Electrochemical evaluation of dual-doped LiMn₂O₄ spinels synthesized via co-precipitation method as cathode material for lithium rechargeable batteries

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• 作者：R. Thirunakaran ; ^{rthirunakaran@yahoo.com} ; R. Ravikumar ; S. Gopukumar ; A. Sivashanmugam
• 关键词：Dual doping ; Co-precipitation method ; Terephthalic acid ; Differential capacity ; Li-ion battery
• 刊名：Journal of Alloys and Compounds
• 出版年：2013
• 出版时间：15 April, 2013
• 年：2013
• 卷：556
• 期：Complete
• 页码：266-273
• 全文大小：1013 K

文摘

LiMn₂O₄ and LiZn_xW_yMn_2?x?yO₄ (x = 0.15-0.20; y = 0.10-0.05) powders are synthesized via co-precipitation method using terephthalic acid as chelating agent. The synthesized samples have been subjected to physical studies viz., thermo-gravimetric and differential thermal analysis (TG/DTA), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies. Zinc and tungsten doped particles of average 100 nm size are present with clear grain boundaries. Charge-discharge studies show the pristine LiMn₂O₄ delivers the discharge capacity of 121 mAhg^?1 in the first cycle. Among the investigated dopant concentrations, LiZn_0.15W_0.10Mn_1.75O₄ sample delivers superior performance (120 mAhg^?1) with very low capacity fade of 0.84 mAhg^?1cycle^?1 over the investigated 25 cycles as compared to the undoped and doped spinels and is well accorded with impedance measurements.