Hybrid Thermal Management System Research Articles

Optimizing Hybrid Active–Passive Thermal Management of Prismatic Li‐Ion Batteries Using Phase Change Materials and Porous‐Filled Mini‐Channels

ABSTRACTTackling climate change is crucial, and electrifying the vehicular transportation sector is essential to reduce greenhouse gas emissions. Lithium‐ion (Li‐ion) batteries are highly efficient for electric vehicles (EVs) but face challenges such as thermal management, risk of thermal runaway, and high costs of lithium and cobalt. Overcoming these challenges is vital for the widespread adoption of hybrid and EVs. To overcome this drawback, this article proposed a large‐kernel attention graph convolutional network (LKAGCN) with leaf in wind optimization algorithm (LWOA) named as LKAGCN‐LWOA technique, which enhances the thermal management of prismatic Li‐ion batteries by integrating both active and passive cooling techniques. The system incorporates phase change materials (PCMs) with porous‐filled mini‐channels to regulate battery temperature effectively. The LKAGCN analyze thermal properties, battery conditions, and PCM characteristics to predict and optimize the thermal behavior of the battery pack using LWOA. The proposed methods tune the parameters of the hybrid thermal management system, ensuring efficient thermal regulation and improved performance. The proposed method is compared to various existing methods such as convolutional neural network (CNN), Taguchi method, and Finite element model (FEM).

A hybrid battery thermal management system composed of MHPA/PCM/Liquid with a highly efficient cooling strategy

Hybrid battery thermal management system (BTMS) has received a lot of attention lately because of its excellent heat dissipation. However, the performance of hybrid BTMS is impacted by several elements, including basic technologies, structural design, and control methods. To improve the temperature and temperature uniformity of prismatic batteries, a novel hybrid BTMS composed of the U-shaped micro heat pipe array (U-MHPA) and the liquid cold plate filled with composite phase change material (cPCM) was proposed. Furthermore, a performance evaluation method and delayed cooling strategy were proposed and used to optimize the hybrid BTMS. Results showed that adhering a U-MHPA to the surface of the battery can effectively mitigate temperature non-uniformity in the prismatic battery. The cold plate filled with cPCM addressed the issue of significant temperature gradients parallel to the long flow direction of the cold plate. Compared to the single liquid cooling, the hybrid BTMS exhibited outstanding cooling performance under extreme operating conditions, reducing the Tmax of the battery module by 4.2 °C and the ΔTmax by 8.39 °C. The delayed cooling strategy based on the principles of phase change reduced the energy consumption of the hybrid thermal management system by 41.7%.

Numerical simulations on hybrid thermal management of mini-channel cold plate and PCM for lithium-ion batteries

This study presents a novel hybrid thermal management system (HTMS) leveraging the mature technology of mini-channel cold plates (MCPs) and the superior thermal properties of phase change material (PCM). For single-cell scales to study their hybrid structures, it is found that the structure of 3channel and 5 mm PCM can reduce the battery temperature from 64.45 °C to 42.83 °C for a 2C discharge by 33.55 %. Furthermore, this study investigates the influence of coolant flow rate, temperature, and PCM thickness on the thermal management system. The findings indicate that HTMS can fulfill thermal management tasks that are not possible with the single-side PCM cooling system, while simultaneously saving 13 times the energy compared to the single-side MCPs cooling system to achieve the similar effect. For battery-pack scales to study their coupled structures, and the results show that the PCM alone effectively cools the battery, reducing its temperature from 55.34 °C to 42 °C at an ambient temperature of 35 °C during low-multiplication discharge. Furthermore, under the New European Driving Cycle (NEDC) condition, the battery pack temperature is maintained within 30 °C with a temperature difference of 0.03 °C, highlighting the exceptional performance of HTMS.

Expression of concern for article entitled “Hybrid thermal management system for a lithium-ion battery module: Effect of cell arrangement, discharge rate, phase change material thickness and air velocity”

Expression of concern for article entitled “Hybrid thermal management system for a lithium-ion battery module: Effect of cell arrangement, discharge rate, phase change material thickness and air velocity”

Thermal performance enhancement with snowflake fins and liquid cooling in PCM-based battery thermal management system at high ambient temperature and high discharge rate

The application of phase change materials (PCMs) in battery thermal management system (BTMS) is restricted by their low thermal conductivity and the challenge of heat-storage saturation after latent heat depletion, particularly in conditions with high ambient temperature and discharge rate. To enhance the performance of thermal management, this study firstly evaluates the thermal behaviors of two designs, Batteries-PCM and Batteries-PCM-Fins, under discharge rates of 3C and 5C, in conjunction with ambient temperatures of 25 °C and 40 °C. Building on this foundation, a hybrid thermal management system that incorporates snowflake fins and liquid cooling is proposed. The cooling efficiency of five different liquid cooling plate configurations (Design I-V) is compared, and the impact of coolant flow rate is explored. The results indicate that the snowflake fins in the Batteries-PCM-Fins design effectively reduce battery temperatures at a 3C discharge rate, maintaining a max temperature difference below 3 °C. However, at a 5C discharge rate and 40 °C ambient temperature, there is a noticeable increase in the peak temperature of the battery module across numerous cycles. Among the tested designs, Design IV shows the best performance. Specifically, when the coolant flow rate is 0.1 m/s, the discharge rate is 5C, and the ambient temperatures are 25 °C and 40 °C, compared to the design lacking a liquid cooling plate, the maximum temperature of the battery module decreases by 17.40 % and 21.36 % respectively, with respective decreases of 42.53 % and 55.77 % in the maximum temperature difference.

Numerical study on hybrid battery thermal management system integrating water, phase change material, and fins, under New European Driving Cycle

This study introduced a hybrid thermal management system for a 4×4 cylindrical lithium-ion battery module, simulating New European Driving Cycle (NEDC) conditions. The system integrated water, phase change material (PCM), and fins for enhanced heat dissipation. The batteries, attached to an aluminium shell, incorporated PCM and a central coolant path. Fins were introduced between the coolant channel and Al shell to enhance heat transfer between batteries, PCM, and water. Comparative analysis against passive (PCM only) and active (liquid) cooling systems revealed the hybrid system’s superior performance. With a water flow rate of 2×10−8 m3/s, the system consistently kept temperatures below 50°C during charge-discharge cycles. Compared to active cooling, it achieved a significant temperature reduction of 18.47% and 5.01% after the charge and discharge processes. An intermittent cooling strategy further demonstrated its effectiveness in preventing thermal runaway (> 60°C) compared to the active cooling system. The proposed hybrid system demonstrated efficient thermal performance with low pumping power, suggesting its potential for multiple charge/discharge cycles.

Hybrid cooling system with phase change material and liquid microchannels to prevent thermal runaway propagation within lithium-ion battery packs

Thermal runaway propagation in battery pack can cause catastrophic hazards without timely countermeasures. This paper presents the establishment of lumped thermal resistance model for battery pack and introduces an innovative hybrid thermal management system designed to suppress thermal runaway propagation. First, a heat generation model describing the reaction dynamics of cell thermal runaway is developed and validated by experiment. Subsequently, a lumped thermal resistance network is formulated for the large-scale battery pack using electrical circuit elements and simulation studies for the thermal runaway propagation are carried out. The results reveal that the thermal runaway propagation progress triggered by four cells can accelerate by nearly 40 % compared to that initiated by a single cell. Consequently, a hybrid thermal management incorporating phase change material and liquid microchannels is designed. Comparative analysis with individual cooling systems demonstrates the superior effectiveness of the proposed system in suppressing the first round of thermal runaway propagation. The temperatures of neighbor cells only have a marginal climb to about 80 ℃ in the initial 600 s, which is well below the thermal runaway triggering temperature. This work can provide valuable insights into the structural design of thermal management systems for battery packs in practical applications.

A thermal management control using particle swarm optimization for hybrid electric energy system of electric vehicles

A metaheuristic algorithm, Particle Swarm Optimization (PSO), was employed for developing the optimal control strategies for an innovative hybrid thermal management system (IHTMS) in a proton exchange membrane fuel cell (PEMFC)/battery electric vehicles (EVs). The goals were to shorten the period of low-efficiency temperatures during the initial startup of EVs, and to maintain temperatures of PEMFCs and batteries at their optimal-efficiency zones, where significantly enhances the traveling range and power output of EVs. Prior to simulation for benefit analysis, eight IHTMS subsystems were mathematically constructed. For the multi-input-multi-output PSO control strategy, two inputs were the fuel cell and battery coolant temperatures; while two outputs were the coolant mass flow rate and the flow rate ratio between two energy sources. A rule-based (RB) control strategy for four actuators was designed as the baseline case. Another RB using the PSO to derive the initial conditions (PSOi) was developed as well. In this research, the IHTMS was tested under two driving patterns, WLTP and NEDC, where outstanding thermal management performance was exhibited. The results demonstrate that: in WLTP driving cycle, to compare PSO and PSOi-RB with the RB strategies, the rise time of optimal temperature decreased 13.655 % and 9.505 % for the PEMFC; while 8.77 % and 4.385 % for the battery. For the NEDC driving cycle, the rise time of optimal temperature decreased 8.908 % and 7.318 % for the PEMFC, while 5.226 % and 3.136 % for the battery. The improvements of average temperature errors of the PEMFC were 19.759 % and 11.023 %; the improvements of the average temperature errors of the battery were 57.027 % and 3.67 %. For NEDC driving cycle, the improvements of average temperature errors of the PEMFC were 18.879 % and 9.551 %; the improvements of the average temperature errors of the battery were 29.144 % and 20.221 %. In the future work, the IHTMS will be integrated to a hybrid-energy EV for experimental verification.

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.

Thermal performance of a hybrid thermal management system that couples PCM/copper foam composite with air-jet and liquid cooling

The performance and safety of lithium-ion batteries (LIBs) is significantly dependent on the battery thermal management system (BTMS). A LIB module typically comprises multiple components, such as battery holders and positive and negative electrode terminals. Despite the advantages of hybrid BTMS that utilize phase-change material (PCM) and liquid cooling, challenges remain in achieving uniform temperature in irregular-shaped LIBs. Herein, a hybrid BTMS integrated PCM/copper foam (PCM/CF), along with an air jet pipe (AJP) and a liquid channel (LC) for cylindrical LIBs, is proposed. Numerical simulations are performed to evaluate the cooling performance of the hybrid BTMS. The results indicate that the battery holders decrease the heat dissipation capacity. Thermally conductive polymers as a material for the battery holder can mitigate heat build-up in LIBs. PCM/CF integrated with AJP and LC can decrease the maximum temperature (Tmax) and the temperature difference (ΔT) of LIB. Tmax and ΔT are optimized at 29.3 °C and 1.2 °C using an orthogonal experimental design. At ambient temperatures of 15 °C and 35 °C, the LIB achieves a Tmax of 19.1 °C and 35.6 °C with a corresponding ΔT of 1.6 °C and 2.3 °C, respectively, using specified inlet velocities and inlet temperatures. The proposed hybrid BTMS demonstrates improved heat dissipation performance and provides valuable insights for the designer.

PCM/metal foam and microchannels hybrid thermal management system for cooling of Li-ion battery

Temperature rising in Lithium-ion batteries is an inevitable phenomenon that can cause several issues in electric vehicles (EVs). Battery thermal management system (BTMS) has the role of controlling maximum temperature (Tmax) of batteries as well as temperature difference (∆T) during charge/discharge process. Many kinds of BTMS have been proposed including passive, active and hybrid cooling systems to maintain the Tmax and ∆T in the acceptable ranges. In this work, a hybrid cooling system consisting of microchannels and phase change materials (PCM) which enhanced by metal foam is proposed and its performance compared with active and passive cooling methods. Results revealed that using merely passive BTMS (i.e. PCM/metal foam) has better temperature distribution and lower temperature difference (∼1 K) but it experiences higher Tmax (∼319 K). On the other hand, active BTMS (i.e. microchannels) experiences lower Tmax (∼312 K) but leads to higher ∆T (∼9 K). By using the hybrid system (i.e. PCM/metal foam and microchannels), both maximum temperature and temperature difference are in acceptable ranges. In this case, the maximum temperature rises to 308.4 K and the temperature difference is about 3.4 K.

Thermal performance and structural optimization of a hybrid thermal management system based on MHPA/PCM/liquid cooling for lithium-ion battery

It is crucial to propose an efficient hybrid Battery Thermal Management System (BTMS) and a multi-objective optimization method with high-accuracy and low computational load due to many factors greatly influence the performance and energy density (ED) of hybrid BTMS. In this paper, a novel hybrid BTMS combined with phase change material (PCM), micro heat pipe array, and liquid cooling is proposed, whose cooling performance is verified experimentally. Then, the effects of the main structural parameters of BTMS on cooling performance and ED were numerically analyzed with the Box-Behnken design (BBD). Finally, a multi-objective optimization with Multiple Objective Particle Swarm Optimization based on Response Surface Methodology (RSM) is introduced to optimize ED and cooling performance. The experimental result shows that the temperature difference of the hybrid module is maintained within a safe range reducing from 6.9 °C to 3.9 °C, and the maximum temperature is reduced by 13.78% from 46.0 °C to 39.8 °C during 2C discharging progress compared with the module only PCM cooling. The optimization outcomes predict that the optimized BTMS’s ED can rise 11.23% to 157.8 Wh/kg with only a slight variation in cooling performance in comparison to the original module.

A hybrid thermal management system combining liquid cooling and phase change material for downhole electronics

The electronics inside the logging tools are prone to failure due to the extreme thermal environments. In this study, a hybrid thermal management system using liquid cooling and phase change material (PCM) for downhole electronics is proposed to extend the workable time. In this system, a spiral pipe and a S-shaped pipe are respectively arranged inside the PCM and the cold plates to strengthen the heat exchange. To investigate the performance of this system, the transient flow and heat transfer simulation are implemented using finite element method. The accuracy is validated by comparing with the reported experimental results, showing an error of less than 6.7 %. The results show that the hybrid thermal management system increases the operating time of the electronics from 230 min to 450 min, which is attributed to the introduction of liquid cooling. The maximum temperature difference between the electronics and PCM reduces from 30 °C to 2 °C. Moreover, the effect of flow rate, spiral pipe spacing, heating power and ambient temperature on the temperature control performance are explored. This work provides a guidance for the design and optimization of logging tools, which is significative to shorten their research and development cycle.

PCM-based hybrid thermal management system for photovoltaic modules: A comparative analysis.

Proper temperature regulation of photovoltaic (PV) modules increases their performance. Among various cooling techniques, phase change materials (PCMs) represent an effective thermal management route, thanks to their large latent heat at constant temperatures. Radiative cooling (RC) is also recently explored as a passive option for PV temperature regulation. In this paper, a heat sink (HS), phase change materials, and radiative cooling are integrated with photovoltaic modules to achieve low and uniform temperature distribution along the PV module and improved performance. Eight different combinations are considered for the proposed system, including HS, PCM, and RC, and their various combinations. The PCM is selected according to the environmental conditions ofthe selected location. A comprehensive 2-D model is developed and analyzed in COMSOL-Multiphysics software by solving the governing equations using the finite element method. The performance analysis is carried out for the climatic conditions of the Atacama Desert, having high solar radiation and ambient temperature. The effects of PCM height, ambient temperature, wind velocity, and solar radiation on the performance of the proposed system are studied. The performance of eight different configurations is also compared. The maximum reductions in PV temperature, maximum PV power, and a minimum drop in PV conversion efficiency are observed to be 22oC, 152W, and 14% using a combined heat sink and radiative cooling systems, among all other configurations. The findings of this study can be used to select the best PV cooling method among different configurations.

A comprehensive coupled 0D-ECM to 3D-CFD thermal model for heat pipe assisted-air cooling thermal management system under fast charge and discharge

Prediction of electrical and thermal behavior of lithium-ion capacitor (LiC) technology as an asymmetric technology is feasible by designing a precise model. Such a model should mimic the behavior of LiCs in heavy-duty applications where high current rates are applied. The developed model is used to design a management system based on efficient modeling tools, including 0D (zero-dimensional) electro-thermal models and 3D computational fluid dynamics (CFD) thermal models. A validated model is essential for LiCs as they operate at high dynamic current rates. In this article, the 0D second-order equivalent circuit model is developed to extract the electrical parameters of LiCs. Then, the thermal model is developed to be linked to the electrical model to make an electro-thermal platform capable of identifying the electro-thermal parameters. The characterization tests are performed within a wide range of temperatures, from the freezing temperature of −30 °C to the hot temperature of + 60 °C. Such a temperature range has never been carried out before. The validation is performed based on the owned experimental results. The applied current rates are from 0.1 A to 500 A, which shows the work's uniqueness in the field of electro-thermal modeling. Later, the extracted parameters have been set as inputs to the 3D CFD thermal model to design and develop a hybrid thermal management system (TMS) based on air cooling and heat pipes. Such a hybrid TMS maintains the maximum temperature at 24.6 °C when the temperature difference between the hottest and coldest cells is only 0.5 °C.

Thermal performance of a hybrid thermal management system based on the half helical coil coupled with air jet cooling for cylindrical Lithium-ion battery

The Battery Thermal Management System (BTMS) is crucial for the efficient and safe operation of Lithium-ion batteries (LIBs). It is challenging for liquid cooling to apply to areas of battery modules with complex surface forms, such as the positive and negative cell terminals, cell holders, etc. Herein, the thermal management scheme integrated with the half helical coil and air jet impingement is proposed for cylindrical LIBs. Heat is transferred from the LIBs' sides by helical flow and dissipated from the LIBs' ends by air jet impingement. The three-dimensional computational fluid dynamics model of battery modules with cell holders is developed. The thermal performance of the LIBs at various BTMS strategies, the number of turns of the helical coil, airflow inlet velocity, inlet temperature, and contact resistance are investigated. When the impinging air jets are arranged on both ends of the cylindrical form, the maximum values of temperature difference (ΔT) of the LIBs fall from 5.7°C to 4.0°C compared with that of liquid-based BTMS. The arrangement of the half helical duct divided into two separate sections reduces the coolant flow path length, which decreases the maximum temperature (Tmax) and ΔT to 28.9°C and 3.6°C. The proposed BTMS exhibits an enhanced heat dissipation performance and provides a design guideline for developing the hybrid BTMS.

An improved hybrid thermal management system for prismatic Li-ion batteries integrated with mini-channel and phase change materials

Battery thermal management systems play a significant role in the safety, performance, and maintenance of electric vehicles. This paper proposes a new hybrid cooling system incorporated with phase change material (PCM) and liquid cooling to achieve high performance and safety for the pack of prismatic batteries. Each four battery cells are grouped as a module and placed between vertically orientated mini-channel cold plates. PCM plates are also placed horizontally between the battery cells. This new design is simple enough to be implemented easily in common cooling systems and could provide parallel cooling of the active and passive methods with subsequent improvement in thermal performance and system safety. Three-dimensional numerical simulations are validated against previous empirical and numerical works. The thermal performance, power consumption, and safety of the hybrid cooling systems are investigated in a variety of battery discharge rates and mini-channel inlet velocities using different numbers of PCM plates. Also, the system performance is tested in a real driving cycle. This new design could notably improve the battery thermal management characteristics. The maximum battery temperatures in the hybrid system with three PCM plates at 2C and 3C discharge rates were 5.6 K and 16.2 K lower than those without PCM plates. Besides, adding three PCM plates reduced the temperature difference by up to 33 % at 3C discharge rate. Another key finding was that at 3C discharge rate, by simultaneously utilizing three PCM plates and decreasing the fluid inlet velocity, the power consumption per battery cell is reduced by 68 % (from 1.187 mW to 0.0375 mW). Furthermore, considering the PCM plates as the emergency backup, the time to reach the critical temperature increased by 38 % and 105 % in the systems with 1 and 3 PCM plates, respectively. Testing in a real driving cycle reveals the superiority of the hybrid system over the active cooling method by peak shaving of the thermal loads and reducing thermal fluctuations and maximum temperature. This novel design for battery thermal management could provide high performance for batteries and reduce fabrication and maintenance costs.

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.

Experimental and numerical study on hybrid battery thermal management system combining liquid cooling with phase change materials

A kind of new hybrid thermal management system combining phase change materials with a series of liquid cooling is designed. The characteristics of the temperature change is studied experimentally and numerically when the ambient temperature is 25 °C to 40 °C. The results indicate that the temperature of phase change cooling system is reduced by 44.2%, 30.1% and 5.4%, respectively, compared with air cooling system, liquid cooling system and pure phase change material cooling system. To further enhance heat transfer, copper fins are added around the battery, the results shows that the maximum longitudinal difference of the battery temperature decreased by 69.7%. The research of this paper provides a theoretical basis for the thermal characteristics of hybrid cooling system and a design method with higher cooling efficiency and better temperature uniformity for the design of power battery thermal management system.

Cooling performance and optimization of a new hybrid thermal management system of cylindrical battery

To enhance the temperature uniformity of liquid cooling system, an effective strategy was proposed based on liquid cooling and micro heat pipe array (MHPA) for prismatic batteries. But whether this hybrid battery thermal management system (BTMS) still works effectively for cylindrical lithium-ion batteries needs to be verified and its optimal design has not been worked due to complex factors and paraments of hybrid BTMS. In this paper, a novel hybrid BTMS for the cylindrical batteries is proposed based on MHPA and liquid cooling, whose cooling performance is investigated experimentally and numerically. The result shows that compared with the module without MHPA, the maximum temperature of the hybrid module is reduced by 34.11 % and the temperature difference is decreased from 3.66 °C to 0.66 °C, in 1C discharging progress. Even in 3C, the maximum temperature and temperature difference decreased to 41.03 °C and 2.16 °C, respectively. To optimize the energy density and cooling performance, multi-objective optimization is applied based on the Non-dominated Sorting Genetic Algorithm Ⅱ (NSGA-Ⅱ) coupled with the Response Surface Methodology (RSM). According to the Pareto-optimal solution, the energy density of the optimized BTMS can increase 13.75 % to 122.39 Wh/kg with the cooling performance changed lightly, compared with the original module.