(Li, Al)-co-doped spinel, Li(Li_0.1Al_0.1Mn_1.8)O₄ as high performance cathode for lithium ion batteries

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• 作者：M. Prabu^a ; ^b ; M.V. Reddy^a ; ^{phymvvr@nus.edu.sg} ; ^{reddymvvr@gmail.com} ; S. Selvasekarapandian^b ; ^{sekarapandian@rediffmail.com} ; G.V. Subba Rao^a ; B.V.R. Chowdari^a ; ^{phychowd@nus.edu.sg}
• 关键词：(Li ; Al)-co-doped LiMn2O4 ; Cathode material ; Li-ion batteries
• 刊名：Electrochimica Acta
• 出版年：2013
• 出版时间：15 January, 2013
• 年：2013
• 卷：88
• 期：Complete
• 页码：745-755
• 全文大小：2385 K

文摘

(Li, Al)-co-doped manganese oxide spinel compounds, Li(Li_0.1Al_0.1Mn_1.8)O₄ are prepared at temperatures (T), 600, 650 and 750 ¡ãC by polymer precursor method using polyvinyl pyrrolidone (PVP). The structure and morphology of the porous and sub-micron size particles of the compounds are characterized by the Rietveld refined X-ray diffraction (XRD), infrared and Raman spectroscopy, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and Brunauer, Emmett and Teller (BET) surface area techniques. Galvanostatic charge-discharge cycling in the voltage range of 3.5-4.3 V vs. Li at various current (C) rates, 0.5-3 C at 24 ¡ãC up to 60 cycles and at 0.5 C and at 55 ¡ãC up to 50 cycles is carried out. The influence of the Li-excess, the type of Al³⁺ dopant cation and the amount of fuel (polyvinyl pyrrolidone) used in the synthesis on the electrochemical behavior of the spinel in a Li-cell at room (24 ¡ãC) and at elevated temperature (55 ¡ãC) has been studied. Results show that at 24 ¡ãC and at 0.5 C, the phases prepared at 600 ¡ãC (I) and 650 ¡ãC (II) showed reversible capacities of 79 and 105 mAh g^?1 and retained 99 (¡À1) % of the capacity after 50 cycles. At 1 C, 2 C and 3 C rates, II showed stable capacities of 97, 83 and 57 mAh g^?1, respectively. At 55 ¡ãC and at 0.5 C, II showed a reversible capacity of 114 mAh g^?1 and retains 92 % of it at the end of 50 cycles, signifying the best cathodic performance for a doped-LiMn₂O₄. Complementary cyclic voltammetry, impedance spectra and ex situ XRD data are described and discussed.