Arockia Shyamala Paniyarasi S, Padmaja S, Pushpa Selvi M, Gnanamuthu R M, Nimma Elizabeth R
Department of Physics, Lady Doak College, Madurai 625002, Tamil Nadu, India.
Batteries and Metal-Finishing Research Lab (BMRL), Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur, Chennai 603203, Tamil Nadu, India.
J Nanosci Nanotechnol. 2021 Dec 1;21(12):6227-6233. doi: 10.1166/jnn.2021.19322.
The significant role of Tris(2,2,2-trifluoroethyl) phosphite (TTFP) as an efficient additive during cycling of the layered nanostructured LiNiMgCoO₂ and olivine LiFePO₄ cathode materials in EC/DMC and 1M LiPF electrolyte for Li-ion battery are extensively investigated in this work. The electrochemical characterization techniques such as cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy show that TTFP improves cycling stability and reduces the irreversible capacity of LiNiMgCoO₂ and LiFePO₄ electrodes. Also, the presence of TTFP in electrolyte solution reduces the impedance in LiNiMgCoO₂ and LiFePO₄ cathode materials at room temperature. A family of Nyquist plots was obtained from LiNiMgCoO₂ and LiFePO₄ electrodes for various potentials during the course of charging. The addition of TTFP in the electrolyte reduces the surface impedance of lithiated LiNiMgCoO₂ and LiFePO₄ which can be attributed to the reaction of the additive on the electrode's surface. Also, the presence of the additive TTFP in LiNiMgCoO₂ and LiFePO₄ cell enhances the lithium diffusion rate and improves the electronic conductivity of the cathode material.
在这项工作中，对亚磷酸三（2,2,2 - 三氟乙基）酯（TTFP）作为一种高效添加剂，在锂离子电池的层状纳米结构LiNiMgCoO₂和橄榄石型LiFePO₄正极材料于EC/DMC和1M LiPF₆电解液中循环过程中的重要作用进行了广泛研究。循环伏安法、恒电流充放电和电化学阻抗谱等电化学表征技术表明，TTFP提高了LiNiMgCoO₂和LiFePO₄电极的循环稳定性并降低了其不可逆容量。此外，电解液中TTFP的存在降低了LiNiMgCoO₂和LiFePO₄正极材料在室温下的阻抗。在充电过程中，从LiNiMgCoO₂和LiFePO₄电极获得了一系列不同电位下的奈奎斯特图。电解液中添加TTFP降低了锂化LiNiMgCoO₂和LiFePO₄的表面阻抗，这可归因于添加剂在电极表面的反应。此外，LiNiMgCoO₂和LiFePO₄电池中添加剂TTFP的存在提高了锂扩散速率并改善了正极材料的电子导电性。
