Search

Electric Vehicles (EVs) have emerged as a viable and environmentally sustainable alternative to traditional internal combustion vehicles by utilizing a clean energy source. The advancement and expansion of electric cars rely on the progress of electrochemical batteries. The utilization of Lithium-Ion Batteries is widespread primarily because of its notable energy density. Changes influence the performance of these batteries in temperature. The Thermal Management System of the battery is one of the very important systems in EVs to improve the performance and life of the battery. The geometrical spacing of the cell modules is considered identical for a more accurate comparison of temperature distribution. For better cooling and heat dissipation, the battery pack's two sides are kept entirely open to facilitate the inflow of air. In this work, active BTMS solutions are selected and analyzed using the development of three-dimensional free, open-source OpenFOAM computational fluid dynamics simulations for accurate thermal modeling and hotspot zones in cylindrical battery packs. The outcome of the simulations is compared using parameters like temperature distribution in battery cells, battery modules, and heat generation. Among all the cell temperature zones, the temperature maximum is near the sixth cell of the module depth. OpenFOAM results validated with the existing literature's experimental and Ansys results. Air cooling is utilized for cooling performance because of its relatively simple structure and lightweight. [ABSTRACT FROM AUTHOR]

Existing cooling strategies have shown reasonable performance enhancement in the design of air-cooled battery thermal management systems (BTMSs). However, some of these strategies are accompanied with drawbacks such as increase in pressure drop, poor flow uniformity and poor thermal homogeneity. This study adopts hybrid cooling strategy (HCS), through combination of existing air-cooling strategies to investigate the performance of Z–Type BTMSs. Computational Fluid Dynamics (CFD) method was used to evaluate the performance of the HCSs. The method was validated by comparing Z–Type BTMS numerical simulation results with experimental result from literature. Findings from the study revealed that each strategy provides distinct maximum temperature ( T max ), maximum temperature difference ( Δ T max ), pressure drop ( Δ P ) and pumping power ( P p ) performances for the same operational parameters. For designs with single enhancement, step-like design produced best thermal performance with T max = 331.16 K and P p = 0.0841 W . A design with combination of two strategies, also produced reduction in T max and Δ T max by 4.25 K and 8.66 K, respectively, with 2.34 Pa increase in Δ P , when compared with the Z–Type BTMS. Another design with single strategy produced reduction in T max and Δ T max by 4.42 K and 8.01 K, respectively with 3.52 Pa increase in Δ P when compared with the same Z–Type BTMS. This performance shows 3.85% increase in T max and with 33.5% reduction in Δ P . Several other designs also exhibited similar performance trend. Hence, this study concludes that adopting hybridization of air-cooled technique in BTMS is a promising technique with wide potential unexplored.Article Highlights: Two existing air-cooling strategies were combined and their performance investigated. Three existing air-cooling strategies were combined and their performance investigated. Battery temperature of single air-cooled strategies BTMS improved by hybrid strategy. Pressure drop can be minimized through hybrid cooling strategy. [ABSTRACT FROM AUTHOR]

Background: Pre‐eclampsia is a severe pregnancy complication affecting about 4%–5% of pregnancies, but the causes and clinical management were full of controversial. Bone turnover markers (BTMs) were sensitive indicators for estimating bone metabolism and were found to be changed in many pregnancy‐related diseases. However, the characteristic and prognostic value of serum BTMs with pre‐eclampsia was uncovered. Methods: A multicenter prospective cohort study was performed in three different hospitals in West China. Pre‐eclampsia patients and healthy pregnant women were recruited from January 2023 to January 2024. Clinical information of included participants was collected, and serum BTM levels were detected by electrochemiluminescence immunoassay. Clinical outcomes including disease aggravation (severe pre‐eclampsia, eclampsia, and HELLP syndrome), low live birth weight (LBW), and premature delivery were followed up. Results: A total of 69 pre‐eclampsia patients and 75 healthy pregnant women were recruited finally, and 48 pre‐eclampsia patients and 48 healthy controls who matched for age and gestational weeks were selected among them. The pre‐eclampsia patients had elevated BTM levels compared with healthy controls. ß‐CTX was an independent risk factor for disease aggravation, LBW, and premature delivery among pre‐eclampsia patients. ß‐CTX was a valuable predictive factor for disease aggravation, LBW, and premature delivery among pre‐eclampsia patients (AUC were 0.772, 0.768, and 0.930, respectively, and p values were 0.001, 0.002, and < 0.001, respectively). Conclusion: Pre‐eclampsia patients may have an activated bone metabolism status compared with healthy controls. Pre‐eclampsia patients with elevated bone resorptive marker ß‐CTX should pay more attention to the risk of disease aggravation and adverse pregnancy outcomes. [ABSTRACT FROM AUTHOR]

This study delves into the computational exploration of the impact of magnetic intensity, magnetic nanofluid, flow rates and heat transfer coefficient in the form of Nusselt number on inclined ribbed channels with both parallel and staggered configurations for the cooling of sodium-ion and lithium-ion batteries in electric vehicles. Employing Fe3O4 + H2O as the working fluid, within a minichannel with multiple magnets at different locations, namely 15 mm, 25 mm and 15 mm and 25 mm, the parallel and staggered inclined ribbed channel Nusselt number (Nu) increased with magnetic field intensity, reaching maximum of 152.81% for staggered ribbed minichannel configuration at 2000 Gauss (G). Similarly, the skin friction experienced an increment with magnetic field intensity for staggered ribbed minichannel configuration and for parallel ribbed minichannel when both the magnets were placed at the location of 15 mm and 25 mm from the inlet but decreased with increasing Reynolds number. Notably, the thermal enhancement factor (TEF) consistently surpassed greater than unity for all investigated cases. These findings carry significant implications, particularly in EV cooling, offering valuable insights for developing more efficient and tailored cooling solutions for advanced EV battery thermal management. [ABSTRACT FROM AUTHOR]

The modern world is moving towards electric vehicles (EV) due to the increment in greenhouse gas (GHG) emissions, global warming, and the lack of fossil fuels. EVs can overcome these issues by using batteries instead of fuel. But increasing and maintaining the batteries is a major challenge in EVs because of the large heat emissions from the batteries. In order to overcome these issues and increase the performance of the batteries, a heat pipe (HP) is attached to the passive cooling system. This study aims to improve the performance of batteries and the thermal conductivity of HP with a combination of refrigerant and nanofluid (nanorefrigerant) as working fluids. Copper HP with R-134a or SWCNT is selected for this study. The thermal resistance and thermal conductivity of HP with R-134a and SWCNT were observed for several heat conditions. From the study, it was well observed that changing the working fluid inside the HP affects the thermal performance and the cooling capacity of batteries. Fixing an HP to a battery would decrease the battery's temperature effectively. Furthermore, increasing the heat power in an evaporator section decreases the thermal resistance and enhances thermal conductivity with the shortest time limit because of Brownian motion. [ABSTRACT FROM AUTHOR]

Abstract Existing cooling strategies have shown reasonable performance enhancement in the design of air-cooled battery thermal management systems (BTMSs). However, some of these strategies are accompanied with drawbacks such as increase in pressure drop, poor flow uniformity and poor thermal homogeneity. This study adopts hybrid cooling strategy (HCS), through combination of existing air-cooling strategies to investigate the performance of Z–Type BTMSs. Computational Fluid Dynamics (CFD) method was used to evaluate the performance of the HCSs. The method was validated by comparing Z–Type BTMS numerical simulation results with experimental result from literature. Findings from the study revealed that each strategy provides distinct maximum temperature ( $${T}_{max}$$ T max ), maximum temperature difference ( $${\Delta T}_{max}$$ Δ T max ), pressure drop ( $$\Delta P$$ Δ P ) and pumping power ( $${P}_{p}$$ P p ) performances for the same operational parameters. For designs with single enhancement, step-like design produced best thermal performance with $${T}_{max}=331.16 K$$ T max = 331.16 K and $${P}_{p}=0.0841 W$$ P p = 0.0841 W . A design with combination of two strategies, also produced reduction in $${T}_{max}$$ T max and $$\Delta {T}_{max}$$ Δ T max by 4.25 K and 8.66 K, respectively, with 2.34 Pa increase in $$\Delta P$$ Δ P , when compared with the Z–Type BTMS. Another design with single strategy produced reduction in $${T}_{max}$$ T max and $$\Delta {T}_{max}$$ Δ T max by 4.42 K and 8.01 K, respectively with 3.52 Pa increase in $$\Delta P$$ Δ P when compared with the same Z–Type BTMS. This performance shows 3.85% increase in $${T}_{max}$$ T max and with 33.5% reduction in $$\Delta P$$ Δ P . Several other designs also exhibited similar performance trend. Hence, this study concludes that adopting hybridization of air-cooled technique in BTMS is a promising technique with wide potential unexplored.

Objective: To evaluate the correlation between the triglyceride-glucose (TyG) index and bone turnover markers (BTMs) in osteoporotic fractures (OPFs) patients hospitalized for surgical intervention. Methods: A retrospective cross-sectional study was conducted on 3558 OPFs patients hospitalized for surgical intervention between January 2017 and July 2022. The study obtained baseline values for various biomarkers and covariates, including fasting blood glucose, b-C-terminal telopeptide of type I collagen (bCTX), procollagen type 1 N-terminal propeptide (P1NP), triglycerides, age, sex, body mass index, smoking, drinking, low-density lipoprotein, high-density lipoprotein, aspartate aminotransferase, uric acid, the score of American society of anesthesiologists, homocysteine, parathyroid hormone, apolipoprotein B, apolipoprotein A, magnesium, phosphorus and calcium. Multiple linear regression, curve fitting, threshold effects, and subgroup analyses were also applied. Results: After adjusting for covariates in the regression analysis, the results revealed a negative correlation between b-CTX and P1NP levels and the baseline TyG index. Specifically, a one-unit increase in the TyG index was associated with a reduction in b-CTX levels of -0.06 (95% CI: -0.10, -0.01; Pvalue = 0.012) and a reduction in P1NP levels of -4.70 (95% CI: -9.30, -0.09; Pvalue = 0.046). Additionally, the inflection points for the nonlinear correlation between the TyG index and b-CTX and P1NP were found to be K = 6.31 and K = 6.63, respectively. Conclusion: The study demonstrated a negative, non-linear relationship among the TyG index, b-CTX and P1NP in OPFs patients hospitalized for surgical intervention. These findings suggest that elevated TyG index levels may adversely affect bone turnover, potentially contributing to the progression of OP. [ABSTRACT FROM AUTHOR]

In recent years, large power batteries have been widely used not only in automobiles and other vehicles but also in maritime vessels. The thermal uniformity of large marine battery packs significantly affects the performance, safety, and longevity of the electric ship. As a result, the thermal management of large power batteries has become a crucial technical challenge with traditional battery management system (BMS) that cannot effectively solve the battery heating problem caused by electrochemical reactions and joule heating during operation. To address this gap, a battery thermal management system (BTMS) has been newly designed. This article presents the design of a large marine battery pack, which features a liquid cooling system integrated into both the bottom and side plates of each pack. The flow plate is constructed from five independent units, each connected by manifold structures at both ends. These connections ensure the formation of a stable and cohesive flow plate assembly. Although research on the BTMS is relatively advanced, there is a notable lack of studies examining the effects of liquid temperature, flow rate, and battery discharge rate on the temperature consistency and uniformity of large marine battery packs. This work seeks to design the cooling system for the battery pack and analyzes the impact of the temperature, flow rate, and battery discharge rate of the liquid fluid on the consistency and uniformity of the battery pack temperature on the overall structure of the battery pack. It was found that, in low discharge conditions, there was good temperature consistency between the battery packs and between the different batteries within the battery pack, and the temperature difference did not exceed 1 °C. However, under high discharge rates, a C-rate of 4C, there might have been a decrease in temperature consistency; the temperature rise rate even exceeded 50% compared to when the discharge rate was low. The flow rate in the liquid flow characteristics had little effect on the temperature consistency between the batteries and the temperature uniformity on the battery surface, and the temperature fluctuation was maintained within 1 °C. Conversely, the liquid flow temperature had little effect on the temperature distribution between the batteries, but it caused discrepancies in the surface temperature of the batteries. In addition, the liquid flow temperature could cause the overall temperature of the battery to increase or decrease, which also occurs under different discharge rates. [ABSTRACT FROM AUTHOR]

This study leverage numerical simulation (NS) and artificial neural network (ANN) capabilities to carry out additional investigations on step-like plenum battery thermal management system (BTMS). Different cooling strategies have been developed over the years in BTMSs’ design. Yet, air-cooling strategies still remains relevant, especially in battery-powered aircrafts, where light-weight is important and air is the preferred cooling fluid. Hence, additional study become necessary especially on the step-like plenum design to provide more insight on the performance of the design by considering several number of step, varied air inlet temperature and velocity. Computational fluid dynamics (CFD) approach was employed to obtained results for different number of step; Ns = 1, 3, 4, 7, 9, 15 and 19, varied air inlet temperature; Ti = 278, 298 and 318 K, and varied air inlet velocity; Vi = 3, 3.5, 4, 5 and 6 m/s. Artificial Neural Network (ANN) approach was then employed to predict the BTMSs’ performance for additional values of Ti and Vi. Minimum temperature (Tmin), maximum temperature (Tmax), maximum temperature difference (ΔTmax) and pressure drop (ΔP) were computed. By comparing the CFD results with the result predicted by the ANN, the percentage difference, for the entire dataset were 0.01 %, 0.005 %, 1 % and 0.14 % for Tmax, Tmin ΔTmax and ΔP, respectively. Based on the optimum design parameters predicted using ANN, for Tmax = 299.24 comprises Ns = 4, Vi = 6 m/s and Ti = 278 K, while for ΔP, comprises Ns = 1, Vi = 3 m/s and Ti = 318 K.

Abstract Introduction This study examines bone turnover marker (BTM) variations between bone marrow and peripheral blood in osteoporotic and non-osteoporotic patients. BTMs offer insights into bone remodeling, crucial for understanding osteoporosis. Methods A total of 133 patients were categorized into osteoporotic and non-osteoporotic cohorts. BTMs—C-telopeptide cross-linked type 1 collagen (β-CTX), serum osteocalcin (OC), Procollagen type I N-propeptide (P1NP), 25(OH)D—were measured in bone marrow and peripheral blood. Lumbar spine bone mineral density (BMD) was assessed. Results Osteoporotic patients exhibited elevated β-CTX and OC levels in peripheral blood, indicating heightened bone resorption and turnover. β-CTX levels in osteoporotic bone marrow were significantly higher. Negative correlations were found between peripheral blood β-CTX and OC levels and lumbar spine BMD, suggesting their potential as osteoporosis severity indicators. No such correlations were observed with bone marrow markers. When analyzing postmenopausal women separately, we obtained consistent results. Conclusions Elevated β-CTX and OC levels in osteoporotic peripheral blood highlight their diagnostic significance. Negative β-CTX and OC-BMD correlations underscore their potential for assessing osteoporosis severity. Discrepancies between peripheral blood and bone marrow markers emphasize the need for further exploration. This research advances our understanding of BTM clinical applications in osteoporosis diagnosis and treatment.

The transport sector is responsible for nearly a quarter of global CO2 emissions annually, underscoring the urgent need for cleaner, more sustainable alternatives such as electric vehicles (EVs). However, the electrification of heavy goods vehicles (HGVs) has been slow due to the substantial power and battery capacity required to match the large payloads and extended operational ranges. This study addresses the research gap in battery pack design for commercial HGVs by investigating the electrical and thermal behaviour of a novel battery pack configuration using an electro-thermal model based on the equivalent circuit model (ECM). Through computationally efficient 1D modelling, this study evaluates critical factors such as cycle ageing, state of charge (SoC), and their impact on the battery’s range, initially estimated at 285 km. The findings of this study suggest that optimal cooling system parameters, including a flow rate of 18 LPM (litres per minute) and actively controlling the inlet temperature within ±7.8 °C, significantly enhance thermal performance and stability. This comprehensive electro-thermal assessment and the advanced cooling strategy set this work apart from previous studies centred on smaller EV applications. The findings provide a foundation for future research into battery thermal management system (BTMS) design and optimised charging strategies, both of which are essential for accelerating the industrial deployment of electrified HGVs.

Due to its high self-heat rate, most researchers have avoided using lithium cobalt oxide (LiCoO2) in their work, although, major car companies use it to power some car models because of its high-power density. A thermal management system benefits from phase change material (PCM) and serves as a reliable cooling system to ensure the safety, performance, and lifespan of Li-ion batteries. In this study, we conducted an experimental investigation of a new hybrid battery thermal management system (BTMS) using PCM combined with aluminum fins and forced air to enhance the cooling performance of Liion battery type 18 650 LiCoO2. Furthermore, the hybrid model's thermal behaviors are compared with other models that use only air or PCM for cooling. The cooling performance of different BTMS models was tested under a high temperature of 40°C and various discharge rates, as well as, various air velocities. The results demonstrate that the hybrid model effectively minimizes the battery heat accumulation and can reduce the maximum operating temperature by 1.5°C, 5.5°C, and 9.5°C compared to the air-cooling model and by 2.8°C, 5.1°C, and 16.1°C compared to the PCM model for discharge of 1C, 2C, and 3C rates, respectively. Furthermore, the maximum temperature difference within the battery pack did not surpass 3.1°C with our hybrid model. Moreover, the use of our model has a significant advantage in minimizing the air-cooling power consumption by 89%. [ABSTRACT FROM AUTHOR]

Introduction: This study examines bone turnover marker (BTM) variations between bone marrow and peripheral blood in osteoporotic and non-osteoporotic patients. BTMs offer insights into bone remodeling, crucial for understanding osteoporosis. Methods: A total of 133 patients were categorized into osteoporotic and non-osteoporotic cohorts. BTMs—C-telopeptide cross-linked type 1 collagen (β-CTX), serum osteocalcin (OC), Procollagen type I N-propeptide (P1NP), 25(OH)D—were measured in bone marrow and peripheral blood. Lumbar spine bone mineral density (BMD) was assessed. Results: Osteoporotic patients exhibited elevated β-CTX and OC levels in peripheral blood, indicating heightened bone resorption and turnover. β-CTX levels in osteoporotic bone marrow were significantly higher. Negative correlations were found between peripheral blood β-CTX and OC levels and lumbar spine BMD, suggesting their potential as osteoporosis severity indicators. No such correlations were observed with bone marrow markers. When analyzing postmenopausal women separately, we obtained consistent results. Conclusions: Elevated β-CTX and OC levels in osteoporotic peripheral blood highlight their diagnostic significance. Negative β-CTX and OC-BMD correlations underscore their potential for assessing osteoporosis severity. Discrepancies between peripheral blood and bone marrow markers emphasize the need for further exploration. This research advances our understanding of BTM clinical applications in osteoporosis diagnosis and treatment. [ABSTRACT FROM AUTHOR]

The need to offset heat generated by batteries in electric vehicles (EVs) necessitated the design and development of battery thermal management systems (BTMS), one of which adopt air cooling technique. The redesign of plenums of the BTMS has been beneficial in the enhancement of the BTMS's performance. In view of these, this study considered wave and straight design of plenums in an attempt to enhance the performance of the system. The proposed designs were investigated using Computational Fluid Dynamics (CFD) methodology. The CFD methodology was validated by first investigating the conventional Z-design of BTMS with straight plenums and the results were compared with existing results from experiments in literature. Findings from the study revealed that by replacing straight-horizontal plenum with straight-inclined plenum, maximum temperature (Tmax), and maximum temperature difference (ΔTmax) of the Z-design was reduced by 3.47 K and 6.82 K, respectively, with increase in pressure drop (ΔP) by 2.24 Pa and pumping power (Pp) by 0.01 W.Furthermore, by adopting wave-inclined plenum design, Tmax, and ΔTmax were reduced by 4.61 K and 8 K, respectively when compared with the conventional Z-design BTMS. More so, the pressure drop (ΔP) and pumping power (Pp) increased by 3.17 Pa and 0.0133 W, respectively. The study generally revealed that careful redesign of divergence plenum with inclined straight and wave-like structure will enhance the thermal performance of BTMS.

Battery technology is the main driving force behind the shift towards emission-free transportation. However, a major obstacle to the widespread adoption of this technology is the need to maintain the battery's temperature at a standard of 27 °C. Traditionally, a mixture of ethylene glycol and water is circulated through the battery pack for cooling, but this method is not sufficient. By contrast, the use of graphene nanoplatelets (GNPs) can improve heat transfer, reducing temperature rise in the battery cell. In this study, a customized battery pack has been simulated using coolants containing varying concentrations of GNPs (ranging from 0.001 vol% to 0.01 vol%) to assess their effectiveness in lowering the operating temperature. The Lagrangian approach has been employed to track the discrete phase particles which couples with Eulerian continuous phase fluid. Results have shown that the pure EG/Water coolant decreases the peak temperature of the system by 16.67% (60 °C–50 °C) which further decreases to 26.85 °C (reduction of 55.25%) till the addition of optimum 0.03 vol% GNP. With the addition of only 0.001 vol% of GNPs, the difference in the peak temperature in the model increases from 10 °C to 31.15 °C as compared to the pure mixture. Higher thermal conductivity, greater surface area and higher specific heat capacity of the particles are attributed for this enhanced cooling.

Objective To study the correlation between serum bone turnover markers and FRAX fracture risk score in healthy middle-aged and elderly people, and to explore the value of serum bone turnover markers in fracture risk prediction. Methods The data of age, sex, body mass index (BMI), bone mineral density, and serum bone turnover indexes in 121 healthy middle-aged and elderly people over 50 years old were collected retrospectively, and the FRAX fracture probability was calculated. Patients with FRAX major osteoporotic fracture probability (FRAX-M) ≥20% or FRAX hip fracture probability (FRAX-H) ≥3% were classified as high fracture risk group, and patients with FRAX low-medium fracture risk group were classified as low fracture risk group. The correlation between FRAX fracture probability and serum bone turnover markers was analyzed, and multiple-linear-regression analysis was carried out with FRAX fracture probability as dependent variables. Results Univariate analysis showed that serum levels of osteocalcin (OC) and total type 1 procollagen N-terminal peptide (tP1NP) were higher in the FRAX high-risk group than in the FRAX low-medium risk group (P<0.05). In the correlation analysis, OC and tP1NP were positively correlated with the probability of major osteoporotic fracture in FRAX (r=0.385,0.378, P<0.001), while OC and tP1NP were positively correlated with the probability of hip fracture in FRAX (r = 0.308, 0.287, P < 0.001) . In the multiple linear regression analysis with the probability of FRAX major osteoporotic fracture and hip fracture as dependent variables, PINP remained in the regression equation, and the β= 0.258 (P < 0.001),0.306 (P = 0.001), respectively. Moreover, hierarchical analyses showed a significant increase in the ability of the regression model to predict fracture risk after the addition of tPINP. Conclusion The total type 1 procollagen N- terminal peptide (tP1NP) may be an important factor in the risk of brittle fracture. It is suggested that the value of serum bone turnover marker tP1NP should be considered in clinical fracture risk prediction. [ABSTRACT FROM AUTHOR]

The rapid increase in emissions and the depletion of fossil fuels have led to a rapid rise in the electric vehicle (EV) industry. Electric vehicles predominantly rely on lithium-ion batteries (LIBs) to power their electric motors. However, the charging and discharging processes of LIB packs generate heat, resulting in a significant decline in the battery performance of EVs. Consequently, there is a pressing need for effective battery thermal management systems (BTMSs) for lithium-ion batteries in EVs. In the current study, a novel experimental BTMS was developed for the thermal performance enhancement of an LIB pack comprising 2 × 2 cells. Three distinct fin configurations (circular, rectangular, and tapered) were integrated for the outer wall of the lithium-ion cells. Additionally, the cells were fully submerged in phase change material (PCM). The study considered 1C, 2C, and 3C cell discharge rates, affiliated with their corresponding volumetric heat generation rates. The combination of rectangular fins and PCM manifested superior performance, reducing the mean cell temperature by 29.71% and 28.36% compared to unfinned lithium-ion cells under ambient conditions at the 1C and 2C discharge rates. Furthermore, at the 3C discharge rate, lithium-ion cells equipped with rectangular fins demonstrated a delay of 40 min in reaching the maximum surface temperature of 40 ° C compared to the unfinned ambient case. After 60 min of battery discharge at the 3C rate, the cell surface temperature of the rectangular fin case only reached 42.7 ° C. Furthermore, numerical simulations showed that the Nusselt numbers for lithium-ion cells with rectangular fins improved by 9.72% compared to unfinned configurations at the 3C discharge rate. [ABSTRACT FROM AUTHOR]

This study proposes a simulation technique for investigating a battery thermal management system based on direct refrigerant cooling (BTMS-DRC). The main focus is to investigate the temperature uniformity and working temperature of the module housing. The simulation technique employs a finite element method for a combined conduction–convection heat transfer to predict the module housing temperature. The refrigerant side is based on two-phase flow evaporation, which is represented by the convection heat transfer under a certain refrigerant saturation temperature. The real BTMS-DRC, which is based on the dual-evaporator vapor compression refrigeration system, is constructed for experimentation with the test bench. The simulated result is validated with the experimental results to ensure correction of the modelling. Error rates of approximately 2.9–7.2% are noted throughout the specified working conditions. The BTMS can produce temperatures of less than 35 °C under conditions where 80–320 W heat is generated. The difference in the temperature of the module is around 1.7–4.2 °C. This study also investigates the impact of heat generation, the convection heat transfer coefficient (href), the refrigerant saturation temperature, and thermal conductivity on the module's temperature. The thermal conductivity ranges from 25 to 430 W/m·K, while the href ranges from 80 to 400 W/m2·K. [ABSTRACT FROM AUTHOR]

Given the growing demand for increased energy capacity and power density in battery systems, ensuring thermal safety in lithium-ion batteries has become a significant challenge for the coming decade. Effective thermal management plays a crucial role in battery design optimization. Air-cooling temperatures in vehicles often vary from ambient due to internal ventilation, with external air potentially overheating due to vehicle malfunctions. This article highlights the efficiency of lateral side air cooling in battery packs, suggesting a need for further exploration beyond traditional front side methods. In this study, we examine the impact of three different temperature levels and two distinct air-cooling directions on the performance of an air-cooling system. Our results reveal that the air-cooling direction has a more pronounced influence compared with the air-cooling temperature. By employing an optimal air-cooling direction and ambient air-cooling temperature, it is possible to achieve a temperature reduction of approximately 5 K in the battery, which otherwise requires a 10 K decrease in the air-cooling temperature to achieve a similar effect. Therefore, we propose an empirical formula for air-cooling efficiency under various conditions, aiming to provide valuable insights into the factors affecting air-cooling systems for industrial applications toward enhancing the fire safety of battery energy storage systems. [ABSTRACT FROM AUTHOR]

A novel Loop Heat Pipe (LHP) is developed as passive cooling system for Battery Thermal Management System (BTMS). LHPs are more efficient than traditional heat pipes at transferring heat at larger distances, which is essential for keeping the batteries in a safe and efficient temperature range. The Single Evaporator Loop Heat Pipe (SE-LHP) BTMS is tested on a battery module comprising of twelve 18,650 lithium-ion battery cells. The tests are conducted at various charge and discharge rates (1C, 1.5C, and 2C) and ambient temperatures ranging from 30°C to 45°C. The SE-LHP BTMS significantly reduces the maximum cell temperature compared to a module without BTMS. At an ambient temperature of 35°C, the SE-LHP BTMS attains temperature drops of 15%, 16.4%, and 16.29% during battery charge rates of 1C, 1.5C, and 2C, respectively. The SE-LHP BTMS also increases the discharge capacity of the battery module. For the 1.5C discharge rate, the discharge capacity increases from 41% State of Charge (SOC) to 0% SOC with the SE-LHP BTMS, compared to 39% SOC without BTMS. For the 2C discharge rate, the discharge capacity increases from 59% SOC to 0% SOC with the SE-LHP BTMS, compared to 56% SOC without BTMS. The SE-LHP BTMS also helps to keep even temperature spreading among the battery cells. When the module is exposed to ambient temperatures ranging from 30°C to 45°C, the SE-LHP BTMS keeps a temperature difference of less than 2.43°C and 3.38°C among the battery cells for all charge and discharge rates, respectively. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the feasibility of a novel dual-evaporator loop heat pipe (DE-LHP) in battery thermal management systems (BTMS). A 3S4P (3-series and 4-parallel) Li-ion battery module with a 12.6 V and 10 Ah capacity is made and tested under various C rates for different environmental conditions. The battery generates an average heat of 11.28 W@1C and 24.44 W@1.5C with 100% discharge and 43.36 W@2C with 50% discharge at an ambient temperature of 30 °C. An increase in temperature from 30 to 40 °C results in a decline in the depth of discharge. The proposed DE-LHP is evaluated using deionized water with filling volumes of 12, 16, 20, and 24 mL. The DE-LHP started working above 5 W regardless of the filling volume, and before the evaporator reached dry-out, the DE-LHP transferred heat loads of 10, 30, 35, and 55 W with filling volumes of 12, 16, 20, and 24 mL, respectively. At a heat load of 30 W, the evaporator section of the 20-mL filled LHP demonstrated a minimum thermal resistance of 0.274 KW-1, while the condenser section exhibited a minimum thermal resistance of 0.372 KW-1 at a heat load of 35 W. The DE-LHP is found to be effective in transferring heat of 35 W to keep the module temperature below 60 °C. Based on these initial findings, it is suggested that incorporating the multi-evaporator LHP-based BTMS could be a feasible and efficient solution for the thermal management of battery modules/packs for electric vehicles. [ABSTRACT FROM AUTHOR]

Due to the extreme sensitivity of temperature in Li‐ion batteries, thermal management is a significant issue that must be addressed. Since the battery in electric vehicles produces an enormous amount of heat, it reduces its efficiency and its performance. Currently, there is a need for electric vehicles (EVs) because conventional IC engines produce an enormous amount of pollution which affects the environment, so an electric vehicle produces a very small amount of pollution. It is now being recommended and used by many people. But the electric vehicle faces some major problems due to overheating in their battery module. Nowadays, battery temperature is regulated by a system called battery thermal management system (BTMS). Modern EVs use active and passive cooling systems. Thermal management tries to improve battery architecture for greater autonomy or quick charging. To meet future difficulties in thermal management, such as air or liquid cooling, are needed. As a result of the battery's overheating, the vehicle's performance, power, energy storage, charging, and discharging are all negatively impacted; hence, a reliable thermal management system for the battery is essential for resolving these problems. This study provides an overview of the BTMS of the future, beginning with the problems involving temperature and safety. The following is a list of the benefits and drawbacks of BTMSs, which are used to maintain acceptable temperatures for battery packs. In conclusion, an analysis of the progress made in developing temperature management systems for future batteries is presented. As a first look at potential BTMSs for locomotive applications, it has been proposed to conduct a comprehensive analysis and classification of both existing and potential battery management systems. [ABSTRACT FROM AUTHOR]

The temperature of the battery pack is regulated using a Battery Thermal Management System (BTMS). In this study, a Computational Fluid Dynamics (CFD) method was employed to improve the intake and output channel heights of the traditional Z and U-type BTMS to produce different flow and temperature distributions. Geometry of 6×145×225 mm was used with channel intake and output height, length and width set to 20, 100 and 3 mm, respectively. Channel height varied from 20 to 25 mm. The results show that increasing the intake and output channel heights improves the performance of regular Z-type flow cooling. For this study, the best performance is height with 25 mm intake and 25 mm output channel height. The peak temperature dropped by 11.2 °C while its power consumption and peak difference in temperature reduced by 25% and 5.33 °C, respectively. The cooling effectiveness of a standard U-type flow BTMS is enhanced by increasing the intake and output channel heights to 25 mm. Accordingly, the peak temperature decreased by 8.92 °C, the peak temperature differential diminished by 2.94 °C, and the power usage decreased by 16%. Generally, the outcomes show that intake and output channel height are crucial for BTMS optimization. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries are a crucial part of transportation electrification. Various battery thermal management systems (BTMS) are employed in electric vehicles for safe and optimum battery operation. With the advancement in power demand and battery technology, there is an increasing interest in enhancing BTMS' performance. Liquid cooling is gaining a lot of attention recently due to its higher heat capacity compared to air. In this study, an air-cooled BTMS is replaced by a liquid cooled with nanoparticles, and the impacts of different nanoparticles and flow chrematistics are modeled. Furthermore, a unique approach that involves transient analysis is employed. The effects of nanofluid in enhancing the thermal performance of lithium-ion batteries are assessed for two types of nanoparticles (CuO and Al2O3) at four different volume concentrations (0.5%, 2%, 3%, and 5%) and three fluid velocities (0.05, 0.075, and 0.1 m/s). To simulate fluid flow behavior and analyze the temperature distribution within the battery pack, a conventional k-ε turbulence model is used. The results indicate that the cooling efficiency of the system can be enhanced by introducing a 5% volume concentration of nanofluids at a lower fluid velocity as compared to pure liquid. Al2O3 and CuO reduce the temperature by 7.89% and 4.73% for the 5% volume concentration, respectively. From transient analysis, it is also found that for 600 s of operation at the highest power, the cell temperature is within the safe range for the selected vehicle with nanofluid cooling. The findings from this study are expected to contribute to improving BTMS by quantifying the benefits of using nanofluids for battery cooling under both steady-state and transient conditions. [ABSTRACT FROM AUTHOR]

The battery thermal management system (BTMS) for lithium-ion batteries can provide proper operation conditions by implementing metal cold plates containing channels on both sides of the battery cell, making it a more effective cooling system. The efficient design of channels can improve thermal performance without any excessive energy consumption. In addition, utilizing phase change material (PCM) as a passive cooling system enhances BTMS performance, which led to a hybrid cooling system. In this study, a novel design of a microchannel distribution path where each microchannel branched into two channels 40 mm before the outlet port to increase thermal contact between the battery cell and microchannels is proposed. In addition, a hybrid cooling system integrated with PCM in the critical zone of the battery cell is designed. Numerical investigation was performed under a 5C discharge rate, three environmental conditions, and a specific range of inlet velocity (0.1 m/s to 1 m/s). Results revealed that a branched microchannel can effectively improve thermal contact between the battery cell and microchannel in a hot area of the battery cell around the outlet port of channels. The designed cooling system reduces the maximum temperature of the battery cell by 2.43 °C, while temperature difference reduces by 5.22 °C compared to the straight microchannel. Furthermore, adding PCM led to more uniform temperature distribution inside battery cell without extra energy consumption. [ABSTRACT FROM AUTHOR]

The temperature range of 25–35 °C provides the most suitable conditions for the best performance of batteries. This study introduced an advanced new thermal management system for batteries designed based on thermoelectric elements and radiators. The battery system is modeled during a real driving cycle. The simulation results showed that the temperature pattern of the battery surface followed a fluctuation pattern before reaching a steady-state condition in cold seasons. A similar model for hot months followed the velocity profile of the vehicle. Besides, the temperature profile was linear with a positive slope in hot seasons for the battery charge time. The surface temperature of the cold plate of the thermoelectric elements in cold seasons reduced with velocity from the cold to hot season while following the velocity profile of the vehicle in hot seasons, with a positive slope and linear trend. Concerning the surface temperature of the hot plate of the thermoelectric elements, the profile was linear and incremental. Furthermore, the increasing trend experienced some fluctuations that declined from the cold to hot season, while there were no fluctuations for the temperatures above 25 °C. In the cold seasons of the year, as the temperature increases from 6.9 to 15.5 °C, the oscillating state decreases for 500 s, and when it increases again to 21.5 °C, the time interval decreases for 100 s. Also, for thermal management in the hot season, kfan is reduced from 0.81 to 0.21 W K−1 to achieve balance and optimal operation of thermoelectric elements. The same fluctuation trend applies to all the results obtained from the energy stored in the battery diagram. It can be concluded that the newly introduced thermal management system can maintain the battery temperature at an appropriate temperature range. The results followed similar patterns for various thermal conditions wherein different parameters of the thermal management system were examined. The new cycle introduced using the fuzzy logic algorithm and the PID controller could manifest proper efficiency for real applications. [ABSTRACT FROM AUTHOR]

This paper addresses cylindrical lithium-ion cells' heating and non-uniform cooling by simulating a simple battery pack design with 24 cells and axial airflow. Cooling a battery pack using forced air convection in a rectangular container causes non-homogeneous temperature distribution. The middle cells and the second half of the battery pack (near the exit) get less cooling compared to the cells near the inlet. To solve this issue of non-uniform cooling, in this paper, we propose an optimized Battery Thermal Management System (BTMS) which allows higher amounts of turbulent kinetic energy to be generated near the cells closer to the exit and farther away from the inlet. We attempted to create a narrow region in the middle of the pack which leads to an increase in mixing and turbulence in the airflow. This directs the flow precisely, hence getting rid of dead air flow zones behind the cells. The convergence functions like a nozzle, propelling the air flow into the second half of the battery pack. Using COMSOL Multiphysics, the mixing and turbulence of the airflow, as well as the temperature increase and homogeneity inside the battery pack, are investigated. Three separate investigations are conducted in order to determine the optimal shape for the BTMS control volume as well as to determine the effect of system's inlet pressure and outlet velocity on the cooling performance. Results indicated that the system's temperature decreased significantly by lowering the outlet dimensions and introducing convergence to the BTMS's central area. Increasing outlet velocity increased cooling in a case with a single fan significantly, whereas increasing pressure in a case with two fans increased cooling slightly.

Electric vehicles (EVs) are eco-friendly alternative to internal combustion (IC) engine based vehicles to combat with global warming. Lithium-ion batteries (LIBs) are adopted in EVs and their performance and longevity depends on thermal environment. Inadequate thermal management results in suboptimal performance, thermal runaway and consequent explosion in extreme cases. The present study delves into the experimental investigation on catastrophic failure of a Lithium ion cell under abusive conditions. The temperature variations leading up to the point of explosion were meticulously monitored, revealing a critical temperature of 440 K just before the explosion. The pressure waves during the explosion gives the sound pressure levels from 46.2 dB to 83.85 dB within a 34 ms time window and the predominant portion of sound generated during the explosion lies in the range of 129 to 3488 Hz. The battery pack discharge experiments show a temperature rises above the critical limit of 313.15 K and sudden voltage drops to the cut of value of 20 V at t = 850 s during 1C discharge condition, which shows the warning of explosion. Numerical model was developed to simulate the complex conjugate heat transfer in the cell and simulation results are validated. To underscore the practical implications, a case study of fire accident during battery cooling experiment was presented. From the insights gained by explosion of single-cell and fire accident of battery, several recommendations are provided, which includes the orientation of cells within the EVs aiming at the safety of battery design and operation. • Catastrophic failure in Li-ion cells under abuse condition. • 2D numerical thermal model for conjugate heat transfer in Li-ion batteries. • Real-world study for EV battery design and operational safety. • Emphasized importance of efficient BTMS to maximize battery safety. • Tangible recommendations including battery cell orientation. [ABSTRACT FROM AUTHOR]

Taking advantage of electric vehicles’ low pollution, the world is changing its face toward electric vehicle (EV) production. As EVs rely heavily on specialized batteries, it’s important to manage them safely and properly to prevent thermal runaway. High ambient temperatures and varied charging/discharging rates increase battery temperature. To address these challenges, Battery Thermal Management System (BTMS) come into play. This work focuses on passive cooling in BTMS, which is one of two categories of BTMS, with the other being active cooling using liquid-air systems. Passive BTMS has gained prominence in research due to its cost-effectiveness, reliability, and energy efficiency, as it avoids the need for additional components like pumps/fans. This article specifically discusses recent experimental studies regarding phase change material (PCM)-based thermal management techniques for battery packs. It explores methods for enhancing thermal conductivity in PCMs and identifies methodologies for BTMS experiments using PCMs. Also recommends the importance of optimization techniques like machine learning, temperature sensors, and state-of-charge management, to ensure accuracy and uniform temperature distribution across the pack. While paraffin wax has been a popular choice in experimental studies for its capacity to absorb and release heat during phase transitions, as a matter of its low thermal conductivity (0.2 to 0.3 Wk ^−1 m ^−1 ) limits reaction in rapid charging/discharging of batteries. So integration with highly thermally conductive additives is recommended. Additives such as heat pipes offer superior thermal conductivity compared to expanded graphite (5 to 200 Wk ^−1 m ^−1 ). As a result, the integration of heat pipes further reduces the temperature of battery by 28.9% in addition to the reduction of 33.6% by pure PCMs in time of high charge/discharge rates (5 C to 8 C). So high-conductivity additives correlate directly with improved thermal performance and are essential for maintaining optimal battery temperatures and overall reliability in EV battery packs.

The rapid increase in emissions and the depletion of fossil fuels have led to a rapid rise in the electric vehicle (EV) industry. Electric vehicles predominantly rely on lithium-ion batteries (LIBs) to power their electric motors. However, the charging and discharging processes of LIB packs generate heat, resulting in a significant decline in the battery performance of EVs. Consequently, there is a pressing need for effective battery thermal management systems (BTMSs) for lithium-ion batteries in EVs. In the current study, a novel experimental BTMS was developed for the thermal performance enhancement of an LIB pack comprising 2 × 2 cells. Three distinct fin configurations (circular, rectangular, and tapered) were integrated for the outer wall of the lithium-ion cells. Additionally, the cells were fully submerged in phase change material (PCM). The study considered 1C, 2C, and 3C cell discharge rates, affiliated with their corresponding volumetric heat generation rates. The combination of rectangular fins and PCM manifested superior performance, reducing the mean cell temperature by 29.71% and 28.36% compared to unfinned lithium-ion cells under ambient conditions at the 1C and 2C discharge rates. Furthermore, at the 3C discharge rate, lithium-ion cells equipped with rectangular fins demonstrated a delay of 40 min in reaching the maximum surface temperature of 40 °C compared to the unfinned ambient case. After 60 min of battery discharge at the 3C rate, the cell surface temperature of the rectangular fin case only reached 42.7 °C. Furthermore, numerical simulations showed that the Nusselt numbers for lithium-ion cells with rectangular fins improved by 9.72% compared to unfinned configurations at the 3C discharge rate.

Batteries have wide applications in engineering. They are extensively used in hybrid electric vehicles (HEVs) and electric vehicles (EVs), where a suitable battery thermal management system (BTMS) is vital in ensuring the safety and reliability operations of batteries. The purpose of this study is to offer an air-cooling system that utilizes a novel V-type staggered arrangement of plate-fin heat sink for forced air cooling. To keep the temperature of a lithium-ion battery pack within the optimal temperature range for the safety of the battery and the consumer to prevent the battery from catching fire. The paper also presents a comparison between straight rectangular fins and V-type staggered arrangement heat sinks. The thermal management of batteries equipped with a heat sink is numerically controlled, to ensure the battery's overall performance and longevity modules/packs for electric cars. A three-dimensional heat sink model was constructed and a numerical approach was used to explore the impacts of the number of fins on the heat sink, fin spacing and angle of inclination of the fins at different inlet air mass flow rates and varied heat input. The analysis presents a computational approach and traditional heat transfer theory. [ABSTRACT FROM AUTHOR]

Degradation and heat generation are among the major concerns when treating Lithium-ion batteries' health and performance parameters. Due to the high correlation between the battery's degradation, autonomy and heat generation to the cell's operational temperature, the Battery Thermal Management System plays a key role in maximizing the battery's health. Given the fact that the ideal temperature for degradation minimization usually does not match the ideal temperature for heat generation minimization, the BTMS must manage these phenomena in order to maximize the battery's lifespan. This work presents a new definition of the discharge operation point of a lithium-ion battery based on degradation, autonomy and heat generation. Two cells of different electrodes formulation were modeled and evaluated in a case study. The results demonstrated a 50% improvement on total useful battery cycles in best-case scenarios. [ABSTRACT FROM AUTHOR]