Opra Denis P, Neumoin Anton I, Sinebryukhov Sergey L, Podgorbunsky Anatoly B, Kuryavyi Valery G, Mayorov Vitaly Yu, Ustinov Alexander Yu, Gnedenkov Sergey V
Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 690022 Vladivostok, Russia.
Nanomaterials (Basel). 2022 Jun 2;12(11):1905. doi: 10.3390/nano12111905.
Nanocrystalline layer-structured monoclinic NaTiO is currently under consideration for usage in solid state electrolyte applications or electrochemical devices, including sodium-ion batteries, fuel cells, and sensors. Herein, a facile one-pot hydrothermal synthetic procedure is developed to prepare self-assembled moss-like hierarchical porous structure constructed by ultrathin NaTiO nanotubes with an outer diameter of 6-9 nm, a wall thickness of 2-3 nm, and a length of several hundred nanometers. The phase and chemical transformations, optoelectronic, conductive, and electrochemical properties of as-prepared hierarchically-organized NaTiO nanotubes have been studied. It is established that the obtained substance possesses an electrical conductivity of 3.34 × 10 S/cm at room temperature allowing faster motion of charge carriers. Besides, the unique hierarchical NaTiO architecture exhibits promising cycling and rate performance as an anode material for sodium-ion batteries. In particular, after 50 charge/discharge cycles at the current loads of 50, 150, 350, and 800 mA/g, the reversible capacities of about 145, 120, 100, and 80 mA∙h/g, respectively, were achieved. Upon prolonged cycling at 350 mA/g, the capacity of approximately 95 mA∙h/g at the 200th cycle was observed with a Coulombic efficiency of almost 100% showing the retention as high as 95.0% initial storage. At last, it is found that residual water in the un-annealed nanotubular NaTiO affects its electrochemical properties.
纳米晶层状单斜晶系NaTiO目前正被考虑用于固态电解质应用或电化学装置,包括钠离子电池、燃料电池和传感器。在此,开发了一种简便的一锅水热合成方法,以制备由外径为6 - 9纳米、壁厚为2 - 3纳米、长度为几百纳米的超薄NaTiO纳米管构建的自组装苔藓状分级多孔结构。对所制备的分级组织的NaTiO纳米管的相和化学转变、光电、导电和电化学性质进行了研究。已确定所获得的物质在室温下具有3.34×10 S/cm的电导率,使电荷载流子能够更快地移动。此外,独特的分级NaTiO结构作为钠离子电池的负极材料表现出有前景的循环和倍率性能。特别是,在50、150、350和800 mA/g的电流负载下进行50次充/放电循环后,分别实现了约145、120、100和80 mA∙h/g的可逆容量。在350 mA/g下长时间循环时,在第200次循环时观察到容量约为95 mA∙h/g,库仑效率几乎为100%,显示出高达95.0%的初始存储保持率。最后,发现未退火的管状NaTiO中的残留水会影响其电化学性质。