Solution combustion synthesis and electrochemical properties of yttrium-doped LiMnPO4/C cathode materials for lithium ion batteries
来源期刊：Journal of Rare Earths2020年第9期
论文作者：Redouan El Khalfaouy Abdellah Addaou Ali Laajeb Ahmed Lahsini
文章页码：976 - 982
摘 要：Phospho-olivine pristine LiMnPO4/C and yttrium-substituted LiMn1-xYxPO4/C（x=0,0.01,0.03,0.05）were synthesized by a solution combustion method.The effects of Y-doped on structure,morphology and electrochemical performances were investigated.From powder X-ray diffraction pattern,all substituted materials adopt an identical structure to that of the LiMnPO4 olivine structure,suggesting that the yttrium ion was well inco rporated into the crystal lattice,without any changes in the host crystal structure.The electrochemical impedance spectroscopy provides clearly that yttrium-substituting reduces the charge transfer impedance and improves the lithium ion diffusion through the structure.When x=0.01,the material shows an excellent capacity and stability during charge/discharge process.The initial specific discharge capacity can reach up to 156.84 mAh/g at C/20,with a coulombic efficiency of about 96.11%,which is 14% higher than that of the pristine material.The results confirm that the cyclic stability and the electrochemical performances of LiMnPO4/C are highly improved by Y-doping.
Redouan El Khalfaouy1，Abdellah Addaou1，Ali Laajeb1，Ahmed Lahsini1
1. Sciences and Technologies of Process Engineering Laboratory,Sidi Mohamed Ben Abdellah University
摘 要：Phospho-olivine pristine LiMnPO4/C and yttrium-substituted LiMn1-xYxPO4/C（x=0,0.01,0.03,0.05）were synthesized by a solution combustion method.The effects of Y-doped on structure,morphology and electrochemical performances were investigated.From powder X-ray diffraction pattern,all substituted materials adopt an identical structure to that of the LiMnPO4 olivine structure,suggesting that the yttrium ion was well inco rporated into the crystal lattice,without any changes in the host crystal structure.The electrochemical impedance spectroscopy provides clearly that yttrium-substituting reduces the charge transfer impedance and improves the lithium ion diffusion through the structure.When x=0.01,the material shows an excellent capacity and stability during charge/discharge process.The initial specific discharge capacity can reach up to 156.84 mAh/g at C/20,with a coulombic efficiency of about 96.11%,which is 14% higher than that of the pristine material.The results confirm that the cyclic stability and the electrochemical performances of LiMnPO4/C are highly improved by Y-doping.
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