Tomar Anubha, Singh Jay, Singh Satendra Pal, Kim Jaekook, Rai Alok Kumar
Department of Chemistry, University of Delhi, Delhi-110007, India.
Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Bukgu, Gwangju, 500-757, Republic of Korea.
Phys Chem Chem Phys. 2024 May 1;26(17):13152-13163. doi: 10.1039/d3cp06156f.
The current work describes a facile synthesis of spinel-type ZnCoO along with an additional phase, CoO, by simply maintaining a non-stoichiometric ratio of Zn and Co precursors. Pure ZnCoO and CoO were also synthesized using the same method to compare results. The obtained morphologies of samples show that small-sized nanoparticles are interconnected and form a porous nanosheet-like structure. When used as anode materials for Li-ion batteries, the ZnCoO/CoO nanocomposite electrode exhibits a highly stable charge capacity of 1146.2 mA h g at 0.5C after 350 cycles, which is superior to those of other two pure electrodes, which can be attributed to its optimum porosity, synergistic effect of ZnCoO and CoO, increased active sites for Li ion diffusion, and higher electrical conductivity. Although the pure CoO electrode displayed a much higher rate capability than the ZnCoO/CoO nanocomposite electrode at all investigated current rates, the CoO morphology apparently could not withstand long-term cycling, and the electrode became pulverized due to the repeated volume expansion/contraction, resulting in a rapid decrease in the capacity.
当前工作描述了一种通过简单地保持锌和钴前驱体的非化学计量比来 facile 合成尖晶石型 ZnCoO 以及额外相 CoO 的方法。还使用相同方法合成了纯 ZnCoO 和 CoO 以比较结果。所获得的样品形态表明，小尺寸纳米颗粒相互连接并形成多孔纳米片状结构。当用作锂离子电池的负极材料时，ZnCoO/CoO 纳米复合电极在 350 次循环后于 0.5C 下表现出 1146.2 mA h g 的高度稳定充电容量，这优于其他两个纯电极，这可归因于其最佳孔隙率、ZnCoO 和 CoO 的协同效应、锂离子扩散活性位点增加以及更高的电导率。尽管在所有研究的电流速率下，纯 CoO 电极显示出比 ZnCoO/CoO 纳米复合电极高得多的倍率性能，但 CoO 的形态显然无法承受长期循环，并且电极由于反复的体积膨胀/收缩而粉碎，导致容量迅速下降。
