摘要
LiMn<sub>2</sub>O<sub>4</sub> and LiCu<sub>x</sub>Cr<sub>y</sub>Mn<sub>2-x-y</sub>O<sub>4</sub> (x = 0.50;y = 0.05 - 0.50) powders have been synthesized via sol-gel method for the first time using Myristic acid as chelating agent. The synthesized samples have been taken to physical and electrochemical characterization such as thermo gravimetric analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies, electrochemical impedance spectroscopy (EIS) and differential capacity curves (dQ/dE). XRD patterns of LiMn<sub>2</sub>O<sub>4</sub> and LiCu<sub>x</sub>Cr<sub>y</sub>Mn<sub>2-x-y</sub>O<sub>4</sub> confirm high degree of crystallinity with good phase purity. FESEM image of undoped pristine spinel lucidly depicts cauliflower morphology with good agglomerated particle size of 50 nm while 0.5-Cu doped samples depict the pebbles morphology. TEM images of the spinel LiMn<sub>2</sub>O<sub>4</sub> and LiCu<sub>0.5</sub>Cr<sub>0.05</sub>Mn<sub>1.45</sub>O<sub>4</sub> authenticate that all the synthesized particles via sol-gel method are nano-sized (100 nm) with spherical surface and cloudy particles morphology. The LiMn<sub>2</sub>O<sub>4</sub> samples calcined at 850℃ deliver the high discharge capacity of 130 mA·h/g with cathodic efficiency of 88% corresponds to 94% columbic efficiency in the first cycle. Among all four compositions studied, LiCu<sub>0.5</sub>Cr<sub>0.05</sub>Mn<sub>1.45</sub>O<sub>4</sub> delivers 124 mA·h/g during the first cycle and shows stable performance with a low capacity fade of 1.1 mA·h/g cycle over the investigated 10 cycles.
LiMn<sub>2</sub>O<sub>4</sub> and LiCu<sub>x</sub>Cr<sub>y</sub>Mn<sub>2-x-y</sub>O<sub>4</sub> (x = 0.50;y = 0.05 - 0.50) powders have been synthesized via sol-gel method for the first time using Myristic acid as chelating agent. The synthesized samples have been taken to physical and electrochemical characterization such as thermo gravimetric analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies, electrochemical impedance spectroscopy (EIS) and differential capacity curves (dQ/dE). XRD patterns of LiMn<sub>2</sub>O<sub>4</sub> and LiCu<sub>x</sub>Cr<sub>y</sub>Mn<sub>2-x-y</sub>O<sub>4</sub> confirm high degree of crystallinity with good phase purity. FESEM image of undoped pristine spinel lucidly depicts cauliflower morphology with good agglomerated particle size of 50 nm while 0.5-Cu doped samples depict the pebbles morphology. TEM images of the spinel LiMn<sub>2</sub>O<sub>4</sub> and LiCu<sub>0.5</sub>Cr<sub>0.05</sub>Mn<sub>1.45</sub>O<sub>4</sub> authenticate that all the synthesized particles via sol-gel method are nano-sized (100 nm) with spherical surface and cloudy particles morphology. The LiMn<sub>2</sub>O<sub>4</sub> samples calcined at 850℃ deliver the high discharge capacity of 130 mA·h/g with cathodic efficiency of 88% corresponds to 94% columbic efficiency in the first cycle. Among all four compositions studied, LiCu<sub>0.5</sub>Cr<sub>0.05</sub>Mn<sub>1.45</sub>O<sub>4</sub> delivers 124 mA·h/g during the first cycle and shows stable performance with a low capacity fade of 1.1 mA·h/g cycle over the investigated 10 cycles.
作者
Ramasamy Thirunakaran
Gil Hwan Lew
Won-Sub Yoon
Ramasamy Thirunakaran;Gil Hwan Lew;Won-Sub Yoon(CSIR-Central Electrochemical Research Institute, Karaikudi, India;Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea)
