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Strong metal-support interaction (SMSI), namely the strong electronic and structural interaction between metal nanoparticles and supports, one of the most typical synergetic catalytic effects in composite catalysts, has been found critically important in the design of catalyst for thermocatalysis in the past. Recently, however, important and great progress of SMSI-based synergetic effects has been made in electrocatalysis, such as electrocatalyst design and electrocatalytic mechanism investigations. To better understand the nature of the synergetic effect assisting the further development of electrocatalysts, a comprehensive and in-depth overview highlighting and discussing the recent advances of SMSI in electrocatalysis is necessary and highly desirable but still absent. Herein, this review firstly presents various strategies of designing and constructing composite catalysts featuring SMSI. Further from the perspectives of electrocatalysis, the characterization techniques towards the electron structure, local interfacial and morphological features and active sites for SMSI-based electrocatalysts, have been summarized in detail. Importantly, the recent advances in the design of single- and bi-functional electrocatalysts [ABSTRACT FROM AUTHOR]

Zero-sodium-excess solid-state batteries (ZSBs) are promising to overcome the disadvantage of low energy density for Na-ion batteries, but the interfacial issues between the solid-state electrolytes and current collectors remain bottlenecks for their practical applications. Herein, we report a self-regulated stratification of the artificial interphase through the conversion reaction between MgF2 modification layer and Na metal. Ascribed to the huge adsorption energy difference between Al-Mg and Al-NaF, the sodiophilic Mg concentrated at the bottom side and served as the nucleophilic seed for Na, while sodiophobic NaF on the top side provided high thermodynamic stability for Na dendrite and side reaction suppressions. Consequently, the as constructed ZSBs with Na3V2(PO4)3 cathode exhibited prominent energy density of 254.4 Wh kg-¹ (calculated based on the total mass of electrode and electrolyte) with a capacity retention of 82.7% over 350 cycles. This work paves a feasible way to achieve high performance and stable ZSBs. [ABSTRACT FROM AUTHOR]

The pairing of lithium metal anode (LMA) with Ni-rich layered oxide cathodes for constructing lithium metal batteries (LMBs) to achieve energy density over 500 Wh kg-¹ receives significant attention from both industry and the scientific community. However, notorious problems are exposed in practical conditions, including lean electrolyte/capacity (E/C) ratio (< 3 g (Ah)-¹), high cathode mass loading (> 3 mAh cm-²), and low negative/positive (N/P) ratio (< 3), which creates a significant disparity between the current performance of LMBs and the desired requirements for commercial applications. In the review, we present a summary of the recent achievements made in understanding the mechanistic degradation of LMA, followed by practical strategies that are utilized to address these issues. We also consider the detrimental issues of Ni-rich layered oxide cathodes. Furthermore, we highlight current progresses in the field of practical LMBs in coin/pouch cells to stimulate further innovation. In the end, we propose the issues and prospects for development from the perspective of practical LMBs. [ABSTRACT FROM AUTHOR]

Developing advanced nanocomposite phase change materials (PCMs) integrating zero-energy thermal management, microwave absorption, photothermal therapy and electrical signal detection can promote the leapfrog development of flexible wearable electronic devices. For this goal, we propose a multidimensional collaborative strategy combining two-dimensional (2D) MXene nanosheets with metal-organic framework-derived onedimensional (1D) carbon nanotubes (CNTs) and zero-dimensional (0D) metal nanoparticles. After encapsulating paraffin wax (PW) in three-dimensional (3D) networked multidimensional MXene/CoNi-C, the resulting composite PCMs exhibit excellent thermal energy storage capacity and long-term thermally reliable stability. Benefiting from the synergistically enhanced photothermal effects of CNTs, Co/Ni nanoparticles and MXene, PW@MXene/CoNi-C can capture photons efficiently and transfer phonons quickly, yielding an ultrahigh photothermal conversion and storage efficiency of 97.5%. Additionally, PW@MXene/CoNi-C composite PCMs exhibit high microwave absorption with a minimum reflection loss of -49.3 dB at 8.03 GHz in heat-related electronic application scenarios. More attractively, the corresponding flexible phase change film can simultaneously achieve thermal management and electromagnetic shielding of electronic devices, as well as photothermal therapy and electrical signal detection for individuals. This functional integration design provides an important reference for developing advanced flexible multifunctional wearable materials and devices. [ABSTRACT FROM AUTHOR]

The miniaturization of electronic devices has led to an increase in power density and functional integration, resulting in rapid heat accumulation that adversely affects operational stability and service life. Dielectric composite films with excellent thermal conductivity and insulating properties are highly desired for addressing thermal management issues in electronic packaging applications. Hexagonal boron nitride (h-BN) is a promising filler for such composites due to its outstanding thermal conductivity, insulating properties, and chemical stability. However, the inherent platelike structure of h-BN causes significant anisotropy and poor miscibility with polymers, limiting the uniform conduction of heat. This study proposes a high-temperature sintering method that transforms flaky h-BN plates into irregular multifaceted particles. This transformation reduces thermal anisotropy and creates uniform heat conduction pathways. The resulting sintered BN/Epoxy (s-BN/EP) composite films exhibit exceptional thermal conductivity, with in-plane thermal conductivity increased by 36 % to 6.0 W m−1 K−1 and through-plane thermal conductivity increased by 39 % to 1.2 W m−1 K−1 compared to pristine h-BN/epoxy composites. Moreover, s-BN/EP films could maintain low dielectric constant (D k , 3.22) and dielectric loss (D f , 0.015) at 5 GHz. This innovative approach provides a significant advancement in the development of high-performance insulating polymer composites, offering a promising solution for thermal management in high-power-density electronic packaging. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights Maintaining uniform dispersion of nano filler under high content is critical for fabricating polymer‐based composites with great mechanical and thermally conductive properties. In this work, BNNS/PA12T nanocomposite with the highest boron nitride nanosheet (BNNS) content of 23.1 wt% was successfully prepared by the aqueous solution‐assisted in‐situ polymerization method. Results demonstrate that the BNNS can be uniformly dispersed in the composite due to the low viscosity during the polymerization process. As a result, when the content of BNNS is 23.1 wt%, the mechanical properties and thermal conductivity of BNNS/PA12T nanocomposite are 62 MPa and 1.55 W/(m·K). Furthermore, the composites also possess excellent high‐temperature resistance with the coefficient of thermal expansion (CTE) of 60 ppm/°C, about one third of pure PA12T, and the thermal deformation temperature also reaches 139.4°C. Therefore, the fabricated BNNS/PA12T nanocomposite can be effectively applied as thermal management and packaging materials for electronic devices. BNNS/PA12T nanocomposites were prepared by aqueous solution‐assisted method. BNNS can be uniformly dispersed at the filling content up to 23 wt%. The thermal conductivity of BNNS/PA12T nanocomposite can reach 1.55 W/(m·K). Possessing excellent mechanical properties and dimensional stability. The nanocomposite can be effectively applied for thermal management. [ABSTRACT FROM AUTHOR]

In the rapidly advancing field of 5G technology, efficient thermal management is essential for enhancing the performance and reliability of high-power-density integrated circuits (ICs). This paper introduces an innovative approach to cooling these critical components, significantly surpassing traditional methods. Our design optimizes heatsink and fan configurations through systematic experimentation, varying fin shapes, heatsink dimensions, and fan speeds. The results demonstrate that fan velocity is the most critical factor in reducing IC temperatures, as increased airflow dramatically lowers thermal output. Expanding the heatsink surface area further improves heat dissipation by enhancing airflow interaction, while a larger copper heatsink boosts thermal conduction, effectively reducing the final IC temperature. These optimizations streamline the cooling process, minimizing the need for more complex and expensive equipment. This research sets a new benchmark in thermal management, fostering the development of more efficient and reliable electronic systems in the era of advanced wireless communications. Our approach brings a new dimension to existing research by focusing on the optimization of heatsink and airflow designs specifically for ICs. While previous studies have explored broader thermal management strategies, our work addresses specific challenges in heat dissipation by refining geometric configurations and fan speed adjustments. These optimizations result in measurable improvements in both efficiency and scalability, particularly within the context of high-power 5G systems. [ABSTRACT FROM AUTHOR]

An experimental investigation was carried out on high porosity metal foams subjected to array jet impingement with an objective to develop enhanced heat transfer configurations. In this study, we propose an integrated thermal management system (TMS) aimed toward leveraging the conjugate heat transfer capabilities of target plate, metal foam, and the jet plate--all made from aluminum and assembled such that a proper contact between them can be established. Steady-state heat transfer experiments were carried out for 10 and 20 pores per inch (PPI) aluminum foams of 0.93 porosity. Both metal foams were 12.7-mm thick. The normalized jet-to-jet spacing was varied from 2 to 12 times the jet diameter, while the jet diameter was fixed. The ratio of the jet plate thickness and jet diameter (nozzle aspect ratio) was 6.35, which ensured proper development of jets inside the nozzles. Experiments were conducted over a wide range of Reynolds number (based on jet diameter) varied from 100 to 5000. The obtained convective heat transfer coefficient for different configuration was evaluated in context with pressure drop. The analysis of experimental results reveal that large open area ratio jets combined with high porosity metal foams provide highly efficient and high-performance cooling for the investigated range of Reynolds numbers. [ABSTRACT FROM AUTHOR]

The wide spread adoption of heat pipes in automotive and aviation application is hampered by the fact that they require protection against frost damage caused by the repetitive exposure to subzero temperatures. Here, we present heat pipe with ethylene glycol and water as working fluid that can prevent damage to the copper container on exposure to cyclic freezing and thaw. In this research, different mass concentrations of water and ethylene glycol have been tested for freeze protection of heat pipes. Experimental investigations have shown that 3.5% by mass concentration of ethylene glycol in water is able to sustain the cyclic freezing and avoid any damage to the copper pipe. In this research, the freezing and heating cycle is set to operate between -40 °C and 90 °C. Heat pipes used for testing in this research were 6 mm in diameter and 150 mm long with copper fiber spiral wick. Thermal performance tests were carried out on these heat pipes with charging ratio of working fluid varying between 10% to 30% by volume. It is observed that the thermal resistance of heat pipe with working fluid charging ratio in range of 10% to 25% by volume varies from 0.6 °C/W to 0.2 °C/W for the rate of heat transfer of 10 W-50 W. While the charging ratios beyond 25% have shown the higher thermal resistance in the range of 0.8 to 1.0 °C/W for similar rate of heat transfer. All the samples were subjected to 150 freezing and thaw cycles and did not show any signs of frost damage. Accelerated life tests were performed on these heat pipes for up to 500 h and did not presented any signs of degradation in their thermal performance. [ABSTRACT FROM AUTHOR]

This work presents a novel approach to achieve directional and normal thermal emission from epsilon‐near–zero (ENZ) materials. ENZ materials exhibit near–zero permittivity at the ENZ point, resulting in some unique properties compared to conventional optical materials including infinite wavelength, constant phase distribution, and decoupling of spatial and temporal fields inside the ENZ material. These properties are used to engineer the far‐field thermal emission from optical antennas fabricated on ENZ film in the mid‐infrared. By coupling the antenna resonance mode with the Berreman mode of the ENZ material, highly directional and normal emission is demonstrated. This approach could have significant implications for thermal management, energy conversion, and sensing applications. [ABSTRACT FROM AUTHOR]

In the present work, direct contact the refrigerant and the cells was employed for thermal management. This study experimentally investigates cooling the battery pack by allowing the refrigerant to directly contact the cells. Furthermore, it presents the first experimental evaluation of combining this approach with various active and passive cooling methods. According to the results, the cells' maximum temperature decreased by 34°C at the end of the discharge. In the proposed system, the heatsink served as the only heat transfer path to the environment, where. heat transfer occurred via free convection. To enhance heat dissipation from the heatsink, the system was combined with active or passive Battery Thermal Management Systems (BTMSs). Using hydrogel between the fins of the heatsink decreased the cells' maximum temperature by 0.5°C. However, the use of forced airflow between the fins of the heatsink did not affect the cells' maximum temperature. The proposed system was also combined with an active forced liquid cooling system, and various water flow rates were investigated. At a flow rate of 200 LPH, the cells' maximum temperature was reduced by 1.5°C compared to the mode without forced water flow. Additionally, different inlet water temperatures were examined, revealing that increasing the inlet water temperature leads to a significant rise in the cells' maximum temperature. [ABSTRACT FROM AUTHOR]

The design of an efficient thermal management system for a lithium-ion battery pack hinges on a deep understanding of the cells' thermal behavior. This understanding can be gained through theoretical or experimental methods. While the theoretical study of the cells using electrochemical and numerical methods requires expensive computing facilities and time, the Equivalent Circuit Model (ECM) offers a more direct approach. However, upfront experimental cell characterization is needed to determine the ECM parameters. In this study, the behavior of a cell is characterized experimentally, and the results are used to build a second-order equivalent electrical circuit model of the cell. This model is then integrated with the cooling system of the battery pack for effective thermal management. The Equivalent Circuit Model estimates the internal heat generation inside the cell using instantaneous load current, terminal voltage, and temperature data. By extrapolating the heat generation data of a single cell, we can determine the heat generation of the cells in the pack. With the implementation of the ECM in the cooling system, the coolant flow rate can be adjusted to ensure the attainment of a safe operating cell temperature. Our study confirms that 14% of pumping power can be reduced when compared to the conventional constant flow rate cooling system, while still maintaining the temperature of the cells within safe limits. [ABSTRACT FROM AUTHOR]

As the CMOS technology continuously scales down into the deep submicron regime and approaches the physical limits of minimization, Moore's Law is hindered. The proposed 3-D integrated circuit technology based on through silicon via brings hope. Although 3-D integrated circuits bring many advantages over 2-D integrated circuits, the thermal management challenges still need to be addressed effectively. The through silicon via carry signals while facilitating the thermal transfer of stacked chips due to their high thermal conductivity and offer a potential thermal management solution for 3-D integrated circuits. The through silicon via are structured in arrays to significantly improve heat dissipation. This paper proposes a cellular array structure that offers better heat dissipation capabilities compared to conventional rectangular arrays. First, the through silicon via cellular arrangement is described. Secondly, a method for modelling the equivalent thermal conductivity of through silicon via arrays is proposed. Finally, the excellent performance of the cellular structure on thermal conductivity is verified by a comparative analysis of the thermal characteristics of the through silicon via array in the COMSOL system using finite element method. The results presented in this paper are beneficial for designers to optimize the through silicon via array arrangement and predict the thermal performance of through silicon via arrays. In addition, it provides a reference for 3-D integrated circuit reliability design. [ABSTRACT FROM AUTHOR]

Purpose: Transient response of continuous composite material (CCM) fin made of high thermally conductive composite material is presented. The continuously varying effective properties of composite material such as thermal conductivity, heat capacity and density have been modelled using the Mori-Tanaka homogenization theory and rule of mixture. Additionally, temperature dependency of thermal conductivity, heat generation (composite materials) and convection coefficient (fluid properties) have also been incorporated. Different base boundary conditions are addressed such as oscillating heat flow, oscillating temperature, step-changing heat flow and step-changing temperature. At the other boundary, the fin is assumed to have a convective tip. Design/methodology/approach: Lattice Boltzmann method is implemented using an in-house source code for obtaining the numerical solution of typical non-linear heat balance equation of the aforementioned problem under various transient base boundary conditions. Findings: The effects of various thermal parameters such as material diffusivity ratio and conductivity ratio, area ratio and Biot number on transient response of fin and temperature distribution of fins are studied and interpreted. The heat transfer rate and time for attainment of steady state temperature of metal matrix composite (MMC) fin are found to be proportionally dependent on their diffusivity ratio. Additionally for higher values of area ratio and biot number, MMC fins are reported to dissipate the heat more efficiently in comparision to homogeneous fins in terms of time required to attain the steady state and surface temperature. Practical implications: Response of transient fin associated with advanced class of material can facilitates the practicing engineers for designing high-performance and/or miniaturized thermal management devices as used in electronic packaging industries. Originality/value: Studies of composite fin consisting of laminating second layer of material over the first layer have been reported previously, however transient response of CCM fin fabricated by continuously varying the volume fraction of two materials along the fin length has not been reported till date. Such material finds its application in thermal management and electronic packaging industries. Results are plotted in form of a graph for different application-wise material combinations that have not been reported earlier, and it can be treated as design data. [ABSTRACT FROM AUTHOR]

Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties. In order to solve the interfacial problem between diamond and aluminium, a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum composites. The effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was investigated. The results show that the diamond/Al-12Si composites exhibit high relative density and a uniform microstructure. Both thermal conductivity and coefficient of thermal expansion increase with increasing particle size, while the bending strength exhibits the opposite trend. When the average diamond particle size increases from 45 µm to 425 µm, the thermal conductivity of the composites increases from 455 W·m-1·K-1 to 713 W·m-1·K-1 and the coefficient of thermal expansion increases from 4.97×10-6 K-1 to 6.72×10-6 K-1, while the bending strength decreases from 353 MPa to 246 MPa. This research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries still remain a cornerstone for the sustainable transportation by the way of its usage in electric vehicles (EVs). However, their optimal performance hinges on maintaining at consistent thermal conditions especially during operation, and at high discharge rates. The present study proposes a novel mini-channel cooling system specifically designed for a 10 Ah lithium-ion pouch cell. This innovative design incorporates cold plates on both battery surfaces for enhanced heat dissipation. In addition, the efficacy of silver (Ag) and copper oxide (CuO) nanofluid coolants by comparing with traditional water cooling in three distinct battery design configurations was also studied. Design 1 and 2 comprises respectively with partially and fully encased cold plates with mini-channels distributed both segmentally and centrally, and Design 3 the present proposed model featuring a fully covered cold plate with a serpentine flow layout for optimized heat transfer efficiency. Extensive computational analysis using ANSYS FLUENT 18.1 software reveals the superiority of Design 3. Notably, this configuration achieved significantly a lower maximum cell temperature (306.7 K and 305.0 K) with 0.25% and 0.5% Ag nanofluid coolants compared to Design 1 and 2, at a discharge rate of 5C. This underscores the potential of silver nanofluids for superior battery thermal management, particularly within the optimized Design 3 framework. These findings offer valuable insights for developing enhanced battery thermal management systems in EVs. [ABSTRACT FROM AUTHOR]

High-performance thermally conductive composites are increasingly vital due to the accelerated advancements in communication and electronics, driving the demand for efficient thermal management in electronic packaging, light-emitting diodes (LEDs), and energy storage applications. Controlling the orderly arrangement of fillers within a polymer matrix is acknowledged as an essential strategy for developing thermal conductive composites. In this study, isotactic polypropylene/GNP (iPP/GNP) composite filament tailored for fused deposition modeling (FDM) was achieved by combining ball milling with melt extrusion processing. The rheological properties of the composites were thoroughly studied. The shear field and pressure field distributions during the FDM extrusion process were simulated and examined using Polyflow, focusing on the influence of the 3D printing processing flow field on the orientation of GNP within the iPP matrix. Exploiting the unique capabilities of FDM and through strategic printing path design, thermally conductive composites with GNPs oriented in the through-plane direction were 3D printed. At a GNP content of 5 wt%, the as-printed sample demonstrated a thermal conductivity of 0.64 W/m · K, which was 1.5 times the in-plane thermal conductivity for 0.42 W/m · K and triple pure iPP for 0.22 W/m · K. Effective medium theory (EMT) model fitting results indicated a significantly reduced interface thermal resistance in the through-plane direction compared to the in-plane direction. This work shed brilliant light on developing PP-based thermal conductive composites with arbitrarily-customized structures. [ABSTRACT FROM AUTHOR]

The power density of electronic components grows continuously, and the subsequent heat accumulation and temperature increase inevitably affect electronic equipment’s stability, reliability and service life. Therefore, achieving efficient cooling in limited space has become a key problem in updating electronic devices with high performance and high integration. Two-phase immersion is a novel cooling method. The computational fluid dynamics (CFD) method is used to investigate the cooling performance of two-phase immersion cooling on high-power electronics. The two-dimensional CFD model is utilized by the volume of fluid (VOF) method and Reynolds Stress Model. Lee’s model was employed to calculate the phase change rate. The heat transfer coefficient along the heated walls and the shear-lift force on bubbles are calculated. The simulation data are verified with the literature results. The cooling performance of different coolants has been studied. The results indicate that the boiling heat transfer coefficient can be enhanced by using a low boiling point coolant. The methanol is used as the cooling medium for further research. In addition, the mass flow rate and inlet temperature are investigated to assess the thermal performance of twophase immersion cooling. The average temperature of the high-power electronics is 80°C, and the temperature difference can be constrained to 8°C. Meanwhile, the convective heat transfer coefficient reaches 2740 W/(m2·°C) when the inlet temperature is 50°C, and the mass flow rate is 0.3 kg/s. In conclusion, the results demonstrated that two-phase immersion cooling has provided an effective method for the thermal management of high-power electronics. [ABSTRACT FROM AUTHOR]

• The TRP model of NCM 811 and LFP batteries is established, the model parameters are determined, and the model accuracy is evaluated experimentally. • The TRP models of typical AB battery configurations are established, and their TRP characteristics are obtained through simulation and experiments. • The typical AB battery configurations are optimized to achieve both high energy density and high safety, providing valuable references for the design of hybrid-cell battery packs. Thermal runaway (TR) and its propagation (TRP) in lithium-ion batteries are critical safety concerns. The emergence of hybrid battery packs, combining different battery types (referred to as AB batteries), has gained significant attention as a potential solution to enhance battery safety. However, there is a lack of evaluation regarding the TRP characteristics of these configurations. In this study, various AB battery configurations, incorporating NCM 811 and LFP batteries, are examined through simulations and experiments to investigate their TRP behavior. The findings reveal that: (1) A well-designed AB battery configuration can effectively suppress TR, achieving a balance between high energy density and safety. The high TR trigger temperature and specific heat capacity of LFP batteries play a vital role in impeding TRP. (2) The 8L8L battery configuration successfully suppresses TRP, while the 88L88 configuration requires the addition of heat-insulating sheets for effective TRP suppression. (3) Increasing the number of LFP batteries proves to be an effective approach in preventing TRP. For instance, configurations such as 88LL88 and 888888LL888888 demonstrate no occurrence of TRP. The study concludes by summarizing the TRP characteristics of different AB battery configurations, offering valuable insights for the design of high-safety battery packs. [ABSTRACT FROM AUTHOR]

Qualified thermal management is an important guarantee for the stable work of electronic devices. However, the increasingly complex cooling structure needs several hours or even longer to simulate, which hinders finding the optimal heat dissipation design in the limited space. Herein, an approach based on conditional generative adversarial network (cGAN) is reported to bridge complex geometry and physical field. The established end-to-end model not only predicted the maximum temperature with high precision but also captured real field details in the generated image. The impact of amount of training data on model prediction performance was discussed, and the performance of the models fine-tuned and trained from scratch was also compared in the case of less training data or using in new electronic devices. Furthermore, the high expansibility of geometrically encoded labels makes this method possible to be used in the heat dissipation analysis of more electronic devices. More importantly, this approach, compared to the grid-based simulation, accelerates the process by several orders of magnitude and saves a large amount of energy, which can vastly improve the efficiency of the thermal management design of electronic devices. [ABSTRACT FROM AUTHOR]

The timely detection and accurate differentiation of concurrent diverse faults within lithium-ion battery packs are essential for triggering targeted countermeasures by the battery management system, thereby ensuring the safe and stable operation of the battery system. Existing methods for multi-fault diagnosis in lithium-ion battery packs often assume that different types of faults do not occur simultaneously and face difficulties when determining accurate diagnosis thresholds. Therefore, this work proposes a method based on random convolution kernel transformation and Gaussian process classifier to achieve concurrent multi-fault diagnosis of lithium-ion battery packs without establishing battery models or setting diagnosis thresholds. First, an interleaved voltage measurement circuit is employed to capture information about various faults without increasing the number of sensors. Subsequently, a multitude of convolution kernels with random parameters are employed to extract features that effectively represent various fault patterns from voltage measurements. Finally, a diagnosis model based on a Gaussian process classifier is constructed to detect and isolate different types of concurrent faults while integrating the utilized interleaved voltage measurement circuit to pinpoint the specific locations of fault occurrences. The experimental results demonstrate that the proposed method can achieve a diagnosis accuracy of 98.44%, and thus confirms its effectiveness and feasibility. • The proposed method is capable of diagnosing concurrent multiple faults. • The proposed method does not require setting thresholds and is independent of models. • The proposed method takes into account the inconsistency among cells. • Earlier-stage micro short circuit and concealed connection faults are diagnosed. [ABSTRACT FROM AUTHOR]

To design such a hybrid battery thermal management system (BTMS), it is crucial to establish a practical and realistic approach from the point of view of: i. simulated operating conditions, ii. assumed materials/compounds, iii. Fast-charging performance test. To avoid oversizing, this work considers the World Harmonized Light-duty Vehicle Test Procedure Class 3 (WLTP3) driving cycle, instead of constant charge/discharge rates. Power requirements of a medium-sized vehicle during this WLTP3 cycle have been used to estimate the heat generated by the proposed battery module (18650 NMC cylindrical cells, hexagonal arrangement). This allows the minimum mass required by the phase change materials (PCM) to maintain the battery module at a given temperature threshold to be determined. Once this PCM mass requirement was established, a comprehensive optimization of the key thermal properties that characterize PCMs was carried out, investigating carbon-based additives (CBAs) to improve the low thermal conductivity of PCMs. The results show that the proposed approach can sustain up to 10 consecutive WLTP3 driving profiles without the need for additional energy input. This approach passively minimizes energy consumption during operation and absorbs up to 27 % of the heat emitted by the cell during fast charging, reducing the liquid cooling power requirement. • A hybrid BTMS composed of ssPCMs and liquid cooling is optimized. • WLTP3 drive cycle used instead of constant rates are used to size PCM thickness. • Hexagonal cell arrangement ensures minimum space use in battery packs. • Optimal properties: Cp eff ∼85 kJ/(kg·K) and k eff ∼8 W/(m·K) with 20 wt% additive. • SsPCM holder absorbs 27 % of battery heat during fast charging. [ABSTRACT FROM AUTHOR]

Battery safety design is important to consider from the individual Li-ion cell to the level of the macro-system. On the macro-level, failure in one single cell can lead to propagation of the thermal runaway and rapidly set a whole battery pack on fire. Factors that can impact the propagation outcome, such as cell model/chemistry and electrical connection are here investigated using a combination of measurements. Several abusive tests were conducted, combining two different cell models (Molicel P42A and LG M50, both 21700s) in series and parallel connections (16 tests per configuration). Overall, a propagation outcome of 56% was measured from the 32 conducted tests, a minimum temperature of 150 °C was required to initiate propagation, and the fastest propagation occurred in 123 s. Temperature measurements were higher in series connected cells, initiating the discussion of cell chemistry and internal resistance on this effect. The difference in current-flow during thermal runaway in series and parallel connections, and how this can affect the temperature evolution is further discussed. Spatio-temporal mapping of X-ray radiography allowed us to derive the speed of thermal runaway evolution inside the battery and has shown that series connected cells, in particular P42A, occur faster. It was further observed that deviant sidewall behaviors such as temperature-induced breaches and pressure-induced ruptures occurred in P42As only respective nail-penetrated cells only. • 56% chance of Li-ion battery failure propagation for abusive test scenarios conducted. • Spatio-temporal mapping of Li-ion battery failure from High-Speed X-ray Imaging. • Cell chemistry and electrical connection influence failure temperature and speed. [ABSTRACT FROM AUTHOR]

The demand for thermal management in electronic packaging (EP) and its allied industries, especially in high-power electronics, has grown in the last three decades due to the continuous miniaturization of electronic components. The thermal management of EP warrants metal/alloys/composite with uniquely low thermal expansion and high thermal conductivity. Controlled expansion (CE) materials play a significant role and impart tunable thermal properties. The first and second generations of CE alloys, like Invar, Kovar, and Elinvar, are unsuitable to provide high thermal conductivity for heat sinking along with low density, which are essential for EP materials. The third-generation hypereutectic Al-Si alloys overcome these limitations. The capability to tune the CTE values of the Al-Si CE alloys combined with their lower densities and high thermal conductivities has made them a preferred choice for electronic applications, such as carriers and heat sinks. However, poor machinability and the inability to prepare geometrically complex Al-Si CE alloy with conventional manufacturing processes pose challenges. A paradigm shift is taking place in fabricating components through additive manufacturing and friction stir processing, assisting in mitigating machining and shape complexity. The present work attempts to provide comprehensive details on the properties, microstructures, and processing techniques of hypereutectic Al-Si CE alloys and recent advancements. [ABSTRACT FROM AUTHOR]

As epoxy resin (EP) is widely used in the microelectronic field, it is essential to improve its electromagnetic wave (EMW) absorption and flame retardancy simultaneously. In this work, we synthesized a novel nanohybrid, RMN (Fe 3 O 4 /NHS@M(OH)(OCH 3)@rGO (M = Co, Ni)), with petal-shaped anisotropic interfaces, by using graphene oxide as the core and the 2D nanosheets M(OH)(OCH 3) (M = Co, Ni) as the petal, with nickel hydroxystannate and ferrite as further modifications. The RMN combines carbon-based materials, ferrites and conductors, and represents the petal-like structure with rich nondirectional interfaces. The results show that EP composite containing 25 wt% RMN represented excellent EMW absorption, with a minimum reflection loss of −55.79 dB (with 7.4 mm thickness at 3.1 GHz). Moreover, the EP composite with 15 wt% RMN (EP/RMN700-3) had the lowest peak heat release rate of 470.9 kW m−2, which was 69.7 % lower than pure EP, showing a significantly improving in flame retardant. The thermal conductivity efficiency of EP/RMN700-3 increased to 128.4 % compared with the pure EP, which effectively reduces fire risk caused by heat accumulation. This study provides a valuable solution to overcome the challenges of EMW absorption and flame retardant for EP in the microelectronic materials field. [Display omitted] • The nonoriented petal-like structure provides rich interface. • Carbon materials, ferrites and conductors support the multiple absorbing mechanisms. • EMW absorption, flame retardant and thermal management suit for electronic packaging. [ABSTRACT FROM AUTHOR]

Thermal discomfort is a driver of negative user experiences with modern VR headsets since they are similar to head-worn gaming computers. Here, we examined the effect of microclimate temperature (MCT; i.e., the air between headset and user) and the effect of standing and seated use on thermal discomfort for a goggle style headset. Users played VR games across three 48-min sessions with different thermal profiles ranging between 28°–43 °C. Perceived thermal and weight discomfort were rated by participants every 12-min. Thermal, but not weight comfort declined during the study period as MCT increased. Users sweat more and had greater forehead temperatures while standing with the lowest thermal profile, suggesting thermal management is more critical for active experiences. Overall, this study recommends MCT should be kept below 36 °C. Finally design for thermal comfort should be tailored to the individual, experience duration and activity level. • Thermal discomfort is an important design factor for VR headsets. • Microclimate temperatures above 36 °C decrease user discomfort. • Lower microclimate temperatures should be a target for active or roomscale experiences. • Headset cleanability is important as increased temperatures drove increased sweating. • Monitoring user skin and microclimate temperature or humidity may help users identify optimal times for rest breaks. [ABSTRACT FROM AUTHOR]