Diaz-Lopez Maria, Cutts Geoffrey L, Allan Phoebe K, Keeble Dean S, Ross Allan, Pralong Valerie, Spiekermann Georg, Chater Philip A
Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom.
School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
J Synchrotron Radiat. 2020 Sep 1;27(Pt 5):1190-1199. doi: 10.1107/S160057752000747X. Epub 2020 Jul 10.
In situ electrochemical cycling combined with total scattering measurements can provide valuable structural information on crystalline, semi-crystalline and amorphous phases present during (dis)charging of batteries. In situ measurements are particularly challenging for total scattering experiments due to the requirement for low, constant and reproducible backgrounds. Poor cell design can introduce artefacts into the total scattering data or cause inhomogeneous electrochemical cycling, leading to poor data quality or misleading results. This work presents a new cell design optimized to provide good electrochemical performance while performing bulk multi-scale characterizations based on total scattering and pair distribution function methods, and with potential for techniques such as X-ray Raman spectroscopy. As an example, the structural changes of a nanostructured high-capacity cathode with a disordered rock-salt structure and composition LiMnO are demonstrated. The results show that there is no contribution to the recorded signal from other cell components, and a very low and consistent contribution from the cell background.
原位电化学循环结合全散射测量能够为电池充放电过程中存在的晶相、半晶相和非晶相提供有价值的结构信息。由于需要低背景、恒定且可重复的背景,原位测量对于全散射实验来说尤其具有挑战性。不良的电池设计可能会在全散射数据中引入伪像,或者导致不均匀的电化学循环,从而导致数据质量差或产生误导性结果。这项工作提出了一种新的电池设计,该设计经过优化,在基于全散射和对分布函数方法进行体相多尺度表征时能提供良好的电化学性能,并且具有用于诸如X射线拉曼光谱等技术的潜力。作为一个例子,展示了具有无序岩盐结构且组成为LiMnO的纳米结构高容量阴极的结构变化。结果表明,记录信号中没有来自其他电池组件的贡献,并且电池背景的贡献非常低且一致。