High Discharge Rates Research Articles

Investigation on the thermal management performance of a non-contact flow boiling cooling system for prismatic batteries

It is a great challenge to control the temperature of high energy-density lithium-ion batteries within an appropriate working range during rapid charging and discharging with a battery thermal management system (BTMS). As a hot topic in current BTMS research, boiling cooling technology with high heat transfer efficiency is a reliable way to solve these thermal management problems. In this study, a novel thermal management system for prismatic batteries based on cooling by non-contact flow boiling is proposed, and various cold-plate structures are considered with different numbers and locations of coolant inlets and outlets inside the cold plate cavity, and with different numbers and arrangements of ribs and fins. A three-dimensional transient model was conducted to investigate the effect on the cooling performance of the boiling BTMS of several variables — notably inner-channel design schemes, the number of ribs or fins in the cold plate, coolant inlet temperatures, and inlet Reynolds numbers. The results indicate that among the six design schemes that were considered, the best comprehensive heat transfer performance is achieved with two pairs of inlets and outlets, a vertical fin arrangement, and fin height equal to 3/4 of the inner channel dimension. With an increase in the number of fins, the maximum temperature and maximum temperature difference of the structures that were considered decrease by no <0.8 °C and 0.2 °C, respectively. Also, the temperature uniformity of the battery pack can be improved by appropriately increasing the coolant inlet temperatures and reducing the inlet coolant flow rate. When the number of fins is 19, the inlet temperature is 29 °C, and the inlet Reynolds number is 893, the preferred BTMS is always able to maintain its maximum temperature below 35.67 °Cand the maximum temperature difference to below 4.47 °C, at 3C high discharge rate.

Introducing a flexible insulation network to the expanded graphite-based composite phase change material to enhance dielectric and mechanical properties for battery thermal management

Expanded graphite (EG)-based composite phase change materials (PCMs) are often applied in battery thermal management due to their excellent thermal and leakage-proof performance. However, the high electrical conductivity and poor adaptability have become critical limitation. Herein, a novel composite phase change material (CPCM) with high resistivity and flexibility is synthesized for extensive battery thermal management. Natural rubber formed a flexible insulation network between expanded graphite and OP44E PCM. The CPCM possesses a high energy storage density (156.5 J/g), high improved resistivity (2700 Ω·cm), and excellent thermal conductivity (3.4 W/m·K). Moreover, the flexibility and shape adaptability properties of the CPCMs can be achieved at room temperature and are especially promoted when the phase change occurs. The resultant CPCMs show high efficiency and reliability of thermal management by keeping the operating temperature of the battery pack within 45 °C and temperature difference within 2 °C under 3 C high-rate discharge cycles. Our works provide a promising choice for efficient heat-related applications.

Noise and vestibular perception of passive self-motion.

Noise defined as random disturbances is ubiquitous in both the external environment and the nervous system. Depending on the context, noise can degrade or improve information processing and performance. In all cases, it contributes to neural systems dynamics. We review some effects of various sources of noise on the neural processing of self-motion signals at different stages of the vestibular pathways and the resulting perceptual responses. Hair cells in the inner ear reduce the impact of noise by means of mechanical and neural filtering. Hair cells synapse on regular and irregular afferents. Variability of discharge (noise) is low in regular afferents and high in irregular units. The high variability of irregular units provides information about the envelope of naturalistic head motion stimuli. A subset of neurons in the vestibular nuclei and thalamus are optimally tuned to noisy motion stimuli that reproduce the statistics of naturalistic head movements. In the thalamus, variability of neural discharge increases with increasing motion amplitude but saturates at high amplitudes, accounting for behavioral violation of Weber's law. In general, the precision of individual vestibular neurons in encoding head motion is worse than the perceptual precision measured behaviorally. However, the global precision predicted by neural population codes matches the high behavioral precision. The latter is estimated by means of psychometric functions for detection or discrimination of whole-body displacements. Vestibular motion thresholds (inverse of precision) reflect the contribution of intrinsic and extrinsic noise to perception. Vestibular motion thresholds tend to deteriorate progressively after the age of 40 years, possibly due to oxidative stress resulting from high discharge rates and metabolic loads of vestibular afferents. In the elderly, vestibular thresholds correlate with postural stability: the higher the threshold, the greater is the postural imbalance and risk of falling. Experimental application of optimal levels of either galvanic noise or whole-body oscillations can ameliorate vestibular function with a mechanism reminiscent of stochastic resonance. Assessment of vestibular thresholds is diagnostic in several types of vestibulopathies, and vestibular stimulation might be useful in vestibular rehabilitation.

Synthesis and characterization of Co-free NMA cathodes for fast charging lithium-ion batteries

The new high nickel cathode LiNi1−x−yMnxAlyO2 (NMA) has attracted the attention of researchers, but the high rate performance has shortcoming compared to the conventional cobalt-cathode. In this paper, NaAlO2 was used as the aluminum source to effectively inhibit the preferential precipitation of Al(OH)3 and the chemical composition was uniformly distributed in particles. LiNi0.80Mn0.1Al0.1O2 (NMA80), LiNi0.90Mn0.05Al0.05O2 (NMA90) and LiNi0.95Mn0.025Al0.025O2 (NMA95) cobalt-free materials were synthesized by this optimized chemical co-precipitation method and calcinations and all three materials show high crystallinity and purity. The electrochemical performance and phase characterization analysis of Ni-Mn-Al materials were carried out and the effects of Al and Mn elements on the materials were investigated. The specific capacity of NMA95 is 210.6 mAh/g at 0.1 C under a voltage range of 2.75–4.30 V and NMA90 can also reach 201.1 mAh/g. In addition, NMA95 and NMA90 also have excellent specific capacity at 1 C, the discharge capacity are 195.3 and 183.2 mAh/g respectively. However, the cyclic stability of NMA95 at 1 C is slightly inadequate with 81.10% retention rate and NMA90 is the best with 95.52% retention rate. As for NMA80, the overall capacity is low. In particular, the rate performance of NMA90 is much higher than the other two materials. The discharge capacity of NMA90 can still reach 172.3 mAh/g at 5 C high discharge rate. Excellent specific capacity at high rate is promising for the development of fast charging technology. NaAlO2 effectively control the precipitation rate of Al, and the rate performance of the synthetic material is optimized. It is expected that performance of NMA for next-generation lithium-ion batteries could be improved by this process.

Ti–Fe based alloys prepared by ball milling for electrochemical hydrogen storage

In this study, the Ti1.04Fe0.6Ni0.1Zr0.1Mn0.2Sm0.06 composite was prepared by using vacuum induction melting under inert atmosphere. Then, the specimen was milled with 5 wt% Ni powders for 10–40 h to realize the general improvements in hydrogenation performance. The phase component was determined and the morphology and microscopic structure were observed using XRD, SEM and HRTEM, respectively. The electrochemical properties of the alloys were studied. The results showed that the as-milled specimens got the maximal discharge capacity without any activation. It reached 305 mAh/g for the 30 h milling specimen, which was better than the other specimens. Besides, ball milling can enhance the electrochemical cyclic stability of the experimental alloys. The capacity retention rate (S100) increased from 57.6 to 70.2% after 100 charging and discharging cycles with increasing milling duration from 10 to 40 h. The high rate discharge ability of the 30 h milling specimen had the maximal value of 92.8%.

Synthesis of Ni nanoparticles embedded porous Mo2C nanospheres for enhancing the electrochemical hydrogen storage properties of Co2B material

The porous Mo2C nanospheres were prepared by a high temperature calcination process. Different proportions of Ni nanoparticles were anchored and evenly distributed within the internal structure of porous Mo2C nanospheres via a hydrothermal process. Co2B hydrogen storage material was synthesized by a high temperature solid phase method. The Co2B + Mo2C and Co2B + Ni/Mo2C composites were manufactured via ball milling to improve the electrochemical hydrogen storage properties of Co2B. Eventually, the active materials doped Co2B composites electrodes revealed higher discharge capacities than conventional Co2B. More electrochemical active sites were provided for hydrogen adsorption and charger transfer owing to the extraordinary porous nanostructure and large specific surface area of Mo2C nanospheres. Moreover, the loaded Ni nanoparticles could further promote the electrical conductivity and electrocatalytic activity of Co2B. As a result, the Ni/Mo2C-1 modified Co2B electrode achieved a highest discharge capacity of 688.7 mAh/g. The two active species of porous Mo2C nanospheres and Ni nanoparticles played a synergistic role during the charging/discharging processes. In addition, the high-rate dischargeability (HRD), kinetic properties and corrosion resistance of Co2B were improved with the addition of Mo2C and Ni/Mo2C-1.

Enhanced electrochemical and thermal behavior of lithium-ion batteries with ultrathick electrodes via oriented pores

The increasingly extensive application scale compels the development of lithium-ion batteries toward higher energy densities to eliminate endurance anxiety. Developing ultrathick electrodes to compress the proportion of inactive components is the most direct strategy to improve battery energy densities, although overshadowed by the enthusiasm of searching for new chemistry; however, sluggish ion transport kinetics, especially at high discharge rates, is the main challenge faced by thick electrodes. Here, we demonstrate two variants of oriented pore structures to enable ion fast transport in thick electrodes, and develop a quasi-3D electrochemical-thermal coupled model for lithium-ion batteries based on an open-source computational fluid dynamics platform to investigate their electrochemical and thermal behavior. The results show that the oriented pore electrodes yield an over 2-fold increase in the areal energy density of full-cells at the high discharge rate of 3C, and have a more uniform local distribution of Li ions in both electrolyte and electrodes. Meanwhile, the heat generation rate of battery can be reduced clearly due to their lower ohm resistance. Additionally, a comprehensive critical parameter analysis of oriented pores is performed with the aim of providing a further understanding for ultrathick electrodes that can help maximize the areal energy density of full-cells.

Slurry-Coated LiNi0.8Co0.1Mn0.1O2-Li3InCl6 Composite Cathode with Enhanced Interfacial Stability for Sulfide-Based All-Solid-State Batteries.

The implementation of all-solid-state lithium batteries (ASSLBs) is regarded as an important step toward the next-generation energy storage systems. The sulfide solid-state electrolyte (SSE) is a promising candidate for ASSLBs due to its high ionic conductivity and easy processability. However, the interface stability of sulfide SSEs toward high-capacity cathodes like nickel-rich layered cathodes is limited by the interfacial side reaction and narrow electrochemical window of the electrolyte. Herein, we propose introducing the halide SSE Li3InCl6 (LIC) with high (electro)chemical stability and superior Li+ conductivity to act as an ionic conductive additive in the Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM) cathode mixture through a slurry coating, aiming to build a stable cathode-electrolyte interface. This work demonstrates that the sulfide SSE Li5.5PS4.5Cl1.5 (LPSCl) is chemically incompatible with the NCM cathode, and the indispensable role of the substitution of LPSCl with LIC in enhancing the interfacial compatibility and oxidation stability of the electrolyte is highlighted. Accordingly, this new configuration shows superior electrochemical performance at room temperature. It shows a high initial discharge capacity (136.3 mA h g-1 at 0.1C), cycling performance (77.4% capacity retention at the 100th cycle), and rate capability (79.3 mA h g-1 at 0.5C). This work paves the way for investigating interfacial challenges regarding high-voltage cathodes and provides new insights into possible interface engineering strategies.

An ultrafast rechargeable and high durability lithium metal battery using composite electrolyte with the three-dimensional inorganic framework by Li6.4La3Zr1.4Ta0.6O12 surface functionalization

The liquid electrolyte used in traditional lithium-ion batteries has risks of leakage, combustion and explosion. Solid electrolyte is one of the effective strategies to solve the safety problems of lithium-ion batteries. And the use of solid electrolytes makes it possible to use lithium metal as an anode to achieve higher energy densities. At present, the main factors restricting the performance improvement of all-solid-state lithium batteries are the low electrochemical performance of electrolytes and poor solid-solid interface contact. The composite electrolyte has the advantages of both inorganic materials and polymers, but its electrochemical performance is still not up to the requirements of use. In situ synthesis of LaRuO3 with perovskite structure on the surface of Li6.4La3Zr1.4Ta0.6O12(LLZTO) induces the formation of Li2Zr2O7 while introducing defects. The Li2Zr2O7 phase "welds" inorganic particles into three-dimensional(3D) inorganic framework, increasing the reaction sites between inorganic fillers and polymers. Compared with the primitive sample, the ionic conductivity of the modified electrolyte is increased by an order of magnitude at room temperature, wherein the lithium-ion conductivity of the composite electrolyte with 3% LaRuO3 is as high as 6.06 × 10−4 S cm−1. At 5C, the discharge specific capacity of LiFePO4 | [email protected] 3% LRO | Li can reach 114.6 mAh g−1; After 400 cycles, the discharge specific capacity remains at 129.6 mAh g−1. Under the same conditions, the discharge specific capacities of the unmodified samples are only 92.4 mAh g−1 and 35 mAh g−1. The high rate discharge performance of solid-state lithium metal battery supports the high torque output of motor, which improves the acceleration performance of electric vehicles or ships. The high capacity and excellent cycle performance of solid-state lithium metal battery can significantly extend the driving range and service life of electric vehicles.

Modern Developments for Textile-Based Supercapacitors.

Smart textiles are transforming the future of wearable technology, and due to that, there has been a great deal of new research looking for alternative energy storage. Supercapacitors offer high discharge rates, flexibility, and long life cycles and can be integrated fully into a textile. Optimization of these new systems includes utilizing electrically conductive materials, employing successful electrostatic charge and/or faradaic responses, and fabricating a textile-based energy storage system without disrupting comfort, washability, and life cycle. This paper examines recent developments in fabrication methods and materials used to create textile supercapacitors and what challenges still remain.

Battery Thermal Management: An Application to Petrol Hybrid Electric Vehicles

Battery thermal management systems (BTMS) in hybrid electric vehicles can be complex and heavy. They tend to increase energy consumption, leading to higher carbon dioxide emissions. In this study, a new approach was investigated for the potential use of four fuel components as coolants for direct liquid-cooled (LC)-BTMS, N-Pentane, N-Hexane, N-Butane, and Cyclo-Pentane. The performance of the fuel components was numerically analysed and CFD modelled using ANSYS Fluent software. Several meshing iterations of the lithium-ion battery (LIB) module were performed to conduct mesh independence check for higher accuracy and less computational time. The LIB module was simulated, in comparison to a free air convection (FAC)-BTMS as a benchmark, at three discharge rates (1C, 1.5C, 2C) for each of the inlet velocity values (0.1, 0.5, 1 m/s). Results show that FAC-BTMS exceeded the LIB module optimal operating temperature range (293–313 K) at 2C. On average, at the worst condition (lowest inlet velocity and highest discharge rate), all fuel components of the LC-BTMS were able to maintain the LIB module temperature below 288 K. That is at least 4.7% cooler compared to FAC-BTMS, which renders the new approach viable alternative to the conventional BTMS.

STUDY OF INTERMIXING OF LEAD ACID - LITHIUM ION CHARGING &amp; DISCHARGING CHARACTERISTICS

Earlier Lead Acid batteries were available and used widely since Lithium Ion batteries were not discovered .The Lead Acid are still used since they have low cost of initial investment and have low specific energy and are capable of high discharge rates . When Lithium Ion batteries came into practice , they were found to be having light weight , able to provide constant power ,are temperature tolerant and charging is fast and safe .Though Lead Acid battery are cheap in initial investment but lithium Ion battery although costly requires less investment and service . Since now days both batteries intermixed charging is used. The mobile charging is done in car itself. The car charged from lead acid or lithium ion depends upon type of battery used. Whereas mobile has lithium ion battery. So when mobile charging is done in car, there is intermixing of two batteries. And so a study forcasing the characteristics nature in regards to charging and discharging regimes i.e. state of charge and current nature hood during these period is enviable. So now we are charging Lithium Ion battery with Lead Acid or Lithium Ion or vice –versa .So due to this at times, we observe that there is too much delay in charging. So it becomes evident to check the Charging and Discharging characteristics of both Lead Acid and Lithium Ion batteries separately and also through their series-parallel combinations to discover the malfunctioning in it in order to raise the points so that further more work could be done in this respect . By studying the nature both through the display and waveforms , we are able to demonstrate the peculiarities and able to derive the basic inbuilt in their charging and discharging patterns. Thus we are getting much better throughput in understanding. “Batteries with good characteristics will help the user to operate their devices safely .A good battery has to be dependable and reliable on load varying working conditions .A rectified Battery management system not only possess good energy density but it also not affected by the temperature variations developed in working environment .So an attempt is made to survey the SOC and current characteristics to understand their limitations.

STUDY OF BATTERY CHARGING AND DISCHARGING CHARACTERISTICS OF DIFFERENT BATTERIES ON DIFFERENT LOADS

Earlier Lead Acid batteries were available and used widely since Lithium Ion batteries were not discovered .The Lead Acid are still used since they have low cost of initial investment and have low specific energy and are capable of high discharge rates . When Lithium Ion batteries came into practice , they were found to be having light weight , able to provide constant power ,are temperature tolerant and charging is fast and safe .Though Lead Acid battery are cheap in initial investment but lithium Ion battery although costly requires less investment and service . Since nowdays both batteries intermixed charging is used . The mobile charging is done in car itself. The car charged from lead acid or lithium ion depends upon type of battery used . Whereas mobile has lithium ion battery . So when mobile charging is done in car , there is intermixing of two batteries. And so a study forcasing the characteristics nature in regards to charging and discharging regimes i.e state of charge and current naturehood during these period is envitable . So now we are charging Lithium Ion battery with Lead Acid or Lithium Ion or vice –versa .So due to this at times , we observe that there is too much delay in charging . So it becomes evident to check the Charging and Discharging characteristics of both Lead Acid and Lithium Ion batteries separately and also through their series-parallel combinations to discover the malfunctioning in it in order to raise the points so that further more work could be done in this respect . By studying the nature both through the display and waveforms , we are able to demonstrate the peculiarities and able to derive the basic inbuilt in their charging and discharging patterns . Thus we are getting much better throughput in understanding . “Batteries with good characteristics will help the user to operate their devices safely .A good battery has to be dependable and reliable on load varying working conditions .A rectified Battery management system not only possess good energy density but it also not affected by the temperature variations developed in working environment .So an attempt is made to survey the SOC and current characteristics to understand their limitations .

A Qualitative Analysis of Hospitalist Perceptions of Self-Directed Discharge Among Inpatients with Opioid Use Disorder

Background: People with opioid use disorder (OUD) have high rates of hospital admissions and high rates of patient-directed discharge, leading to significant morbidity and mortality. In this study, we aimed to understand hospitalist attitudes toward patients with OUD leaving before treatment completion and their willingness to collaborate with patients in future initiatives focused on improving the experience of hospital-based care for patients with OUD. Methods: We conducted semi-structured interviews with hospitalists at two hospitals in Philadelphia, PA to explore their perspectives on social and structural factors that contribute to patients with OUD leaving the hospital before treatment completion. Interviews were recorded, transcribed, and coded with NVivo using conventional content analysis. Results: Twenty-two hospitalists (64% female, 72.7% White, mean age 37) were interviewed between February and April 2021. Hospitalists listed the following as reasons for patients with OUD leaving before treatment completion: untimely and inadequate pain/withdrawal treatment, limited prescribing options in medications for OUD, restrictive visitor and smoking policies, and patient social and other obligations. Twenty out of 22 hospitalists were willing to engage in collaborative patient-centered care but noted institutional barriers. Conclusion: Hospitalists stated willingness to collaborate with patients on identifying and developing systems-level solutions that would allow for patient-centered care. In-hospital access to addiction consult service, staff with lived experience, and other culturally competent resources are key to reducing self-directed discharge, as is training to address stigma and reframe perceptions of appropriate dosing for pain and withdrawal. Hospitalists note a need for transitions to outpatient care after hospital discharge.

Toward the High-Performance Lithium Primary Batteries by Chemically Modified Fluorinate Carbon with δ-MnO2.

Li/CFx battery is one of the most promising lithium primary batteries (LPBs) which yields the highest energy density but with poor rate capability. This Achilles'' heel hinders the large-scale applications of Li/CFx batteries. This work first reports a facile chemical modification method of CFx with δ-MnO2 . Having benefited from the chemical bonding, the electrochemical performance at high-rate discharge is remarkably enhanced without compromising the specific capacity. The coin cells exhibit an energy density of 1.94 × 103 Wh kg-1 at 0.2 C, which is approaching the theoretical energy density of commercial fluorinated graphite (2.07 × 103 Wh kg-1 ). A power density of 5.49 × 104 W kg-1 at 40 C associated with an energy density of 4.39 × 102 Wh kg-1 , which is among the highest value of Li/CFx batteries, are obtained. Besides, the punch batteries achieve an ultrahigh power density of 4.39 × 104 W kg-1 with an energy density of 7.60 × 102 Wh kg-1 at 30 C. The intrinsic reasons for this outstanding electrochemical performance, which are known as the fast Li+ diffusion kinetics guided by thin δ-MnO2 flakes and the low formation energy barrier caused by chemical bonding, are explored by the galvanostatic intermittent titration technique (GITT) and theoretical calculations.

A shape-memory, room-temperature flexible phase change material based on PA/TPEE/EG for battery thermal management

The development of conventional battery thermal management (BTM) based on phase change material (PCM) is restricted by its low thermal conductivity, leakage and high rigidity. To solve these problems, the thermally induced flexible phase change materials (FPCMs) have been proposed, but their flexibility only manifests at temperatures above the phase change temperature, which is detrimental to the assembly at room temperature. Herein, using paraffin (PA) as PCM, thermoplastic polyether ester elastomer (TPEE) as flexible support material and expanded graphite (EG) as heat transfer enhancement material, a novel FPCM with shape memory property and wider flexible temperature (−15 to 60 °C) was successfully prepared through melt-mixing method. And then it was skillfully assembled on power batteries at room temperature through flexibility in conjunction with shape memory property. On this basis, the flexibility of FPCM can be utilized to reduce thermal contact resistance during the whole process of battery operation. The results revealed that the measured thermal contact resistance of the above BTM was 0.272 °C/W, lower than that of previous thermally induced FPCM reported. Furthermore, the maximum temperature of the battery module with the passive BTM based on FPCM could be maintained below 55 °C and the temperature difference was within 3 °C under the high discharge rate of 5C and 40 °C ambient temperature.

Developing ternary composite phase change materials with two different phase change temperatures for battery thermal management

Paraffin wax (PW), as a phase change material (PCM), with high latent heat, is likely to be used in battery thermal management. However, the application of PW is remarkably limited due to its low thermal conductivity, poor mechanical properties, and easy leakage after melting. Here, we prepared a novel ternary composite phase change material (CPCM) to eliminate melt leakage with high thermal conductivity, stable morphology, and two different phase change temperatures. The step cooling data confirmed that when the proportions of myristic acid (MA), palmitic acid (PA), and PW are 3:1:4, there are two phase transition points at 35.88 ℃ and 46.26 ℃, respectively. The addition of short carbon fiber (SCF) and carbon black (CB) with different particle sizes significantly improved the thermal conductivity of the PCM up to 8.7 W/mK. The addition of silicone rubber (SR) film not only avoids the liquid PCM leakage but also improves its mechanical properties. At the highest discharge rate, the maximum temperature of a large capacity square terpolymer lithium battery is 47.03 ℃ due to excellent thermos conductivity. Furthermore, the ternary CPCM does not melt completely at the end of discharge. Compared with the CPCM with single phase transition temperature, the two different phase transition temperatures have excellent balanced performance. After two phase change temperature controlling processes, the rise of battery surface temperature is effectively delayed, and the working time of the CPCM is prolonged. Hence, the developed CPCM is more suitable for the battery thermal management system (BTMS).

Experimental study on nano-encapsulated inorganic phase change material for lithium-ion battery thermal management and thermal runaway suppression

Although widely used in the thermal management of lithium-ion batteries, organic phase change material (PCM) with flammability has been reported to aggravate the fire risk and heat hazards of battery thermal runaway (TR). To reduce the fire risk of PCM during battery TR, an encapsulated inorganic PCM (EIPCM) was synthesized by a nano-encapsulation method of interfacial polymerization in this study. Na2HPO4·12H2O was used as the inorganic core material and silica was adopted as the encapsulated matrix to reduce the inherent defects. The synthesized EIPCM was characterized by a series of tests, demonstrating good phase change properties and thermal stability. The melting temperature of the EIPCM was measured as 51 °C associated with the latent heat of 111.69 kJ/kg. The thermal management effects of EIPCM were further investigated on battery modules at various discharge rates. The results show that EIPCM exhibited good cooling performance, leading to a 23.7% reduction of the peak battery temperature from 86.6 °C to 66.1 °C at a high discharge rate of 3C, and the temperature difference was kept within 3 °C. The TR behavior of batteries with IPCM was further explored, and the results indicate that EIPCM could delay the occurrence of TR by 495 s and decrease the peak surface temperature of the battery by 194 °C. With the nonflammable EIPCM, the fire of TR showed rapid extinction, protecting the batteries from heavier fire hazards. It is also found that EIPCM could inhibit the heat propagation of TR. The prepared EIPCM in this work with good thermal management effects and TR suppression performance has great prospects in practical battery applications, energy storage and other fields.

Research Progress of Nanofluid Heat Pipes in Automotive Lithium-ion Battery Heat Management Technology

Power batteries are a crucial component of electric vehicles and other electric equipment. Their long-term high-rate discharge generates a lot of heat, which can lead to battery failure, shortened battery life, and even safety accidents if not managed properly. Due to its high thermal conductivity, the heat pipe can quickly conduct heat away from the battery and separate the heat source from the heat sink. In addition, due to its excellent isothermal performance, the heat pipe can also achieve the characteristics of low-temperature preheating and high-temperature cooling of the power battery by reducing the inhomogeneity of the battery temperature field to reduce the temperature difference. In this paper, we review the current state of the art in thermal management of automotive lithium-ion battery, and highlight the current state of thermal management of batteries based on the combination of nanofluids and heat pipes. Finally, the development of nanofluidic heat pipes in lithium-ion battery heat management systems is prospected.

Experimental and Numerical Investigations of a Thermal Management System Using Phase-Change Materials and Forced-Air Cooling for High-Power Li-Ion Battery Packs

The thermal management system of a power battery is crucial to the safety of battery operation; however, for the phase-change material (PCM) thermal management system of a battery, the thermal cycling of phase-change material under large discharge rate conditions will lead to thermal conductivity degradation and thermal stress problems. A method of manufacturing PCM containers with metal fins to package pure phase-change material is put forward to solve the problem. The system temperature under different conditions is studied using numerical and experimental methods. A thermal resistance model is built to analyze the thermal transfer performance of PCM containers with fins. The results show that the PCM container structure can effectively control the battery temperature within the suitable temperature range under the low discharge rate, but the maximum temperature of the battery pack at the high discharge rate of 3 C will exceed the optimum operating temperature range. Adding fins can reduce the maximum temperature and improve the system temperature uniformity. By combining fins with forced-air cooling, the maximum temperature and maximum temperature difference of the battery pack at a high discharge rate can be effectively reduced.