Yamamoto Kazuo, Iriyama Yasutoshi, Hirayama Tsukasa
Nanostructures Research Laboratory, Japan Fine Ceramics Center, 2-4-1 Mutsuno, Atsuta-ku, Nagoya, Aichi456-8587, Japan.
Department of Materials, Physics and Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi464-8601, Japan.
Microscopy (Oxf). 2017 Feb 8;66(1):50-61. doi: 10.1093/jmicro/dfw043.
All-solid-state Li-ion batteries having incombustible solid electrolytes are promising energy storage devices because they have significant advantages in terms of safety, lifetime and energy density. Electrochemical reactions, namely, Li-ion insertion/extraction reactions, commonly occur around the nanometer-scale interfaces between the electrodes and solid electrolytes. Thus, transmission electron microscopy (TEM) is an appropriate technique to directly observe such reactions, providing important information for understanding the fundamental solid-state electrochemistry and improving battery performance. In this review, we introduce two types of TEM techniques for operando observations of battery reactions, spatially resolved electron energy-loss spectroscopy in a TEM mode for direct detection of the Li concentration profiles and electron holography for observing the electric potential changes due to Li-ion insertion/extraction reactions. We visually show how Li-ion insertion/extractions affect the crystal structures, electronic structures, and local electric potential during the charge-discharge processes in these batteries.
具有不可燃固体电解质的全固态锂离子电池是很有前景的储能装置，因为它们在安全性、寿命和能量密度方面具有显著优势。电化学反应，即锂离子嵌入/脱出反应，通常发生在电极与固体电解质之间的纳米级界面周围。因此，透射电子显微镜（TEM）是直接观察此类反应的合适技术，可为理解基本的固态电化学和改善电池性能提供重要信息。在这篇综述中，我们介绍了两种用于电池反应原位观察的TEM技术，即TEM模式下的空间分辨电子能量损失谱，用于直接检测锂浓度分布，以及电子全息术，用于观察由于锂离子嵌入/脱出反应引起的电势变化。我们直观地展示了锂离子嵌入/脱出在这些电池的充放电过程中如何影响晶体结构、电子结构和局部电势。
