scholarly journals A Thermal Investigation and Optimization of an Air-Cooled Lithium-Ion Battery Pack

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2956 ◽  
Author(s):  
Xiongbin Peng ◽  
Xujian Cui ◽  
Xiangping Liao ◽  
Akhil Garg

An effective battery thermal management system (BTMS) is essential to ensure that the battery pack operates within the normal temperature range, especially for multi-cell batteries. This paper studied the optimal configuration of an air-cooling (AC) system for a cylindrical battery pack. The thermal parameters of the single battery were measured experimentally. The heat dissipation performance of a single battery was analyzed and compared with the simulation results. The experimental and simulation results were in good agreement, which proves the validity of the computational fluid dynamics (CFD) model. Various schemes with different battery arrangements, different positions of the inlet and outlet of the cooling system and the number of inlets and outlets were compared. The results showed that an arrangement that uses a small length-width ratio is more conducive to promoting the performance of the cooling system. The inlet and outlet configuration of the cooling system, which facilitates fluid flow over most of the battery pack over shorter distances is more beneficial to battery thermal management. The configuration of a large number of inlets and outlets can facilitate more flexible adjustment of the fluid flow state and can slow down battery heating to a greater extent.

2021 ◽  
Vol 38 (11) ◽  
pp. 118201
Author(s):  
Jianglong Du ◽  
Haolan Tao ◽  
Yuxin Chen ◽  
Xiaodong Yuan ◽  
Cheng Lian ◽  
...  

Lithium-ion battery packs are made by many batteries, and the difficulty in heat transfer can cause many safety issues. It is important to evaluate thermal performance of a battery pack in designing process. Here, a multiscale method combining a pseudo-two-dimensional model of individual battery and three-dimensional computational fluid dynamics is employed to describe heat generation and transfer in a battery pack. The effect of battery arrangement on the thermal performance of battery packs is investigated. We discuss the air-cooling effect of the pack with four battery arrangements which include one square arrangement, one stagger arrangement and two trapezoid arrangements. In addition, the air-cooling strategy is studied by observing temperature distribution of the battery pack. It is found that the square arrangement is the structure with the best air-cooling effect, and the cooling effect is best when the cold air inlet is at the top of the battery pack. We hope that this work can provide theoretical guidance for thermal management of lithium-ion battery packs.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Xinxi Li ◽  
Zhaoda Zhong ◽  
Jinghai Luo ◽  
Ziyuan Wang ◽  
Weizhong Yuan ◽  
...  

Electric vehicles (EVs) powered by lithium batteries, which are a promising type of green transportation, have attracted much attention in recent years. In this study, a thermoelectric generator (TEG) coupled with forced convection (F-C) was designed as an effective and feasible cooling system for a battery thermal management system. A comparison of natural convection cooling, F-C cooling, and TEG cooling reveals that the TEG is the best cooling system. Specifically, this system can decrease the temperature by 16.44% at the discharge rate of 3C. The coupled TEG and F-C cooling system can significantly control temperature at a relatively high discharge rate. This system not only can decrease the temperature of the battery module promptly but also can reduce the energy consumption compared with the two other TEG-based cooling systems. These results are expected to supply an effective basis of the design and optimization of battery thermal management systems to improve the reliability and safety performance of EVs.


Author(s):  
Xiangping Liao ◽  
Chong Ma ◽  
Xiongbin Peng ◽  
Akhil Garg ◽  
Nengsheng Bao

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.


2021 ◽  
Author(s):  
Nicholas Choi ◽  
Nhi V. Quach ◽  
Yoonjin Won

Abstract Due to the high-power efficiency of lithium-ion batteries, there is an increased interest in integrating batteries into vehicles to create a more sustainable transportation method. However, batteries require thermal management systems to maintain heat generation within ranges lower than 40 kJ and operation temperatures between 25°C and 40°C. When exposed to extremely high or low temperatures, the battery efficiency decreases, and adverse consequences may occur. To combat this, research is conducted to explore various options to create thermofluidic systems that utilize fluids to regulate the battery pack’s temperatures. Developments in cooling systems have commonly used air as the cooling fluid, but research in recent years is innovating towards liquids to encourage a higher heat dissipation rate. This paper introduces battery thermal management system applications, current technologies and challenges, and innovations for improving existing models. The current technologies discussed involve manufactured systems based on air- and liquid-cooling for cylindrical and prismatic battery cells. We provide information on new engineered fluids for improvements in fluid properties. In addition to this, new directions related to manufacturing techniques or materials are highlighted to showcase potential changes to current systems to integrate complicated cooling channels in a three-dimensional design. This paper thereby aims to summarize the holistic view showing the direction of the field and possible techniques for battery thermal management.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4194
Author(s):  
Martin Henke ◽  
Getu Hailu

Stationary battery systems are becoming increasingly common worldwide. Energy storage is a key technology in facilitating renewable energy market penetration and battery energy storage systems have seen considerable investment for this purpose. Large battery installations such as energy storage systems and uninterruptible power supplies can generate substantial heat in operation, and while this is well understood, the thermal management systems that currently exist have not kept pace with stationary battery installation development. Stationary batteries operating at elevated temperatures experience a range of deleterious effects and, in some cases, serious safety concerns can arise. Optimal thermal management prioritizes safety and balances costs between the cooling system and battery degradation due to thermal effects. Electric vehicle battery thermal management has undergone significant development in the past decade while stationary battery thermal management has remained mostly stagnant, relying on the use of active and passive air cooling. Despite being the default method for thermal management, there is an absence of justifying research or comparative reviews. This literature review seeks to define the role of stationary battery systems in modern power applications, the effects that heat generation and temperature have on the performance of these systems, thermal management methods, and future areas of study.


2021 ◽  
Author(s):  
Yasong Sun ◽  
Ruihuai Bai

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.


Author(s):  
Junkui (Allen) Huang ◽  
Shervin Shoai Naini ◽  
Richard Miller ◽  
Denise Rizzo ◽  
Katie Sebeck ◽  
...  

Enhanced battery pack cooling remains an open thermal management challenge in hybrid electric vehicle applications. A robust cooling system should maintain the battery pack core temperature within a prescribed operating range to improve system performance, durability, and reliability while minimizing power consumption. This paper proposes a smart battery thermal management system utilizing heat pipes as a thermal bus to efficiently remove heat. The system couples a standard air conditioning system with traditional ambient air ventilation. The two loops can run independently or in tandem to achieve the desired control. A nonlinear model predictive controller was developed to maintain the battery core temperature within a designated range using the compressor and fan speeds as the control inputs. A mathematical battery thermal model was developed to estimate the core and surface temperatures. The system performance and power requirements were evaluated for various driving cycles and ambient conditions. Numerical results showed that the proposed cooling system can regulate the battery core temperature within the desired temperature range (maximum tracking error of 2.1°C) while compensating for ambient temperature conditions using a suitable cooling strategy. The simulation results showed the ability to remove up to 1135 kJ of heat. The simulation also presents the power consumed by system components under varying modes and ambient conditions.


Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Franck Pra ◽  
Jad Al Koussa ◽  
Sebastian Ludwig ◽  
Carlo M. De Servi

The temperature and the temperature gradient within the battery pack of an electric vehicle have a strong effect on the life time of the battery cells. In the case of automotive applications, a battery thermal management (BTM) system is required to maintain the temperature of the cells within a prescribed and safe range, and to prevent excessively high thermal gradients within the battery pack. This work documents the assessment of a thermal management system for a battery pack for an electric van, which adopts a combination of active/passive solutions: the battery cells are arranged in a matrix or composite made of expanded graphite and a phase change material (PCM), which can be actively cooled by forced air convection. The thermal dissipation of the cells was predicted based on an equivalent circuit model of the cells (LG Chem MJ1) that was empirically calibrated in a previous study. It resulted that, in order to keep the temperature of the battery pack at or below 40 °C during certain charge/discharge cycles, a purely passive BTM would require a considerable amount of PCM material that would unacceptably increase the battery pack weight. Therefore, the passive solution was combined with an air cooling system that could be activated when necessary. To assess the resulting hybrid BTM concept, CFD simulations were performed and an experimental test setup was built to validate the simulations. In particular, PCM melting and solidification times, the thermal discrepancy among the cells and the melting/solidification temperatures were examined. The melting time experimentally observed was higher than that predicted by the CFD model, but this discrepancy was not observed during the solidification of the PCM. This deviation between the CFD model results and the experimental data during PCM melting can be attributed to the thermal losses occurring through the mock-up casing as the heating elements are in direct contact with the external walls of the casing. Moreover, the temperature range over which the PCM solidifies was 6 °C lower than that estimated in the numerical simulations. This occurs because the simple thermodynamic model cannot predict the metastable state of the liquid phase which occurs before the onset of PCM solidification. The mockup was also used to emulate the heat dissipation of the cells during a highway driving cycle of the eVan and the thermal management solution as designed. Results showed that for this mission of the vehicle and starting from an initial temperature of the cells of 40 °C, the battery pack temperature could be maintained below 40 °C over the entire mission by a cooling air flow at 2.5 m/s and at a temperature of 30 °C.


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