Maximum Temperature Of Battery Research Articles

Critical thickness of nano-enhanced RT-42 paraffin based battery thermal management system for electric vehicles: A numerical study

Use of electric vehicles has increased worldwide. Lithium Ion (Li-Ion) batteries are widely used to power them due to their high energy density and low self-discharge rates as compared to other conventional batteries such as lead acid. But at 3C discharge rates (where 3C means 3 times the rated Ah capacity of the battery cell), there is a sharp rise in temperature which impacts battery cell performance. After temperature exceeding 50 °C, the Li-Ion battery cells become unstable and catch fire and thus, its thermal management became a priority. Battery thermal management system (BTMS) aims to control battery cell temperature within operating limits at high discharge rates and ambient temperatures. BTMS utilizes either a fluid medium to carry away heat or working material in the form of Phase Change Material (PCM). In the present numerical investigation RT-42 paraffin is used as working material to control battery temperatures. In this investigation the performance of RT-42 paraffin for different thicknesses ranging from 1 mm to 7 mm around the battery cell was used to control battery temperature effectively. It is observed that up to 4 mm thickness of RT-42 paraffin gain in controlling the temperature is maximum. But low thermal conductivity of pure RT-42 impacts on its heat transfer performance. Therefore investigation of performance of Al2O3/RT-42 paraffin nano PCM (NePCM) with percentage weight fractions of 0.5, 1, 2, and 5 at critical thickness 4 mm was carried out. NePCM was able to maintain the maximum battery temperature 42.77 °C and remains in partially liquefied state at the end of discharge cycle of 1200 s.

Feasibility study of a novel oil-immersed battery cooling system: Experiments and theoretical analysis

The successful application of oil-immersed transformers inspires the thought about the feasibility of the transformer oil on developing an oil-immersed battery thermal management system. This paper tentatively designs a model-scale transformer oil-immersed battery thermal management system to investigate the feasibility of the cyclic transformer oil fluid on cooling the battery. It is found that at 2C discharge rate, the battery immersed in the stationary transformer oil fluid exhibits a maximum temperature of 37.35 °C and a maximum temperature inhomogeneity of 2.64 °C, much lower than that exposed to the open air. To further improve the heat dissipation performance of the oil-immersed cooling system, different oil volumetric flow rates ranging from 3 to 50 mL/min are tested to examine the cooling effectiveness. As the oil fluid circulates, the maximum battery temperature can maintain below 35 °C. The increasing TO volumetric flow rate can continuously lower the battery temperature, while this effect gradually wanes as the flow rate exceeds 15 mL/min. The theoretical analysis indicates that as the heat transfer mode is dominated by natural convection, the increasing TO flow rate will significantly improve the cooling effectiveness of the system. In other cases, the increasing flow rate improves the cooling performance to a small extent, and concurrently intensifies the consumption of pumping power. The TO fluid with a flow rate of 15 mL/min (Reynolds number = 0.59) is suggested as the optimal choice for the current TO-immersed BTMS. The current oil-immersed battery cooling system validates the concept of direct-contact cooling method through model-scale experiments and theoretical considerations, which provides novel insights into the development of more efficient oil-immersed battery thermal management systems utilizing the dielectric oils.

Pack-level modeling of a liquid cooling system for power batteries in electric vehicles

An efficient pack-level battery thermal management system is essential to ensure the safe driving experience of electric vehicles. In this work, we perform three-dimensional modeling of a liquid thermal management system for a real-world battery pack powering electrical vehicles. The effects of system structures, coolant flow direction layout, coolant flow rates, and inlet temperatures on the thermal performance are investigated. Under 2.0 C discharge, the system structure with interspersed cooling plates reduces the maximum temperature of the battery pack to 36.3 °C, which is 15% lower than that of the conventional design with bottom-mounted cooling plates. With the present system structure, around 62.2% of the heat produced by the batteries is dissipated. Moreover, the temperature difference is decreased by 10.5% with appropriately arranging coolant flow directions in different liquid cooling plates. In addition, increasing the coolant flow rate and lowering the inlet coolant temperature can greatly reduce the maximum battery temperature, while the latter parameter shows little influence on the pack temperature difference, which only changes 0.3 °C when the inlet temperature is decreased by 6 °C. This work provides valuable guidance for the development of pack-level liquid battery thermal management systems in electric vehicles.

Multi-objective optimization of a mini channeled cold plate for using thermal management of a Li-Ion battery

Mini channeled cold plates (MCCP) are an impressive choice for electric vehicles with a liquid-based thermal management system to keep the battery temperature within the desired range and to achieve a homogeneous temperature distribution. This paper came up with an optimum solution for maximum battery temperature (MBT), maximum temperature difference on the battery surface (MTD) and pressure drops in the channels (ΔP), which are vital parameters. Multi-objective optimization of geometric parameters and coolant flow rate of a designed MCCP which is experimentally investigated is carried out using the Desirability Function Approach. Firstly, the design of experiments (DoE) is generated using response surface method after determining the input variables and their levels. Then, each sample of DoE are modeled and analyzed numerically. Furthermore, the regression equations of the objective functions (MBT, MTD and ΔP) depending on the design parameters are developed and their variance analyzes are performed. Prediction accuracies of model equations developed for MBT, MTD and ΔP are 97.75%, 95.49% and 97.15%, respectively. As a result, optimum values of design variables, namely channel width (mm), distance between branches (mm), channel depth (mm), number of crossovers in branches and coolant flow rate (l/min) are 5, 5, 10, 13 and 0.7061, respectively.

Simulation Battery Cooling System for Small Scale Electric Vehicle (Light EV)

The Battery Thermal Management System (BTMS) has widely used for Electric Vehicle (EV) as cooling system to reduce high temperature occurred from batteries source during discharge and charge process. Since the performance and cycle life of batteries are very sensitive to temperature, it important to maintain the proper temperature range in order to avoid the thermal issues and improve the performance. Therefore, the purpose of this project is to study the effectiveness of different type of cooling system for small scale Electric Vehicle (EV). The study is conducted by using two main types of cooling system that available in electricity grid which is air cooling and liquid cooling. In order to evaluate the effectiveness of those cooling system, an analysis is conducted by developing an EV model using MATLAB/Simulink software and simulated at different speed of the vehicle from the few driving cycle that commonly used in researcher paper. Based on the analysis, the maximum temperature of battery for liquid cooling system under NEDC, WLTP, and HWFET is 23.14 ⁰C, 23.3 ⁰C and 23.09 ⁰C compare to air cooling system which is 24.66 ⁰C, 26.3 ⁰C and 24.4 ⁰C respectively at 23 ⁰C of ambient temperature. As the result of this project is showed that the liquid cooling system are more effective to maintain the temperature of battery as the temperature rise more controlled compare to air cooling.

Evaluation of Spoiler Model Based on Air Cooling on Lithium-Ion Battery Pack Temperature Uniformity

Electric vehicles (EVs) and hybrid electric vehicles (HEVs) are a new trend for the vehicle industry, due to the environmental regulations of the internal combustion engine (ICE) and pollutant emission of transportation. However, despite being very promising, the durability of the battery, due to overheating, is still an obstacle. In particular, electric vehicle batteries are manufactured with high voltage and high capacity to ensure power and energy efficiency. For this reason, a high temperature is generated in the system, which reduces the battery performance and life cycle. In this study, three different layouts, based on a direct contact air-cooled system, are designed to compare and improve the cooling performance. Further, a battery cooling test is conducted to verify the designed model. The results show that the spoiler model reduces the maximum battery temperature by (about) 16%, and effectively improves the temperature distribution of the battery cell by (about) 65%, when compared with a conventional cooling method without a spoiler.

Combining an active method and a passive method in cooling lithium-ion batteries and using the generated heat in heating a residential unit

In this paper, a gentle air flow is simulated among cylindrical lithium-ion battery (LIIB) cells using COMSOL software. A circular PCM compartment is placed around the battery cells. The hot air from cooling the battery is used to heat the house. By changing the battery position in three modes in PCM in the air speed range of 1 × 10−3 to 5 × 10−3m/s, the volume fraction of solid PCM, the average PCM temperature (TAve−PCM), the maximum battery temperature (Tmax−b) and the exhaust air temperature at different times from 0 to 1000 seconds are analyzed. The percentage of time energy provided by this system of the total energy required for this residential house has also been examined. The results of this study show that over time at high speeds, the Tmax−b of the LIIB first increases and then decreases. The passage of time also reduces the amount of TOutlet. If the LIIB is placed on the air inlet side of the PCM instead of the air outlet side, the Tmax−b is reduced by 1.53 degrees at high speeds. Placing the LIIB on the left side of the PCM causes the output temperature (TOutlet) to be higher and also increases the amount of solid PCM by up to 5% in 1000 seconds compared to placing the LIIB on the right side. Using 50 cells of LIIB and air flow of 0.005 m/s in this system can provide up to 22% of the required energy for heating the building in a winter day.

Phase change material selection using simulation-oriented optimization to improve the thermal performance of lithium-ion battery

Battery thermal management system (BTMS) is highly essential to maintain battery temperature in Electric Vehicles. The phase change material (PCM) based BTMS is highly effective due to its high latent heat and can also be used without any power consumption. The present work aims to propose the most suitable PCM used for BTMS. Six commercially available PCMs are studied with the battery pack at three different charging rates low (1C), moderate (2C), and high (3C), and three different ambient conditions, i.e., cold (20 °C), moderate (30 °C), and hot (40 °C) conditions. As critical thermal parameters, the maximum battery temperature (Tmax) and maximum temperature difference (ΔTmax) are studied. As both Tmax and ΔTmax are required to be minimum to increase the performance of the battery, a method of Multi-attribute decision making (MADM) named Weighted Product Method (WPM) is used in the present study. At different charging rates 1C, 2C, and 3C, PCMs RT31, RT35, and RT42 are found as most suitable, respectively. While, RT24, RT35, and RT50 are found as most suitable PCM at the ambient temperature of 20 °C, 30 °C, and 40 °C, respectively. It is found out from the result that ambient temperature should be given more consideration than charging rate in PCM selection. These PCMs are found suitable on a battery performance basis; however, if a safe range of lithium-ion batteries (60 °C) is considered, it is noticed that only RT42 and RT50 successfully maintain battery temperature below 60 °C at each operating condition. Finally, it is concluded that PCM with melting temperature lower than ambient temperature and quite higher than ambient temperature is not effective, but PCM with melting temperature 5–10 °C more than ambient temperature can provide better battery performance.

Study on the Influence of Flat Heat Pipe Structural Parameters in Battery Thermal Management System

Battery performance and lifespan are greatly dependent on its temperature, and a good battery thermal system (BTMS) can make the battery work at its favorable temperature range, improve its electrical performance, and extend its lifespan. Due to the high heat conductivity and large surface area of flat heat pipe (FHP), the FHP-based BTMS can quickly remove the heat produced by the battery and improve the temperature homogeneity among cells in the pack. In this study, the FHP is applied to the BTMS, and the influence of its structure on the battery thermal dynamics is studied. Firstly, a coupled thermal model for the FHP-based BTMS is established and verified by the experiment. This model integrates the resistance-based thermal model of the battery and FHP model based on the thermal resistance network. Then, the effect of the structure parameters of FHP such as the thickness, porosity, and particle diameter of sintered wick on the thermal performance of the battery is investigated. According to the results, the temperature variation among battery cells rises significantly when the dimensionless thickness of the wick is greater than 0.7. Moreover, the change of the porosity and particle diameter of the wick results in a nonlinear development of the wick thermal resistance which finally changes the heat conductivity of the FHP and battery temperature. Finally, a neural network model (NNM) is used to establish the relationship between the FHP parameters and battery thermal performance for optimizing the BTMS structure. According to optimization result, the optimized FHP can keep the maximum battery temperature below 40°C at a discharge rate of 2C and reduce the temperature variation in the battery by 7.4%.

Liquid-cooled structure design and heat dissipation characteristics analysis of cross-flow channels for lithium batteries

A detailed three-dimensional thermal model is developed to examine the thermal behaviour of a lithium-ion battery. This model is a cross-flow liquid cooling model, which can make the heat dissipation of lithium-ion battery pack achieve higher safety. Two kinds of fluids are used for cooling, and the polynomial fitting function is used as the heat source term of lithium battery pack. The battery temperature distribution under the conditions of different Reynolds numbers, different numbers of micro-channel and different micro-channel radii are studied for this model. The simulation results show that the maximum battery temperature is 295.84 K, the minimum battery temperature is 293.14 K, and the maximum temperature difference of the battery pack is 2.7 K. The maximum temperature and temperature difference of the battery under the model are in line with the reasonable operating temperature range of lithium-ion battery pack. The maximum temperature of battery pack decreases with the increase of Reynolds number, but the effect of Reynolds number on heat dissipation of lithium-ion battery pack has a critical value. As the number of micro-channels increases, the maximum temperature of the battery string decreases. However, when the number of micro-channels increases to a certain value, the maximum temperature of the battery pack decreases slowly. The maximum temperature of the battery pack does not decrease monotonically as the radius of the micro-channel increases. Orthogonal analysis results show that the Reynolds number has the greatest influence on the cooling effect of the model, followed by the size of the micro-channel radius, and the number of micro-channels has the least influence. The optimized liquid cooling model can effectively reduce the maximum temperature of lithium-ion battery in theory, and the maximum temperature of lithium-ion battery decreases by 26.24 K in comparison with that of single battery at 2C discharge rate. The reliability of the cross-flow channel model is proved by numerical analysis, and it is also proved that the cross-flow channel has an equilibrium point between the perturbation gain and the flow retarding effect. The heat dissipation effect of lithium- ion battery pack is correlated with the number and radius of micro-channels, but not a single positive correlation. Reasonably increasing the number and size of micro-channels can effectively enhance the heat dissipation effect of battery pack.

Investigation of the use of extended surfaces in paraffin wax phase change material in thermal management of a cylindrical lithium-ion battery: Applicable in the aerospace industry

The use of phase change materials (PCMs) for cooling lithium-ion batteries is examined in this research. Because of the unique benefits of lithium-ion batteries, their use in electric cars has gotten a lot of attention. The lithium-ion battery is one of the most extensively utilized components as the heart of a hybrid car. These batteries generate a lot of heat while charging or discharging. If the batteries are not correctly handled, their life will be drastically shortened. In this study, a cylindrical battery is submerged in a PCM-filled chamber. Several fins of the same length are placed on the battery. The aim is to find the ideal battery compartment size and fin count to lower maximum battery temperature during the discharging process. COMSOL Multiphysics commercial software is used for the simulations. The results show that the battery with 15 fins has the best PCM melting performance at the beginning of cooling process. After one third of the cooling time, the maximum melting of PCM that is equal to 26.159% takes place. Also, in the entire cooling process, the lowest maximum temperature and the maximum volume fraction of the liquid occur when the number of fins is 9. The battery temperature rises as the number of fins increases beyond nine. Furthermore, an enclosure with the lowest maximum temperature is supplied to enclosure the lithium-ion battery.

Thermal simulation and prediction of high-energy LiNi0.8Co0.15Al0.05O2//Si-C pouch battery during rapid discharging

Accurate thermal simulation of lithium-ion batteries is of great significance for evaluating and predicting the battery performance to avoid safety hazards. In this paper, research focused on the effects of current rates and ambient temperature on the thermal behavior of high-energy LiNi0.8Co0.15Al0.05O2//Si-C pouch battery is presented. The heat generation rate as a function of discharge rate is calculated by the means of electrochemical calorimetric study. Then by using the finite element analysis method, a three-dimensional model is developed to predict the battery temperature distribution at different discharge rates (0.33, 1.0, 3.0, and 5.0 C). The results reveal a minimum temperature difference of less than 1 °C between simulations and experiments even at 5.0 C rate. Notably, the increased rate leads to an enlarged temperature gradient field of battery, where the maximum battery temperature appears at its geometric center, then it gradually decreases from the center to edges in an annular gradient radiation manner. Accordingly, the simulation results provide a comprehensive evaluation and prediction for the thermal behavior of high-energy battery, which are well consistent with the experimental measurements.

A numerical and statistical implementation of a thermal model for a lithium-ion battery

Lithium-ion batteries are substantial technologies to improve energy storage. If a detailed understanding of thermal behavior for a range of operating conditions is achieved, lithium-ion batteries can be used more effectively in various applications. This study focuses on the effect of ambient temperature, discharge rate, depth-of-discharge, and convective heat transfer coefficient on the maximum battery temperature and maximum battery temperature difference of a commercially available LiMn2O4 prismatic battery. The statistical evaluation showed that the ambient temperature with the delta value of 0.55 was the most influential discharge parameter while the effect of the depth-of-discharge on the maximum battery temperature can be neglected. The maximum battery temperature difference is dominated by the C-rate with the delta value of 15.5399 and the convective heat transfer coefficient with the delta value of 4.2624. More attention is paid to both the C-rate and the convective heat transfer coefficient to simultaneously control and improve the maximum battery temperature and maximum battery temperature difference due to they fulfilled the requirement for a significance level of 95%. The statistical results provide unique insights into the difficult-to-determine effect of the discharge parameters that are closely monitored and controlled to improve the battery thermal management systems.

Topology optimization design and numerical analysis on cold plates for lithium-ion battery thermal management

In this paper, the cold plates are designed to cool the rectangular lithium-ion battery packs by the topology optimization method. The topology optimization method obtains the channel structure in the two-dimensional model, and three-dimensional cold plate models are then established according to their two-dimensional structure. In a simple model for a battery pack, numerical analyses of topology optimization cold plate (TCP) are implemented using COMSOL software. Numerical results were compared with conventional rectangular-channel cold plate (RCP) and serpentine-channel cold plate (SCP) to investigate the cooling performance and flow characteristics of the cold plate. The results demonstrate that the flow channel structure of the cold plate has a significant influence on the temperature distribution of the battery. At 150 Pa inlet pressure, the maximum temperature of batteries with TCPs is reduced by 0.27% and 1.08% compared to that with RCP or SCP, and the temperature difference is lowered by 19.50% and 41.88%. Appropriately increasing the inlet pressure of the cold plate can also reduce the maximum temperature and temperature difference of batteries. Due to low flow resistance and high heat transfer coefficient, topology optimization will be widely used to design battery cold plates.

A simplified thermal model for a lithium-ion battery pack with phase change material thermal management system

The present work is aimed at developing a simplified model for investigating numerically a Li-Ion battery pack storage with phase change material (PCM). The developed model is based on the energy balances for the battery cells and the PCM with a heat generation source. To simulate the phase transition phenomena in the PCM, the PCM specific heat capacity is expressed as a temperature-dependent function. The verification of the proposed model is carried out by comparing the numerical results with the experimental data from the literature and the maximum relative error obtained is approximately 6%. With the help of the validated model, the battery pack is explored during both charge and discharge cycles and the effect of various design and operating parameters on the battery temperature is reported and discussed. Results show that the use of PCM in the battery pack is appropriate and reduces the maximum battery temperature by up to 3 °C compared to a battery pack without PCM. Improving the airflow around the storage system can significantly increase the thermal management performance of the PCM and reduce the maximum temperature of the batteries by up to 2.5 °C. It has been also shown that PCM A-32 H is suitable for the battery pack than PCMs RT-31, RT-35 HC and A-36 due to its transition temperature and to its high latent heat of fusion. Eventually, the fast and simplified thermal model can be employed by battery pack designers to explore and optimize the thermal management system of the PCM with reasonable accuracy.

Novel hybrid thermal management for Li-ion batteries with nanofluid cooling in the presence of alternating magnetic field: An experimental study

Lithium-ion batteries' dependability, efficiency, and security significantly rely on thermal management systems. This paper aims to design a novel battery thermal management system consisting of metal foam-paraffin PCM composite, nanofluid cooling, and heat sink, which all were subjected to a magnetic field. The battery surrogate was utilized to experimentally simulate the battery heat generation, where the occurrence of the thermal runaway was considered as the most crucial criterion for battery performance. The combined effect of various conditions on the paraffin wax melting process and maximum battery temperature was also investigated. Furthermore, the battery's temperature uniformity was also measured in the presence and absence of porous media. Compared to the base case, the maximum temperature of the battery in the best scenario was reduced by about 7.5 °C, while the working time of the system is increased by 179% at Re = 1250. Likewise, this improvement on battery cooling was 151% when the Reynolds number was 890. Further, the temperature difference of the proposed hybrid battery thermal management system (BTMS) was mainly below 4 °C. The experimental results revealed that the proposed hybrid BTMS has a striking cooling effect on eliminating the generated battery's heat and transferring it to the surrounding environment.

A new design for hybrid cooling of Li-ion battery pack utilizing PCM and mini channel cold plates

• Two BTMSs (MCP, HMCP) are studied under constant and pulsed heat generation rates. • The optimal configuration decreased up to 30 K the maximum battery temperature. • Cold plates with shorter mini channels have better performance in BTMS. • Temperature uniformity is improved in hybrid cooling system (HMCP). • HMCP has superior performance over MCP in constant heat generation. By the growing applications of lithium-ion batteries in electric vehicles, the need to develop highly efficient and improved battery cooling systems has become significantly important. In this paper, a novel battery thermal management system (BTMS) for cooling of battery pack, using phase change materials (PCM) and mini-channel cold plates (MCPs), has been designed and numerically studied. Each battery module includes five prismatic Li-ion battery, sandwiched between cold plates. Also, the effect of battery module orientation on the cooling performance of BTMS has been investigated. A new type of cold plate, named as hybrid mini-channel cold plates (HMCPs) has also been designed by adding PCM (n-eicosane) inside the cold plates. The performances of the two mentioned types of cold plates have been studied and compared under constant and pulsed heat generation. The results showed that the battery orientation significantly affected the BTMS performance. Therefore, it was observed that the maximum temperature in the battery packs was 30 K lower in the optimum orientation. Under the constant heat generation, the temporal average of the maximum battery temperature in hybrid cooling system was decreased by 10.35 K compared to the active cooling. However, under multiple pulsed heat generation, the difference in temporal averages of maximum temperature was less than 1 K between the two cooling systems.

Heatsinks to Cool Batteries for Unmanned Aerial Vehicles

This study aims to develop several different models of heatsinks, designed to cool a vertical take-off and landing unmanned aerial vehicle (UAV) battery, through topology optimization, aimed at being manufactured through selective laser melting (SLM) technology. A battery’s temperature must be properly managed for a safe and efficient operation. The methodology developed was with the support of software to carry out several simulations which, starting from several scenarios and restrictions imposed by the small space available to accommodate these small batteries in this type of aircraft. The conception resulted in several battery thermal management systems (BTMS) models, with different applications and efficiency degrees. A relevant aspect is the topology optimization being coupled to computational thermal analysis to reduce the mass of the heatsink whilst ensuring a maximum battery temperature threshold. Together with the use of topology optimization, the SLM process was selected to manufacture the heat sinks, under conditions of geometric freedom, using several high thermal conductivity metal alloys, such as, aluminium and copper to obtain the designed models.

Experimental investigation on the impact of the battery charging/discharging current ratio on the operating temperature and heat generation

This paper presents an experimental investigation on the Li-ion battery operating temperature and surface heat generation. Measurements are carried on the experimental laboratory test bench using a 60 Ah prismatic li-ion battery. A large data base of the battery local heat flux and temperature distributions in the three battery sides is obtained under various operating conditions. It shows that the reversible heat generation affects strongly the temperature profile in quasi-stationary regime. Moreover, the irreversible heat generation has a strong peak in SOCs values higher than 80%. A difference of 3°C was obtained between maximum battery shell temperature and minimum battery surface temperature. The electrodes temperature could be considered the maximum battery temperature and a main key in analyzing battery thermal behavior. For SOC ranging from 0% to 40%, the battery temperature decreases during charging phase and increases during discharging. For SOC ranging from 40% to 100%, it becomes constant during both the charging/discharging phases for the charge/discharge current ratio higher than 1.

Numerical study of combined air and phase change cooling for lithium-ion battery during dynamic cycles

A combined thermal management system for lithium-ion battery, which conjugates the air cooling and phase change material (PCM) cooling, is proposed. Based on the three-dimensional flow and heat transfer models coupled with electrochemical reaction, the thermal performances of battery pack during the discharge-charge cycles with natural convection only, combined natural convection and PCM cooling, and combined forced convection and PCM cooling are investigated and compared. The results show that the maximum battery temperature with natural convection only exceeds the optimum temperature at 1C. The thermal performance of battery pack with combined forced convection and PCM is superior to that with combined natural convection and PCM, and the maximum temperature and maximum temperature difference are both controlled within the ideal range at 2C. For combined forced convection and PCM cooling, the recommended PCM thickness is 2 mm for application considering both cooling performance and cost. The phase change temperature of 35 °C is most advantageous to the proposed thermal management system at the ambient temperature of 26.5 °C, and the maximum temperature and maximum temperature difference can still fall within the optimal operation criteria even at the ambient temperature of 35 °C.