Particle-Size Effects on the Entropy Behavior of a LixFePO4 Electrode
Particle-Size Effects on the Entropy Behavior of a LixFePO4 Electrode
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DOI：
10.1002/cphc.201301219
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发表时间：
2014-07-21
期刊：
影响因子：
2.9
通讯作者：
Yamada, Atsuo
中科院分区：
文献类型：
--
作者：
Kai, Kazuhiko;Kobayashi, Yo;Yamada, Atsuo
粒径对 LixFePO4 电极热力学性质和动力学行为的影响对电极性能有直接影响。因此，开发含有 LixFePO4 阴极的高性能锂离子电池需要完全了解原子/纳米/介观尺度的反应机制。在这项工作中，我们报告了对不同粒径的 LixFePO4 电极的电化学量热和电位研究，并基于（脱）锂化的熵变阐明了粒径对反应机理的影响。电化学量热法结果表明，粒径的减小缩小了 LixFePO4 的混溶间隙，而电位测量表明 LixFePO4 颗粒根据粒径平衡成动力学亚稳态或热力学稳定态。
The particle-size effects on the thermodynamic properties and kinetic behavior of a LixFePO4 electrode have a direct influence on the electrode properties. Thus, the development of high-performance Li-ion batteries containing a LixFePO4 cathode requires a complete understanding of the reaction mechanism at the atomic/nano/meso scale. In this work, we report electrochemical calorimetric and potentiometric studies on LixFePO4 electrodes with different particle sizes and clarify the particle-size effect on the reaction mechanism based on the entropy change of (de)lithiation. Electrochemical calorimetry results show that a reduction in particle size shrinks the miscibility gap of LixFePO4 while potentiometric measurements demonstrate that the LixFePO4 particles equilibrate into either a kinetically metastable state or a thermodynamically stable state depending on the particle size.