Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries (LIBs) due to the abundant availability of sodium, lower costs, and comparable electrochemical performance characteristics. A thorough understanding of their performance features is essential for the widespread adoption and application of SIBs. Therefore, in this study, we investigate the output characteristics and electrochemical impedance spectroscopy (EIS) features of sodium-ion batteries (SIBs) under various states. The research results show that, unlike conventional lithium iron phosphate (LFP) batteries, SIBs exhibit a strong linear relationship between state of charge (SOC) and open-circuit voltage (OCV) across various SOC and temperature conditions. Additionally, the discharge capacity of the battery remains relatively stable within a temperature range of 15 °C to 35 °C; when the temperatures are outside this range, the available capacity of the sodium-ion battery reduces significantly. Moreover, the EIS profiles in the high-frequency region are predominantly influenced by the ohmic internal resistance, which remains largely unaffected by SOC variations. In contrast, the low-frequency region demonstrates a significant correlation between SOC and impedance, with higher SOC values resulting in reduced impedance, indicated by smaller semicircle radii in the EIS curves. This finds highlights that EIS profiling can effectively monitor SOC and state of health (SOH) in SIBs, offering a clear correlation between impedance parameters and the battery’s operational state. The research not only advances our understanding of the electrochemical properties of SIBs but also provides a valuable reference for the design and application of sodium-ion battery systems in various scenarios.

The use of platinum-free (Pt) cathode electrocatalysts for oxygen reduction reactions (ORRs) has been significantly studied over the past decade, improving slow reaction mechanisms. For many significant energy conversion and storage technologies, including fuel cells and metal–air batteries, the ORR is a crucial process. These have motivated the development of highly active and long-lasting platinum-free electrocatalysts, which cost less than proton exchange membrane fuel cells (PEMFCs). Researchers have identified a novel, non-precious carbon-based electrocatalyst material as the most effective substitute for platinum (Pt) electrocatalysts. Rich sources, outstanding electrical conductivity, adaptable molecular structures, and environmental compatibility are just a few of its benefits. Additionally, the increased surface area and the simplicity of regulating its structure can significantly improve the electrocatalyst’s reactive sites and mass transport. Other benefits include the use of heteroatoms and single or multiple metal atoms, which are capable of acting as extremely effective ORR electrocatalysts. The rapid innovations in non-precious carbon-based nanomaterials in the ORR electrocatalyst field are the main topics of this review. As a result, this review provides an overview of the basic ORR reaction and the mechanism of the active sites in non-precious carbon-based electrocatalysts. Further analysis of the development, performance, and evaluation of these systems is provided in more detail. Furthermore, the significance of doping is highlighted and discussed, which shows how researchers can enhance the properties of electrocatalysts. Finally, this review discusses the existing challenges and expectations for the development of highly efficient and inexpensive electrocatalysts that are linked to crucial technologies in this expanding field.

Phase change materials (PCMs) have been widely recognized as a highly efficient medium for thermal energy storage. Many studies have identified the low thermal conductivity of PCMs. In the current investigation, the researchers have blended PCM with nanoparticles to enhance its thermal conductivity and electrical efficiency. Lauric acid (LA) is combined with three different nanoparticles: aluminum oxide (Al₂O₃), copper oxide (CuO), and magnesium oxide (MgO) in an optimal weight proportion of 94: 6. This results in the production of nanoparticle composited phase change materials (nc-PCMs). Lauric acid and these nanoparticles are chosen based on their ability to provide a significantly lower cost compared to commercial nanoparticles, availability in Thailand, and high thermal conductivity. Additionally, this investigation selected lauric acid (fatty acid) as the PCM due to Thailand's ambient temperature (T_amb) of 38 °C. Consequently, the optimum PCM has a melting point between 41 °C and 44 °C. Research has demonstrated that the incorporation of nanoparticles increases thermal conductivity, resulting in a decrease in the PV module's temperature. The findings indicate that a combination of LA and MgO in a proportion of 94:6 constitutes the optimal nc-PCM. This composition demonstrated a 5.2 °C reduction in PV module temperature, which resulted in a notable enhancement in the average electrical efficiency of 14.11 %. Furthermore, the power output increased significantly to 14.18 %. Additionally, it compared the energy production of PV modules with nc-PCMs to that of modules without PCM. It measured the energy production differences between LA: MgO, LA: Al₂O₃, and LA: CuO at 4.38 Wh, 2.99 Wh, and 2.62 Wh, respectively, when compared to PV without cooling.