On the stability of LiFePO4 olivine cathodes under various conditions (electrolyte solutions, temperatures)
On the stability of LiFePO4 olivine cathodes under various conditions (electrolyte solutions, temperatures)
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DOI：
10.1149/1.2403974
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发表时间：
2007-01-01
影响因子：
--
通讯作者：
Ellis, Brian
中科院分区：
文献类型：
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作者：
Koltypin, Maxim;Aurbach, Doron;Ellis, Brian
LiFePO 4是近年来研究最多的锂离子电池正极材料之一。令人印象深刻的工作已经揭示了重要的结构方面以及结构和组成与电化学性能之间的相关性。较少的努力已经致力于这种材料的表面化学方面。我们在此报告的稳定性方面的LiFePO 4在两个温度，30和60摄氏度的研究。使用基于EC-DMC 1：1溶剂混合物的三种类型的溶液，不涉及酸性污染的那些（使用LiClO 4作为电解质）、被HF污染的那些（使用LiPF 6作为Li盐）和故意被H2O污染的LiPF 6溶液。铁从LiFePO 4在这些电解质中的溶解，以及作为溶液组成和老化的函数的电化学响应，在两个温度下进行了研究。还研究了中和溶液中酸性物质的添加剂的作用。一般来说，LiFePO 4具有独特的表面化学性质。当溶液不含酸性或质子污染物时，观察并测量了LiFePO 4阴极的高度稳定行为，在升高的温度下没有任何实质性的铁溶解。(c)2006年电化学学会。
LiFePO4 is one of the most important cathode materials for Li-ion batteries studied over the past few years. Impressive work has revealed important structural aspects and the correlations between structure and composition and electrochemical properties. Fewer efforts have been devoted to the surface chemical aspects of this material. We report herein on a study of the stability aspects of LiFePO4 at two temperatures, 30 and 60 degrees C. Three types of solutions were used based on EC-DMC 1:1 solvent mixtures those involving no acidic contamination (using LiClO4 as the electrolyte), those contaminated by HF (using LiPF6 as the Li salt), and LiPF6 solutions deliberately contaminated with H2O. Iron dissolution from LiFePO4 in these electrolytes, as well as the electrochemical response as a function of solution composition and aging, were studied at the two temperatures. The effect of additives that neutralize acidic species in solution was also studied. In general, LiFePO4 develops a unique surface chemistry. Highly stable behavior of LiFePO4 cathodes, without any substantial iron dissolution at elevated temperatures, was observed and measured when the solution contains no acidic or protic contaminants. (c) 2006 The Electrochemical Society.