Precise preparation of high performance spherical hierarchical LiNi0.5Mn1.5O4 for 5 V lithium ion secondary batteries
Precise preparation of high performance spherical hierarchical LiNi0.5Mn1.5O4 for 5 V lithium ion secondary batteries
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DOI：
10.1039/c3ta10980a
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发表时间：
2013-04
影响因子：
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通讯作者：
Zhi Zhu;Ding Zhang;Hui Yan;Wei Li;Qilu
中科院分区：
文献类型：
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作者：
Zhi Zhu;Ding Zhang;Hui Yan;Wei Li;Qilu
本工作开发了一种新型的草酸铵-碳酸盐复合共沉淀法制备尖晶石LiNi0.5Mn1.5O4。该方法结合简单的水热处理和特殊的冷却工艺，获得了化学计量比精确的典型Fd3m结构的理想尖晶石，并且可以严格限制Mn3+的含量。此外，所制备的LiNi0.5Mn1.5O4具有球状的分级形貌，由纳米或亚微米级的一次粒子组成。LiNi0.5Mn1.5O4表现出最好的电化学性能。其放电容量为141.2 mA h g−1，4.7V放电容量为98.2%。在0.3C、1C和3C循环200次后，容量保持率分别为96.3%、94.4%和91.1%。化学和电化学测试表明，LiNi0.5Mn1.5O4中大部分Mn3+的消除导致了4.7V的高容量比例，此外，保留的Fd3m结构和球形的分级结构也有效地有利于循环和倍率性能。
This work developed a novel ammonium oxalate–carbonate composite co-precipitation method to prepare spinel LiNi0.5Mn1.5O4. By this method combined with a facile hydrothermal treatment and particular cooling process, an ideal spinel with precise stoichiometric Ni/Mn and classic Fd3m structure is obtained, and furthermore, the Mn3+ content can be strictly limited. Additionally, the prepared LiNi0.5Mn1.5O4 has a spherical hierarchical morphology, composed of nano or submicron primary particles. This LiNi0.5Mn1.5O4 shows superlative electrochemical performance. It delivers a discharge capacity of 141.2 mA h g−1, and importantly 98.2% of which discharges at 4.7 V. After 200 cycles at 0.3 C, 1 C and 3 C, the capacity retentions are 96.3%, 94.4% and 91.1%, respectively. Chemical and electrochemical measurements indicate that the elimination of the majority of Mn3+ in the obtained LiNi0.5Mn1.5O4 results in the high capacity proportion at 4.7 V. Additionally, the retained Fd3m structure and spherical hierarchical morphology also effectively favour the cycling and rate performances.