Holistic 1D Electro-Thermal Model Coupled to 3D Thermal Model for Hybrid Passive Cooling System Analysis in Electric Vehicles

Thermal management is the most vital element of electric vehicles (EV) to control the maximum temperature of module/pack for safety reasons. This paper presents a novel passive thermal management system (TMS) composed of a heat sink (HS) and phase change materials (PCM) for lithium-ion capacitor (LiC) technology under the premise that the cell is cycled with a continuous 150 A fast charge/discharge current rate. The experiments are validated against numerical analysis through a computational fluid dynamics (CFD) model. For this purpose, a comprehensive electro-thermal model based on an equivalent circuit model (ECM) is designed. The designed electro-thermal model combines the ECM model with the thermal model since the performance of the LiC cell highly depends on the temperature. Then, the robustness of the model is evaluated using a precise second-order ECM. The extracted parameters of the electro-thermal model are verified by the experimental results in which the voltage and temperature errors are less than ±5% and ±4%, respectively. Finally, the thermal performance of the HS-assisted PCM TMS is studied under the fast charge/discharge current rate. The 3D CFD results exhibit that the temperature of the LiC when using the PCM-HS as the cooling system was reduced by 38.3% (34.1 °C) compared to the natural convection case study (55.3 °C).

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Thermal Performance of a Cylindrical Lithium-Ion Battery Module Cooled by Two-Phase Refrigerant Circulation

Energies ◽

10.3390/en14238094 ◽

2021 ◽

Vol 14 (23) ◽

pp. 8094

Author(s):

Bichao Lin ◽

Jiwen Cen ◽

Fangming Jiang

Keyword(s):

Thermal Management ◽

Management System ◽

Cooling System ◽

Maximum Temperature ◽

Two Phase ◽

Battery Thermal Management ◽

Thermal Management System ◽

Battery Thermal Management System ◽

Li Ion ◽

Battery Module

It is important for the safety and good performance of a Li-ion battery module/pack to have an efficient thermal management system. In this paper, a battery thermal management system with a two-phase refrigerant circulated by a pump was developed. A battery module consisting of 240 18650-type Li-ion batteries was fabricated based on a finned-tube heat-exchanger structure. This structural design offers the potential to reduce the weight of the battery thermal management system. The cooling performance of the battery module was experimentally studied under different charge/discharge C-rates and with different refrigerant circulation pump operation frequencies. The results demonstrated the effectiveness of the cooling system. It was found that the refrigerant-based battery thermal management system could maintain the battery module maximum temperature under 38 °C and the temperature non-uniformity within 2.5 °C for the various operation conditions considered. The experimental results with 0.5 C charging and a US06 drive cycle showed that the thermal management system could reduce the maximum temperature difference in the battery module from an initial value of 4.5 °C to 2.6 °C, and from the initial 1.3 °C to 1.1 °C, respectively. In addition, the variable pump frequency mode was found to be effective at controlling the battery module, functioning at a desirable constant temperature and at the same time minimizing the pump work consumption.

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Performance of an Environmentally Friendly Alternative Fluid in a Loop Heat Pipe-Based Battery Thermal Management System

Energies ◽

10.3390/en14227738 ◽

2021 ◽

Vol 14 (22) ◽

pp. 7738

Author(s):

Marco Bernagozzi ◽

Nicolas Miché ◽

Anastasios Georgoulas ◽

Cedric Rouaud ◽

Marco Marengo

Keyword(s):

Environmental Impact ◽

Heat Pipe ◽

Thermal Management ◽

Thermal Performance ◽

Management System ◽

Maximum Temperature ◽

Loop Heat Pipe ◽

Fast Charge ◽

Thermal Management System ◽

Thermal Medium

The present investigation aims to devise a thermal management system (TMS) for electric vehicles able to improve on limitations like charging time and all-electric range, together with the safety and environmental impact of the chosen thermal medium. A research gap is identified, as focus is often on addressing system thermal performance without considering that the thermal medium must not only provide suitable performances, but also must not add risks to both passengers and the environment. Thus, this work proposes an innovative cooling system including graphite sheets and a Loop Heat Pipe, filled with Novec™ 649 as working fluid, due to its exceptional environmental properties (GWP = 1 − ODP = 0) and safety features (non-flammable, non-toxic, dielectric). A three-cell module experimental demonstrator was built to compare temperatures when the proposed TMS is run with Novec™ 649 and ethanol. Results of testing over a bespoke fast charge driving cycle show that Novec™ 649 gave a faster start-up and a slightly higher maximum temperature (0.7 °C), meaning that the gains in safety and lower environmental impact brought by Novec™ 649 came without lowering the thermal performance. Finally, the TMS was tested under three different fast charge conditions (1C, 2C, 3C), obtaining maximum temperatures of 28.4 °C, 36.3 °C and 46.4 °C, respectively.

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Temperature Distribution Optimization of an Air-Cooling Lithium-Ion Battery Pack in Electric Vehicles Based on the Response Surface Method

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4042922 ◽

2019 ◽

Vol 16 (4) ◽

Cited By ~ 6

Author(s):

Xiangping Liao ◽

Chong Ma ◽

Xiongbin Peng ◽

Akhil Garg ◽

Nengsheng Bao

Keyword(s):

Temperature Distribution ◽

Lithium Ion Battery ◽

Electric Vehicles ◽

Cooling System ◽

Lithium Ion ◽

Battery Pack ◽

Maximum Temperature ◽

Air Cooling ◽

Optimized Design ◽

Original Design

Electric vehicles have become a trend in recent years, and the lithium-ion battery pack provides them with high power and energy. The battery thermal system with air cooling was always used to prevent the high temperature of the battery pack to avoid cycle life reduction and safety issues of lithium-ion batteries. This work employed an easily applied optimization method to design a more efficient battery pack with lower temperature and more uniform temperature distribution. The proposed method consisted of four steps: the air-cooling system design, computational fluid dynamics code setups, selection of surrogate models, and optimization of the battery pack. The investigated battery pack contained eight prismatic cells, and the cells were discharged under normal driving conditions. It was shown that the optimized design performs a lower maximum temperature of 2.7 K reduction and a smaller temperature standard deviation of 0.3 K reduction than the original design. This methodology can also be implemented in industries where the battery pack contains more battery cells.

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Lithium-Ion Capacitor Lifetime Extension through an Optimal Thermal Management System for Smart Grid Applications

Energies ◽

10.3390/en14102907 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2907

Author(s):

Danial Karimi ◽

Sahar Khaleghi ◽

Hamidreza Behi ◽

Hamidreza Beheshti ◽

Md Sazzad Hosen ◽

...

Keyword(s):

Thermal Management ◽

Management System ◽

Cooling System ◽

Lithium Ion ◽

Cell Temperature ◽

Thermal Management System ◽

Capacity Degradation ◽

Lithium Ion Capacitor ◽

Grid Applications ◽

Lifetime Extension

A lithium-ion capacitor (LiC) is one of the most promising technologies for grid applications, which combines the energy storage mechanism of an electric double-layer capacitor (EDLC) and a lithium-ion battery (LiB). This article presents an optimal thermal management system (TMS) to extend the end of life (EoL) of LiC technology considering different active and passive cooling methods. The impact of different operating conditions and stress factors such as high temperature on the LiC capacity degradation is investigated. Later, optimal passive TMS employing a heat pipe cooling system (HPCS) is developed to control the LiC cell temperature. Finally, the effect of the proposed TMS on the lifetime extension of the LiC is explained. Moreover, this trend is compared to the active cooling system using liquid-cooled TMS (LCTMS). The results demonstrate that the LiC cell temperature can be controlled by employing a proper TMS during the cycle aging test under 150 A current rate. The cell’s top surface temperature is reduced by 11.7% using the HPCS. Moreover, by controlling the temperature of the cell at around 32.5 and 48.8 °C, the lifetime of the LiC would be extended by 51.7% and 16.5%, respectively, compared to the cycling of the LiC under natural convection (NC). In addition, the capacity degradation for the NC, HPCS, and LCTMS case studies are 90.4%, 92.5%, and 94.2%, respectively.

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Thermal Analysis and Improvements of the Power Battery Pack with Liquid Cooling for Electric Vehicles

Energies ◽

10.3390/en12163045 ◽

2019 ◽

Vol 12 (16) ◽

pp. 3045 ◽

Cited By ~ 4

Author(s):

Xia ◽

Liu ◽

Huang ◽

Yang ◽

Lai ◽

...

Keyword(s):

Thermal Management ◽

Electric Vehicles ◽

Thermal Performance ◽

Lithium Ion ◽

Battery Pack ◽

Maximum Temperature ◽

Design Solution ◽

Liquid Cooling ◽

Power Battery ◽

Reference Design

In order to ensure thermal safety and extended cycle life of Lithium-ion batteries (LIBs) used in electric vehicles (EVs), a typical thermal management scheme was proposed as a reference design for the power battery pack. Through the development of the model for theoretical analysis and numerical simulation combined with the thermal management test bench, the designed scheme could be evaluated. In particular, the three-dimensional transient thermal model was used as the type of model. The test result verified the accuracy and the rationality of the model, but it also showed that the reference design could not reach the qualified standard of thermal performance of the power battery pack. Based on the heat dissipation strategy of liquid cooling, a novel improved design solution was proposed. The results showed that the maximum temperature of the power battery pack dropped by 1 °C, and the temperature difference was reduced by 2 °C, which improved the thermal performance of the power battery pack and consequently provides guidance for the design of the battery thermal management system (BTMS).

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Isothermalization of an IGBT Power Electronic Chip

Volume 4: Electronics and Photonics ◽

10.1115/imece2010-41019 ◽

2010 ◽

Cited By ~ 1

Author(s):

Peng Wang ◽

F. Patrick McCluskey ◽

Avram Bar-Cohen

Keyword(s):

Thermal Management ◽

Hybrid Electric Vehicles ◽

Cooling System ◽

Heat Fluxes ◽

Maximum Temperature ◽

Power Electronic ◽

Liquid Cooling ◽

Thermo Electric ◽

Critical Issues ◽

System Designs

Rapid increases in the power ratings and continued miniaturization of power electronic semiconductor devices have pushed chip heat fluxes well beyond the range of conventional thermal management techniques. The heat flux of power electronic chips for hybrid electric vehicles is now at the level of 100 to 150W/cm2 and is projected to increase to 500 W/cm2 in next generation vehicles. Such heat fluxes lead to higher and less uniform IGBT chip temperature, significantly degrading the device performance and system reliability. Maintaining the maximum temperature below a specified limit, while isothermalizing the surface of the chip, have become critical issues for thermal management of power electronics. In this work, a hybrid cooling system design, which combines microchannel liquid cooling and thermoelectric solid-state cooling, is proposed for thermal management of a 10mm × 10mm IGBT chip. The microchannel heat sink is used for global cooling of the chip while the embedded thermo-electric cooler is employed for isothermalization of the chip. A detailed package level 3D thermal model is developed to explore the potential application of this concept, with an attention focused on isothermalization and temperature reduction of IGBT chip associated with variations in thermoelectric cooler sizes, thermoelectric materials, cooling system designs, and trench structures in the DBC substrate. It is found that a thin-film superlattice TEC can deliver a superior cooling performance by eliminating more than 90% of the temperature non-uniformity on 100∼200 W/cm2 IGBT chips.

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Investigation of the Applicability of Helium-Based Cooling System for Li-Ion Batteries

Electrochem ◽

10.3390/electrochem2010011 ◽

2021 ◽

Vol 2 (1) ◽

pp. 135-148

Author(s):

Mohammad Alipour ◽

Aliakbar Hassanpouryouzband ◽

Riza Kizilel

Keyword(s):

Thermal Management ◽

Cooling System ◽

Flow Direction ◽

Maximum Temperature ◽

Li Ion Batteries ◽

Battery Thermal Management ◽

Thermal Management System ◽

Inlet Flow Rate ◽

Battery Thermal Management System ◽

Li Ion

This paper proposes a novel He-based cooling system for the Li-ion batteries (LIBs) used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). The proposed system offers a novel alternative battery thermal management system with promising properties in terms of safety, simplicity, and efficiency. A 3D multilayer coupled electrochemical-thermal model is used to simulate the thermal behavior of the 20 Ah LiFePO4 (LFP) cells. Based on the results, He gas, compared to air, effectively diminishes the maximum temperature rise and temperature gradient on the cell surface and offers a viable option for the thermal management of Li-ion batteries. For instance, in comparison with air, He gas offers 1.18 and 2.29 °C better cooling at flow rates of 2.5 and 7.5 L/min, respectively. The cooling design is optimized in terms of the battery’s temperature uniformity and the battery’s maximum temperature. In this regard, the effects of various parameters such as inlet diameter, flow direction, and inlet flow rate are investigated. The inlet flow rate has a more evident influence on the cooling efficiency than inlet/outlet diameter and flow direction. The possibility of using helium as a cooling fluid is shown to open new doors in the subject matter of an effective battery thermal management system.

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Development and Analysis of a New Cylindrical Lithium-ion Battery Thermal Management System

10.21203/rs.3.rs-934197/v2 ◽

2021 ◽

Author(s):

Yasong Sun ◽

Ruihuai Bai

Keyword(s):

Thermal Management ◽

Electric Vehicles ◽

Management System ◽

Optimization Design ◽

Cooling System ◽

Lithium Ion ◽

Simulation Software ◽

Parameter Analysis ◽

Battery Thermal Management ◽

Thermal Management System

Abstract With the development of modern technology and the economy, environmental protection and sustainable development have become the focus of global attention. In this paper, the promotion and development of electric vehicles have bright prospects, and they are also facing many challenges. Under different operating conditions, various safety problems of electric vehicles emerge one after another, especially the potential safety hazards caused by battery overheating that threaten electric vehicles' development process. In this paper, a new indirect liquid cooling system is designed and optimized for cylindrical lithium-ion batteries. A variety of design schemes for different cooling channel structures and cooling liquid inlet direction are proposed, and the corresponding solid-fluid coupling model is established. COMSOL Multiphysics simulation software models, simulates and analyses cooling systems. An approximate model is constructed using the Kriging method，and it is considered to optimize the battery cooling system and improve the optimization results. Sensitivity parameter analysis and system structure optimization design are also carried out on the influencing factors of the battery thermal management. The results indicate it effectively balances and reduces the maximum core temperature and temperature difference of the battery pack. Compared with the original design, from the optimized design of these factors, which based on method of the non-dominated sorting genetic algorithm (NSGA-II), there is an excellent ability on the optimized thermal management system to dissipate thermal energy and keep the overall cooling uniformity of the battery and thermal management system. Furthermore, under thermal abuse conditions, the optimized system can also prevent thermal runaway propagation. In summary, this research is expected to provide some practical suggestions and ideas for the engineering and production applications and structural optimization design carried by electric vehicles.

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Numerical Investigation of Thermal Properties for Li-Ion Battery

ASME 2020 Heat Transfer Summer Conference ◽

10.1115/ht2020-9108 ◽

2020 ◽

Author(s):

Xiuling Wang

Keyword(s):

Electric Vehicles ◽

Discharge Rate ◽

High Energy ◽

Maximum Temperature ◽

Li Ion Batteries ◽

Li Ion Battery ◽

Battery Design ◽

Fast Charging ◽

Li Ion ◽

Charge Discharge

Abstract Li-ion battery is becoming a popular energy storage device in Hybrid Electric Vehicles (HEV) and Electric Vehicles (EV) due to its high energy density, high voltage and low self-discharge rate. The major concerns in designing Li-ion batteries are their life, performance and safety, which have close relations to their thermal behaviors. The temperature of Li-ion batteries rises during charge/discharge process. It goes faster especially with high charge/discharge rate during fast charging procedure. In this research, CFD models are developed based on ANSYS/FLUENT MSMD battery model coupled with electrochemical submodel-Newman, Tiedeman, Gu and Kim (NTGK) empirical model. Detailed simulation results are obtained in battery thermal and electrochemical behavior for different bi-cell electrode and current collector tab configurations. The temperature, potential, current density distribution at the battery length scale are determined, temperature gradient distribution is computed, and the maximum temperature at different discharge rate are also compared. The thermal investigation can provide valuable input for Li-ion battery design and analysis, especially for fast-charging batteries where heat distribution and cooling is critical for the battery design.

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