Ambalkar Anuradha A, Kawade Ujjwala V, Sethi Yogesh A, Kanade Sandip C, Kulkarni Milind V, Adhyapak Parag V, Kale Bharat B
Centre for Materials for Electronics Technology (C-MET), Ministry of Electronics and Information Technology (MeitY) Panchavati Pune 411008 India
Indian Institute of Science Education and Research Dr Homi Bhabha Rd Pune 411008 India.
RSC Adv. 2021 Jun 1;11(32):19531-19540. doi: 10.1039/d1ra01678d. eCollection 2021 May 27.
A SnO/Ni/CNT nanocomposite was synthesized using a simple one-step hydrothermal method followed by calcination. A structural study XRD shows that the tetragonal rutile structure of SnO is maintained. Further, X-ray photoelectron spectroscopy (XPS) and Raman studies confirm the existence of SnO along with CNTs and Ni nanoparticles. The electrochemical performance was investigated cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The nanocomposite has been used as an anode material for lithium-ion batteries. The SnO/Ni/CNT nanocomposite exhibited an initial discharge capacity of 5312 mA h g and a corresponding charge capacity of 2267 mA h g during the first cycle at 50 mA g. Pristine SnO showed a discharge/charge capacity of 1445/636 mA h g during the first cycle at 50 mA g. This clearly shows the effects of the optimum concentrations of CNTs and Ni. Further, the nanocomposite (SnNiCn) shows a discharge capacity as high as 919 mA h g after 210 cycles at a current density of 400 mA g in a Li-ion battery set-up. Thus, the obtained capacity from the nanocomposite is much higher compared to pristine SnO. The higher capacity in the nanoheterostructure is due to the well-dispersed nanosized Ni-decorated stabilized SnO along with the CNTs, avoiding pulverization as a result of the volumetric change of the nanoparticles being minimized. The material accommodates huge volume expansion and avoids the agglomeration of nanoparticles during the lithiation and delithiation processes. The Ni nanoparticles can successfully inhibit Sn coarsening during cycling, resulting in the enhancement of stability during reversible conversion reactions. They ultimately enhance the capacity, giving stability to the nanocomposite and improving performance. Additionally, the material exhibits a lower Warburg coefficient and higher Li ion diffusion coefficient, which in turn accelerate the interfacial charge transfer process; this is also responsible for the enhanced stable electrochemical performance. A detailed mechanism is expressed and elaborated on to provide a better understanding of the enhanced electrochemical performance.
采用简单的一步水热法并随后进行煅烧合成了SnO/Ni/CNT纳米复合材料。XRD结构研究表明，SnO保持四方金红石结构。此外，X射线光电子能谱（XPS）和拉曼研究证实了SnO与CNT和Ni纳米颗粒的共存。通过循环伏安法（CV）、电化学阻抗谱（EIS）和恒电流充放电测量研究了其电化学性能。该纳米复合材料已被用作锂离子电池的负极材料。在50 mA g的电流密度下，SnO/Ni/CNT纳米复合材料在首次循环时的初始放电容量为5312 mA h g，相应的充电容量为2267 mA h g。原始SnO在50 mA g的电流密度下首次循环时的放电/充电容量为1445/636 mA h g。这清楚地显示了CNT和Ni最佳浓度的影响。此外，在锂离子电池装置中，该纳米复合材料（SnNiCn）在400 mA g的电流密度下经过210次循环后，放电容量高达919 mA h g。因此，与原始SnO相比，从纳米复合材料获得的容量要高得多。纳米异质结构中较高的容量归因于纳米尺寸的Ni修饰的稳定SnO与CNT的良好分散，使纳米颗粒体积变化导致的粉碎最小化。该材料能够承受巨大的体积膨胀，并避免在锂化和脱锂过程中纳米颗粒的团聚。Ni纳米颗粒可以成功抑制循环过程中Sn的粗化，从而提高可逆转化反应过程中的稳定性。它们最终提高了容量，使纳米复合材料具有稳定性并改善了性能。此外，该材料表现出较低的Warburg系数和较高的Li离子扩散系数，这反过来加速了界面电荷转移过程；这也有助于增强稳定的电化学性能。文中阐述了详细的机理，以便更好地理解增强的电化学性能。
