Approaching theoretical capacity of LiFePO4 at room temperature at high rates
Approaching theoretical capacity of LiFePO4 at room temperature at high rates
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DOI：
10.1149/1.1396695
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发表时间：
2001-10-01
影响因子：
--
通讯作者：
Nazar, LF
中科院分区：
文献类型：
--
作者：
Huang, H;Yin, SC;Nazar, LF
采用两种不同的方法制备了LiFePO4与导电碳的纳米复合材料，提高了该绝缘材料中铁氧化还原中心的电化学可及性。方法A采用磷酸盐与间苯二酚-甲醛前体形成的碳干凝胶的复合物；方法B使用表面氧化的碳颗粒作为磷酸盐生长的成核剂。颗粒尺寸最小化和密切的碳接触是优化电化学性能的必要条件。虽然这两种方法都能满足第一个标准，但后一个标准最好用方法A实现，在室温液体电解质电池中提供优异的特性。所得LiFePO4 /C复合材料在C/2下达到90%的理论容量，具有良好的倍率性能和优异的稳定性。(C) 2001电化学学会。
Nanocomposites of LiFePO4 and conductive carbon were prepared by two different methods which lead to enhanced electrochemical accessibility of the Fe redox centers in this insulating material. Method A employs a composite of the phosphate with a carbon xerogel formed from a resorcinol-formaldehyde precursor; method B uses surface-oxidized carbon particles to act as a nucleating agent for phosphate growth. Both particle size minimization and intimate carbon contact are necessary to optimize electrochemical performance. Although both methods succeed for the first criteria, the latter is best achieved with method A, affording excellent characteristics in room temperature, liquid electrolyte cells. The resultant LiFePO4 /C composite achieves 90% theoretical capacity at C/2, with very good rate capability and excellent stability. (C) 2001 The Electrochemical Society.