Inadequate Temperature Research Articles

Performance comparison of battery cold plates designed using topology optimization across laminar and turbulent flow regime

Liquid cooling with cold plates offers an efficient solution for battery thermal management. However, conventional cold plates in turbulent regime often result in inadequate temperature uniformity within battery modules and generate significant pressure drops. In this study, we employ the turbulent conjugate heat transfer topology optimization method based on the k-ε turbulent model for cold plate design. Then we derive two novel cold plate designs based on the laminar and turbulent topology optimization method, respectively, and the effectiveness of the two design methods are compared. A multi-objective function which minimizes pressure drop and average temperature is established to balance the thermal and hydraulic performance of the cold plates. The electrochemical-thermal coupled model is utilized to simulate heat production of the battery pack. The fluid flow and heat transfer performance of turbulent topology-optimized cold plate (TTCP) during constant rate discharging is analyzed and compared with that of laminar topology-optimized cold plate (LTCP), serpentine cold plate (SCP), and rectangular cold plate (RCP). Numerical simulation results show that TTCP gives the best overall cooling results among all the designs despite a slight disadvantage against LTCP at very low flow rates. At high-speed turbulent flow (8.488 × 10−2 kg/s), the performance evaluation criterion (PEC) number improvements for TTCP, LTCP, and SCP compared with RCP are 86.7 %, 78.5 %, and 85.4 %, respectively. Hence, cold plate topology optimization using turbulent conditions and methods is recommended for power battery systems, especially those with fast charging/discharging requirements.

Effect of Analytical Method on Vitamin C Tablet Levels Stored under Different Temperature Conditions

Vitamin C tablets are commonly consumed by the public as antioxidant supplements. Vitamin C is highly susceptible to oxidation, which is accelerated by factors such as heat, light, alkali, enzymes, oxidizers, and the presence of copper and iron catalysts. Oxidation will be inhibited if vitamin C is left in an acidic state or at low temperatures. However, many vitamin C tablets are not stored according to recommended conditions due to inadequate temperature control during storage or distribution, leading to changes in their vitamin C levels. Vitamin C levels can be analyzed using the Iodimetry method and UV-Vis spectrophotometry. This study aims to determine the effect of the analysis method on the content of vitamin C tablets stored at various temperature variations. This is an experimental research. The independent variable of this study is the analytical method of determining vitamin C content and the dependent variable of this research is the content of vitamin tablets stored at low temperature (2-6°C), room temperature (27-30°C), and high temperature (48°C). Quantitative analysis of vitamin C levels was conducted using both iodimetry and UV-Vis spectrophotometry methods. The highest vitamin C content was found in the analysis of levels using the UV-Vis spectrophotometry method. Statistical analysis shows significant differences, indicating that the method of analyzing the levels of vitamin C tablets stored under varying temperature conditions affects the levels of vitamin C tablets.

Economic viability and overall performance analysis of optimized Cu-Fe-ZSM-5 catalyst for NOx and particulate matter removal using NH3-SCR

The necessity of a broader working temperature range of NH3-SCR catalysts has been considered as the need of the hour to tackle air pollutants like NOx and particulate matter (PM). The catalysts currently being used pose varied difficulties in the form of sulphur poisoning, inadequate temperature range, catalyst regeneration etc. An innovative and economic bimetallic combination of Cu-Fe on ZSM-5 with minimum weight percentage of metals and optimum efficiency has been synthesized in this study. In this research, we further focus on this Cu-Fe combination, to understand its feasibility for commercial applications. This bimetallic combination, used on the self-synthesized zeolite (ZSM-5), showed a consistent NOx removal efficiency of above 90% over the entire test temperature range, when compared with a commercially available zeolite. This Cu-Fe combination catalyst performed outstandingly in resisting sulphur poisoning and had NOx and PM emission coefficients well below the standard emissions control of Taiwan. It showed a good N2 selectivity as well. The study also analyses the cost-benefit ratio for the production of this catalyst for industrial applications with an annual net profit of around 14,66,124.09 USD for five parallel units.

Enhancing piezoelectric coefficient and thermal stability in lead-free piezoceramics: insights at the atomic-scale

Given the highly temperature-sensitive nature of the polymorphic phase boundaries, attaining excellent piezoelectric coefficient with superior temperature stability in lead-free piezoceramics via direct compositional design remains a formidable challenge. We demonstrate the synergistic improvement of piezoelectric coefficient and thermal stability in lead-free piezoceramics via atomic-scale local ferroelectric structure design. Via modulation of the local Landau energy barrier at doping sites, we effectively mitigate fluctuations in piezoelectric d33. Our approach achieves an impressive d33 of ~430 pC/N with a minimal temperature fluctuation range (△d33 ~ 7%) across the room temperature to 100 °C in potassium sodium niobate ceramics. Further optimization through annealing extends this temperature up to 150 °C (△d33 ~ 8%) while maintaining a high d33 of ~380 pC/N, rivaling the performance of classic temperature stable lead zirconate titanate. This work establishes a framework for addressing the dilemma between high piezoelectric coefficient and inadequate temperature stability in lead-free piezoceramics.

Developing Flowcharts for Hazard Analysis in Seafood Retail: Critical Control Point Verification

Background: Implementing Hazard Analysis and Critical Control Point (HACCP) management across the supply chain is promoted globally to ensure the safety of marine food products due to their rapid quality deterioration. However, many seafood retail stores deviate from adopting these practices. Therefore, in this study, we aimed to create a flowchart based on HACCP and validate it in retail stores. Methods: Chub mackerel (Scomber japonicus), scallops (Patinopecten yessoensis), and whiteleg shrimp (Litopenaeus vannamei) specimens were purchased from a supermarket from August to December 2020. The handling information of these products from receipt to sales was obtained to prepare an HACCP plan for retail stores. Groups adhering to and deviating from flowchart conditions were categorized as Critical Control Point (CCP)-compliant and CCP-deviant, respectively. Four samples of each product for each condition were analyzed. Bacterial viability was evaluated using the flat agar culture method. Escherichia coli and Vibrio parahaemolyticus were detected using the Brilliant Green-Lactose-Bile and material point methods, respectively. Product freshness was assessed by determining K-values using High-Performance Liquid Chromatography. Results were compared using Student’s t-test. Results: At elevated storage temperatures, bacterial growth rates were higher in chub mackerel and whiteleg shrimp than those in scallops. E. coli was not detected in any sample, whereas V. parahaemolyticus was detected in scallops and whiteleg shrimp but not in chub mackerel. CCP-deviant refrigerated scallops had increased V. parahaemolyticus counts; however, it did not differ between the frozen scallop and whiteleg shrimp. K-values increased more rapidly in CCP-deviant chub mackerel, whiteleg shrimp, and refrigerated scallops, but not in frozen scallops. Inadequate temperature control during display and sale markedly deteriorated the quality of marine products. Conclusion: Setting CCPs for marine food product display and sale while controlling temperature can preserve product quality. The flowchart created in this study can be broadly used for marine retail stores.

Investigation of Salmonella enteritidis Growth under Varying Temperature Conditions in Liquid Whole Egg: Proposals for Smart Management Technology for Safe Refrigerated Storage

This study investigates the growth characteristics of Salmonella enteritidis (S. enteritidis) in liquid whole egg under both isothermal and non-isothermal storage conditions to understand the risks associated with inadequate temperature management in the egg industry. Using controlled laboratory simulations, liquid whole egg samples inoculated with S. enteritidis were stored under various isothermal (5, 15, 25, 35, and 45 °C) and non-isothermal conditions (5–10, 15–20, 25–30, 35–40, and 45–50 °C). The growth behavior of the S. enteritidis was analyzed using a two-step predictive modeling approach. First, growth kinetic parameters were estimated using a primary model, and then the effects of temperature on the estimated specific growth rate and lag time were described using a secondary model. Independent growth data under both isothermal and non-isothermal conditions were used to evaluate the models. The results showed that S. enteritidis exhibits different growth characteristics depending on temperature conditions, emphasizing the need for strict temperature control to prevent foodborne illnesses. To address this, a predictive growth model tailored for non-isothermal conditions was developed and validated using experimental data, demonstrating its reliability in predicting S. enteritidis behavior under dynamic temperature scenarios. Additionally, temperature management technologies were proposed and tested to improve food safety during refrigerated storage. This study provides a scientific basis for improving food safety protocols in the egg industry, thereby protecting public health and maintaining consumer confidence amid temperature fluctuations.

Optimizing cooperative catalysis of multiple defective interfaces in Pt/mullite catalysts for NO oxidation

Nitric oxide (NO) oxidation is an integral part of the nitrogen chemical cycle, but competitive activation of NO/O2 over single platinum (Pt)-based catalysts result in inadequate low temperature performance. Here, we constructed catalysts with BiMn2O5/CeO2 and Pt/BiMn2O5 defective interfaces (sufficient activation of NO/O2). The constructed catalyst achieved 95 % NO conversion at 260 °C in NO/O2 atmosphere, superior to most known catalysts. Even after aging (800 °C for 16 h), the NO conversion was up to 76 %. Further, the catalyst can be applied to actual diesel exhaust. Detailed oxygen vacancies (Ov) characterization reveals that BiMn2O5/CeO2 defective interface created by Ce3+-Ov + Mn4+-O ↔ Ce4+-O + Mn3+-Ov promote the activation of NO (on Mn3+ sites) and O2 (on Mn3+-Ov sites). Besides, the Ov on Pt/BiMn2O5 defective interface compensate for the loss of Pt sites ensuring hydrothermal stability. And this construction of multiple defective interfaces develops a pathway for boosting catalytic reactions.

A new bi-directional surface modification cathode based on conventional cathode La0.6Sr0.4Co0.2Fe0.8O3-δ

The commercialization of proton solid oxide fuel cells (H-SOFCs) is hindered by the lack of high active and durable cathode materials exposed to evil operation conditions. Here, this groundbreaking study addresses two critical challenges impeding the practicality of La0.6Sr0·4Co0·2Fe0·8O3-δ (LSCF), one of the most popular proton-conducting cathode materials contemporarily: inadequate temperature activity and durability issues stemming from surface Sr segregation. The research introduces a transformative solution through the creation of a novel nanofiber cathode, denoted as PrBaCo1.4Fe0·6O6-δ@LSCF, comprising a nanoscale LSCF FP host and PBCF NP guest. Advanced electron microscopy and scanning electron microscopy techniques confirm the seamless integration of the two phases, highlighting a distinctive fiber structure adorned with impregnated nanoparticles. Meanwhile, efficiently reducing oxygen vacancies within the LSCF bulk phase significantly suppresses Sr segregation. Systematic simulations based on density functional theory reveal that the incorporation of PSCF reduces the polarization energy barrier. In practical terms, electrochemical testing of a single cell supported by PBCF@LSCF shows a polarization resistance of only 0.053 Ω cm2 at 700 °C, translating to a remarkable fifty percent reduction. Furthermore, a sustained 100-h test reveals no notable decline in performance. Consequently, a novel dual modification approach is proposed for crafting cathodes tailored for SOFCs.

Linking Occupant Behavior and Window Design through Post-Occupancy Evaluation: Enhancing Natural Ventilation and Indoor Air Quality

This study investigates how window design features, such as size, placement, and orientation, might impact occupants’ behavior related to natural ventilation in residential houses and how residents manage natural ventilation to affect indoor air quality (IAQ), comfort, and energy efficiency. By analyzing responses from a questionnaire distributed among 200 occupants, this article reveals that stuffy air, perceived outdoor pollutants, odors, and relative humidity, along with factors like inadequate ventilation, temperature fluctuations, and energy consumption concerns, emerge as primary issues affecting occupants’ comfort and well-being. This study proposes design recommendations for enhancing IAQ, including optimal window placement for cross-ventilation, window-to-wall ratio (WWR) considerations, and the integration of smart window technologies. This research recognizes that window design is not just a technical matter but involves understanding social and behavioral factors as well. By analyzing occupant responses, it aims to provide insights into the socio-technical parameters that should be considered in window design. The findings offer valuable strategies for architects, designers, and homeowners to optimize natural ventilation and underscore the importance of an occupant-centered approach in sustainable building design.

The influence of tool shoulder size and plate position on the characteristics of friction stir welded different aluminum alloys

ABSTRACT Welding is a main manufacturing method for fabricating various engineering components. Fusion welding techniques encounter solidification associated problems while joining light weight structures. Friction stir welding is a solid state welding technique that is developed to address these shortcomings. As the superior conductive properties of AA6101-T6 and AA1350 aluminum alloys, they are frequently utilized in electrical industries. The goal of this study is to examine how the plate position and tool shoulder diameter (D) affect the qualities of these dissimilar Al-alloys joints. It is discovered that plate positioning is the most influential welding parameter in determining the tensile properties of weldment. Furthermore, the joint fabricated with AA6101-T6 as an advancing side material and a 15 mm tool shoulder diameter produces sufficient weld reaction temperature, better plastic flow and tensile properties. However, the joint fabricated with AA1350 as an advancing side material and 12 mm tool shoulder diameter generates inadequate reaction temperature, poor plasticization, and tensile properties. The formation of precipitates as well as the interface layer at the weld nugget is greatly dominated by the tool shoulder size, which affects the wear properties of weldment.

The optimization of roll-bond cold plate based on Taguchi-grey theory for server chips thermal management

The roll-bond cold plate, an economical and straightforward electronics liquid cooling approach, is highly promising to address the increasing electronics chip thermal management challenges. However, the roll-bond cold plate with staggered cellular flow channels, while having a sizable solid-liquid contact area and high heat dissipation potential, suffers from inadequate temperature uniformity and fluidity. This study addresses flow and temperature uniformity issues in current roll-bond cold plates by proposing a design—Direct Liquid Cooling Roll-Bond Plates (DLCRBP) tailored for high-performance server architectures. To investigate how regional combination, cellular diameter, and longitudinal spacing affect both thermal and flow performance, orthogonal experiments with diverse flow channel structures were conducted using the Taguchi-grey theory. COMSOL-based numerical simulation were used to analyze these experiment conditions. Multi-objective optimization, considering pressure drop, heat source temperature uniformity, and coolant temperature difference, was then performed using the grey correlation method. The optimized DLCRBP (A3B5C1) was fabricated, and its performance was compared with the staggered cellular DLCRBP (SCS), which is the control group without optimization, under various inlet flow velocities, heat source powers, and coolant inlet temperatures. Experimental comparisons illustrate that the optimized structure ensures outstanding temperature uniformity even at low inlet flow velocities. Specifically, at an inlet flow velocity of 0.2 m/s, the average and maximum temperature differences on the heat source's upper surface are 36.5 % and 75.3 % lower, respectively, compared to pre-optimization levels. Furthermore, A3B5C1's temperature uniformity improves with higher coolant inlet flow velocity and lower coolant inlet temperatures. At a coolant inlet flow velocity of 0.5 m/s or higher, A3B5C1 sustains the surface temperature of a 600 W chip below the thermal design's safe temperature of 77.8 °C, highlighting its enhanced performance.

Fabrication of the SiC/HfC Composite Aerogel with Ultra-Low Thermal Conductivity and Excellent Compressive Strength.

Aerogels, as a new type of high-temperature-resistant insulation material, find extensive application in aerospace, high-temperature industrial furnaces, new energy batteries, and various other domains, yet still face some limitations such as inadequate temperature resistance and pronounced brittleness. In this work, SiC/HfC composite aerogels were prepared through a combination of sol-gel method, atmospheric pressure drying technique, and carbothermal reduction reaction. The effects of different molar ratios, calcination time, and temperatures on the microstructural features and physicochemical properties of the resulting SiC/HfC composite aerogels were investigated. The aerogel exhibited an elevated BET-specific surface area of 279.75 m2/g, while the sample displayed an extraordinarily low thermal conductivity of 0.052 W/(m·K). Most notably, the compressive strength reached an outstanding 5.93 MPa after a carbonization temperature of 1500 °C, far exceeding the values reported in prior aerogel studies. This research provided an innovative approach for advancing the development of carbide aerogels in the realm of high-temperature applications.

The Use of an Advanced Intelligent-Responsive Polymer for the Study of Dynamic Water-Carbon Dioxide Alternating Displacement.

Addressing the issue of inadequate temperature tolerance in traditional polymers, in this study, we successfully executed a one-step synthesis of intelligent-responsive polymers which have excellent adaptability in water-gas alternating displacement scenarios. Utilizing the fatty acid method, we produced OANND from oleic acid (OA) and N,N-dimethyl-1,3-propanediamine (NND). Upon testing the average particle size in the aqueous solution both prior and subsequent to CO2 passage, it became evident that OANND assumes the form of a small-molecule particle in the aqueous phase, minimizing damage during formation. Notably, upon CO2 exposure, it promptly organizes into stable micelles with an average size of 88 nm and a relatively uniform particle distribution. This unique characteristic endows it with a rapid CO2 response mechanism and the ability to form a highly resilient gel. In the exploration of viscoelastic fluids, we observed the remarkable behavior of the AONND aqueous solution when CO2/N2 was introduced. This system displayed repeatable transitions between aqueous and gel states, with the highest viscosity peaking at approximately 3895 mPa·s, highlighting its viscosity reversibility and reusability properties. The rheological property results that we obtained indicate that an elongated micellar structure is present in the solution system, with the optimal concentration ratio for its formation determined as 0.8, which is the molar ratio of the OANND-NaOA system. In the sealing performance tests, a 1.0 wt% concentration of the gel system exhibited excellent injectability properties. At 80 °C, this gel effectively reduced the permeability of a sand-filled model to 94.5% of its initial value, effectively sealing potential leakage paths or gas fluxes. This remarkable ability to block leakage paths and reduce seepage capacity highlights the material's superior blocking effect and erosion resistance properties. Furthermore, even at a temperature of 90 °C and an injection pore volume (PV) of 3, this plugging system could reduce the permeability of a high-permeability sand-filled model to over 90% of its initial value.

Urban heat island analysis based on high resolution measurement data: A case study in Beijing

Urban heat island (UHI) is a widely concerned urban climate which impacts billions of residents worldwide. Nevertheless, inadequate rigorous air temperature (Tair) measurement has become an obstacle to UHI research and mitigation, especially in megacities like Beijing. In this study, we applied a 1-km hourly Tair dataset interpolated from records of 521 stations in Beijing. The dataset enables us to analyze UHI patterns on a block scale and the impacts of landscapes combined with the local climate zones (LCZ) scheme. Our results indicate that: (1) Tair and its temporal variation in each LCZ vary significantly, which are highly relevant to their morphology and thermal-radiative properties. (2) LCZ 1 and LCZ 2 have the highest nocturnal UHI intensities (UHII). Discrepancies among LCZs also cause various temporal variations in their UHII. (3) The spatial pattern of LCZs affects regional temperature. Area ratio and aggregation extent of LCZ 1&2 show significant positive correlations with regional temperature, while LCZ A&D&G have the opposite regularity. (4) Distinct mitigation strategies are put forward for each subarea in Beijing with various endowments of population and the LCZ structure. The study provides insight into Beijing UHI and plausible mitigation advice in megacities like Beijing.

Design of ultra-efficient and automatically temperature-variable cycle (TVC) Sieverts apparatus for testing sorption properties of hydrogen storage materials

The evaluation of hydrogen sorption properties in materials is crucial for their widespread applications. However, existing volumetric apparatuses often suffer from low accuracy and efficiency due to inadequate calibration techniques, temperature gradients, and limited automation. To address these limitations, a Temperature-Variable Cycle (TVC) Sieverts apparatus has been developed. Besides conventional tests, the device is capable of efficiently performing TVC tests, such as TVC Pressure-Composition-Temperature (PCT) isotherm and kinetics, through the integration of RS485 serial communication and automatic dosing techniques. The instrument's component selection and configuration were described in detail. Furthermore, novel methods for volume calibration and anti-thermal gradient were presented, where a continuous function was proposed to overcome temperature gradients across the entire range of test temperatures. Finally, a series of tests were conducted using La0.5Ce0.5Ni4Co alloy and Mg material as benchmark materials to validate the setup and methods. The accuracy of volumes and the feasibility of the methods were confirmed through null PCT tests and data comparisons of PCT with kinetic of La0.5Ce0.5Ni4Co alloy, respectively. By employing these methods, the accuracy of null tests is improved by nearly tenfold. The efficiency and robustness of the unit were demonstrated through Temperature-Programmed Desorption/Absorption (TPD/TPA), TVC PCT, and TVC kinetics tests on MgH2 powder. The results produced by the TVC system align well with the reliable data in literature.

A Novel Temperature Drift Error Estimation Model for Capacitive MEMS Gyros Using Thermal Stress Deformation Analysis.

Because the conventional Temperature Drift Error (TDE) estimation model for Capacitive MEMS Gyros (CMGs) has inadequate Temperature Correlated Quantities (TCQs) and inaccurate parameter identification to improve their bias stability, its novel model based on thermal stress deformation analysis is presented. Firstly, the TDE of the CMG is traced precisely by analyzing its structural deformation under thermal stress, and more key decisive TCQs are explored, including ambient temperature variation ∆T and its square ∆T2, as well its square root ∆T1/2; then, a novel TDE estimation model is established. Secondly, a Radial Basis Function Neural Network (RBFNN) is applied to identify its parameter accurately, which eliminates local optimums of the conventional model based on a Back-Propagation Neural Network (BPNN) to improve bias stability. By analyzing heat conduction between CMGs and the thermal chamber with heat flux analysis, proper temperature control intervals and reasonable temperature control periods are obtained to form a TDE precise test method to avoid time-consuming and expensive experiments. The novel model is implemented with an adequate TCQ and RBFNN, and the Mean Square Deviation (MSD) is introduced to evaluate its performance. Finally, the conventional model and novel model are compared with bias stability. Compared with the conventional model, the novel one improves CMG's bias stability by 15% evenly. It estimates TDE more precisely to decouple Si-based materials' temperature dependence effectively, and CMG's environmental adaptability is enhanced to widen its application under complex conditions.

Microbiological quality of raw milk: community expansion tanks in Alagoas

Milk is a highly nutritious food consumed by a large part of the population, and due to its nutritional composition, its quality can be altered by the amount of microorganisms present. The objective of this study was to evaluate the microbiological quality of raw milk from community expansion tanks in the state of Alagoas. A total of 160 milk samples were aseptically collected from the three mesoregions of the state for microbiological analysis. It was observed that 10.83% (13/120) of the samples had Staphylococcus coagulase-positive counts lower than 105 CFU/mL, and 10.83% (13/120) had counts higher than 105 CFU/mL. For coliforms, 18.8% (30/160) were found to have counts less than 1.1×103 MPN/mL, while 81.2% (130/160) of the samples had values higher than 1.1×103 MPN/mL. No Salmonella spp. or Listeria spp. were found in any of the samples. Aeromonas spp. was found in 28.7% (46/160) of the samples. For mesophilic microorganisms, 15% (24/160) of the samples were within the standard required by legislation, while 85% (136/160) were outside the established limit of up to 6×105 CFU/mL. Psychrotrophic microorganism counts were higher than 5×106 CFU/mL in 41.9% (67/160) of the samples analyzed. It was concluded from this study that the high microorganism counts in the analyzed milk and the inadequate temperature of the tanks at the time of collection can lead to the production of a low-quality product due to the deteriorative or pathogenic action of the microorganism. Therefore, the implementation of good practices during milking, transportation, and storage of refrigerated raw milk is suggested to prevent contamination of the raw material, ensuring a product with certified quality.

Budidaya tanaman hidroponik melalui pendampingan pemanfaatan limbah anorganik sebagai media tanam di sekolah

Hydroponic farming has emerged as an effective alternative to overcome land limitations, especially in urban and compact residential areas. Focusing on two Madrasah Aliyah in East Lombok, the Community Service Program by the Biology Education Department of Universitas Hamzanwadi implemented hydroponic techniques as an innovative farming method. This initiative aimed to enhance environmental awareness and farming skills among students, while utilizing styrofoam waste as a planting medium. The process included socialization, seedling production, planting, maintenance, and harvesting, using plants such as water spinach, lettuce, and spinach. The implementation method incorporated Participatory Rural Appraisal (PRA), enabling active participation from students and teachers. The program was conducted from March to November 2023 at MA NWDI Juet and MA Ridlol Walidain NW Batu Bangka - Jenggik. The mentoring process involved various stages, from introducing hydroponic techniques to creating planting media and planting, including the use of AB Mix nutrients and rockwool as planting media. The results of the activity showed successful cultivation of hydroponic water spinach, while lettuce and spinach experienced crop failure. The primary causes of this failure were inadequate care, light, and temperature. Nevertheless, the activity successfully educated students on the importance of hydroponic agriculture and creative waste utilization, providing new insights into urban farming. In conclusion, the hydroponic approach can be an efficient solution for cultivating plants in limited spaces, offering educational and environmental benefits. This program also highlighted the potential of styrofoam waste as a hydroponic planting medium, underscoring the importance of waste utilization for environmental sustainability.

Viability of all-solid-state lithium metal battery coupled with oxide solid-state electrolyte and high-capacity cathode

Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g−1 and oxide-based ceramic solid-state electrolytes (SE), e.g., garnet-type Li7La3Zr2O12 (LLZO), all-state-state lithium metal batteries (ASLMBs) have been widely accepted as the promising alternatives for providing the satisfactory energy density and safety. However, its applications are still challenged by plenty of technical and scientific issues. In this contribution, the co-sintering temperature at 500 °C is proved as a compromise method to fabricate the composite cathode with structural integrity and declined capacity fading of LiNi0.5Co0.2Mn0.3O2 (NCM). On the other hand, it tends to form weaker grain boundary (GB) inside polycrystalline LLZO at inadequate sintering temperature for LLZO, which can induce the intergranular failure of SE during the growth of Li filament inside the unavoidable defect on the interface of SE. Therefore, increasing the strength of GB, refining the grain to 0.4 μm, and precluding the interfacial defect are suggested to postpone the electro-chemo-mechanical failure of SE with weak GB. Moreover, the advanced sintering techniques to lower the co-sintering temperature for both NCM-LLZO composite cathode and LLZO SE can be posted out to realize the viability of state-of-the-art ASLMBs with higher energy density as well as the guaranteed safety.

Assessing the combined effects of local climate and mounting configuration on the electrical and thermal performance of photovoltaic systems. Application to the greater Sydney area

Extremely high urban temperatures adversely affect photovoltaic (PV) system performance. Accurate PV cell temperature assessment relies on local weather conditions, exacerbated by urban overheating, often overlooked by inadequate temperature models and non-local data. This study investigates the electrical and thermal PV performance, considering mounting configurations and local conditions. Data from ten weather stations in Greater Sydney (NSW) during 2016–2017, including a hot summer, are used. The Sandia model is used to predict cell temperatures and power output for four mounting configurations, from open rack to building-integrated (BIPV). A PV thermal model is implemented to analyse daytime convection, crucial for understanding PV impact on local climate. Results show peak cell temperatures of 60 °C (open rack) to over 90 °C (BIPV), causing up to 50% power loss and 11% reduction in monthly performance ratio. Local climate variations impact PV energy output up to 6%, with mounting configuration effects up to 11%. Daytime convective flux averages 150–180 W/m2, peaking at 700 W/m2. Convective release varies up to 22% based on local climate, generally higher for open rack than close roof mounts, with potential reversals under low wind speed conditions. These findings can improve the knowledge of PV performances in urban areas facing extreme temperatures.