied to manufacturing in the polymerization processes. Due to thermal instability and high exothermic behaviors of MEKPO, if any operation is undertaken recklessly or some environmental effect is produced suddenly during the processes, fires and explosions may inevitably occur. In this study, thermal analysis was evaluated for MEKPO by differential scanning calorimetry (DSC) test. Vent sizing package 2 (VSP2) was used to analyze the thermal hazard of MEKPO under various stirring Rates in a batch reactor. Thermokinetic and safety parameters, including exothermic onset temperature ( T _0), maximum temperature ( T _max), maximum Pressure ( P _max), self-heating Rate (d T d t ^−1), Pressure Rise Rate (d P d t ^−1), and so on, were discovered to identify the safe handling situation. The stirring Rates of reactor were confirmed to affect runaway and thermal hazard characteristics in the batch reactor. If the stirring Rate was out of control, it could soon cause a thermal hazard in the reactor.
Yih-wen Wang - One of the best experts on this subject based on the ideXlab platform.
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Thermal stability evaluation of lithium-ion polymer batteries
Journal of Thermal Analysis and Calorimetry, 2015Co-Authors: Wun-cheng Jhang, Wei-chun Chen, Yih-wen Wang, Ron-hsin Chang, Chi-min ShuAbstract:Lithium-ion polymer battery (LIPB) is a thin and high-aspect-ratio fabrication, which provides the high specific energy; it is widely used in consumer electronics. The calorimetry method was conducted by using an adiabatic calorimeter, vent sizing package 2, to identify the thermal runaway hazards of various state-of-charges (SOCs) on LIPB. The relationships between temperature, Pressure, and time under adiabatic condition for LIPB could evaluate the safe performance characteristics. Furthermore, the measurements of thermokinetic parameters, such as apparent onset temperature ( T _0), maximum temperature ( T _max), maximum Pressure ( P _max), maximum self-heating Rate [(d T d t ^−1)_max], and maximum Pressure Rise Rate [(d P d t ^−1)_max], would rank the thermal hazards for various SOC LIPB and design the safer protective devices. The higher self-heating Rate and Pressure Rise Rate of 600 mAh LIPB at 100 % SOC were determined as approximately 7200 °C min^−1 and 12,600 psig min^−1, respectively. In addition, the experimental results are distinguished the thermal response from SOC levels and the loss prevention considerations provided a reference for the applications of LIPB.
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thermal runaway potential of licoo2 and li ni1 3co1 3mn1 3 o2 batteries determined with adiabatic calorimetry methodology
Applied Energy, 2012Co-Authors: Yih-wen WangAbstract:Thermal runaway hazards related to adiabatic runaway reactions in various 18650 Li-ion batteries were studied in an adiabatic calorimeter with vent sizing package 2 (VSP2). We selected two cathode types, LiCoO2 and Li(Ni1/3Co1/3Mn1/3)O2, and tested Li-ion batteries to determine the thermal runaway features. The charged 18650 Li-ion batteries were tested to evaluate the thermal hazard characteristics, such as the initial exothermic temperature (T0), self-heating Rate (dT/dt), Pressure Rise Rate (dP/dt), Pressure–temperature profiles, maximum temperature (Tmax) and Pressure (Pmax), which are measured by VSP2 with a customized stainless steel test can. The thermal reaction behaviors of the Li-ion battery packs were shown to be an important safety concern for energy storage systems for power supply applications. The thermal abuse trials of the adiabatic calorimetry methodology used to classify the self-reactive ratings of the various cathodes for Li-ion batteries provided the safety design considerations.
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thermal runaway features of 18650 lithium ion batteries for lifepo4 cathode material by dsc and vsp2
Journal of Thermal Analysis and Calorimetry, 2012Co-Authors: Yih-wen Wang, Chung-cheng ChiangAbstract:Abstract In view of availability, accountability, and applicability, LiFePO4 cathode material has been confirmed to be better than LiCoO2 cathode material. Nevertheless, few related researches were conducted for thermal runaway reaction of the LiFePO4 batteries. In this study, vent sizing package 2 (VSP2) and differential scanning calorimetry were employed to observe the thermal hazard of 18650 lithium-ion batteries and their content—LiFePO4 cathode material, which were manufactured by Commercial Battery, Inc. Two states of the batteries were investigated, which was charged to 3.6 V (fully charged) and 4.2 V (overcharged), respectively, and important parameters were obtained, such as self-heating Rate (dT dt−1), Pressure-Rise Rate (dP dt−1), and exothermic onset temperature (T0). The results showed that T0 for fully charged is about 199.94 °C and Tmax is about 243.23 °C. The entire battery for LiFePO4 cathode material is more stable than other lithium-ion batteries, and an entire battery is more dangerous...
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Self-reactive rating of thermal runaway hazards on 18650 lithium-ion batteries
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: Yih-wen Wang, Chung-cheng ChiangAbstract:Vent sizing package 2 (VSP2) was used to measure the thermal hazard and runaway characteristics of 18650 lithium-ion batteries, which were manufactured by Sanyo Electric Co., Ltd. Runaway reaction behaviors of these batteries were obtained: 50% state of charge (SOC), and 100% SOC. The tests evaluated the thermal hazard characteristics, such as initial exothermic temperature (T 0), self-heating Rate (dT dt −1), Pressure-Rise Rate (dP dt −1), Pressure temperature profiles, maximum temperature, and Pressure which were observed by adiabatic calorimetric methodology via VSP2 using customized test cells. The safety assessment of lithium-ion cells proved to be an important subject. The maximum self-heating Rate (dT dt −1)max and the largest Pressure-Rise Rate (dP dt −1)max of Sanyo 18650 lithium-ion battery of 100% SOC were measured to be 37,468.8 °C min−1 and 10,845.6 psi min−1, respectively, and the maximum temperature was 733.1 °C. Therefore, a runaway reaction is extremely serious when a lithium-ion battery is exothermic at 100% SOC. This result also demonstRated that the thermal VSP2 is an alternative method of thermal hazard assessment for battery safety research. Finally, self-reactive ratings on thermal hazards of 18650 lithium-ion batteries were studied and elucidated to a deeper extent.
Zhaowu Shen - One of the best experts on this subject based on the ideXlab platform.
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effects of vessel height and ignition position upon explosion dynamics of hydrogen air mixtures in vessels with low asymmetry ratios
Fuel, 2021Co-Authors: Lu-qing Wang, Zhaowu ShenAbstract:Abstract The explosion characteristics of hydrogen-air mixtures in a wide range of equivalence ratios in closed vessels were investigated experimentally. The maximum explosion Pressure, maximum Pressure Rise Rate (along with deflagration index), explosion time and heat loss were evaluated. Three vessels with low asymmetry ratios ( H / D ) of 0.146, 0.244 and 0.341 were used to study the effect of vessel height on explosion parameters, in which H and D are the height and inner diameter of the vessel, respectively. In the H / D = 0.341 vessel, the effect of ignition position on explosion behaviors was also considered. The results show that, with the increase of the vessel height, the maximum explosion Pressure increase correspondingly, and the explosion time decreases orderly. In the lowest height vessel ( H / D =0.146), the ignitor-regulating column acts as a ‘turbulence-generator’. Thus, the maximum Rate of Pressure Rise could be increased significantly while the heat loss could be decreased. Compared with the central ignition scenario, both the maximum explosion Pressure and maximum Pressure Rise Rate are decreased for the asymmetrical ignition; meanwhile, the explosion time and the heat loss during the explosion are increased.
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The influence of an orifice plate on the explosion characteristics of hydrogen-methane-air mixtures in a closed vessel
Fuel, 2019Co-Authors: Lu-qing Wang, Zhaowu Shen, Dai-guo ChenAbstract:Abstract We reported an experimental study on the explosion characteristics of hydrogen-methane-air mixtures in a closed vessel at normal Pressure and temperature. The explosion parameters, such as the maximum explosion Pressure, the explosion time, the maximum Pressure Rise Rate and the deflagration index were derived based on the Pressure-time evolution. The effect of the blockage ratio as well as the position of the orifice plate on these explosion parameters were analyzed. The results show that the maximum explosion Pressure was decreased in the presence of an orifice plate due to the heat transfer to the baffle. At the early stage of the flame propagation, the flame was suppressed. Subsequently, the flame speed was increased at the later stage in some cases. Combined with the various reactivities of the mixtures, the explosion times obtained in all cases were very close. For a given mixture and an orifice plate position, the maximum Pressure Rise Rate and the deflagration index were increased with the increase of blockage ratio. Besides, the maximum Pressure Rise Rate as well as the deflagration index were decreased when the orifice plate was close to the ignitor and oppositely, increased when the orifice plate was away from the ignitor.
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Effect of a single orifice plate on methane-air explosion in a constant volume vessel: Position and blockage ratio dependence
Experimental Thermal and Fluid Science, 2019Co-Authors: Lu-qing Wang, Zhaowu Shen, Dai-guo ChenAbstract:Abstract In this study, the explosion behaviors of methane-air mixtures were investigated experimentally in a cylinder vessel (210 mm inner diameter and 210 mm height) filled with a single orifice plate at atmospheric Pressure (1 atm) and room temperature (298 K). The equivalence ratios of the test mixtures ranged from 0.7 to 1.3. The blockage ratios of the orifice plates were from 0.49 to 0.94, and the distance between the orifice plates and the ignition point ( S ) were 25 mm, 50 mm and 75 mm. The results show that the maximum explosion Pressure in the presence of an orifice plate. However, the effects of the orifice plate on the maximum Rate of Pressure Rise are various. At the fuel-lean side, the maximum Pressure Rise Rate is increased significantly (larger than that of the stoichiometric condition). As the distance between the orifice plate and ignitor increases, the maximum Pressure Rise Rate increases. In the case of the fuel-rich conditions, the maximum Pressure Rise Rate is the smallest for S = 25 mm, followed by the no plate condition, S = 50 mm and S = 75 mm. The mechanisms are left for further study.
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On the explosion characteristics of hydrogen-air mixtures in a constant volume vessel with an orifice plate
International Journal of Hydrogen Energy, 2019Co-Authors: Lu-qing Wang, Zhaowu ShenAbstract:Abstract In this study, we performed experiments in a cylinder vessel with a single orifice plate to study the explosion characteristics of hydrogen-air mixtures at room temperature (298K) and ambient Pressure (1atm). The blockage ratio ( B R ) and position of the orifice plate were various. Explosion characteristics, i.e., maximum explosion Pressure ( P m a x ), combustion duration ( θ ) and maximum Pressure Rise Rate ( ( d p / d t ) m a x ) were derived based on the Pressure evolution. The results show that both the maximum explosion Pressure and combustion duration are independent of the orifice plate. However, the effects of the orifice plate on the maximum Rate of Pressure Rate are significant. Depending on the position and blockage ratio, the effects are different. The orifice plate acts as a heat sink when the distance between the orifice plate ( S ) is very close, making ( d p / d t ) m a x decrease (compared with that obtained without the orifice plate). The orifice plate acts as “turbulence-generator” as S increases; thus, ( d p / d t ) m a x increases. Further, the influences of the blockage ratio as well as laminar burning velocity on the maximum Pressure Rise Rate are also analyzed.
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effects of hydrogen addition on the explosion characteristics of n hexane air mixtures
International Journal of Hydrogen Energy, 2019Co-Authors: Li Zhang, Lu-qing Wang, Zhaowu Shen, Jun Pan, Rui Liu, Kai ZhaoAbstract:Abstract To study the effects of hydrogen addition on the explosion characteristics (the explosion Pressure and maximum Rate of Pressure Rise) of n-hexane/air mixtures, experiments were performed in a cylindrical vessel at 100 kPa, 353 K, with equivalence ratios of 0.8–1.7 and hydrogen addition range from 0% to 80%. Concurrently, flame images were captured by high-speed schlieren photography to study the burning performance. The results indicate that both the explosion Pressure and maximum Pressure Rise Rate increase with the increase in hydrogen addition in terms of the lean n-hexane/hydrogen/air mixtures. With respect to the richer mixtures, however, the inverse tendency is observed. With increasing hydrogen fractions, the explosion Pressure and maximum Pressure Rise Rate decrease. The peak values of the explosion Pressure and maximum Pressure Rise Rate shift to the leaner mixture with increased hydrogen proportion. Moreover, the laminar burning velocities of n-hexane/hydrogen/air mixture were also obtained via the expanding spherical method and the Pressure-time histories, respectively. Variation of laminar burning velocity with hydrogen proportion from both methods were studied as well, and the results show that the laminar burning velocity changes significantly under different hydrogen addition.
Lu-qing Wang - One of the best experts on this subject based on the ideXlab platform.
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effects of vessel height and ignition position upon explosion dynamics of hydrogen air mixtures in vessels with low asymmetry ratios
Fuel, 2021Co-Authors: Lu-qing Wang, Zhaowu ShenAbstract:Abstract The explosion characteristics of hydrogen-air mixtures in a wide range of equivalence ratios in closed vessels were investigated experimentally. The maximum explosion Pressure, maximum Pressure Rise Rate (along with deflagration index), explosion time and heat loss were evaluated. Three vessels with low asymmetry ratios ( H / D ) of 0.146, 0.244 and 0.341 were used to study the effect of vessel height on explosion parameters, in which H and D are the height and inner diameter of the vessel, respectively. In the H / D = 0.341 vessel, the effect of ignition position on explosion behaviors was also considered. The results show that, with the increase of the vessel height, the maximum explosion Pressure increase correspondingly, and the explosion time decreases orderly. In the lowest height vessel ( H / D =0.146), the ignitor-regulating column acts as a ‘turbulence-generator’. Thus, the maximum Rate of Pressure Rise could be increased significantly while the heat loss could be decreased. Compared with the central ignition scenario, both the maximum explosion Pressure and maximum Pressure Rise Rate are decreased for the asymmetrical ignition; meanwhile, the explosion time and the heat loss during the explosion are increased.
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The influence of an orifice plate on the explosion characteristics of hydrogen-methane-air mixtures in a closed vessel
Fuel, 2019Co-Authors: Lu-qing Wang, Zhaowu Shen, Dai-guo ChenAbstract:Abstract We reported an experimental study on the explosion characteristics of hydrogen-methane-air mixtures in a closed vessel at normal Pressure and temperature. The explosion parameters, such as the maximum explosion Pressure, the explosion time, the maximum Pressure Rise Rate and the deflagration index were derived based on the Pressure-time evolution. The effect of the blockage ratio as well as the position of the orifice plate on these explosion parameters were analyzed. The results show that the maximum explosion Pressure was decreased in the presence of an orifice plate due to the heat transfer to the baffle. At the early stage of the flame propagation, the flame was suppressed. Subsequently, the flame speed was increased at the later stage in some cases. Combined with the various reactivities of the mixtures, the explosion times obtained in all cases were very close. For a given mixture and an orifice plate position, the maximum Pressure Rise Rate and the deflagration index were increased with the increase of blockage ratio. Besides, the maximum Pressure Rise Rate as well as the deflagration index were decreased when the orifice plate was close to the ignitor and oppositely, increased when the orifice plate was away from the ignitor.
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Effect of a single orifice plate on methane-air explosion in a constant volume vessel: Position and blockage ratio dependence
Experimental Thermal and Fluid Science, 2019Co-Authors: Lu-qing Wang, Zhaowu Shen, Dai-guo ChenAbstract:Abstract In this study, the explosion behaviors of methane-air mixtures were investigated experimentally in a cylinder vessel (210 mm inner diameter and 210 mm height) filled with a single orifice plate at atmospheric Pressure (1 atm) and room temperature (298 K). The equivalence ratios of the test mixtures ranged from 0.7 to 1.3. The blockage ratios of the orifice plates were from 0.49 to 0.94, and the distance between the orifice plates and the ignition point ( S ) were 25 mm, 50 mm and 75 mm. The results show that the maximum explosion Pressure in the presence of an orifice plate. However, the effects of the orifice plate on the maximum Rate of Pressure Rise are various. At the fuel-lean side, the maximum Pressure Rise Rate is increased significantly (larger than that of the stoichiometric condition). As the distance between the orifice plate and ignitor increases, the maximum Pressure Rise Rate increases. In the case of the fuel-rich conditions, the maximum Pressure Rise Rate is the smallest for S = 25 mm, followed by the no plate condition, S = 50 mm and S = 75 mm. The mechanisms are left for further study.
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On the explosion characteristics of hydrogen-air mixtures in a constant volume vessel with an orifice plate
International Journal of Hydrogen Energy, 2019Co-Authors: Lu-qing Wang, Zhaowu ShenAbstract:Abstract In this study, we performed experiments in a cylinder vessel with a single orifice plate to study the explosion characteristics of hydrogen-air mixtures at room temperature (298K) and ambient Pressure (1atm). The blockage ratio ( B R ) and position of the orifice plate were various. Explosion characteristics, i.e., maximum explosion Pressure ( P m a x ), combustion duration ( θ ) and maximum Pressure Rise Rate ( ( d p / d t ) m a x ) were derived based on the Pressure evolution. The results show that both the maximum explosion Pressure and combustion duration are independent of the orifice plate. However, the effects of the orifice plate on the maximum Rate of Pressure Rate are significant. Depending on the position and blockage ratio, the effects are different. The orifice plate acts as a heat sink when the distance between the orifice plate ( S ) is very close, making ( d p / d t ) m a x decrease (compared with that obtained without the orifice plate). The orifice plate acts as “turbulence-generator” as S increases; thus, ( d p / d t ) m a x increases. Further, the influences of the blockage ratio as well as laminar burning velocity on the maximum Pressure Rise Rate are also analyzed.
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effects of hydrogen addition on the explosion characteristics of n hexane air mixtures
International Journal of Hydrogen Energy, 2019Co-Authors: Li Zhang, Lu-qing Wang, Zhaowu Shen, Jun Pan, Rui Liu, Kai ZhaoAbstract:Abstract To study the effects of hydrogen addition on the explosion characteristics (the explosion Pressure and maximum Rate of Pressure Rise) of n-hexane/air mixtures, experiments were performed in a cylindrical vessel at 100 kPa, 353 K, with equivalence ratios of 0.8–1.7 and hydrogen addition range from 0% to 80%. Concurrently, flame images were captured by high-speed schlieren photography to study the burning performance. The results indicate that both the explosion Pressure and maximum Pressure Rise Rate increase with the increase in hydrogen addition in terms of the lean n-hexane/hydrogen/air mixtures. With respect to the richer mixtures, however, the inverse tendency is observed. With increasing hydrogen fractions, the explosion Pressure and maximum Pressure Rise Rate decrease. The peak values of the explosion Pressure and maximum Pressure Rise Rate shift to the leaner mixture with increased hydrogen proportion. Moreover, the laminar burning velocities of n-hexane/hydrogen/air mixture were also obtained via the expanding spherical method and the Pressure-time histories, respectively. Variation of laminar burning velocity with hydrogen proportion from both methods were studied as well, and the results show that the laminar burning velocity changes significantly under different hydrogen addition.
Chung-cheng Chiang - One of the best experts on this subject based on the ideXlab platform.
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thermal runaway features of 18650 lithium ion batteries for lifepo4 cathode material by dsc and vsp2
Journal of Thermal Analysis and Calorimetry, 2012Co-Authors: Yih-wen Wang, Chung-cheng ChiangAbstract:Abstract In view of availability, accountability, and applicability, LiFePO4 cathode material has been confirmed to be better than LiCoO2 cathode material. Nevertheless, few related researches were conducted for thermal runaway reaction of the LiFePO4 batteries. In this study, vent sizing package 2 (VSP2) and differential scanning calorimetry were employed to observe the thermal hazard of 18650 lithium-ion batteries and their content—LiFePO4 cathode material, which were manufactured by Commercial Battery, Inc. Two states of the batteries were investigated, which was charged to 3.6 V (fully charged) and 4.2 V (overcharged), respectively, and important parameters were obtained, such as self-heating Rate (dT dt−1), Pressure-Rise Rate (dP dt−1), and exothermic onset temperature (T0). The results showed that T0 for fully charged is about 199.94 °C and Tmax is about 243.23 °C. The entire battery for LiFePO4 cathode material is more stable than other lithium-ion batteries, and an entire battery is more dangerous...
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Self-reactive rating of thermal runaway hazards on 18650 lithium-ion batteries
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: Yih-wen Wang, Chung-cheng ChiangAbstract:Vent sizing package 2 (VSP2) was used to measure the thermal hazard and runaway characteristics of 18650 lithium-ion batteries, which were manufactured by Sanyo Electric Co., Ltd. Runaway reaction behaviors of these batteries were obtained: 50% state of charge (SOC), and 100% SOC. The tests evaluated the thermal hazard characteristics, such as initial exothermic temperature (T 0), self-heating Rate (dT dt −1), Pressure-Rise Rate (dP dt −1), Pressure temperature profiles, maximum temperature, and Pressure which were observed by adiabatic calorimetric methodology via VSP2 using customized test cells. The safety assessment of lithium-ion cells proved to be an important subject. The maximum self-heating Rate (dT dt −1)max and the largest Pressure-Rise Rate (dP dt −1)max of Sanyo 18650 lithium-ion battery of 100% SOC were measured to be 37,468.8 °C min−1 and 10,845.6 psi min−1, respectively, and the maximum temperature was 733.1 °C. Therefore, a runaway reaction is extremely serious when a lithium-ion battery is exothermic at 100% SOC. This result also demonstRated that the thermal VSP2 is an alternative method of thermal hazard assessment for battery safety research. Finally, self-reactive ratings on thermal hazards of 18650 lithium-ion batteries were studied and elucidated to a deeper extent.