Temperature Difference Of Battery Module Research Articles

A channel with hybrid twisted tapes for immersion cooling battery thermal management system

The promotion of transport electrification represents a pivotal strategy in addressing the energy crisis, wherein the adoption of the electric vehicles (EVs) plays a crucial role towards the realization of this goal. Immersion cooling battery thermal management systems (ICBTMS) emerge as an innovative strategy to guarantee the safe operation of the EVs. This study proposes an immersion cooling battery thermal management system with twisted tapes channel (TT-ICBTMS), offering effective temperature regulation of the battery pack. Drawing upon the experimental and simulation results associated with the high-capacity square battery, this paper selects a channel for further experimentation and simulation to elucidate the mechanisms by which various cooling methods and twisted tape configurations impact cooling efficacy. Subsequently, predicated on the comprehensive evaluation results, the channel with the hybrid twisted tapes (H-TT) is proposed. The H-TT, comprising both reverse twisted tapes (R-TT) and hollow reverse twisted tapes (HR-TT), serves to mitigate battery temperature rise, diminish pressure drop, and reduce the maximum temperature difference. This paper examines the heat transfer performance of the channel with the H-TT, revealing that, at the flow rate of 0.5 L/min and the discharge rate of 3C (Idischarge = 654 A), the maximum temperature of battery reaches merely 36.47 °C, with the maximum temperature difference of battery module being confined to 1.81 °C. Finally, a methodology employing the porous structure as the replacement for the H-TT in simulations is introduced in this study, a tactic validated through juxtaposition of experimental and simulation results, and subsequently applies this method in battery pack simulations. The simulation results demonstrate that, within the immersion cooling battery thermal management system with hybrid twisted tapes channel (H-TT-ICBTMS), the maximum temperature is confined to a mere 36.29 °C, with the maximum temperature difference limited to 2.63 °C, under the conditions of the flow rate of 22.5 L/min and the discharge rate of 3C (Idischarge = 654 A). This study posits that the H-TT-ICBTMS heralds novel thermal management paradigms for EVs.

Comprehensive investigation of the electro-thermal performance and heat transfer mechanism of battery system under forced flow immersion cooling

Efficient cooling during rapid battery charging/discharging necessitates forced circulating flow in immersion cooling systems. However, under forced flow immersion cooling (FFIC), the comprehensive impact on the electrical and thermal performance of battery modules remains inadequately explored. This study constructs an immersion-cooled battery module test platform for experimental research on the evolution of electrical and thermal characteristics. The results show that under FFIC, when the depth of discharge (DOD) during 2C and 3C discharges is below 85 %, the voltage deviation of module (δU,t) remains stable within 1 % and 2 %, respectively. At DOD of 100 %, the maximum δU,t for 2C and 3C are 10 % and 24.5 %, respectively. Furthermore, the analysis of Pearson correlation coefficient under FFIC reveals that the δU,t exhibits a very strong positive correlation with temperature difference of battery module and cell, with correlation coefficients of +0.94 and + 0.87, respectively. Higher flow rates accelerate the recovery of module temperature and facilitate voltage distribution equalization after discharge. Additionally, to elucidate the influence of flow rate on FFIC, module-scale heat transfer characteristics during battery discharge are theoretically analyzed, establishing a fitting relationship between C-rates, flow rates, and the Nusselt number (Nu). This study provides a comprehensive understanding of integrated electro-thermal performance and external heat transfer capability for flow regulation in immersion cooling.

Study on thermal–mechanical coupling of vehicle battery module embedded with double-V cellular structure

To further enhance the thermal–mechanical performances of battery module, a novel lithium-ion battery module with double-V cellular structure (DVCS) is proposed. Firstly, the temperature field distributions of battery module are acquired by employing ANSYS/ Fluent simulation analysis software. Subsequently, mechanical properties of the DVCS are acquired and quasi-static compression test is also executed to verify the accuracy of theoretical predictions and emulation analysis. Then, the thermo-mechanical coupling models of DVCS are established, and the optimal geometric parameters of DVCS can be obtained through multi-objective thermal–mechanical coupling optimization method. Based on the above, density gradient of the DVCS can be defined based on the temperature field distribution of battery module. Eventually, in comparisons to battery module with single cooling tube and battery module with the optimal DVCS, the maximum temperature of battery module with density gradient DVCS is 304.97 K at 3C discharge rate, which decreases by 4.51 % and 3.16 %, respectively, the maximum temperature difference of battery module with density gradient DVCS is 4.97 K, which decreases by 74.36 % and 66.71 %, accordingly. As for extrusion conditions, the maximum intrusion displacements of battery module with density gradient DVCS are 0.2295 mm and 0.6518 mm along X and Y directions, separately, which decrease by 94.54 % and 86.87 % compared with those of battery module with single cooling tube. The results indicate that the dissipation efficiency, temperature uniformity and collision performances of battery module with density gradient DVCS can be improved greatly.

Experimental and numerical simulation study on the integrated thermal management system for electric vehicles

Battery thermal management technology can realize the orderly management of heat, which is an important way to improve the safety and lifespan of batteries in electric vehicles (EVs). Herein, we propose an integrated battery thermal management system (IBTMs) that it includes both heat dissipation and low-temperature heating function. In the integrated structure design, the composite phase change materials (CPCM) have a strongly heat absorbed capability due to the large latent heat, and the thin polyimide heating film (PHF) can conveniently assemble into the battery module. The experiment and simulation results verified that the electrochemical performance of battery module can be achieved an excellent recoverable when employed a heating strategy of continuous pulse warm-up combined with battery at low-power self-preheating. Compared with the normal temperature of 10 °C, the capacity of battery module of charge and discharge is recovered to 92.1 % and 93.3 %, respectively. Besides, the heat dissipation performance tests result also show that the IBTMs has an excellent temperature control and uniform capability. The maximum temperature and maximum temperature difference of battery module is always controlled within 52 °C and 1.8 °C respectively, even if the battery module is continuously cycled 5 times with 2C-1C test protocol at extremely high temperature of 40 °C.

Thermal performance of honeycomb-type cylindrical lithium-ion battery pack with air distribution plate and bionic heat sinks

• •Air distribution plate with bionic channel is designed in the honeycomb-type battery pack. • •Temperature difference of battery module with air distribution plate is reduced by 7.0 K. • •Installing bionic heat sinks enhance the temperature uniformity of the battery module. • • An estimation method is proposed to analyze the temperature range of the battery pack. In this paper, the thermal performance of air-cooled battery thermal management (BTM) for honeycomb-type cylindrical lithium-ion battery pack is studied. The battery pack consists of twenty-four hexagonal battery modules, and the pipe network in battery pack transports cooling air to each battery module. Then, an air distribution plate (ADP) is designed for the battery module to improve temperature consistency, and the cooling performance and velocity distribution are studied numerically with computational fluid dynamics (CFD). As compared with the normal battery module without ADP at inlet velocity of 12 m/s and discharge rate of 3 C, the maximum temperature and temperature difference of ADP battery module are reduced by 1.7 K and 7.0 K, respectively. Meanwhile, improving the structure of the ADP and installing some bionic heat sinks in the spaces of batteries can maintain the temperature difference of the battery module within 2 K. In addition, an estimation method is proposed to analyze the temperature range of the battery pack, which uses a simplified model to simulate the relationship between the inlet velocity and pressure drop of battery module. The estimation results show that the temperature difference of battery pack with optimal design of pipe arrangement can be controlled to 2.5 K.

Thermal management of power battery based on flexible Swiss roll type liquid cooling micro-channel

When an electric vehicle is driving uphill and accelerating, it usually requires its battery module to discharge at a high rate to satisfy its driving requirements. If the heat is not eliminated in time, the life and performance of the battery module may be reduced under high temperatures and poor temperature uniformity, potentially leading to thermal runaway. Thus, it is necessary to reduce the maximum temperature and temperature difference of the battery module. Therefore, this paper proposes a thermal management system for a Swiss roll-type battery, and the effects of the structural parameters of the Swiss roll BTMS cooling belt, coolant inlet flow rate, coolant type, and inlet temperature on the heat dissipation performance of the battery module are investigated. The results indicate that the coolant inlet flow rate is the main controlling factor for the heat dissipation performance of the battery module. Finally, the four influencing factors are optimized by combining finite element and orthogonal test methods. After optimization, the maximum temperature, temperature difference and cooling belt arrangement height of the Swiss roll type battery module are 300.4 K, 3.3 K and 55 mm, respectively. Compared with the reference group, the maximum temperature and temperature difference as well as the cooling belt arrangement height of the battery module are reduced by 4 K, 0.2 K and 10 mm, respectively. Compared with the serpentine flow channel BTMS optimized by other researchers, the maximum temperature and temperature difference of the Swiss roll battery module and the height of the cooling belt are reduced by 1.2 K, 0.2 K, and 10 mm, respectively. Therefore, the proposed Swiss roll type battery module can achieve a lower maximum temperature and better temperature uniformity, which is more conducive to the thermal management of large-scale power battery modules. This study also provides a reference for the lightweight design of battery modules.

Investigation on liquid cold plate thermal management system with heat pipes for LiFePO4 battery pack in electric vehicles

An appropriate battery thermal management system is essential for electric vehicles to keep an optimal working temperature range with minimal temperature difference, and meanwhile to ensure the battery is more efficient and safe. In this paper, the liquid cold plate thermal management system with heat pipes is proposed to investigate the thermal characteristic of LiFePO4 battery pack during various discharge rate operations. A three-dimensional numerical model based on standard k-ε turbulent model is developed to realize the visible analysis of fluid flow and heat transfer for the proposed thermal management system. The 50 Ah battery module is used in the experiment to validate the cooling effects of proposed thermal management system relied on heat pipes, and its performance is compared with liquid cold plate without heat pipes. Furthermore, the cooling performance of the cold plate with heat pipes could be further improved through the orthogonal experiment design, the maximum temperature of battery cell and temperature difference of battery module could be dropped by 6.95% and 11.08%, as compared with the original design. What’s more, the channel height of cold plate with heat pipes has the greatest effect on the maximum temperature of battery cells and temperature difference of battery modules.

Thermal performance of cylindrical lithium-ion battery thermal management system integrated with mini-channel liquid cooling and air cooling

To overcome the temperature increase of battery along the flow direction of coolant in cylindrical lithium-ion battery module, a composite thermal management system integrated with mini-channel liquid cooling and air cooling is proposed. The computational fluid dynamics model of battery module is validated using the experiment results to investigate the effects of inlet flow rate of water, amount of cooling tube and mini-channel, tube space, water flow direction, and spacer combination on the thermal performance of mini-channel liquid cooling at 4 C discharge rate. When air cooling is integrated with mini-channel liquid cooling, the corresponding thermal performance of the composite system is analyzed. The results show that the maximum temperature and temperature difference decrease with an increase in the water inlet flow rate with a significant rise of power consumption. When the water inlet flow rate is 3 × 10−4 kg⋅s−1, the increasing amount of the cooling tube and mini-channel could slightly improve the cooling performance. If the cases with suitable values of the tube space, flow direction, and spacer combination are adopted, the temperature difference would remain within 4.13 K, and the maximum temperature decreases to 304.98 K. Moreover, the extra air cooling at the velocity of 4 m⋅s−1 could reduce the maximum temperature and the temperature difference of battery module dropped by 2.22 K and 2.04 K at 80% DOD. More importantly, the maximum temperature difference could be manipulated within 5.0 K when the fan was automatically controlled according to the temperature of the battery module.

Thermal Management of a Li-Ion Battery for Electric Vehicles Using PCM and Water-Cooling Board

A novel thermal management system (TMS) for Li-ion battery module using phase change material (PCM) and cooling water as the heat dissipation source to control battery temperature rise has been developed. Graphite sheets were applied to compensate low thermal conductivity of battery and PCM and improve temperature uniformity of the batteries. One discharge (1C rate)-charge (2C rate) circle was applied in battery modules to test the effectiveness of this TMS. A three dimensional numerical model of the battery module with the TMS was conducted. The results show that this TMS basically meets the demand about the maximum temperature difference of battery module and totally keeps the maximum temperature within the optimum operating temperature range (≤45°C).

Optimization on uniformity of lithium-ion cylindrical battery module by different arrangement strategy

Ensuring temperature uniformity of battery module is an important work for the design of battery thermal management system. In this paper, a lithium-ion cylindrical battery module with different cells distribution strategy is designed to improve its uniformity. A three-dimensional heat transfer – one-dimensional electrochemical coupled finite element model is developed to analyze and optimize the arrangement for battery module. The intervals of cells are arranged based on geometric ratio and arithmetic ratio. It is found that the arrangement of varying intervals among cells is an efficient way to improve homogeneity for battery module, especially the arithmetic arrangement. The maximum temperature difference of the battery module decreases with increasing initial spacing. The maximum temperature difference of battery module with arithmetic arrangement could reduce 13%, and maximum final voltage difference could reduce to 2.5 mV when battery initial spacing reaches 5.5 mm. The uniformities of temperature and discharge inside the battery module with arithmetic ratio arrangement are better than geometric ratio arrangement. The position of cells with the maximum temperature in the module varies with discharge time, but always appear at same position regardless of the arrangement and initial spacing. The position changing process is slower in arithmetic arrangement and large initial spacing.

Sensitivity analysis of factors influencing a heat pipe-based thermal management system for a battery module with cylindrical cells

Structural parameters have a significant effect on the thermal performance of a battery thermal management system (BTMS). In the present study, a thermal management system based on heat pipes is proposed for a battery module with cylindrical cells. A computational fluid dynamics model is built for the BTMS and validated with experimental results. An orthogonal numerical test is conducted to obtain the sensitivity of various parameters, including the battery spacing, the thickness of conduction element, the circumference angle between battery and conduction element, and the height of conduction element on the thermal performance for the proposed BTMS. Results show that the height of conduction element has the most sensitive effect on the maximum temperature and temperature difference of battery module; the circumference angle between battery and conduction element is the second; the battery spacing and the thickness of conduction element has the minimal effect. The best thermal performance is obtained under the condition of 19 mm battery spacing, 4 mm conduction element thickness, 120° circumference angle and 60 mm conduction element height. Based on the optimal parameters, the maximum temperature and the temperature difference of battery module are 27.62 °C and 1.08 °C, respectively.

Thermal performance of cylindrical Lithium-ion battery thermal management system based on air distribution pipe

For a typical air cooling thermal management system, the inlet and outlet of air flow on both sides of the battery module would increase the temperature difference. In here, a novel cooling strategy based on air distribution pipes is proposed for the cylindrical Lithium-ion battery module. The three-dimensional computational fluid dynamics model of battery module is constructed and validated by the experimental tests. The thermal behavior of battery module and the flow field of air have been explored using numerical simulations at different discharge rates, and then the effects of orifice parameters, inlet pressure and discharge rate on the performance of air cooling strategy have been analyzed. The results show that the maximum temperature of the battery module can be effectively reduced by the increase of inlet pressure resulting in a significant rise of power consumption. Meanwhile, it declines when the diameter and number of rows of the orifice increase, following a minor rise in power consumption. When the inlet pressure is 100 Pa, the diameter of the orifice is 1.5 mm, the number of rows of the orifice is 5 and the discharge rate is 3C, the maximum temperature of battery module decreases from 325.9 K to 305.7 K in comparison to that under none air cooling condition. In addition, the maximum temperature difference of battery module is within 3 K. When the battery module discharge at the current rate of 4C and 5C, the maximum temperature of battery module maintains within 313.15 K, but the temperature difference slightly exceeds the optimal range at 5C discharge when the inlet pressure is 200 Pa, the diameter of the orifice is 1.5 mm and the number of rows of the orifice is 5. Moreover, it is an efficient and a practical cooling strategy with no need to modify the arrangement of the battery module.