Bulk-Sensitive Soft X-ray Edge Probing for Elucidation of Charge Compensation in Battery Electrodes
Bulk-Sensitive Soft X-ray Edge Probing for Elucidation of Charge Compensation in Battery Electrodes
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DOI：
10.1021/acs.jpcc.9b06552
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
M. Fehse;C. Sahle;M. Hogan;C. Cavallari;E. Kelder;M. Alfredsson;A. Longo
中科院分区：
文献类型：
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作者：
M. Fehse;C. Sahle;M. Hogan;C. Cavallari;E. Kelder;M. Alfredsson;A. Longo
直到今天，阐明电化学循环时电极材料中的电荷转移过程仍然是一个挑战，主要是由于电极表面化学反应的复杂性。在这里，我们提出了一个优雅的和可靠的方法来探测散装敏感的软边，通过X射线拉曼散射光谱阐明阳极和阴极的电荷补偿的贡献。通过使用硬X射线入射束，该技术避免了表面限制，并且由于其非共振性质而实际上没有自吸收。此外，它不需要复杂的样品制备或实验设置，使其成为电极材料电子结构潜在原位分析的理想工具。在这项研究中，我们第一次监测了在一个完整的电化学循环过程中同时出现的正极材料Li2FeSiO4的氧和过渡金属（铁）的大块软边。我们的研究结果表明，氧化还原机制主要依赖于铁（催化剂）。
To this day, elucidating the charge transfer process in electrode material upon electrochemical cycling remains a challenge, primarily due to the complexity of chemical reactions at the electrode surfaces. Here we present an elegant and reliable method to probe bulk sensitive soft edges for elucidating anodic and cathodic charge compensation contribution via x-ray Raman scattering spectroscopy. By using a hard x-ray incident beam this technique circumvents surface limitations and is practically free of self- absorption due to its non-resonant nature. In addition, it does not require complex sample preparation or experimental setups, making it an ideal tool for potential in situ analysis of the electronic structure of electrode materials. In this study we monitored for the first time bulk soft edges of both oxygen and transition metal (iron) of the cathode material Li2FeSiO4 during one complete electrochemical cycle concurrently. Our results reveal that the redox mechanism relies primarily on the iron (cat...