Search

Li-ion battery is an essential component and energy storage unit for the evolution of electric vehicles and energy storage technology in the future. Therefore, in order to cope with the temperature sensitivity of Li-ion battery and maintain Li-ion battery safe operation, it is of great necessary to adopt an appropriate battery thermal management system (BTMS). In this paper, the current main BTM strategies and research hotspots were discussed from two aspects: small-scale battery module and large-scale electrochemical energy storage power station (EESPS). The practical application situation, advantages and disadvantages, and the future development trend of each heat dissipation method (air, liquid, PCM, heat pipe, hybrid cooling) were described in detail. Among them, the air cooling and liquid cooling were reviewed in-depth based on the engineering application. The PCM, heat pipe and hybrid cooling were reviewed extensively based on the latest explorations. The research provides a comprehensive understanding for the BTMS in all scales. [ABSTRACT FROM AUTHOR]

Currently, the conventional heat pipe form and working fluid are not well suited for power batteries. Existing simulation studies on battery thermal management with coupled heat pipes often overlook the two-phase flow and heat transfer of working fluid within the heat pipe. Additionally, the temperature difference between electrode region and cell is neglected in thermal behaviour simulation of the battery. Aiming at these problems, this paper proposes the design of an L-shaped heat pipe, which aims to efficiently adapt to heat dissipation of square batteries and the spatial arrangement within the battery module. And the phase change, flow and heat transfer processes of working fluid inside heat pipe are simulated and reproduced using the VOF (volume of fluid) method. Additionally, a CFD (computational fluid dynamics) model of an 8S1P ternary lithium-ion battery module is established based on the NTGK (Newman, Tiedemann, Gu, and Kim) method. Focusing upon thermal behaviour properties of the 8S1P battery module at different discharge rates, we investigate and optimize the thermal management efficiency of L-shaped heat pipes coupled with air cooling. The analysis reveals that the battery module model provides a more accurate representation of the temperature field on the body of batteries and the temperature variation among them. The evaporation-condensation process of the working fluid inside the heat pipe can continue in dynamic equilibrium, and the heat transfer effect through phase transition is well. With battery discharge rates varying from 1C to 3.5C, the addition of forced air cooling and introduction of cold air from air conditioning allows efficient control of temperature and temperature difference of the module, resulting in an ideal cooling effect. This study further improves the accuracy of the design and simulation of BTM (battery thermal management) that coupled with heat pipes, which can provide certain reference for related research. [ABSTRACT FROM AUTHOR]

Conventional fuels operated an internal combustion engines are the major sources of carbon emissions and it causes environmental degradation. Electric vehicles (EVs) offers best efficient and cost effective solution for the above said issue. By year 2030 the world is aiming to shift to electric vehicles and one of the hurdles in the path is thermal management in the battery. This study aims to evaluate the performance of popular cooling methods thermodynamically. Lithium -ion batteries are the most commonly used battery type in commercial electric vehicles due to their high energy densities and ability to be repeatedly charged and discharged over many cycles. In order to maximize the efficiency of a li-ion battery pack, a stable temperature range between 15oC to 35oC must be maintained. Battery thermal management system (BTMS) plays a crucial role in enhancing the performance, safety and lifespan of electric vehicle batteries by maintaining optimal temperature conditions. This paper reviews how heat is generated across a li-ion cell as well as the current research work being done on the four main battery thermal management types which include air-cooled, liquid-cooled, phase change material based and thermoelectric based systems. Additionally, the strengths and weaknesses of each battery thermal management type is reviewed in this study. It was determined that air cooled systems are suited for short-distance travel electric vehicles, liquid cooled are for electric vehicles that require long-distance travel, larger battery packs and for high thermal loads, phase change material based are for electric vehicles with constant thermal loads and stable ambient temperatures and thermo-electric battery thermal management systems are best suited in conjunction with the other types for better control. [ABSTRACT FROM AUTHOR]

To ensure the battery works in a suitable temperature range, a new design for distributed liquid cooling plate is proposed, and a battery thermal management system (BTMS) for cylindrical power battery pack based on the proposed cooling plate is also investigated. To verify the accuracy of the battery model and battery pack numerical calculation model used for simulation, an experiment is conducted for the liquid cooling BTMS. The influence of key working parameters, including the cooling water inlet flow, ambient temperature and working conditions, are investigated. The results show that at the discharge rate of 3 C, the best cooling performance can be achieved when the total inlet mass flow rate is 3.2 g/s and the flow distribution is 3:1:1:3. The obtained maximum temperature is 29.6°C and the maximum temperature difference is 2.1°C. When the ambient temperature is in the range of 20°C to 50°C, the proposed BTMS can keep the temperature of battery pack in the proper range. Finally, different inlet flow rates are recommended according to different battery working states. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xi'an Jiaotong University is the property of Editorial Office of Journal of Xi'an Jiaotong University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In response to thermal runaway (TR) of electric vehicles, recent attention has been focused on mitigation strategies such as efficient heat dredging in battery thermal management. Thermal management with particular focus on battery cooling has been becoming increasingly significant. TR usually happened when an electric vehicle is unpowered and charged. In this state, traditional active battery cooling schemes are disabled, which can easily lead to dangerous incidents due to loss of cooling ability, and advanced passive cooling strategies are therefore gaining importance. Herein, we developed an enhanced thermal radiation material, consisting of ∼1 ​μm thick multilayered nano-sheet graphene film coated upon the heat dissipation surface, thereby enhancing thermal radiation in the nanoscale. The surface was characterized on the nanoscale, and tested in a battery-cooling scenario. We found that the graphene-based coating's spectral emissivity is between 91 ​% and 95 ​% in the mid-infrared region, and thermal experiments consequently illustrated that graphene-based radiative cooling yielded up to 15.1 ​% temperature reduction when compared to the uncoated analogue. Using the novel graphene surface to augment a heat pipe, the temperature reduction can be further enlarged to 25.6 ​%. The new material may contribute to transportation safety, global warming mitigation and carbon neutralization.

Herein, the synthesis of a novel microencapsulated phase change material via a sol–gel method is presented, featuring disodium hydrogen phosphate dodecahydrate as the core and a SiO2/graphene oxide composite as the shell. The morphology and core–shell microstructure of the synthesized microcapsules are characterized using scanning electron microscopy. The phase change performance and thermal stability are evaluated by differential scanning calorimetry and a high/low temperature test chamber, respectively. Energy dispersive X‐ray spectroscopy and Fourier transform infrared spectroscopy are employed to determine the chemical composition of the microcapsules. The findings reveal that the MEPCM exhibited a high melting enthalpy of 174.3 J g−1. The degree of supercooling is reduced by 2.1 °C, and after 600 thermal cycles, the phase change enthalpy of the microcapsules showed a minor decrease of ≈6.0%. Notably, the thermal conductivity of the microcapsules is significantly enhanced, increasing by up to 51.8%. When integrated into the thermal management systems of lithium‐ion batteries, the MEPCM effectively maintained the battery temperature below 46 °C under a 3 C charging rate. In summary, these results suggest that the hydrated salt microcapsule with its hybrid silica and graphene oxide shell is a promising material for the thermal management of lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

In this study, flow and thermal analyses of a liquid-cooled electric vehicle battery module were assessed via computational fluid dynamics (CFD) method. In CFD analyses, based on a validated model using battery heat generation data available in literature and obtained experimentally, the effect of contact resistance between the batteries and aluminum blocks and between aluminum blocks and water channels placed in battery module and cooling water flow rate were investigated for different working conditions. Findings revealed that at low discharge rate (C-rate) values, contact resistance could be disregarded, causing only a minor temperature difference of around 0.5°C. However, at high C-rate values, contact resistance became significant, resulting in a temperature difference of up to 2.5°C. Also, increasing the cooling liquid flow rate effectively lowered maximum temperature of battery module by approximately 8°C in high-heat scenarios. Conversely, in low-heat scenarios, excess cooling liquid flow rate led to unnecessary pump energy consumption, which could be reduced by approximately 1/8 while achieving a more homogeneous temperature distribution by choosing an appropriate cooling liquid flow rate. Also, the temperature difference between the batteries decreased and a more homogeneous temperature distribution was achieved in the module by increasing cooling flow rate. [ABSTRACT FROM AUTHOR]

This study presents a bionic structure-based liquid cooling plate designed to address the heat generation characteristics of prismatic lithium-ion batteries. The size of the lithium-ion battery is 148 mm × 26 mm × 97 mm, the positive pole size is 20 mm × 20 mm × 3 mm, and the negative pole size is 22 mm × 20 mm × 3 mm. Experimental testing of the Li-ion battery's heat generation model parameters, in conjunction with bionic structure and micro-channel features, has led to the development of this innovative cooling system. The traditional bionic liquid cooling plate's structure is often singular; however, the flow path of the liquid cooling plate designed in this paper is based on the combination of the distribution of human blood vessel branches and the structure of insect wing veins. The external dimension of the liquid cooling plate is 152 mm × 100 mm × 6 mm (length × width × height). Utilizing numerical simulation and thermodynamic principles, we analyzed the heat transfer efficacy of the bionic liquid cooling module for power batteries. Specifically, we investigated the impact of varying coolant flow rates and the contact radius between flow channels on the thermal performance of the bionic battery modules. Our findings indicate that a liquid flow rate of 0.6 m/s achieves a stable maximum surface temperature and temperature differential across the bionic battery liquid cooling module, with a relatively low overall system power consumption, suggesting room for further enhancement of heat transfer performance. By augmenting the contact radius between flow channels, we observed an initial increase in the maximum surface temperature, temperature differential, and inlet–outlet pressure differential at a flow rate of 0.2 m/s. However, at flow rates equal to or exceeding 0.4 m/s, these parameters stabilized across different design Scenarios. Notably, the pump power consumption remained consistent across various scenarios and flow rates. This study's outcomes offer valuable insights for the development of liquid-cooled battery thermal management systems that are energy-efficient and offer superior heat transfer capabilities. [ABSTRACT FROM AUTHOR]

There are two cooling tube arrangements were designed, and it was found that the double-tube sandwich structure had better cooling effect than the single-tube structure. In order to analyze the effects of three parameters on the cooling efficiency of a liquid-cooled battery thermal management system, 16 models were designed using L16 (43) orthogonal test, and the major and minor factors in the models were analyzed. The results show that among the three parameters, the coolant mass flow rate has the most significant impact on the maximum temperature of the battery module, followed by the inlet coolant temperature, and the coolant thermal conductivity has the least effect. In terms of temperature uniformity, the effects of all three factors on module temperature differences are very remarkable, with coolant mass flow rate and inlet temperature having particularly significant effects. The double-tube structure achieved a maximum temperature reduction of 6.7 °C and improved temperature uniformity with a maximum temperature difference reduction of 2.4 °C. Based on a comprehensive balancing method, parameter optimization was performed to determine the optimal combination of factors, further enhancing the cooling performance of the battery module. [ABSTRACT FROM AUTHOR]

Composite phase change materials (PCMs) consisting of thermally conductive nanofillers and a PCM matrix can provide an effective buffer for battery packs to avoid thermal runaway. However, there remain some challenges to overcome the trade-off between thermal conductivity and phase change enthalpy. Herein, we developed a bidirectionally high thermal conductive composite PCM featuring a radially oriented structure using an arrayed radial freezing method. The advanced composite PCM achieves high radial (6.09 W m–1 K–1) and axial thermal conductivities (4.83 W m–1 K–1) while maintaining high phase transition enthalpy (146.7 J g–1), outperforming most reported composite PCMs. Incorporating this composite PCM into a battery pack lowers the battery surface temperature by at least 10 °C and significantly reduces the temperature difference within the battery pack from 6.7 to 1.3 °C. Our approach is versatile with various thermally conductive nanofillers, providing opportunities for developing next-generation battery thermal management materials. [ABSTRACT FROM AUTHOR]

In order to enhance the safety and service life of automotive 4680 cylindrical batteries during high current discharge state, based on theoretical analysis and numerical simulation, a novel air cooling thermal management system that is integrated with finned heat pipe radiators has been developed and studied in this paper. A triangular heat conduction area was developed by leveraging the gaps within an equilateral triangular arrangement of cylindrical batteries to enhancement heat transfer and improve energy density, and heat exchange between finned heat pipes and cold air is facilitated by varying numbers of fins. Simulation results indicates that with the ambient temperature of 298.15 K and wind speed of 13 m/s, the maximum temperature of the battery module is 310.81 K and the temperature difference is 4.59 K under a 4C discharge rate. In additional, the temperature difference within the battery module reduces by 4.78% through optimizing the airflow duct and structure parameters of fins, which offering insights and references for the optimization and application of thermal management of automotive battery modules in the future. [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) are alternatives to traditional combustion engine-powered vehicles. This work focuses on a thermal management system for battery EVs using liquid cooling and a machine learning (ML) model to predict their thermal-related health. Real-world data of EV operation, battery and cooling conditions were collected. Key influencing factors on the thermal-related health of batteries were identified. The ML model's effectiveness was evaluated against experimental test data. The ML model proved effective in predicting and analyzing battery thermal health, suggesting its potential for use with the thermal management system. [ABSTRACT FROM AUTHOR]

In order to investigate the self-heating thermal runaway problem of ternary lithium-ion battery used in a certain forest plant protection machine, the structural composition of the battery cell, the heat generation mechanism of each side reaction and the three heat transfer modes of heat radiation, heat conduction and convective heat transfer between the battery cell, end plate, heat insulation pad, box body and the environment were first explored. Then based on the thermal runaway modeling method of the equivalent circuit model, the thermoelectric characteristic model of the 280 Ah large-capacity battery module was established in the Amesim one-dimensional simulation software by the physical parameters of the battery cell, the side reaction mechanism, and the exothermic heat transfer model. The heat transfer characteristics of the battery during self-heating thermal runaway and the path of thermal runaway propagation in the module were analyzed and simulated. Finally, according to the national standard GB 38031—2020, the self-heating experiment of the battery module was carried out to obtain the change of the cell temperature with time, and the specific position of the thermal runaway of the trigger cell was confirmed by CT scanning. The simulation and experimental results showed that the established model had high accuracy and reliable performance. The maximum error of the thermal runaway temperature of the cell was 11. 3%, and the maximum error of the thermal runaway trigger time was 4. 2%. It can provide technical reference for the design and development of battery thermal management, such as the prediction of thermal runaway temperature and the safety of preventing thermal diffusion of battery pack. [ABSTRACT FROM AUTHOR]