Lithium-ion Battery Thermal Management System Research Articles

Numerical investigations on thermal performance of PCM-based lithium-ion battery thermal management system equipped with advanced honeycomb structures

Electric vehicles (EVs) have a key role in reducing the greenhouse gas emissions contributed by the transportation sector. Lithium-ion (Li-ion) battery which is composed of different cells is the major component in EV, that serves as the power source due to its superior performance. Battery thermal management systems (BTMS) are essential to improve the life and performance and to reduce the risk of fire hazards. In the present study, a single Li-ion cell with Phase Change Material (PCM) and fins is numerically modeled. The finite volume-based simulation is used to predict the heat transfer and flow characteristics of the systems at various operating conditions. Three different unconventional honeycomb-shaped finned PCM systems including baseline model are simulated and compared against the case of PCM without fins and simple honeycomb fin. Cell maximum temperature, temperature difference, and PCM liquid fraction are selected as the parameters for the performance comparison among the different finned configurations. A reduction of 2.77% in maximum cell temperature is obtained in a simple honeycomb structure compared to no fin design at 5C discharge conditions. It is also concluded that the three advanced honeycomb structure shows similar thermal performance but shows better performance than simple honeycomb structure. It is found that 1-Tetradecanol and n-Eicosane PCMs reduce the maximum cell temperature by 13.36 K and 11.81 K, respectively, compared to RT-35 PCM at 5C discharge. The results show that the proposed BTMS exhibits maximum performance at 309.15 K ambient temperature with copper fins and 1-Tetradecanol as PCM.

Simulation of health assessment model for thermal management system of lithium-ion battery based on fuzzy clustering algorithm

Considering the inadequate assessment of the factor decline index in the thermal management system for lithium-ion batteries, which has a negative impact on their efficient utilization, a fuzzy clustering algorithm is suggested to create a simulation model for evaluating the health of the lithium-ion battery thermal management system. In the process of restoring characteristic data by the fuzzy clustering algorithm, according to the characteristic parameters of energy signal and power signal, the decay characteristic results of the lithium-ion battery thermal management system are extracted. Taking the minimum attenuation as a reference, the evaluation function is calculated, the health trend of the lithium-ion battery thermal management system is evaluated, the health grade is established, and the health evaluation model of the lithium-ion battery thermal management system is constructed. The experimental results show that the prediction of the remaining service life of five kinds of lithium-ion batteries by this model is consistent with the actual value, and the average absolute error is always within 0.02, which is superior in health assessment.

Review on the Lithium-Ion Battery Thermal Management System Based on Composite Phase Change Materials: Progress and Outlook

Review on the Lithium-Ion Battery Thermal Management System Based on Composite Phase Change Materials: Progress and Outlook

Lithium-ion battery thermal management system using MWCNT-based nanofluid flowing through parallel distributed channels: An experimental investigation

In the present research, a newly designed liquid-based battery thermal management system (BTMS) for lithium-ion batteries (LIBs) is developed and its thermal performance at different discharge rates (C-rates) is experimentally examined. The influence of various performance parameters such as the number of channels, flow configurations, working fluids, and C-rates on the cooling performance of the proposed BTMS is evaluated. Pure water, binary fluid (70 % water + 30 % ethylene glycol (EG)), and multi-walled carbon nanotubes (MWCNTs)-based nanofluids at different volume fractions (ϕv) (0.15 %, 0.30 %, and 0.45 %) in the binary fluid are used in this study and their cooling effectiveness to keep battery temperature within ideal ranges is compared. The experiments are performed at 0.5C, 1.2C, and 2.1C rates and it is discovered that nanofluids provide superior cooling performance compared to water and binary fluid mixture. Results demonstrate that the cooling performance is enhanced with the number of channels, nanoparticle concentration, and flow configurations. Nanofluid with 0.45 % ϕv of MWCNTs shows the maximum drop in battery temperature which is about 8.7 °C for configuration I, 11.8 °C for configuration II, and 17.1 °C for configuration III, respectively. Among all the flow configurations, configuration III gives the best cooling effectiveness and lowers the average temperature of cells by 10–17.01 °C using different working fluids. Configuration III also enhances the battery temperature uniformity and maintains the maximum temperature deviation within the battery module (∆Tmax) inside 1.5–2.4 °C for different working fluids at a 2.1C rate, which is well below 5 °C, and hence it helps to prevent the thermal runaway (TR) condition. Additionally, nanofluid with 0.45 % ϕv increases pressure drop (Δp) by 23.98 % and 17.91 % compared to water for single and dual channel arrangements, respectively.

Cooling and preheating performance of dual-active lithium-ion battery thermal management system under harsh conditions

A dual-active battery thermal management system (DA-BTMS) combining liquid cooling with thermoelectric cooling is proposed to improve thermal management. Through numerical simulation and physical experiments, the optimal configuration of the system is determined by comparing three different thermoelectric cooler (TEC) arrangements, and the effects of the TEC’s input current and coolant mass flow rate on the batteries’ heat dissipation are investigated. In addition, the TEC’s cold and hot ends can be interchanged to preheat the battery in a cold environment by reversing the input current. The optimal step-preheating strategy is put forward aiming at the preheating of batteries. The results show that, the DA-BTMS with pure liquid cooling can easily control the temperature within an ideal temperature range with the optimal coolant mass flow rate of 0.59 g/s at a discharge rate of 2C and ambient temperature of 40 °C. While the discharge rate is 3C, DA-BTMS can still reliably keep the system under the action of TEC auxiliary cooling. At an over-high ambient temperature of 50 °C, the system maximum temperature sharply decreases from 50 °C to 42.32 °C at a discharge rate of 2C with the optimal input current of TEC 1.6 A owning to the refrigeration action of TEC. The Step-preheating method is put forward and the optimal strategy is determined, which can ensure the preheating rate of 0.77 °C/min for the battery pack. The proposed system not only improves the space utilization of the battery pack but also maintains the maximum temperature of the battery module in a suitable range under harsh cold and hot ambient conditions. Compared with the conventional pure TEC cooling method, it can effectively save energy consumption.

Lightweight hybrid lithium-ion battery thermal management system based on 3D-printed scaffold

Electric vehicles have been developed rapidly to alleviate energy shortages and environmental pollution. However, battery thermal management is still challenge to the complex structure, heavy weight, and limited heat dissipation under harsh conditions. To address these issues, a honeycomb hybrid thermal management system, which integrates the multi-layered liquid-cooled channels into a 3D-printed metal scaffold to enhance the thermal exchange effect. The impacts of the coolant inlet and outlet arrangement, channel layer number, porosity, coolant flow rate, and continuous charge-discharge cycle on heat dissipation were numerically analyzed at 35 °C and discharge rate of 3C to evaluate the system cooling performance. The results show that the heat dissipation efficiency of the proposed system is greatly improved compared with that of the system with pure phase change materials. An 85 % porosity of 3D-printed metal scaffold performs excellent heat dissipation and low system weight, the system weight can be reduced by 60 % compared to a conventional system with aluminum solid cold plate with a same volume. The system's maximum temperature and temperature difference are kept at 48.1 °C and 2.6 °C, respectively. Additionally, the system performance was validated in the continuous charge-discharge cycle test. This work will help develop the lightweight BTMS with excellent thermal performance for electric vehicles.

Numerical Simulation of Immersed Liquid Cooling System for Lithium-Ion Battery Thermal Management System of New Energy Vehicles

Power batteries generate a large amount of heat during the charging and discharging processes, which seriously affects the operation safety and service life. An efficient cooling system is crucial for the batteries. This paper numerically simulated a power battery pack composed of 8 lithium-ion cells immersed in the coolant AmpCool AC-110 to study the effects of different coolants, different discharge rates, different coolant mass flow rates, different inlet temperatures and different inlet and outlet settings on the maximum temperature, the maximum temperature difference, the pressure drop, and the required pump power in the battery pack. Among the five coolants studied, W-E in water-based fluids has the best cooling effect, but because of high electric conductivity, it requires special considerations to avoid electric leakage. Increasing the mass flow rate of the coolant can significantly decrease Tmax and ΔTmax, but when the mass flow rate is already high, the decrease is limited and not obvious. Both Δp and the required pump power increase as the mass flow rate increases, and the required pump power increases faster. The inlet temperature will affect the physical properties of the coolant, and choosing the appropriate inlet temperature can not only decrease ΔTmax, but also decrease Δp and the required pump power in the battery pack. The range of 25~27 °C of the coolant AC-110 inlet temperature is recommended. For different inlet and outlet settings, the two-inlet two-outlet setting used in Case 7 has the best cooling effect, and the results indicate uniform distribution is very important to decrease temperature.

Experimental and computational analysis on lithium-ion battery thermal management system utilizing air cooling with radial fins

Experimental and computational analysis on lithium-ion battery thermal management system utilizing air cooling with radial fins

Performance study of cooling plates with single and double outlets for lithium-ion battery thermal management system based on topology optimization

ABSTRACT Topology optimization is a technique employed to optimize the distribution of material within a design domain to produce structures with enhanced performance. This study has compared three types of cooling plate designs, such as the topology optimized cooling plates with double-outlet and single-outlet and the conventional straight-channel cooling plate. The topology optimizations are performed under identical boundary conditions, and the subsequent performance comparison among all the designs is carried out based on a numerical analysis by developing a three-dimensional computational fluid dynamics model. The effects of fluid inlet conditions such as velocity and temperature on the behavior of all the designs are investigated, and the performance comparison is also carried out based on temperature, pressure, and velocity distribution. The results show that the topology optimized double-outlet design (DOD) has decreased the maximum temperature by 1.185 K and 0.445 K, mean temperature by 0.604 K and 0.221 K, surface maximum temperature difference by 9.04% and 4.49%, and pressure drop by 5.32% and 33.43%, with respect to the topology optimized single-outlet design and conventional straight-channel design, at a Reynolds number of 213.71.

Experimental and numerical study of lithium-ion battery thermal management system using composite phase change material and liquid cooling

An efficient battery thermal management system can effectively control the temperature of the battery and prevent the occurrence of thermal runaway. In this work, the calibration calorimetry method is first used to determine the specific heat capacity and heat generation rate of a large-capacity battery considering the heat loss. Then three cases of large-capacities battery thermal management systems (BTMSs) are proposed, i.e., Case 1 with composite phase change material (CPCM) cooling only, Case 2 with liquid cooling only, and the hybrid Case 3 combined CPCM with liquid cooling. It is found that Case 3 owns the lowest maximum temperature of the battery module under the same condition. Moreover, the parameters affecting the thermal performance of Case 3 are studied, including the thickness of CPCM, inlet velocity of coolant, ambient temperature and discharge rate. A thickness of 4 mm for CPCM can effectively absorb the heat released by the batteries to achieve higher group efficiency of the battery module and lighter weight of the system. The lower velocity of 0.1 m/s is preferred in the simulation to balance the maximum temperature and pump power consumption. Moreover, Case 3 is well verified to control the maximum temperature and temperature difference of the battery module at 48.97 °C and 4.5 °C, respectively, even under the highest discharge rate of 2C and high ambient temperature of 37 °C, which shows effective improvement in the thermal safety of batteries.

Simulation and Optimization of Lithium-Ion Battery Thermal Management System Integrating Composite Phase Change Material, Flat Heat Pipe and Liquid Cooling

A large-capacity prismatic lithium-ion battery thermal management system (BTMS) combining composite phase change material (CPCM), a flat heat pipe (FHP), and liquid cooling is proposed. The three conventional configurations analyzed in this study are the BTMSs using only CPCM, CPCM with aluminum thermal diffusion plates, and CPCM with FHPs. In addition, a CPCM–FHP assisted with liquid cooling at the lateral sides is established to enhance the thermal performance of large-capacity batteries. Moreover, the influences of coolant temperature, the number of FHPs and cooling pipes, and the coolant direction on the temperature field of a BTMS are discussed. Finally, the orthogonal design method is used for the multi-level analysis of multiple factors to improve the light weight of the system. The optimal parameter combination is obtained to achieve the best thermal performance of the BTMS, with the maximum temperature and the temperature difference at 43.17 °C and 3.36 °C, respectively, under a maximum discharge rate of 2C and a high-temperature environment of 37 °C. The optimal scheme is further analyzed and affirmed through the comprehensive balance method.

Studying carbon fiber composite phase change materials: Preparation method, thermal storage analysis and application of battery thermal management

Carbon fiber composite phase change material (PCM) can serve as an excellent material for thermal storage system. This work presents a new composite PCM prepared with two raw materials of KAl(SO4)2·12H2O (X) and Na2SO4·10H2O (Y), supporting materials activated carbon fibers (ACFs), and thermal conductivity agent nano carbon powder (C). The characterization results show that adding 1 wt% C can increase the thermal conductivity about 81.0 % of mixed materials (C, X, and Y) than that of mixed X, Y; Moreover, the addition of ACFs also increases the thermal conductivity by 130 %. DSC tests reveal that phase change temperatures of XY and CXY are respectively 36.47 °C and 35.67 °C, meantime the enthalpies are 220.84 J/g and 185.24 J/g, respectively. Thus, this new material is suitable for the lithium-ion battery thermal management system (BTMS) applying. The application results show that ACFs composited CXY (ACFs/CXY) tremendously cripples the battery's temperature rise rate after the melting point in comparison with no wrapping material, and the ACFs/CXY-based BTMS can effectively control the battery temperature below 60 °C for 1903 s at the high heating power of 6 W. The ACFs composite PCM has the advantages of low cost, simple preparation, and easy acquisition, which reduces the cost of energy storage system, and has remarkable capacity of temperature controlling.

Numerical analysis of cylindrical lithium-ion battery thermal management system based on bionic flow channel structure

To improve the thermal and flow performance of the battery thermal management system (BTMS), a heat exchanger with a bionic flow channel structure was designed and applied to a cylindrical lithium-ion battery module in this work. To accurately reflect the transient thermal behavior of the battery, a battery thermal model was obtained by experimentally collecting thermodynamic parameters. A computational fluid dynamics model of the BTMS was established. The influences of different bionic flow channel structure parameters on the thermal performance of the BTMS were investigated by a multi-factor optimization analysis. In addition, the thermal performance was also compared with that of a heat exchanger with a bionic honeycomb-like structure and a traditional helical structure. The results show that at the optimum structural parameters, the maximum temperature, maximum temperature difference, and pressure drop of the BTMS were calculated as 302.656 K, 3.726 K and 29.69 Pa respectively. For the same volume fraction and geometrical parameters, the heat exchangers with a spider web-like structure has better thermal and flow characteristics than honeycomb-like and traditional helical structures.

Parameter optimization and sensitivity analysis of a Lithium-ion battery thermal management system integrated with composite phase change material

In order to ensure the performance and to extend the life cycle of power battery module within electric vehicle, a battery thermal management system (BTMS) integrated with composite phase change materials (PCM) was proposed. The heat dissipation performance of BTMS using paraffin/expanded graphite (EG) composite PCM with different mass fraction was investigated. The results showed the optimal heat dissipation performance was observed using composite PCM with 20 wt% EG. The combined effect of liquid volume fraction and thermophysical parameters of composite PCM on heat dissipation performance of battery module was revealed. The phase transition temperature of composite PCM was found to have the largest impact on the maximum temperature and temperature uniformity of battery module, followed by latent heat and thermal conductivity of composite PCM. A 10 % decrease in the phase transition temperature led to a 7.9 % in the maximum temperature of battery module. Both the thermal conductivity and latent heat growth contributed to the reduction in the maximum temperature of battery module. Composite PCM with the thermal conductivity of 3 W m−1 K−1, phase change temperature of 38 °C, and latent heat of 220 J g−1, was found to achieve the optimal heat dissipation performance of BTMS and a high utilization rate of 97.3 % for composite PCM. The findings of this work could be beneficial for future development of highly-efficient and economical composite PCM for BTMS.

Cooling and preheating behavior of compact power Lithium-ion battery thermal management system

A novel honeycomb battery thermal management system with a combination of liquid-cooling and composite phase change material has been proposed for the cylindrical power lithium-ion battery to improve the cooling effect under harsh discharge conditions and the capacity reduction in low-temperature environment. The cooling and preheating performance have been compared at a discharge rate of 4C for three different monomer battery systems without any heat dissipation elements, with passive composite phase change material, or with hybrid cooling elements. The effects of the thickness of composite phase changed material, the size of micro-channel, the channel level number, the flow velocity of inlet liquid and the heating strategy on the cooling behaviour of the monomer battery are studied and examined. Furthermore, the impacts of inlet/outlet arrangement mode and inlet liquid flow velocity on the thermal behaviour of the cell module are analysed. When the environment temperature is 40 °C, the optimal parameters on thermal performance are decided, which reliably control the highest temperature, cell–cell temperature difference and the mass fraction of liquid phase of composite phase change material within an allowable range, and save the space of the module as much as possible. At the discharge rate of 4C and the coolant inlet flow velocity of 0.06 m/s, the highest temperature and cell–cell temperature difference of the module can be controlled at 46.21 °C and 3.5 °C, respectively, and keep the mass fraction of the liquid phase of composite phase change material at around 55% after battery discharge. When the battery module is heated from −15 °C to 10 °C, there are different optimal pulse width modulation heating strategies for 20 W and 10 W heating belts and the battery module can be rapidly heated in about 6 min.

Numerical investigation on a lithium-ion battery thermal management system utilizing a double-layered I-shaped channel liquid cooling plate exchanger

To optimize the working temperature of a vehicular lithium-ion battery, a double-layered I-shaped liquid cooling plate was designed. The upper layer channel uses coolant to dissipate heat, and the lower layer channel recovers the cooling liquid. The effects of three design variables (length ratio, width ratio, and channel spacing) and different inlet conditions on the heat transfer performance of the liquid-cooled plates were investigated. The results showed that the optimum maximum temperature and temperature uniformity were obtained at a length ratio of 0.70, width ratio of 0.85, and channel spacing of 2.0 mm approximately. Moreover, the thermal performances of the optimized structure and serpentine channel under the same channel area and inlet mass flow rate were compared. The optimized I-shaped liquid cooling plate can reduce the maximum temperature from 307.02 K to 303.94 K and the standard deviation of surface temperature from 0.80 K to 0.25 K. In addition, the pressure drop was reduced by 73.36% compared to that in the serpentine channel. The double-layered I-shaped channel can be used to improve the heat dissipation capacity of battery thermal management systems.

Multi-objective optimization of integrated lithium-ion battery thermal management system

Battery thermal management system (BTMS) based on phase change materials (PCM) are demonstrating great performance in the field of high heat flux heat dissipation. However, traditional hybrid PCM modules focus too much on their thermal performance and ignore the weight issue, which greatly reduces their wide application. In this paper, a BTMS integrated air cooling channels, fins and PCM is proposed to improve the thermal performance of the battery. The maximum temperature (Tmax), temperature difference (ΔT) and weight (W) of BTMS are used as indicators for the evaluation of the battery performance. The balance between temperature uniformity and lightness of the lithium-ion battery pack is also analyzed according to the entropy weight-TOPSIS method. The results demonstrate that while the thermal performance of the battery pack is enhanced with PCM thickness (d) increases from 5 mm to 20 mm, the weight of the system increases significantly by 146.7 % as d increases. Besides, as fin height (l) increased from 5 mm to 65 mm, the liquid fraction increases by 20.4 %. According to the entropy weighting method analysis, the index weights of Tmax, ΔT and W are 28.37 %, 26.64 % and 44.99 %, respectively. Furthermore, after TOPSIS algorithm search, d = 7.5 mm and l = 65 mm are the best structural parameters for BTMS, and the corresponding Tmax, ΔT and W of BTMS are 319.29 K, 0.0135 K and 5.13 kg, respectively.

A Review on lithium-ion battery thermal management system techniques: A control-oriented analysis

Lithium-ion batteries are the preferred power source for electric vehicle applications due to their high energy density and long service life, thus significantly contributing to greenhouse gas emissions and pollution reduction. Their performance and lifetime are significantly affected by temperature. Hence, a battery thermal management system, which keeps the battery pack operating in an average temperature range, plays an imperative role in the battery systems’ performance and safety. Over the last decade, there have been numerous attempts to develop effective thermal management systems for commercial lithium-ion batteries. However, only a few analyze and compare thermal management techniques based on a control-oriented viewpoint for a battery pack. To fill this gap, a review of the most up-to-date battery thermal management methods applied to lithium-ion battery packs is presented in this paper. They are broadly classified as non-feedback-based and feedback-based methods. Finally, the paper concludes with a detailed discussion of the strengths and weaknesses of the reviewed techniques, along with some suggestions for future study.

Numerical optimization for a phase change material based lithium-ion battery thermal management system

The phase change material (PCM), as a passive and high latent heat material, is usually used in the passive battery thermal management system (BTMS). However, to achieve efficient and compact battery thermal management system, the property of phase change material needs to be optimized. In this study, phase change material, composed of expanded graphite and paraffin waxes with various melting points, was adopted to explore the effect of composite phase change material 's various phase transition temperature on battery thermal management performance. It was found that the paraffin wax with a transition temperature of 48 °C is the most suitable. In addition, a multi-parameter electrochemical-thermal coupling optimization model was developed to optimise the efficiency of phase change material to determine the battery spacing, convective heat transfer coefficient and expanded graphite mass fraction. The optimization results show that using parameters with a battery interval of 4.4 mm, a convective heat transfer coefficient of 0.8 W/m2/K, and a mass fraction of 10.9 % can not only satisfy the thermal safety requirement but also reduce the volume fraction of phase change material by 18.4 %.

Investigations of Lithium-Ion Battery Thermal Management System with Hybrid PCM/Liquid Cooling Plate

To improve the operating performance of the large-capacity battery pack of electric vehicles during continuous charging and discharging and to avoid its thermal runaway, in this paper we propose a new hybrid thermal management system that couples the PCM with the liquid cooling plate with microchannels. The flow direction of the microchannel structure in the bottom plate is designed according to the characteristics of the large axial thermal conductivity of the battery, and the cooling performance of the whole system under continuous charge/discharge cycles is numerically simulated. The results show that the hybrid PCM/liquid cooling plate can maintain good cooling performance under the discharge process of a large-capacity battery pack. After each cycle the temperature of the battery pack can be reduced to less than 30°, and the maximum temperature change rate of multiple cycles is controlled within 0.8%. With the application of the hybrid PCM/liquid-cooled plate battery cooling system, a safe temperature range of the battery pack is ensured even under multiple cycles of charging and discharging. The present work can facilitate future optimizations of the thermal management system of the large-capacity battery pack of electric vehicles.