Lithium-ion Battery Thermal Management System Research Articles

Analysis of a Phase Change Material for Thermal Management of a Lithium-Ion Battery

A passive thermal management system for a lithium-ion battery by employing phase change material as the heat transfer source to manage lithium-ion battery temperature increase was developed. Lithium-ion battery temperature rise is caused by electrochemical reactions. If the lithium-ion battery temperature is not properly controlled, then it will cause a shortening of its lifespan, faster capacity reduction, or even in severe cases, might cause lithium-ion battery explosion. For commercial big-energy applications, a proper lithium-ion battery thermal management allows us to overcome problems related to heat production and improves significantly the performance of the lithium-ion battery. In this investigation behavior of a phase change material was analyzed. The phase change material was used as a medium for the thermal management of a lithium-ion battery cell. A three dimensional numerical model for the lithium-ion battery thermal management system according to phase change material was accomplished by using Ansys Fluent.

Paraffin/SiC as a Novel Composite Phase-Change Material for a Lithium-Ion Battery Thermal Management System

A lithium-ion battery thermal management system has always been a hot spot in the battery industry. In this study, a novel high-thermal-conductivity composite phase-change material (CPCM) made by paraffin wax and silicon was adopted to facilitate heat transfer. Moreover, high resistance or even insulation of CPCM is capable of preventing short circuits between the cells. The heat transfer mechanism of CPCMs was determined under a scanning electron microscope. A thermogravimetric analyzer was employed to determine the thermal stability. A differential scanning calorimeter was used to explore the thermophysical properties of the composite samples. By comparing the results of the experiment, it was reported that under the silicon carbide content of 5%, the parameters were better than others. The phase-change enthalpy of CPCM was 199.4 J/g, the leakage rate of liquid was 4.6%, and the melting point was 53.6 °C. To verify the practicality of CPCM, a three-dimensional layered battery pack model was built in the COMSOL Multiphysics software. By simulating the thermal runaway inside the battery packs of various materials, it was reported that the addition of CPCM significantly narrowed the temperature range of the battery pack from 300–370 to 303–304 K. Therefore, CPCM can effectively increase the rate of heat transfer to prevent the chain of thermal runaway reactions. It also enables the battery pack to run at a stable temperature.

Lithium-ion battery thermal management system with Al2O3/AgO/CuO nanofluids and phase change material

Nanofluids are emerging heat transfer media. Notably, usage of these materials in electronic cooling applications exhibits many peculiar benefits. This paper attemps to analyze the battery thermal management system for pouch lithium-ion battery modules. The experiments were conducted for pure water and nanofluid type battery thermal management systems combined with copper foam filled with paraffin wax as a phase change material with massive heat storage potential. An aluminum heat sink—specifically designed for this purpose—was considered as the inlet duct. A battery surrogate was employed to simulate the heat generated by Li-ion battery at high current discharge and the onset of thermal runaway conditions. The results of experimental tests revealed that the cooling efficiency of the system based on nanofluids is improved significantly. Different oxide-nanofluid slurries were tested and among all AgO was the best candidate. The maximum temperature of the battery is reduced by about 4.1 K by AgO/water nanofluid with %2 vol concentration compared to the battery thermal management systems based on pure water. It is further found that the maximum battery temperature difference is reduced by approximately 77% in the presence of copper foam with/without phase change material. The results also proved the imperative role of active/passive system combination that benefits the advantages of both approaches at the same time.

Simulation study of lithium-ion battery thermal management system based on a variable flow velocity method with liquid metal

A battery thermal management system (BTMS) is commonly used to control the battery temperature within the optimal temperature range. This paper presents a novel BTMS based on a liquid cooling method with liquid metal, which uses liquid metal as a coolant to achieve better cooling capacity and energy efficiency. An electrochemical-thermal coupled model is proposed to investigate the thermal behavior during discharge. A variable flow velocity strategy (VFVS) that can select the optimal flow velocity according to the discharge stage and specific operating conditions is used in the proposed BTMS. Numerical simulation results show that liquid metal can provide better cooling capacity than water and can be used in some extreme conditions. Within a certain range of the volume flow rate, a structure with a smaller number of copper pipes but higher flow velocity has better cooling performance. In addition, compared with a traditional BTMS, which uses a constant flow velocity strategy (CFVS), the proposed BTMS reduced the power consumption of the pump by 47%, 25.6% and 47% under constant ambient temperature with variable C-rate (CTVC), constant C-rate with variable ambient temperature (CCVT) and variable ambient temperature with variable C-rate (VCVT) operating conditions, which eventually reduced the energy consumption.

Surrogate based multi-objective design optimization of lithium-ion battery air-cooled system in electric vehicles

Abstract An effective and efficient lithium-ion Battery Thermal Management System (BTMS) design can significantly improve the performance of the battery pack. However, it is difficult to achieve an effective design of BTMS as there are several parameters from multidisciplinary fields that are needed to be optimized simultaneously. Thus, to solve this multi-objective optimization problem, a new type of finned forced air-cooled BTMS is designed. An optimization design method based on the surrogate is then proposed. This method decomposes the BTMS optimization problem into three subproblems such as thermodynamic problem, fluid dynamics problem, and mechanical structure problem. The optimization goal is to minimize the average battery temperature, the standard deviation of battery temperature, and the pressure drop of the BTMS system. Besides, the lightweight design of the heat dissipation system structure is also discussed. Finally, the optimal design involving multiple conflicting objectives in BTMS is generated by Multi-objective Genetic Algorithm (MOGA). From set of solutions, an optimal solution is selected. The optimized BTMS find a balance between cooling efficiency, system volume and power consumption.

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.

A computational multi-node electro-thermal model for large prismatic lithium-ion batteries

During operation of large prismatic lithium-ion batteries, temperature heterogeneities are aggravated which affect the performance, lifetime and safety of the cells and packs. Therefore, an accurate model to predict the evolution of temperature profiles in a cell is essential for effective thermal management. In this paper, a pseudo 3D coupled multi-node electro-thermal model is presented for real-time prediction of the heterogeneous temperature field evolution on the surface and inside the battery. The model consists of two parts: a heat generation model based on a second-order equivalent-circuit model and a multi-node heat transfer model based on the battery geometry. Three types of nodes are adopted to describe the thermal characteristics of various components of the cell. Simulation results show that the proposed model has a great consistency with finite element method, and its computational cost is reduced by 90%. The validity of the coupled electrical and thermal model is also demonstrated experimentally for a 105 Ah prismatic cell applying wide ranges of temperature and SOC. The maximum error is less than 2 K throughout the cycles. The proposed model holds a great potential for online temperature estimation in advanced lithium-ion battery thermal management system design.

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.

Vortex generators for active thermal management in lithium-ion battery systems

The aim of the present study is to determine efficacy of using vortex generators in the cooling channels of a lithium-ion battery thermal management system (BTMS). Numerical simulations of a Li-ion battery module containing 20 prismatic lithium ion cells and associated cooling channels with four different winglet configurations were developed. This study examines the effects of vortex generators on the heat transfer performance of typical battery thermal management solutions. The performance of the BTMS is assessed over a Reynolds number range (65⩽Re⩽1650) based on the hydraulic diameter of a rectangular channel. Specialized software designed for studying heat transfer problems in lithium-ion batteries coupled with computational fluid dynamics was used to determine such effects. The performance of the different vortex generator configurations was compared in terms of the Nusselt number, maximum module temperature, and cell-to-cell temperature variation. The addition of vortex generators to the modeled BTMS has shown a significant increase in overall heat transfer of cooling channel, a decrease in the maximum cell temperature, and a lower temperature difference within the cells.

Surrogate based multidisciplinary design optimization of lithium-ion battery thermal management system in electric vehicles

A battery thermal management system (BTMS) is a complex system that uses various heat removal and temperature control strategies to keep battery packs at optimal thermal conditions, thereby improving the lifetime and safety of lithium-ion battery packs in electric vehicles (EVs). However, an optimal design of BTMS is still challenging, due to its large number of sub-systems and/or disciplines involved. To address this challenge, an air-based BTMS is hierarchically decoupled into four sub-systems and/or sub-disciplines in this paper, including the battery thermodynamics, fluid dynamics, structure, and lifetime model. A high-fidelity computational fluid dynamics (CFD) model is first developed to analyze the effects of key design variables (i.e., heat flux, mass flow rate, and passage spacing size) on the performance of BTMS. Aiming to perform the multidisciplinary design optimization (MDO) of BTMS based on the high-fidelity CFD model, surrogate models are developed using an automatic model selection method, the Concurrent Surrogate Model Selection (COSMOS). The surrogate models represent the BTMS performance metrics (i.e., the pressure difference between air inlet and outlet, the maximum temperature difference among battery cells, and the average temperature of the battery pack) as functions of key design parameters. The objectives are to maximize the battery lifetime and to minimize the battery volume, the fan’s power, and the temperature difference among different cells. The MDO results show that the lifetime of the battery module is significantly improved by reducing the temperature difference and battery volume.

Thermal performance of lithium-ion battery thermal management system by using mini-channel cooling

Thermal management is indispensable to lithium-ion battery pack especially within high power energy storage device and system. To investigate the thermal performance of lithium-ion battery pack, a type of liquid cooling method based on mini-channel cold-plate is used and the three-dimensional numerical model was established in this paper. The effects of number of channels, inlet mass flow rate, flow direction and width of channels on the thermal behaviors of the battery pack were analyzed. The results showed that the mini-channel cold-plate thermal management system provided good cooling efficiency in controlling the battery temperature at 5C discharge. A 5-channel cold-plate was enough and the temperature could be evidently reduced by increasing the inlet mass flow rate. Additionally, for the bad temperature uniformity in the design 1, design 2 was proposed and compared with the design 1. The maximum temperature and temperature difference decreased 13.3% and 43.3%, respectively. Temperature uniformity was significantly improved.

Experimental investigation on performance of lithium-ion battery thermal management system using flat plate loop heat pipe for electric vehicle application

The development of electric vehicle batteries has resulted in very high energy density lithium-ion batteries. However, this growth is accompanied by the risk of thermal runaway, which can cause serious accidents. Heat pipes are heat exchangers that are suitable to be applied in electric vehicle battery thermal management for their lightweight and compact size, and they do not require external power supply. This study examined experimentally a flat plate loop heat pipe (FPLHP) performance as a heat exchanger in the thermal management system of the lithium-ion battery for electric vehicle application. The heat generation of the battery was simulated using a cartridge heater. Stainless steel screen mesh was used as the capillary wick. Distilled water, alcohol, and acetone were used as working fluids with a filling ratio of 60%. It was found that acetone gave the best performance that produces a thermal resistance of 0.22 W/°C with 50 °C evaporator temperature at heat flux load of 1.61 W/cm2.