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In recent years, there has been a growing demand for electrical vehicles, which are more energy efficient and environmentally friendly than their traditional counterpart. One of the crucial aspects of electrical systems is energy storage. A promising option for energy storage is Lithium-ion batteries (LIBs) due to their high energy density, longer life cycles, and faster charging when compared to other batteries. The disadvantage of employing LIBs is that they are more difficult to maintain because they are more prone to failure, and they are greatly dependent on the system's thermal behavior, which has led to an emphasis in research on battery thermal management systems (BTMSs). The BTMS aims to address this issue by limiting the temperature fluctuation of the battery cells to maintain the average temperature within recommended limits throughout the charging and discharging processes. There has been a continuous interest in nanofluids and phase change materials (PCMs) because of their unique properties and their potential thermal application as a cooling medium for high-density batteries. Recent studies have aimed to use different active and passive methods with varying materials and cooling system geometries to achieve the highest possible thermal performance. The current review aims to outline the recent studies on thermal management systems for LIBs. Three main sections have been presented in this paper. The first section reviewed studies on nanofluids in different BTMSs, the other one highlighted techniques adopted to overcome the low thermal conductivity drawback in PCMs for BTMs, and the last one focuses on the effects of combining both cooling approaches. We believe that the present review paper provides useful information that could be a significant step toward developing high-performance BTMS. • A summary of the most recent research on BTMS of LIBs. • Nanofluids and PCM-based BTMS attract significant interest in LIBs. • PCM with carbon additives enhance LIB pack temperature uniformity. • Incorporation of fins has demonstrated effectiveness in improving BTMS performance. • Metal foams with PCMs enhance BTMS performance via improved thermal conductivity. [ABSTRACT FROM AUTHOR]

Abstract The thermal safety of electric vehicle battery packs is attracting more and more attention. A research is conducted on emergency cooling and overheating control in this paper. The research work coupled with the direct cooling battery thermal management system proposes an open-loop emergency thermal safety management method that sprays refrigerant directly into the battery box to achieve emergency cooling, oxygen suppression, cutting off heat and combustion once the thermal runaway is about to occur. Three typical spray modes, which are continuous spray, fixed-interval intermittent spray, and non-fixed-interval intermittent spray, are analyzed respectively. Studies indicate that the refrigerant spray cooling has an obvious cooling effect, oxygen suppression performance on the high temperature overheating battery. Among them, continuous spray shows a better cooling capacity, but the oxygen suppression performance is inferior to intermittent spray. Intermittent sprays with various spray states have different degrees of influence on cooling, uniformity, and oxygen suppression performance, but a single spray pattern does not optimize the effects upon all aspects. Additionally, vent position also plays an important role in cooling and oxygen suppression characteristics. Therefore, overheating battery emergency refrigerant spray cooling has important reference significance for the design of battery package and thermal safety management system. Highlights • A novel thermal safety management method is developed for the power battery. • The focus of this method is open-loop emergency refrigerant spray cooling. • The proposed system has a strong capacity for cooling and oxygen suppression. • Continuous and intermittent spray modes are compared and studied. • Reasonable vent position contributes to improving the safety of the battery pack. [ABSTRACT FROM AUTHOR]

Battery thermal barriers are reviewed with regards to extreme fast charging. Present-day thermal management systems for battery electric vehicles are inadequate in limiting the maximum temperature rise of the battery during extreme fast charging. If the battery thermal management system is not designed correctly, the temperature of the cells could reach abuse temperatures and potentially send the cells into thermal runaway. Furthermore, the cell and battery interconnect design needs to be improved to meet the lifetime expectations of the consumer. Each of these aspects is explored and addressed as well as outlining where the heat is generated in a cell, the efficiencies of power and energy cells, and what type of battery thermal management solutions are available in today's market. Thermal management is not a limiting condition with regard to extreme fast charging, but many factors need to be addressed especially for future high specific energy density cells to meet U.S. Department of Energy cost and volume goals. [ABSTRACT FROM AUTHOR]

Conventional cooling approaches that target either a singular tab or outer surface of common format cylindrical lithium-ion battery cells suffer from a high cell thermal resistance. Under an aggressive duty cycle, this resistance can result in the formation of large in-cell temperature gradients and high hot spot temperatures, which are known to accelerate ageing and further reduce performance. In this paper, a novel approach to internal thermal management of cylindrical battery cells to lower the thermal resistance for heat transport through the inside of the cell is investigated. The effectiveness of the proposed method is analysed for two common cylindrical formats when subject to highly aggressive electrical loading conditions representative of a high performance electric vehicle (EV) and hybrid electric vehicle (HEV). A mathematical model that captures the dominant thermal properties of the cylindrical cell is created and validated using experimental data. Results from the extensive simulation study indicate that the internal cooling strategy can reduce the cell thermal resistance by up to 67.8 ± 1.4% relative to single tab cooling, and can emulate the performance of a more complex pack-level double tab cooling approach whilst targeting cooling at a single tab. [ABSTRACT FROM AUTHOR]

Phase change material as the core of latent heat energy storage technology, suffers from the "solid-liquid phase change" problem. In this study, "solid-solid" composite phase change materials (CPCMs) have been developed using olefin block copolymers (OBC) and decanoic acid. With ≥30 wt% OBC, the physical shapes of the developed CPCMs nearly remain unchanged after 100 times of thermal cycling, without significant changes in the phase change properties. The addition of graphite powder leads to a significant enhancement in thermal conductivity of up to 18 times, which leads to excellent control of battery maximum temperature and temperature uniformity. In the battery thermal management test, the developed CPCM achieves a maximum of 3 °C and 10.5 °C reductions in maximum temperature difference and peak temperature, respectively. The CPCMs also prolong the thermal preservation time by 3 times. In the pack level test, the use of CPCM plates leads to a maximum temperature reduction of 15 °C on the commercial battery pack under 55 °C extreme working temperature. • CPCMs retain their shape and properties after 100 times of thermal cycling. • The thermal conductivity of the CPCMs were improved by up to 8 times. • 10.5 °C of peak temperature reduction was achieved with the CPCM. • The developed CPCMs prolonged the thermal preservation time by ∼3 times. [ABSTRACT FROM AUTHOR]

The exposure of electric vehicle batteries to rapid charging and discharging profiles, particularly under uncertainty in the drive schedules, requires effective strategies to forecast and avoid thermal excursions during operation. In this work, we present a light gradient boosting-based machine learning model to create probabilistic forecasts of the discharge current over a forecast horizon in real time. A surrogate of a physics-based computational model provides the functional relationship for the battery temperature, using which a stochastic model-predictive control strategy is developed to derive the optimal cooling schedule based on the probabilistic forecast. The effectiveness of the stochastic model-predictive control approach is assessed on the US06 driving cycle, in comparison to a constant coolant flow and persistence forecast-based control. It is shown that the total number of temperature excursion instances using the stochastic model-predictive control is reduced by about 69% compared to the constant coolant flow case and by over 51% compared to persistence-forecast-based control. Further, the total coolant usage is reduced by about 73% compared to persistence forecast-based control. The stochastic model-predictive control approach provides more flexibility by allowing a wider range of control and battery pack design parameters to obtain optimal performance with minimum coolant use. • Presents model-predictive thermal control of LIBs under drive cycle uncertainty. • Probabilistic forecast of discharge current obtained using machine learning model. • Uses physics-based computational model to derive optimal cooling schedule. • Stochastic model-predictive control approach is assessed on US06 drive cycle. • Reduces temperature excursion instances by ∼ 69% and coolant usage by ∼ 73%. [ABSTRACT FROM AUTHOR]

This paper provides a methodology to assess the average surface temperature of battery cells under realistic transient scenarios. Computational fluid dynamics modelling of battery cooling is conducted for the cases exposed to the ramps of internal heat generation inferred from the standard driving cycles. The results are then post-processed to determine the effectiveness of air and water as the coolant fluids. A quantitative measure of the maximum overshoot, dimensionless settling (DST), heating (DHT), and cooling (DCT) time is subsequently presented. It is shown that, compared to water, air produces a considerably delayed response to temporal changes in the internal heat generation and is slower at reaching the new steady state condition. Cooling battery cells by using water almost always ensures remaining within the safe operating range. Nonetheless, regardless of the coolant type, the long period ramps tend to produce smaller values of DST. The primary origin of the delay is the slow heat conduction within the battery cells. In addition, it is shown that water responds to changes in the internal heat generation far quicker during the heating and the cooling phases. The study highlights the importance of transient analyses for characterising the thermal behaviour of battery packs. • A novel measure of battery heat release due to internal heat generation is presented. • Transient cases with sharp gradients cause large delays in system response. • Air cases always produce an overshoot and are far slower at reaching steady state. • Battery cells remain within the safe operating range in almost all water cases. • Water cases react far quicker to changes in the internal heat generation. [ABSTRACT FROM AUTHOR]

Lithium-ion (Li-ion) battery cooling using a phase change material (PCM)/compressed expanded natural graphite (CENG) composite is investigated, for a cylindrical battery cell and for a battery module scale. An electrochemistry model (average model) is coupled to the thermal model, with the addition of a one-dimensional model for the solution and solid diffusion using the nodal network method. The analysis of the temperature distribution of the battery module scale has shown that a two-dimensional model is sufficient to describe the transient temperature rise. In consequence, a two-dimensional cell-centred finite volume code for unstructured meshes is developed with additions of the electrochemistry and phase change. This two-dimensional thermal model is used to investigate a new and usual battery module configurations cooled by PCM/CENG at different discharge rates. The comparison of both configurations with a constant source term and heat generation based on the electrochemistry model showed the superiority of the new design. In this study, comparisons between the predictions from different analytical and computational tools as well as open-source packages were carried out, and close agreements have been observed. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are extremely sensitive to their temperature and therefore, require a battery thermal management system (BTMS). BTMS is commonly employed to prevent thermal runaway of the LIB pack by controlling their operating temperature. This review paper provides various cooling strategies, including active and passive approaches, utilized in BTMSs. Air-cooled, liquid-based, and PCM-cooled techniques are first reviewed. This article presents an assessment of the application of nanofluids and nano-phase change materials (nano-PCMs) in BTMSs to improve heat dissipation from the LIB pack. This work emphasizes the utilization of these materials to intensify their thermal conductivity and suggests further investigations on their application in BTMSs. • Lithium-ion batteries are extremely sensitive to their temperature. • BTMS is employed to prevent battery thermal runaway by controlling its temperature. • Providing various cooling strategies for BTMS: active and passive approaches. • Presenting an assessment of the application of nanofluids and nano-PCMs) in BTMSs. [ABSTRACT FROM AUTHOR]

The thermal management of a cylindrical battery cell by a phase change material (PCM)/compressed expanded natural graphite (CENG) is investigated in this study. The transient thermal behaviour of both the battery and the PCM/CENG is described with a simplified one-dimensional model taking into account the physical and phase change properties of the PCM/CENG composite. The 1D analytical/computational model yielded nearly identical results to the three-dimensional simulation results for various cooling strategies. Therefore, the 1D model is sufficient to describe the transient behaviour of the battery cooled by a PCM/CENG composite. Moreover, the maximum temperature reached by the PCM/CENG cooling strategy is much lower than that by the forced convection in the same configuration. In the test case studied, the PCM showed superior transient characteristics to forced convection cooling. The PCM cooling is able to maintain a lower maximum temperature during the melting process and to extend the transient time for temperature rise. Furthermore, the graphite-matrix bulk density is identified as an important parameter for optimising the PCM/CENG cooling strategy. [ABSTRACT FROM AUTHOR]

Abstract: Battery electric vehicles (BEVs) offer the potential to reduce both oil imports and greenhouse gas emissions, but have a limited utility that is affected by driver aggression and effects of climate—both directly on battery temperature and indirectly through the loads of cabin and battery thermal management systems. Utility is further affected as the battery wears through life in response to travel patterns, climate, and other factors. In this paper we apply the National Renewable Energy Laboratory's Battery Lifetime Analysis and Simulation Tool for Vehicles (BLAST-V) to examine the sensitivity of BEV utility to driver aggression and climate effects over the life of the vehicle. We find the primary challenge to cold-climate BEV operation to be inefficient cabin heating systems, and to hot-climate BEV operation to be high peak on-road battery temperatures and excessive battery degradation. Active cooling systems appear necessary to manage peak battery temperatures of aggressive, hot-climate drivers, which can then be employed to maximize thru-life vehicle utility. [Copyright &y& Elsevier]

A simplified one-dimensional transient computational model of a prismatic lithium-ion battery cell is developed using thermal circuit approach in conjunction with the thermal model of the heat pipe. The proposed model is compared to an analytical solution based on variable separation as well as three-dimensional (3D) computational fluid dynamics (CFD) simulations. The three approaches, i.e. the 1D computational model, analytical solution, and 3D CFD simulations, yielded nearly identical results for the thermal behaviours. Therefore the 1D model is considered to be sufficient to predict the temperature distribution of lithium-ion battery thermal management using heat pipes. Moreover, a maximum temperature of 27.6 °C was predicted for the design of the heat pipe setup in a distributed configuration, while a maximum temperature of 51.5 °C was predicted when forced convection was applied to the same configuration. The higher surface contact of the heat pipes allows a better cooling management compared to forced convection cooling. Accordingly, heat pipes can be used to achieve effective thermal management of a battery pack with confined surface areas. [ABSTRACT FROM AUTHOR]

Abstract: Many portable devices such as soldier carrying devices are powered by low-weight but high-capacity lithium ion (Li-ion) batteries. An effective battery thermal management (BTM) system is required to keep the batteries operating within a desirable temperature range with minimal variations, and thus to guarantee their high efficiency, long lifetime and great safety. However, the rigorous constraints imposed by the budgets in weight and volume for this specific application eliminate the possible consideration of many existing classical cooling approaches and make the development of BTM system very challenging in this field. In this paper, a flexible hydrogel-based BTM system is developed to address this challenge. The proposed BTM system is based on cost-effective sodium polyacrylate and can be arbitrarily shaped and conveniently packed to accommodate any Li-ion stacks. This BTM system is tested through a series of high-intensity discharge and abnormal heat release processes, and its performance is compared with three classical BTM systems. The test results demonstrate that the proposed low-cost, space-saving, and contour-adaptable BTM system is a very economic and efficient approach in handling the thermal surge of Li-ion batteries. [Copyright &y& Elsevier]

Abstract: A novel distributed transient thermal model is proposed to investigate the thermal behavior of nickel–metal hydride (NiMH) batteries under fast-charging processes at constant currents. Based on the method of integral transformation, a series-form solution for the temperature field inside the battery core is obtained that takes account for orthotropic heat conduction, transient heat generation, and convective heat dissipation at surfaces of the battery. The accuracy of the developed theoretical model is confirmed through comparisons with numerical and experimental data for a sample 30 ampere-hour NiMH battery. The comparisons show that even the first term of the series solution fairly predicts the temperature field with the modest numerical cost. The thermal model is also employed to define an efficiency for charging processes. Our calculations confirm that the charging efficiency decreases as the charging current increases. [Copyright &y& Elsevier]

Abstract: A three-dimensional analytical model is proposed to investigate the thermal response of batteries, with a plurality of thin electrodes, to heat generation during their operation. The model is based on integral-transform technique that gives a closed-form solution for the fundamental problem of unsteady heat conduction in batteries with orthotropic thermal conductivities, where the heat generation is a function of both temperature and depth-of-discharge. The full-field solutions take the form of a rapidly converging triple infinite sum whose leading terms provide a very simple yet accurate approximation of the battery thermal behavior with modest numerical effort. The accuracy of the proposed model is tested through comparison with numerical simulations. The method is used to describe spatial and temporal temperature evolution in a sample pouch type lithium-ion polymer battery during galvanostatic discharge processes while subjected to convective–radiative cooling at its surfaces (the most practical case is considered, when surrounding medium is at a constant ambient temperature). In the simulations, emphasis is placed on the maintenance of the battery operational temperature below a critical temperature. Through definition of a surface-averaged Biot number, certain conditions are highlighted, under which a two-dimensional thermal analysis is applicable. [Copyright &y& Elsevier]

Abstract: This work studied the thermal management of lithium ion batteries both numerically and experimentally. Numerically, a two dimensional CFD (computational fluid dynamics) model has been developed to perform detailed simulations of the thermal management issues within a battery pack cooled by air. Experimentally, systematic tests were performed to provide datasets to validate the CFD model. The main components in the experimental facility included a multi-cell battery pack and a wind tunnel. The wind tunnel facility generated well-controlled cooling air flow with velocity up to 30 m s−1 (∼67 miles per hour). So that the study can be performed under flow conditions directly relevant to practice. The major contributions from this combined numerical-experimental study are threefold. First, the CFD model has been shown to capture the dynamics of the cooling of battery modules consisting of multiple battery cells, including temperature non-uniformity among cells. Second, the CFD simulations have been compared directly against experimental data to quantify the accuracy and validity of the CFD models. Third, based on the validated CFD models, a reduced-order model is developed to predict the maximum cell temperature in the battery module. The accuracy and simplicity of the reduced-order model makes it promising for in situ monitoring and control purposes. [Copyright &y& Elsevier]

Abstract: Time-dependent, thermal behaviour of a lithium-ion (Li-ion) polymer cell has been modelled for electric vehicle (EV) drive cycles with a view to developing an effective battery thermal management system. The fully coupled, three-dimensional transient electro-thermal model has been implemented based on a finite volume method. To support the numerical study, a high energy density Li-ion polymer pouch cell was tested in a climatic chamber for electric load cycles consisting of various charge and discharge rates, and a good agreement was found between the model predictions and the experimental data. The cell-level thermal behaviour under stressful conditions such as high power draw and high ambient temperature was predicted with the model. A significant temperature increase was observed in the stressful condition, corresponding to a repeated acceleration and deceleration, indicating that an effective battery thermal management system would be required to maintain the optimal cell performance and also to achieve a full battery lifesapn. [Copyright &y& Elsevier]

The optimal performance of a Li-ion battery is directly impacted by temperature. In order to control the temperature rise and provide even temperature distributions in the battery pack, a thermal management scheme comprises thin heat sinks with multiple phase change materials (PCMs) and air channels is investigated in this paper. The cooling performance and temperature homogenization of the battery thermal management (BTM) system are carefully studied under various configurations of PCMs. The results show that increasing the air inlet velocity has less effect in suppressing the temperature rise at early discharge stage, but ameliorates as the discharge prolonged to 3600 s. The standard deviation of the temperature (STDV) and maximum temperature of the batteries can be decreased by arranging PCMs with a lower melting temperature at the midsection and a higher melting temperature at the air outlet region of the heat sinks. In addition, for volume fraction of PCMs, Case IV, having a PCM with a higher melting point adjacent to the air outlet region and occupying one-half the height of the heat sink, illustrates a lower temperature rise and decreases the maximum temperature in the battery module by 1.024 K, 2.186 K, and 2.553 K, compared to Case I, II, and III, respectively. • Multiple PCMs incorporated thin heat sinks for battery thermal management is proposed. • The thermal performance of the battery based on maximum temperature upsurge is investigated. • The distributions of PCMs based on melting point and latent heat were carefully explored. • The optimal design for the distribution of PCMs is obtained for the proposed battery. [ABSTRACT FROM AUTHOR]

This paper summarizes battery thermal modeling capabilities for: (1) an advanced vehicle simulator (ADVISOR); and (2) battery module and pack thermal design. The National Renewable Energy Laboratory’s (NREL’s) ADVISOR is developed in the Matlab/Simulink environment. There are several battery models in ADVISOR for various chemistry types. Each one of these models requires a thermal model to predict the temperature change that could affect battery performance parameters, such as resistance, capacity and state of charges. A lumped capacitance battery thermal model in the Matlab/Simulink environment was developed that included the ADVISOR battery performance models. For thermal evaluation and design of battery modules and packs, NREL has been using various computer aided engineering tools including commercial finite element analysis software. This paper will discuss the thermal ADVISOR battery model and its results, along with the results of finite element modeling that were presented at the workshop on “Development of Advanced Battery Engineering Models” in August 2001. [Copyright &y& Elsevier]

In this paper, the coupling system of liquid-cooled battery thermal management system (BTMS) and heat pump air conditioning system (HPACS) for battery electric vehicles (BEV) is designed and analyzed. The performances of liquid-cooled BTMS are concerned and analyzed from the perspective of air conditioning based experimental data. Besides, an automatic calibration model of the liquid-cooled BTMS based HPACS is established to predict cooling capacity and system coefficient of performance (COP) of the BTMS by support vector regression (SVR). To better obtain three hyper parameters (the penalty coefficient C , the RBF kernel function parameter γ , and the insensitive loss coefficient ε) of SVR model, particle swarm optimization (PSO) algorithm is introduced to optimize above three parameters. It is found that compared to SVR model, the correlation coefficient (R) of cooling capacity and system COP for the proposed PSO-SVR model in this paper is improved 2.1% and 2.8% respectively, the mean squared error (MSE) of and cooling capacity and system COP is reduced 87.8% and 82.9% respectively, which indicated that PSO-SVR model can be used as a new method to fit the complex nonlinear relationship among the system COP, cooling capacity and other influencing factors of the liquid-cooled BTMS based HPACS. • Comprehensive analysis from the perspective of air conditioning system. • Automatic calibration model for battery thermal management system. • The battery thermal performance estimation based on the SVR model. • SVR model with RBF kernel exhibits better generalization ability. [ABSTRACT FROM AUTHOR]

Air-cooled battery thermal management system (BTMS) is universally adopted in electric vehicles for temperature control of battery packs. In the present study, we develop an efficient transient model for accurately predicting the battery cell temperature in different types of parallel air-cooled BTMSs. A flow resistance network model for BTMS with I-type flow is established according to law of momentum conservation. Based on energy equations, a transient heat transfer model is derived to calculate the temperature distribution of battery pack in the BTMSs. The model results are in good agreement with experimental data, verifying the effectiveness and efficiency of this model. The deviations of T max and Δ T max between the models and experiment are less than 1.5 K. Furthermore, by using the developed transient models, the deviations of T max and Δ T max respectively decrease by 70% and 26%, in comparison with previous study. Finally, based on the developed models, the widths of parallel channels and divergence/convergence ducts in the BTMSs are designed, leading to remarkably enhanced cooling performance. The present study provides an efficient transient heat transfer model for parallel cooling systems, which can provide a deeper insight into the system performance and be applied to structural optimization of the systems. • A flow resistance network model for BTMS with I-type flow is developed.. • A transient heat transfer model for parallel BTMSs is derived mathematically. • Experiments are conducted to verify the developed transient heat transfer model. • The optimized BTMSs based on the developed models achieve good performance. [ABSTRACT FROM AUTHOR]

The temperature control technology based on phase change material (PCM) demonstrates excellent performance in the field of battery thermal management. However, the compact and bulky structure of the traditional composite PCM (CPCM) module reduces the energy density of the battery pack greatly, and is unfavorable to the secondary heat dissipation. In this work, we develop a novel PCM cooling structure by substituting the common block-shaped CPCM (B-CPCM) module with serpentine CPCM (S-CPCM) plates. The S-CPCM plates with high shape stability provide a much larger surface area and many air flow channels in comparison to the B-CPCM module, thus endowing the module with outstanding secondary heat dissipation capability. For example, under the same fan power of forced air convection (5.2 W), the S-CPCM module delivers a much lower maximum temperature than the B-CPCM module (51.9 vs. 54.2 °C) during the repeated charge-discharge process. As highlighted here, on the basis of guaranteeing the cooling performance, the S-CPCM cooling structure also saves ~70% of the CPCM amount, and thereby the energy density of the battery module is increased by 13.8 Wh kg−1. Image 1 • Novel serpentine composite phase change material (S-CPCM) plates are designed. • The S-CPCM cooling structure saves 70% of the CPCM amount in the battery module. • The energy density of the module with S-CPCM cooling is increased by 13.8 Wh kg−1 • S-CPCM plates provide air flow channels and large surface area for heat dissipation. • The S-CPCM cooling structure shows much enhanced heat dissipation performance. [ABSTRACT FROM AUTHOR]

Battery modeling and state estimation are critical to the battery safety and vehicle driving range. Currently, electrochemical mechanism based models require huge computation effort for solving partial differential equations, equivalent circuit models do not consider actual battery mechanism, while machine learning models are lack of generalization ability due to their data-driven nature. All these problems bring the challenges to guarantee the model effectiveness in wide temperature and large current conditions. To estimate the battery state of charge (SOC) and state of temperature (SOT) under these conditions, an electrochemical-thermal-neural-network (ETNN) model is formulated in this paper. Specifically, a simplified single particle model and a lumped thermal model are served as the sub-models of ETNN to predict core temperature and provide approximate terminal voltage. Then a neural network is incorporated to enhance the performance of sub-models. According to the extensive experiments, ETNN model is able to accurately estimate battery voltage and core temperature under the ambient temperatures of -10–40 °C and the discharge rate of 10-C. After that, an unscented Kalman filter (UKF) is integrated with ETNN to achieve reliable co-estimation of SOC-SOT. Experimental results illustrate that proposed ETNN-UKF can rapidly eliminate initial errors and provide satisfactory co-estimation performance. • Formulation of a hybrid battery electrochemical-thermal-neural-network model. • High model accuracy under large currents and wide range of ambient temperatures. • Accurate co-estimation of SOC and SOT by integrating the unscented Kalman filter. [ABSTRACT FROM AUTHOR]

The effect of vibration on a passive battery thermal management (BTM) system is investigated. The BTM system includes phase change material (PCM) in an enclosure hosting a battery pack. Rubitherm® 35HC PCM is used in the current investigation with a goal to maintain the battery temperature within the range of 25 °C to 40 °C. The simulated batteries are made of aluminum cylinders containing ceramic cartridge heaters at their cores, which mimic 2300 mAh 18650 Lithium-ion batteries. A series of experimental tests have been carried out to study the transient thermal field behaviour of the battery pack under various discharge rates (i.e., 1C–5C). The ranges of applied frequency and amplitude during the experiments are 20–30 Hz and 30 mm/s to 50 mm/s, respectively, which are typically observed in plug-in hybrid electric vehicles (PHEV) on the road during normal operation. The temperature at the battery surface shows an increasing trend with increasing frequency and amplitude of vibration. However, the transient temperature variation pattern of batteries in the centre of the battery pack is slightly different than the batteries in the corners. • Effect of vibration on PCM based battery thermal management system was investigated. • Temperature profiles under vibration was characterized by four distinct regimes. • Battery surface temperature increases with increasing vibration frequencies. • Battery surface temperature increases with increasing discharge rates. [ABSTRACT FROM AUTHOR]