Martínez-Morales Carmen, Romero-Serrano Antonio, López-Rodríguez Josué, Arellanes-Lozada Paulina
Departamento de Metalurgia y Materiales, Instituto Politécnico Nacional-ESIQIE, UPALM-Zacatenco, Av. Instituto Politécnico Nacional s/n, Lindavista, G. A. Madero, CDMX, Ciudad de Mexico 07738, Mexico.
Dirección de Investigación, Instituto Mexicano del Petróleo. Eje Central Norte Lázaro Cárdenas No. 152, San Bartolo Atepehuacan, G. A. Madero, CDMX, Ciudad de Mexico 07730, Mexico.
Materials (Basel). 2025 Aug 18;18(16):3869. doi: 10.3390/ma18163869.
Different composites of manganese oxides (MnO) containing sodium (Na) and silver (Ag) were synthesized by the molten salt method with various MnSO·HO/NaNO (M/N) molar ratios (between 0.3 and 1), and different AgNO and NaOH amounts, obtaining two groups of materials: without the addition of AgNO (labeled as M/N) and with AgNO (labeled as M/N-A). As for the M/N group, the system with the lowest M/N ratio yielded the highest specific capacitance (160.5 F g-1), attributed to the formation of MnO and sodium birnessite. In the M/N-A group, the 1 M/N-0.5A system, produced with M/N ratio of 1 and addition of 0.5 g of AgNO, exhibited the highest specific capacitance (229.1 F g-1), associated with the presence of MnO, silver hollandite, and metallic Ag. This enhancement is attributed to the synergistic effects of Na and Ag ions, which improve charge transfer kinetics and electrochemical performance. It was demonstrated that decreasing the MnSO·HO/NaNO ratio in the M/N group and increasing AgNO content in the M/N-A group enhances the electrochemically active surface area. Galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques confirmed that the 1 M/N-0.5A system exhibited the best performance, characterized by high energy retention, stable cycling behavior, and low capacitance dispersion, indicating its strong potential as an active material for pseudocapacitor applications.
采用熔盐法，通过改变硫酸锰·水合物（MnSO₄·H₂O）与硝酸钠（NaNO₃）的摩尔比（0.3至1之间）以及不同的硝酸银（AgNO₃）和氢氧化钠（NaOH）用量，合成了含钠（Na）和银（Ag）的不同锰氧化物（MnO）复合材料，得到两组材料：未添加AgNO₃的（标记为M/N）和添加了AgNO₃的（标记为M/N-A）。对于M/N组，M/N比最低的体系具有最高的比电容（160.5 F g⁻¹），这归因于MnO和钠水钠锰矿的形成。在M/N-A组中，M/N比为1且添加0.5 g AgNO₃的1 M/N-⁃0.5A体系表现出最高的比电容（229.1 F g⁻¹），这与MnO、银硬锰矿和金属Ag的存在有关。这种增强归因于Na和Ag离子的协同效应，它们改善了电荷转移动力学和电化学性能。结果表明，降低M/N组中MnSO₄·H₂O/NaNO₃的比例以及增加M/N-A组中AgNO₃的含量可提高电化学活性表面积。恒电流充放电（GCD）和电化学阻抗谱（EIS）技术证实了1 M/N-0.5A体系表现出最佳性能，其特点是能量保持率高、循环行为稳定且电容分散低，表明其作为赝电容器应用的活性材料具有很大潜力。
