LiMnPO4 as an Advanced Cathode Material for Rechargeable Lithium Batteries
LiMnPO4 as an Advanced Cathode Material for Rechargeable Lithium Batteries
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DOI：
10.1149/1.3125765
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发表时间：
2009-01-01
影响因子：
3.9
通讯作者：
Exnar, I.
中科院分区：
文献类型：
--
作者：
Martha, S. K.;Markovsky, B.;Exnar, I.
研究了多元醇法制备的LiMnPO4纳米颗粒作为先进锂离子电池正极材料的性能。通过x射线衍射、高分辨率扫描电镜、高分辨率透射电镜、拉曼光谱、傅立叶变换红外光谱、光电子能谱以及标准电化学技术对其结构、表面形貌和性能进行了表征。在bbb4v vs Li/Li+放电电位下，可测量到高达145 mAh g（-1）的稳定可逆容量，并在长时间充放电循环中保持合理的容量。本文所研究的LiMnPO4电极的速率能力高于LiNi0.5Mn0.5O2和LiNi0.8Co0.15Al0.05O2 （NCA）在类似实验和测量中的速率能力。本文研究的活性物质在烷基碳酸酯/LiPF6溶液中似乎是最不具表面活性的。与锂离子电池正极材料的锂化过渡金属氧化物相比，我们将这种材料的低表面活性归因于橄榄石化合物中氧原子的相对低碱性和亲核性。与过渡金属氧化物阴极相比，LiMnPO4材料在溶液中的热稳定性（通过差示扫描量热法测量）要高得多。本文通过与NCA电极的比较证明了这一点。(C) 2009电化学学会。[DOI: 10.1149/1.3125765]版权所有。
LiMnPO4 nanoparticles synthesized by the polyol method were examined as a cathode material for advanced Li-ion batteries. The structure, surface morphology, and performance were characterized by X-ray diffraction, high resolution scanning electron microscopy, high resolution transmission electron microscopy, Raman, Fourier transform IR, and photoelectron spectroscopies, and standard electrochemical techniques. A stable reversible capacity up to 145 mAh g(-1) could be measured at discharge potentials > 4 V vs Li/Li+, with a reasonable capacity retention during prolonged charge/discharge cycling. The rate capability of the LiMnPO4 electrodes studied herein was higher than that of LiNi0.5Mn0.5O2 and LiNi0.8Co0.15Al0.05O2 (NCA) in similar experiments and measurements. The active mass studied herein seems to be the least surface reactive in alkyl carbonate/LiPF6 solutions. We attribute the low surface activity of this material, compared to the lithiated transition-metal oxides that are examined and used as cathode materials for Li-ion batteries, to the relatively low basicity and nucleophilicity of the oxygen atoms in the olivine compounds. The thermal stability of the LiMnPO4 material in solutions (measured by differential scanning calorimetry) is much higher compared to that of transition-metal oxide cathodes. This is demonstrated herein by a comparison with NCA electrodes. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3125765] All rights reserved.