低温自蔓延燃烧合成Li1.2Fe0.2Mn0.6O2纳米颗粒及电化学性能

Low temperature self-propagating combustion synthesis and electrochemical properties of Li1.2Fe0.2Mn0.6O2 nanoparticles

摘要:

利用自蔓延燃烧在450℃低温下合成了Li1.2Fe0.2Mn0.6O2纳米颗粒(LFMO-450)，借助X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)及恒流充放电测试研究了其晶体结构、微观形貌、超微结构和电化学性能。结果表明，样品LFMO-450具有良好的α-NaFeO2层状结构，为粒径分布于45~88 nm的纳米颗粒。恒流充放电测试结果表明，在室温及2.0~4.8 V充放电范围内，该样品在电流密度为0.1、0.2、0.5、1和2C时首次放电比容量分别为237.5、170.7、124.1、101.9和82.8 mA·h/g，表现出良好的倍率性能；在1C倍率下，样品首次与循环60次后放电比容量分别为106.4和87.8 mA·h/g，容量保持率为82.5%，表现出良好的循环性能。

Abstract:

Abstract: Li1.2Fe0.2Mn0.6O2 nanoparticles were synthesized by self-propagating combustion at low temperature of 450℃(LFMO-450). Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscope (TEM) and galvanostatic charge-discharge tests were applied to analyze the crystal structure, micromorphology, ultrastructure and electrochemical properties of Li1.2Fe0.2Mn0.6O2 nanoparticles. The results show that simple LFMO-450 has a well-ordered layered α-NaFeO2 and are evenly distributed between 45~88 nm particles. The galvanostatic charge and discharge method test results show that the specific discharge capacity of the LFMO-450 at 0.1, 0.2, 0.5, 1 and 2C is, respectively, up to 237.5, 170.7, 124.1, 101.9 and 82.8 mA·h/g between 2.0 and 4.8 V at room temperature, which shows good rate performance. Under 1C rate, the specific discharge capacity of the sample is 106.4 and 87.8 mA·h/g for the first time and after 60 cycles, and the capacity retention rate is 82.5%, which shows good cycle performance.