The impact of the mushy zone parameter ( A mushy ) and thermal properties during the solidification of a commercial paraffin-type PCM in a vertical cylinder under T-history conditions was examined numerically. First, the thermal properties of the paraffin-type PCM and its temperature profile during solidification under T-history conditions were experimentally obtained. The solidification process is simulated by using a numerical model and it was conducted via the commercial CFD code ANSYS FLUENT 2022. R2. The enthalpy‒porosity model was employed by the ANSYS FLUENT for solidification and melting. The accuracy of a simulation is highly sensitive to the software inputs and assumptions. Therefore, selecting the correct values for thermal properties and the mushy constant is essential for achieving precise simulation results. To determine the precise boundary conditions, radiative heat transfer between surfaces is considered. The results indicate that, between the four thermal properties, although increasing the thermal conductivity accelerates the solidification rate, the opposite effect is observed with increasing latent heat, density, and specific heat, as higher values of these properties lead to slower cooling. Moreover, the results highlight that choosing the correct mushy zone parameter is crucial for accurate solidification modeling. Although the impact of   A mush on solidification is generally less pronounced because conductive heat transfer dominates compared with the melting process, for paraffin-type PCMs, a higher   A mush value yields results that better align with experimental data, unlike other PCM materials. Furthermore, the shape and progression of the solidification is influenced by the mushy zone parameter and as A mushy increases, solidification in the bottom layers decreases, with the process becoming more concentrated in the layers closer to the cold wall.

This study explores the synthesis and characterization of proton-conducting polymer electrolyte from cellulose and nanocellulose extracted from coconut shell powder, a sustainable resource in Malaysia. Alkali treatment, bleaching, and acid hydrolysis are used for extraction. Surface modifications through alkalization and esterification produce carboxymethyl cellulose (CMC) and carboxymethyl nanocellulose (CMNC) as polymer hosts. Adding ammonium nitrate (NH 4NO 3) develops the polymer electrolyte, which is then analysed. FTIR and NMR confirm successful modifications of cellulose and nanocellulose to CMC and CMNC, respectively. TGA shows CMNC has the lowest thermal stability due to its porous structure. XRD reveals increased amorphous properties in modified cellulose and nanocellulose. FESEM and TEM analysed the surface area and particle size. EIS indicates that the CMC–NH 4NO 3 system exhibits higher ionic conductivity than the CMNC–NH 4NO 3 system in which it showed 2.87 x 10 -1 S∙cm -1 for CMC-NH 4NO 3 and 2.07 x 10 -3 S∙cm -1 for CMNC-NH 4NO 3 at 30 wt% NH 4NO 3. The findings highlight proton-based electrolytes from modified cellulose and nanocellulose from coconut shell waste for clean, sustainable energy storage such as proton batteries.

The development of affordable and sustainable nanomaterials for energy storage is a top priority and a major focus within the global research community. Among these, carbon nano-onions (CNOs) have emerged as a promising material for supercapacitors due to their distinctive morphology, high surface reactivity, and microporous structure. Zeolitic imidazole frameworks (ZIFs), known for their vast surface area and electrically active inorganic centers, have emerged as a potential material for energy storage. In this context, Zeolitic imidazolate framework (ZIF) rhombic dodecahedron is homogenously decorated with carbon nano-onions (CNOs, size <100 nm) to form a nanocomposite of CNOs/ ZIF (67 and 8) utilizing a simple solvothermal technique. The samples have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction techniques, which confirms the successful synthesis of the samples. The produced material displays a distinct rhombic dodecahedral shape, significant porosity, and a large specific surface area (SSA) confirmed by N 2 sorption studies. The as-prepared samples further tested as electrode material for supercapacitors and among them CNO/ZIF-67 nanocomposite surpasses in terms of SSA, electron and ion transport speed, and structural stability, leading to improved electrochemical performance. The specific capacitance of 1064.2 F g −1 at a current density of 2 A g -1 is observed for CNO/ZIF-67 in a 1 M H 2SO 4 aqueous electrolyte in three-electrode system. Subsequently, a symmetric supercapacitor (SSC) is constructed to investigate the system’s capacitive behavior. Notably, the SSC exhibited a peak device-specific capacitance of 325.40 F g -1 at 2 A g -1, high energy density of 24.51 Wh Kg -1, and achieved a maximum power density of 2.4 kW kg -1. The practical functionality of the device was demonstrated by connecting two symmetrical supercapacitors in series, effectively powering a red LED. These results highlight new opportunities for structural engineering in carbon nano-onion and metal-organic framework-based electrode materials, paving the way for advancements in future energy storage technologies.

This paper presents the synthesis and electrochemical evaluation of nickel sulfide (NiS 2) nanosheet encapsulated polyaniline (PANI) nanofiber nanocomposites. These nanocomposites, synthesized via chemical reflux at 70℃ in varying NiS 2 to PANI mass ratios (1:1, 1:2, 1:3), are designated as NiP1, NiP2, and NiP3. X-ray diffraction (XRD) data reveals the greater crystallite size of NiP2 which further leads to higher surface area. Scanning electron microscopy (SEM) analysis shows that NiP2 is more porous due to well assembled morphology of NiS 2 nanosheets over PANI nanofibers. Among the composites, the NiP2 variant demonstrates superior electrochemical performance, achieving a specific capacitance of 217.88 F g -1 at a current density of 1 A g -1 in a 2M KOH electrolyte. Further enhancing the energy density of supercapacitors for advanced applications, the structure-modulated NiP2 (positive potential electrode) is integrated with functionalized carbon nanotubes (f-CNT) as the negative potential material, extending the voltage window from 0.65 to 1.4V. The NiP2//f-CNT supercapacitor displays an energy density of 16 Wh kg -1 at a power density of 1318.53 W kg -1, maintaining 90.7% of its initial capacitance after 5000 charge-discharge cycles. These findings highlight the transformative potential of NiS 2/PANI nanocomposites, leveraging the synergistic effects between NiS 2 and PANI to significantly enhance ion transport and charge storage capabilities, thus providing a viable solution to the shortcomings of conventional supercapacitor electrodes.

The operational performance of lithium-ion batteries is significantly influenced by ambient temperature. In high-temperature environments, if the temperature of the battery is unable to be rapidly reduced to within the normal range, it will have a significant impact on the battery’s capacity and lifespan. In comparison to alternative cooling techniques, direct evaporative cooling offers the benefits of high efficiency, optimal temperature distribution, and a straightforward system configuration. It is thus imperative to gain a thorough grasp of the design and operational parameters of the direct cooling thermal management system, and to understand its impact on performance. This paper designs a direct cooling system with R134A as refrigerant. The performance of the battery thermal management system is obtained through numerical simulation based on the thermodynamic method in two typical operational scenarios: fast charging cooling and high-speed travel cooling. The results of the study showed that the refrigerant direct evaporative cooling method exhibited superior performance in both typical operating scenarios, with a battery module temperature rise of no more than 10℃ and a maximum temperature difference of less than 5℃. Subsequently, an investigation was conducted to determine the effect of initial temperature, flow rate, evaporative temperature and dryness on system performance.

In this work, the synthesis and characterization of the oil palm empty fruit bunch (OPEFB) activated carbon were studied for battery electrodes application. First, chemical activation carried out by variation concentrations and immersion time of NaOH and KOH. Then, the physical activation was studied using variation of activation temperature. The characterization of OPEFB activated carbon investigated on the surface morphology, surface area and the capacitance specific. Moreover, we designed, assembled and measured the electricity potential of the battery prototype. The activator solution of KOH 2 M showed the highest surface area of 354.25 m 2g -1, capacitance specific of 116.78 F.g -1, and potential of 1.17 V. Furthermore, the optimal immersion time was 18 hours with the highest surface area of 380.28 m 2g -1, capacitance specific of 96.57 F g -1, and the potential of 1.05 V. Finally, the optimal activation temperature is 900 oC which showed with the highest surface area 334.28 m 2g -1, capacitance specific of 96.41 F.g -1, and the potential of 1.12 V. Based on this report, OPEFB activated carbon can be used as the battery electrodes due to the carbon properties.

In this work, we have performed first-principle calculations to investigate the electronic properties, structural stability, and lithium migration pathway of 2D Ti 2CY 2/Graphene (Y = O, S) van der Waals (vdW) Heterostructure. The heterostructure formed by O and S functionalized MXene and graphene layers are separated by 3.04 and 3.40 Å exhibiting weak vdW interaction. It is found that the intercalation of lithium (Li) atoms in between the Ti 2CY 2/Graphene layers is thermodynamically more favorable in comparison with intercalation on the top or below the heterostructures. The Bader charge transfer analysis confirms that O atoms gain less charge -0.13 e during Li intercalation compared to S atoms with charge transfer of -0.47 e due to the larger size of the 3p orbital of S atoms. Each Li atom contributes ~0.88-0.89 e during the intercalation process. As O is more negatively charged in comparison with S atoms in the heterostructures, Li atoms are more localized on the Ti 2CO 2 layers with a tendency to form chemical bonds with Ti 2CO 2 layers while they are less localized on the Ti 2CS 2 layers creating lesser chemical bonds. The diffusion energy barrier is lower for Ti 2CS 2/graphene than Ti 2CO 2/graphene during Li intercalation. The NEB study also confirms that the activation energy barrier decreases with the increase of intercalated Li atoms for both the heterostructures indicating that Li atoms exhibit weak repulsive interaction causing weak Li binding with the heterostructures as they increase in number. Both the Ti 2CO 2/graphene and Ti 2CS 2/graphene heterostructures can be considered promising anode materials for Li-ion batteries due to their structural stability, and lower diffusion energy barrier.

Nanofiller-doped polymer electrolyte-based electrochemical devices are now emerged as a novel material for electrochemical devices. This paper reports a solid polymer electrolyte film doped with a new nanofiller synthesized by the solution casting technique. Electrical, Optical, and photoelectrochemical characterization are presented in detail. Electrochemical impedance spectroscopy (EIS) shows with the dispersion of nanofillers conductivity increases attains maxima and decreases. The maximum conductivity was at 0.05 wt% nanofiller concentration of 3.25 x 10 -5 S/cm. The calculated ionic transference value was 0.92 which shows the domency of the system as ionic. The linear sweep voltammetry confirms a high electrochemical stability window (ESW) of 4.01V. Sandwitched electrical double-layer capacitors (EDLC) has been developed using carbon-based electrodes and sandwitched nanofiller dispersed polymer electrolyte, showing a high specific capacitance value of ~ 200 F/g.

In last two decades, metallic particles of nano-sizes (~10 -9m) are tested profoundly in volumetric absorption solar collectors (VASC) due to their excellent optical properties and broadband absorption in entire solar spectrum. However, availability, ease to synthesise, toxicity, and non-biodegradable nature of these nanofluids are some of the challenges that still needs attention of scientific community for future commercialisation of this technology. Further, based on literature review, very limited studies are available for understanding the performance of integrated energy storage VASC system using nanofluids. Considering all these issues, a hybrid nanofluid of gold nanoparticles in Azadirachta Indica leaves extract has been synthesised by chemical route. The prepared hybrid nanofluid has shown good absorption in 400-700nm wavelength range and hence high photo-thermal conversion efficiency for VASC. Further, commercial available paraffin wax is used as phase change material (PCM) in thermal energy storage (TES) and further integrated with VASC to analyse thermal performance of system even after sunshine hours. The real-time experiments were conducted using different working fluids and at three mass flow rates i.e. 0.5 lpm, 1 lpm and 2 lpm, respectively during mild winter days under tropical climate of India. The study revealed a photo-thermal efficiency enhancement of about 17.1% when hybrid heat transfer fluid was used in VASC system with TES as compared to base fluid water without TES. Further, a maximum zero loss efficiency of 83.8% was estimated at optimal mass flow rate of 2 lpm for TES integrated VASC system.

One of the greatest alternatives to Li-ion batteries is an Al-air battery. The aluminium (Al) is more effective as a battery because of its viability and nontoxicity. The design of cell and electrode stacking affect the performance of Al-air battery. The present study focuses on designing an efficient air cathode host to lengthen the battery’s lifespan using highly porous carbon aerogel. Initially, the carbon aerogel (CA) material is synthesized using sol-gel polymerization process and characterized using XRD, SEM, and BET. The synthesized CA is used to fabricate the electrode stacking using the in-house-built Al-air cell. The performance of carbon aerogel coated on carbon cloth as air cathode has been evaluated using a galvanostatic discharge of the assembly at different current rates, and the specific capacity is recorded. The highest specific capacity observed is ~ 683 mAh g-1 at 2.551 mA cm -2 current density. The acquired results demonstrate the superiority of the present electrodes material compared to currently used air electrode. The improved electrochemical stability and the robust pore network in CA allow oxygen to pass through the cathode end for chemical reaction. Overall, this enhances kinetics and makes the interactions between oxygen and aluminum to generate higher current because of relatively faster chemical reaction.

A document by M Sterlin Leo Hudson. Click on the document to view its contents.

In the present study, an experimental test was conducted to investigate the energetic performance of a novel designed solar air heater (SAH), with and without phase change material (PCM). Two identical in dimensions SAHs were constructed and tested to compare their performance between them, the first is a jacket tube solar air heater (SAH 1), and the second SAH is similar to the first, filled with PCM (SAH 2). Experimental results showed that increasing air flow rate increases the thermal efficiency,. Thermal energy during day hours can be stored in the PCM and used after sunset. SAH 2 gave additional operating time after sunset for 4 hours at 0.01 kg/s, 2.5 hours at 0.035 kg/s, and one hour at 0.06 kg/s. Maximum improvement in the daily thermal efficiency was 15% at SAH 2, more than SAH 1 at 0.01 kg/s air flow rate. Employing PCM, as so as increasing air flow rate can reduce the daily thermal losses..

Thermal energy storage (TES) is an enabling system that provides uninterrupted energy from concentrated solar power (CSP) plants. Packed-bed TES systems have great opportunity to significantly enhance the cost-effectiveness, efficiency and sustainability of CSP plants by employing an affordable and sustainable packing material. The objective of this study is to design a packed bed TES system with a maximum storage capacity of 40 kWh, specifically tailored to store heat within the temperature range of 290 – 565 °C, thereby making it suitable for integration into CSP plants. Performance and thermal behavior of demolition waste-based packed-bed TES system was assessed through numerical analysis. The results demonstrate that a high discharging efficiency of 96.7% was achieved when the HTF flow rate was set at 300 kgh -1. However, it is important to note that at lower HTF flow rates, heat loss increases, leading to a decrease in discharging efficiency to 93.7%. The experiment also revealed a uniform thermal gradient within the packed-bed TES system, up to a fluid flow rate of 300 kgh -1. It is worth mentioning that lower flow rates can further improve the stratification effect; however, they may also result in increased heat loss and reduced storage capacity. Based on these findings, an optimal flow rate range of 100-200 kgh -1 is recommended to achieve the best performance for the packed-bed TES system.

Among organic phase change materials, paraffin is most commonly used, but it is not environmentally friendly due to its petrochemical content. For efficient utilization of solar or thermal energy, new phase change materials are urgently needed, or it is necessary to improve the thermal properties of existing materials. Therefore, the utilization of lamb’s tail fat as a latent heat storage material is of particular importance for the evaluation of bio based waste oils. T-history is one of the simplest and most reliable and the simple equipment setup and reliable results make the T-History method attractive. In this study, new phase change materials were improved by using different concentrations of cyclophosphazene derivatives as an additive to the starting lamb tail fat material. According to the results, 1% HEHCP-doped lamb tail fat can be proposed for application in thermal energy storage systems when used for insulation. In addition, it is found that if the phase change materials developed by inclusion of HBACP can be operated as cooling liquid for photovoltaic panels or as working fluid in concentrated solar power systems, owing to higher fusion of heat value of 1% HBACP and higher specific heat capacity of 2% HBACP consisting lamb tail fat.

Covid-19 has given us a new way to look at our globe with regards to minimize air and noise pollution and thereby upgrading global environmental conditions. This positive pandemic outcome indicates that green energy is the future of energy, and one new origin of green energy is lithium-ion batteries (LIBs). Electric vehicles are constructed with LIBs, but they have a number of disadvantages, including poor thermal performance, thermal runaway, fire dangers, and a higher discharge rate in low- and high-temperature conditions. The underlying fault of LIBs is their temperature reactivity. Extreme temperatures and challenging working circumstances can cause lithium-ion cells to malfunction and cause the battery pack to overheat. For optimal performance in vehicles and long-term lithium-ion battery durability, LIBs must be thermally managed within their operating temperature span. This paper presents an overview of several cooling strategies used to maintain the internal battery pack temperature. This paper discusses cooling techniques using air, liquid, and Phase Change Material (PCM), Heat pipe(HP). Additionally, various battery pack configurations and heat generation techniques are explored. This research also discusses the usage of nanomaterials to address the battery pack’s heat-related problems. This study emphasises the use of nanomaterial to boost the heat conductivity of coolant in order to raise the batteries temperature into their ideal working range (PCM as well as LC). This article also provides some of the research gaps that have been found and the crucial areas on which attention should be directed in order to build the best lithium-ion BTMS technology.

Thermal energy storage systems (TES) have emerged as a vital solution for addressing the gap between energy supply and demand. While research on solar energy storage has primarily focused on flat-plate collectors, limited work has been done to explore the potential of Scheffler solar concentrators. This study proposes an innovative approach to thermal energy storage using a Scheffler solar concentrator and phase change material (PCM) to address the energy needs of rural areas with limited access to electricity. Real-time design and testing were conducted using paraffin wax as the PCM, and CFD analysis was performed using the ANSYS Fluent software to determine the optimal charging and discharging times. The results indicated that the required charging time was 17 min according to the CFD analysis, while the experimental results yielded a charging time of 18 min. The results demonstrated that the proposed approach is a feasible and effective solution for meeting the energy demands of rural communities. The charging time was optimized using the response surface method, yielding an optimal charging time of 20.5 min and an optimal discharging time of 26.2 min. Overall, these findings highlight the potential of utilizing Scheffler solar concentrators and PCMs for sustainable and reliable thermal energy storage.