Fahmy Ahmed, Badry Rania, Khafagy Rasha M, Ibrahim Medhat A
Physics Department, Faculty of Women for Arts, Science and Education, Ain Shams University, Cairo, 11757, Egypt.
Spectroscopy Department, National Research Centre, 33 El-Bohouth St., Dokki, Giza, 12622, Egypt.
Sci Rep. 2024 Oct 23;14(1):24979. doi: 10.1038/s41598-024-75235-1.
Because of the abundance of sodium resources, sodium-ion batteries (NIBs) offer a promising alternative electrochemical energy storage solution. One of the current roadblocks to the development of NIBs technology is a lack of electrode materials capable of reversibly storing/releasing sodium ions for a sufficiently long time. Thus, this work aims to study, theoretically, the effect of glycerin incorporation on polyvinyl alcohol (PVA)/sodium alginate (Na Alg) blend as electrode materials for NIBs. The electronic, thermal, and quantitative structure-activity relationship (QSAR) descriptors of polymer electrolytes based on a blend of PVA and Na Alg and glycerin are the main topics of this work. These properties are examined here using semi-empirical methods and the density functional theory (DFT). Bandgap energy (E) is examined because the structural analysis reveals details regarding the interactions between PVA/Na Alg and glycerin. The findings indicate that the addition of glycerin caused the E value to drop to 0.2814 eV. The molecular electrostatic potential surface, or MESP, shows the electron-rich and deficit regions throughout the electrolyte system as well as the distribution of molecular charges. Thermal parameters that are studied include enthalpy (H), entropy (ΔS), heat capacity (Cp), Gibbs' free energy (G), and heat of formation. Additionally, the study examines several QSAR descriptors, such as total dipole moment (TDM), total energy (E), ionization potential (IP), Log P, and Polarizability. The results show that H, ΔS, Cp, G, and TDM increased with increasing temperature and glycerin content. Meanwhile, heat of formation, IP, and E decreased, improving reactivity and polarizability. Additionally, the cell voltage increased to 2.488 V due to glycerin addition. The overall DFT and PM6 calculations of cost-effective PVA/Na Alg based glycerin electrolytes indicate that they can partially replace lithium-ion batteries due to their multifunctionality, but requires further improvement and investigations.
由于钠资源丰富，钠离子电池（NIBs）提供了一种很有前景的电化学储能解决方案。目前阻碍NIBs技术发展的障碍之一是缺乏能够长时间可逆地存储/释放钠离子的电极材料。因此，这项工作旨在从理论上研究甘油掺入对作为NIBs电极材料的聚乙烯醇（PVA）/海藻酸钠（Na Alg）共混物的影响。基于PVA、Na Alg和甘油共混物的聚合物电解质的电子、热和定量构效关系（QSAR）描述符是这项工作的主要主题。本文使用半经验方法和密度泛函理论（DFT）来研究这些性质。研究了带隙能量（E），因为结构分析揭示了有关PVA/Na Alg与甘油之间相互作用的细节。研究结果表明，添加甘油使E值降至0.2814 eV。分子静电势表面（MESP）显示了整个电解质系统中富电子和缺电子区域以及分子电荷的分布。所研究的热参数包括焓（H）、熵（ΔS）、热容（Cp）、吉布斯自由能（G）和生成热。此外，该研究还考察了几个QSAR描述符，如总偶极矩（TDM）、总能量（E）、电离势（IP）、Log P和极化率。结果表明，H、ΔS、Cp、G和TDM随温度和甘油含量的增加而增加。同时，生成热、IP和E降低，提高了反应活性和极化率。此外，由于添加了甘油，电池电压提高到了2.488 V。基于PVA/Na Alg的具有成本效益的甘油电解质的整体DFT和PM6计算表明，由于其多功能性，它们可以部分替代锂离子电池，但仍需要进一步改进和研究。
