Reactivity, stability and electrochemical behavior of lithium iron phosphates
Reactivity, stability and electrochemical behavior of lithium iron phosphates
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DOI：
10.1016/s1388-2481(01)00298-3
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发表时间：
2002-03
影响因子：
5.4
通讯作者：
Shoufeng Yang;Yanning Song;P. Zavalij;M. Whittingham
中科院分区：
文献类型：
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作者：
Shoufeng Yang;Yanning Song;P. Zavalij;M. Whittingham
lifepo4是下一代二次锂电池的潜在阴极候选材料。测定了其反应性和热力学稳定性。在低电位下，它可以还原成磷酸锂和铁。相对于三角形全四面体形式，正正交态的FePO4是亚稳的；然而，必要的大量结构重排使得室温下的结构变化在动力学上是不利的。lifepo4的制备方法多种多样。当在碳凝胶存在的高温下合成时，即使起始材料是LiFePO4(OH)， x射线衍射也只能检测到LiFePO4。在C/2的充放电速率下，lifepo4在室温循环下保留了约80%的理论容量。水热形态表现出一定的铁无序性，影响了其电化学和化学反应。
LiFePO4is a potential cathode candidate for the next generation of secondary lithium batteries. Its reactivity and thermodynamic stability have been determined. At low potentials it can be reduced to lithium phosphate and iron. The fully charged state, orthorhombic FePO4, is metastable relative to the trigonal all tetrahedral form; however, the massive structural rearrangement necessary makes the structural change kinetically unfavorable at room temperature. LiFePO4has been prepared by a variety of routes. When synthesized at elevated temperatures in the presence of a carbon gel, only LiFePO4was detected by X-ray diffraction even when the starting material was LiFePO4(OH). At a C/2 discharge/charge rate, LiFePO4retained about 80% of the theoretical capacity cycling at room temperature. The hydrothermal form shows some iron disorder, which impacts its electrochemical and chemical reactions.