Prismatic Lithium-ion Batteries Research Articles

Study on the failure behavior of the current interrupt device of lithium‐ion battery considering the effect of creep

The working condition of the CID (current interrupt device) has an important impact on the safety of the prismatic lithium-ion batteries. One of the important factors that causes the failure of the prismatic power battery is the overturning of CID due to material creep. The tensile and creep tests of the MFX2 aluminum alloy which is the material of CID were designed. Based on the experimental data the isotropic hardening multilinear elastic-plastic constitution and creep constitution at the battery working temperature were established. The constitutions were also verified by the notch test. The finite element model of the CID and the cap was established to analyze the effect of creep on the failure behavior of the CID throughout life. The simulation tests in the constant temperature and constant load of CID is designed. The simulation results showed that the constitution characterizes the basic mechanical properties of the CID reasonably. During the life of the CID, the creep behavior would go through the fast stage firstly and then fall into the slow steady-state stage. The creep effect of the material would cause the CID to overturn in advance, overturning pressure would be reduced, the life of the power battery would also be reduced.

An improved resistance-based thermal model for prismatic lithium-ion battery charging

This study proposed a dynamic resistance-based thermal model to predict the temperature evolution of a prismatic lithium-ion battery in fast and regular charging strategies. The effects of battery temperature, state of charge (SOC), and charging current on resistance were investigated to form a dynamic heat generation model. This model included both the heat generation of battery body and the heat generation of electrodes. Then the charging resistance-based thermal model was used to predict the temperature distribution and temperature evolution of a 50 Ah prismatic battery under different charging strategies and ambient temperatures. The charging strategies included a multi-stage constant current-constant voltage (MSCC-CV) for fast charging and a constant current-constant voltage (CC-CV) for regular charging. Experiments verified the prediction accuracy of the proposed thermal model. The results showed that the dynamic thermal model accurately predicted the temperature distribution and its evolution under different charging strategies and ambient temperatures. With regard to temperature distribution prediction, the average root mean square errors (RMSEs) of temperature among the five test points were 0.43 °C for the MSCC-CV charging strategy and 0.3 °C for the CC-CV charging strategy. For the temperature prediction under various ambient temperatures, the average RMSEs at different ambient temperatures were 0.34 °C for the MSCC-CV strategy and 0.25 °C for the CC-CV strategy. Finally, the effect of the charging and discharging resistance on the temperature prediction under the MSCC-CV charging condition was studied. Although the discharging resistance-based thermal model could describe the temperature change with charging time, it showed higher predicted temperatures than the tested values and a larger estimation error than the charging resistance-based thermal model.

Jet behavior of prismatic lithium-ion batteries during thermal runaway

Insights into jet behavior are significant for the safe application of lithium-ion batteries and the design of thermal protection systems. In this study, a fully charged 38Ah Li(Ni1/3Co1/3Mn1/3)O2/graphite prismatic lithium-ion battery was heated on one side to trigger thermal runaway. An unignited jet behavior was characterized by jet manifestation, temperature, and velocity. Results showed that the jet process could be divided into four stages, and special phenomena such as jet tilt, spark burst, and jet ignition might occur at the third stage. The similarity between the maximum temperature of the jet in this work and the jet fire in a previous study indicated that the thermal hazard of the jet could not be underestimated. The average jet velocity of 8.3 m·s−1 at the third stage was obtained with a high-speed imaging technology. A prediction method of the jet velocity was developed on the basis of the internal pressure of the battery. This work could enhance our understanding of the unignited jet behavior and provide references for the safety design and hazard prevention in battery storage systems.

Experimental study on the dynamic behavior of prismatic lithium-ion battery upon repeated impact

The daily use of electric vehicles may cause mechanical loading on their batteries, either from one-time impact or repeated/accumulated impact from vibrations, curbstone impact, or minor contacts/scratches. Such repeated impact may ultimately lead to short-circuit failure of the batteries. Open literature comprehensively discusses the one-time impact, but a gap remains regarding battery safety behaviors in repeated impact cases. Therefore, in this study, the dynamic behavior of prismatic lithium-ion battery (PLIB) under repeated impact is experimentally investigated for the first time. The relationships between battery failure of short circuit with impact velocity, impact energy and impact times are revealed. The quantitative relationship between battery failure and indentation depth is constructed. Results show that the increase of impact velocity and energy significantly decreases the number of short-circuit impact. For the prismatic lithium-ion battery studied in this work, under the drop-weight impact test with 34.6 kg weight and 25 mm diameter of the hemispherical impact indenter, once the impact velocity reaches more than 1.75 and 4.0 m/s, the soft and hard short circuits are triggered, respectively. When the impact speed is less than the corresponding velocity, the battery failure of soft and hard short circuits can occur only after multiple impacts. Results provide new insights for understanding battery failure behaviors upon repeated impact and important guidance for battery design.

Investigation of porous media effects on lithium-ion battery thermal management

The utilization of porous media and its effects on thermal management of internally cooled lithium-ion battery with the aid of porous media has been investigated. Two different configurations of the porous zone have been studied through three-dimensional transient thermal analysis of prismatic lithium-ion battery with liquid electrolyte as a coolant. At first, both configurations of the porous zone were investigated in pursuit of detecting the optimum configuration. Afterward, the effects of various materials, porosities and pores sizes were explored on the standard deviation of the temperature field and maximum temperature inside the battery in the optimum porous zone configuration. In the end, the utilization of the response surface method due to the parametric study and discover the most crucial parameters in battery performance was scrutinized. Compared to the non-inclined porous, the inclined porous zone case decreases the standard deviation of the temperature field significantly. Using the inclined porous zone also indicates that decreasing porosity results in the enhancement of both maximum temperature and standard deviation of the temperature about 20.75%. Hence, the increment of pore size results in decreasing maximum temperature inside the battery, while it could help the standard deviation of the temperature to be improved by about 24.88%.

A computational multi-node electro-thermal model for large prismatic lithium-ion batteries

During operation of large prismatic lithium-ion batteries, temperature heterogeneities are aggravated which affect the performance, lifetime and safety of the cells and packs. Therefore, an accurate model to predict the evolution of temperature profiles in a cell is essential for effective thermal management. In this paper, a pseudo 3D coupled multi-node electro-thermal model is presented for real-time prediction of the heterogeneous temperature field evolution on the surface and inside the battery. The model consists of two parts: a heat generation model based on a second-order equivalent-circuit model and a multi-node heat transfer model based on the battery geometry. Three types of nodes are adopted to describe the thermal characteristics of various components of the cell. Simulation results show that the proposed model has a great consistency with finite element method, and its computational cost is reduced by 90%. The validity of the coupled electrical and thermal model is also demonstrated experimentally for a 105 Ah prismatic cell applying wide ranges of temperature and SOC. The maximum error is less than 2 K throughout the cycles. The proposed model holds a great potential for online temperature estimation in advanced lithium-ion battery thermal management system design.

Particles Released by Abused Prismatic Ni-rich Automotive Lithium-ion Batteries

The particulate matter released by lithium-ion batteries during eruption and combustion caused by thermal runaway may contain heavy metal pollution elements. The aim of this study is to reveal four heavy metal element content and size distribution of particulate matter released by abused prismatic Ni-rich automotive lithium-ion batteries. A fully charged commercial 50 Ah Li(Ni0.6Mn0.2Co0.2)O2 cell was triggered by heating in a sealed chamber at nitrogen environment. The particulate matter with size being below 500 μm were divided into three samples using sieves. Four soil pollution elements, including nickel, copper, zinc, chromium, were detected, and sizes were analyzed. The results show that all these four elements are found, and nickel and copper are found in all samples. Among the four elements, Ni had the largest mass percentage, followed by Cu, Zn and Cr. These particulate matter account for 1.7% of the cell mass, with the minimum size and median size being approximately 1.45 μm and 162.9 um. The element content reveals the pollution from LIBs and the size distribution provides a basis for the design of the particle filter pore.

Dynamic behavior and modeling of prismatic lithium‐ion battery

The inevitable vehicle collision has made the safety of lithium-ion battery (LIB) carried by electric vehicles (EVs) a problem that restricts the further and large-scale promotion of EVs. Therefore, establishing the numerical mechanics model of LIBs and studying their mechanical integrity are imperative. In this study, we design indentation, compression, and drop-weight experiments for prismatic LIBs (PLIBs). Mechanical integrity and internal short circuit are analyzed in consideration of state of charge (SOC) and dynamic effects. A homogeneous PLIB model that considers anisotropic property, SOC, and dynamic effects is developed for the first time for application in different loading conditions. After its effectiveness is validated, the affecting parameters (ie, SOC and impact velocity) of the mechanical behaviors during dynamic loadings are investigated using the established model. The results show that strain rate effect and SOC state have impact on the mechanical properties of PLIB. However, the strain rate effect has much larger influence than the SOC state. Results may shed lights on the safety design of PLIBs in a mechanical aspect.

The Impact of Environmental Factors on the Thermal Characteristic of a Lithium–ion Battery

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 Ah prismatic lithium–ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries’ interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations; (2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell; (3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries’ lifespan.

Thermal Management of Prismatic Lithium-Ion Battery with Minichannel Cold Plate

AbstractA battery thermal management system (BTMS) is crucial to guarantee that lithium-ion (Li-ion) batteries attain high performance, long life, and a high level of safety. To investigate an effe...

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.

Size distribution and elemental composition of vent particles from abused prismatic Ni-rich automotive lithium-ion batteries

Abstract The lithium-ion battery (LIB) jet is often accompanied by particulate matter (PM) (e.g. spark) during vent and combustion caused by thermal runaway. These hot PM could ignite the combustible vent gases, and the settleable matter may promote water and soil pollution. The aim of this study is to reveal the statistical size distribution and elemental composition of the settleable PM released by LIBs after thermal runaway. A fully charged commercial 50 Ah Li(Ni0.6Mn0.2Co0.2)O2 cell was triggered by heating in a sealed chamber. These PM were divided into 4 samples using sieves. The sizes were analyzed and the elements were detected. The results show that these PM account for 11.20% of the cell mass. Nearly 45% of particles by mass were found to have a size less than 0.85 mm, with the median size being approximately 198 um. The main elements are carbon, nickel, cobalt, etc. The content of metallic elements is approximately 40%. The emissions also contain potentially toxic elements, including aluminum, lithium, fluorine, etc. The element species in different samples are similar, but their contents differ. The size distribution provides a basis for the design of the particle filter pore, and elemental composition reveals the pollution of LIB emissions.

Thermal runaway behavior during overcharge for large-format Lithium-ion batteries with different packaging patterns

• Thermal runaway behavior during overcharging is investigated. • The impact of cell packing patterns is revealed. • A specialized test platform is established to conduction experiments. • The thermal runaway behaviors of the tested cells are compared. Lithium-ion batteries are the main energy storage unit for electric vehicles. The prevention of thermal runaway is essential for ensuring safe operation of these batteries. Different cell packaging patterns have an influence on the thermal runaway behavior of lithium-ion batteries during overcharging. In this paper, prismatic and pouch lithium-ion battery cells with the same capacity and chemistries are used to experimentally investigate the internal failure mechanisms and associated external characteristics during overcharging. The entire overcharge process is divided into five stages according to the voltage and temperature curves. The results indicate that the pouch battery cell exhibits better thermal behavior characteristic and overcharge tolerance when compared to the prismatic battery cell in stages I to III. However, the prismatic battery cell has better thermal runaway buffering characteristic, smaller deformation and longer early warning time. This is due to the use of a safety valve which results in subsided damage caused by thermal runaway. Their maximum surface temperature differences increase linearly with the overcharge process, until thermal runaway occurs and rapid rise to the highest temperature point takes place. These results provide an insight into the safety and thermal management design of battery systems.

Coupling multi-physics simulation and response surface methodology for the thermal optimization of ternary prismatic lithium-ion battery

A 3D electrochemical-thermal coupled finite element analysis (FEA) model is established on COMSOL Multiphysics® software for 40 A h ternary prismatic lithium-ion batteries. The input parameters in this model are current C-rate C, battery thickness Thbat, initial battery ambient temperature Tint, positive porous electrode thickness Thpos, positive particle diameter Dpos, positive electrode solid phase volume fraction ε1,pos, respectively. Response surface methodology (RSM) with variance analysis (ANOVA) and parametric scanning is employed for simulating and optimizing the data obtained from the Box-Behnken experimental design based on this model. After that, the optimized parameters are verified to evaluate the reliability of the model on heat generation. The results of response surface optimization show that the optimized model error is less than 0.76% and the final temperature drops is 0.55 K. This novel model is reliable and accurate, which is helpful to improving the electrochemical and thermal performance of the battery. Also, it can provide optimized and feasible solutions for other similar kind of batteries, which offer the reference for design and optimization of the battery management system.

Thermal Runaway Characteristics of a Large Format Lithium-Ion Battery Module

The overheat abuse experiment of a 12S1P 37 Ah prismatic Lithium-ion battery module in a nominal energy of 1.65 kWh is conducted in this work. The cell behaviors and characterization in the process of thermal runaway propagation is investigated, including the gas eruption, the fire ejection, the flame combustion, the audio features, and the heat transfer, respectively. In the experiment, the central cell is heated on both sides until the pole temperature moves beyond 300 °C, the thermal runaway undergoes about 43 min and propagates from the central to both sides in the module, and all 12 cells burn. Results show that the first three runaway cells spout gas at first, and, then, emit sound with close amplitudes, frequencies, and energies, about 200 s earlier than the fire ejection. Then, the characteristic of the internal short circuit is the temperature rate zone of 1.0 K/s with time greater than 20 s. Moreover, the proposed thermal propagation coefficient is used to assess the thermal propagation capabilities of the runaway cells on their adjacent cells, and this explains the runaway sequence. It is anticipated that the experimental results can provide the deep understanding, thermal runaway warning, and evaluation method for the module safety design.

Dynamic thermal behavior of micro heat pipe array-air cooling battery thermal management system based on thermal network model

An effective battery thermal management system is crucial for electric vehicles because the performance of lithium ion battery is sensitive to its operating temperature. In this study, a thermal management system equipped with micro heat pipe array (MHPA) is designed. An equivalent thermal resistance model is developed for MHPA based on thermal circuit method. The accuracy of the proposed model is validated by comparing the simulation results with experimental data under steady and dynamic and operating condition. A validated lumped thermoelectric model is adopted for prismatic lithium ion battery. The proposed thermal resistance model is combined with the battery model in order to predict the transient temperature distribution of a battery pack based on MHPA cooling. Simulations are conducted for air-cooled MHPA thermal management system. Temperature rise and temperature gradients of the designed cooling system are compared with direct forced convection. Simulation results demonstrate that the MHPA-based battery thermal management provides a quick response to ensure the temperature stability during rapid changing operating condition.

Dual-purpose cooling plate for thermal management of prismatic lithium-ion batteries during normal operation and thermal runaway

A dual-purpose cooling plate for prismatic lithium-ion batteries (LIBs) to increase the battery pack life and safety for applications in vehicles, aircraft, and stationary electric storage systems for grid and renewables is proposed. The proposed cooling plate can maintain the temperature of the battery within the manufacturers’ recommended temperatures during the battery normal operation to increase the battery life, and can effectively control and dissipate the generated heat during thermal runaway to prevent propagation of heat from one cell to the adjacent cells in the battery pack to increase the safety. The proposed cooling plate is made of aluminum and works on the principle of the liquid cooling method with 60% ethylene glycol in water as the coolant. The cooling plate is featured with pins with staggered arrangement, which act as heat sinks and disperse the coolant over the surface of the cooling plate. The performance of the cooling plate is examined for heat generation trend of aggressive discharging of the battery during the normal operation and the heat generation during thermal runaway of the fully charged battery. The results show that the designed cooling plate can maintain the LIB surface temperature below 25 °C with the input coolant temperature of 20 °C and flow rate of 0.2 L/min during the normal operation, and can control the LIB temperature during thermal runaway at about 75 °C in 30 s with the input coolant temperature of 20 °C and flow rate of 30 L/min. The pressure-drop of the coolant is also about 75 Pa for the normal operation mode and about 54 kPa for the thermal runaway operation mode of the cooling plate.

Online Temperature Estimation Based on a Coupled Diffusion-Electro-Thermal Model for Lithium-Ion Batteries

The performance of Lithium-ion batteries is strongly influenced by the temperature. Therefore, an accurate estimation of the cells’ temperature becomes a critical issue for a battery thermal management system to reduce its energy consumption and improve the overall performance of the whole battery system. In this paper, a coupled diffusion-electro-thermal model is established to acheive the real-time estimation of the temperature distribution of large prismatic lithium-ion batteries. The presented model consists of two parts: a diffusion-elctro model to calculate the heat generation rate of the cell and a multi-node thermal model to estimate and predict the battery’s internal temperature profile. The two sub-models are parameterized by pulse and constant discharge experiments under different ambient temperatures. Both simulation and experimental results reveal that while the irreversible heat of the cell is governed by its cycling current and overpotential, the reversible heat is dependent on the pseudo surface lithium-ion concentration, which indicates that the thermal behavior of the lithium-ion battery is directly coupled with the diffusion of lithium-ions in the solid phase. The performance of the full model is validated by dynamic driving cycles under liquid cooling conditions and the results show that the model can capture the cell’s temperature distribution during cycling with an acceptable computational cost.

Experimental investigation on electro-thermal characteristics of the commercial Li-ion battery

As the most commonly used power battery in electric vehicles, lithium-ion battery is sensitive to the operation temperature. The performance and lifespan of lithium-ion battery are strongly dependent on its working temperature. Various thermal management systems have been developed to maintain batteries’ operating temperature within an appropriate range. A properly designed thermal management system relies upon the understanding of battery’s heat-generation characteristics and the temperature effect on its discharging performance. In this research, an experimental investigation is carried out to study the electro-thermal characteristics of the commercial prismatic ternary lithium-ion battery under three thermal conditions. Constant temperature condition is built to explore the effect of the operating temperature, while near-adiabatic condition and natural-convection condition are employed to study the heat-generation characteristics of lithium-ion battery. The results show that the effect of operating temperature on discharge performance becomes more pronounced as the discharge rate increases. It is found that the surface temperature decreases when the battery discharges at small rates within the capacity ranged from 17Ah to 27Ah, demonstrating that the reversible heat makes up a large proportion of battery heat generation.

Experimental analysis on Li-ion battery local heat distribution

This work presents experimental analysis on the local heat flux distribution for a prismatic lithium-ion battery at various charge/discharge rates. Experimental setup for a large prismatic lithium-ion battery thermal testing is developed, and experimental investigations of the thermal dissipation of lithium-ion battery are conducted under various charge/discharge rates to provide more information on battery heat generation. The aim of the present study is to evaluate the heat generated by the electrochemical reaction inside a lithium-ion cell during numerous charging/discharging cycles until reaching steady state. In this paper, the distribution of temperature is presented for a prismatic Li-ion battery at different operating conditions. The results show that a higher battery temperature is obtained at the beginning of the charge cycle and the lower temperature is reached at the end of charge cycle and the beginning of discharge cycle. Furthermore, it is observed that the increase in charge/discharge current rate increases the battery temperature, the generated heat flux and the part of the irreversible heat compared to the reversible heat. It can be observed that at C-rate of 3C irreversible heat reaches 80% of the total generated heat.