Synthesis and electrochemical properties of LiFePO4 cathode material by ionic thermal method using eutectic mixture of tetramethyl ammonium chloride-urea

• 作者: Si-Nan Li Shao-Hua Luo Liu Yang Qing Wang Ya-Hui Zhang Xin Liu
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（12）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 3477-3484
• 页数: 8页
• 语种: 英文

摘要

In this study,the LiFePO4 cathode was syn-thesized by the ionic thermal method using the deep eutectic mixture of tetramethyl ammonium chloride and urea.The synthetic conditions were systematically inves-tigated by orthogonal experiments,which indicate that the optimal reaction time,reaction temperature,molar ratio of Li to DES and rotate speed are 96 h,220 ℃,1∶14 and 20 r·min-1,respectively.X-ray diffraction (XRD),scan-ning electron microscope (SEM) and transmission electron microscope (TEM) were characterized to investigate the crystalline structure and morphology of the obtained materials,indicating well-crystallized LiFePO4 with oli-vine structure.And the physical properties of LiFePO4 were explored through Fourier transform infrared spec-troscopy (FTIR),57Fe M(o)ssbauer absorption spectra and Raman spectra.An initial discharge capacity can reach 151 mAh·g-1 at 0.1C rate for LiFePO4 following by calcining at 600 ℃ under the optimal conditions,and it retains 125.1 mAh·g 1 after 100 cycles.These results demon-strated that the addition of ionic liquids can improve the rate performance,cycle performance and ion diffusion rate of LiFePO4.