Galceran Montserrat, Saurel Damien, Acebedo Begoña, Roddatis Vladimir V, Martin Egoitz, Rojo Teófilo, Casas-Cabanas Montse
CIC ENERGIGUNE, Parque Tecnológico de Álava, Albert Einstein 48, ED.CIC, 01510, Miñano, Spain.
Phys Chem Chem Phys. 2014 May 21;16(19):8837-42. doi: 10.1039/c4cp01089b.
The reaction mechanism occurring during the (de)intercalation of sodium into the host olivine FePO4 structure is thoroughly analysed through a combination of structural and electrochemical methods. In situ XRD experiments have confirmed that the charge and discharge reaction mechanisms are different and have revealed the existence of a solid solution domain from 1 < x < 2/3 in Na(x)FePO4 upon charge. The second part of the charge proceeds through a 2-phase reaction between Na(2/3)FePO4 and FePO4 with strongly varying solubility limits. The strong cell mismatch between Na(2/3)FePO4 and FePO4 enhances the effects of the diffuse interface and therefore varying solubility limits are first observed here in micrometric materials.
通过结合结构和电化学方法，对钠在宿主橄榄石FePO₄结构中（脱）嵌入过程中发生的反应机理进行了深入分析。原位XRD实验证实，充电和放电反应机理不同，并揭示了充电时在Na(x)FePO₄中1 < x < 2/3存在固溶体区域。充电的第二阶段通过Na(2/3)FePO₄和FePO₄之间的两相反应进行，其溶解度极限变化很大。Na(2/3)FePO₄和FePO₄之间强烈的电池失配增强了扩散界面的影响，因此在微米级材料中首次观察到变化的溶解度极限。
