Cryo‐Electron Microscopy for Unveiling the Sensitive Battery Materials

Abstract

Deep chemical and structural investigation of battery components is increasingly imperative for exploring new electrode materials and their performance iterations for the next‐generation of energy storage devices with high energy density. This is particularly true in the research realm of lithium (Li) metal and its derivatives for the robust anode. Conventionally, both Li metal and its solid electrolyte interphase (SEI) layer are chemically reactive and sensitive to electron‐beam irradiation, making the high‐resolution observation difficult to perform at native environment. Recently, the emergence of cryo‐electron microscopy (EM) has brought great opportunities to reveal the physicochemical properties of these energy materials. By means of cryo‐EM, the high‐resolution imaging of the samples at the nanometer or even atomic scale while maintaining their native state can be realized. Herein, the contributions of cryo‐EM to the characterization of sensitive battery materials are focused on, which are tentatively classified as the following: the visualization of Li dendrites, inactive Li, and the discussion regarding electrode interface chemistry. The review concludes by providing several proposals for the development of cryo‐EM in the future. It is hoped that this work will shed light on the in‐depth understanding of battery materials for high‐performance rechargeable batteries.

Biomass-Derived Anion-Anchoring Nano-CaCO3Coating for Regulating Ion Transport on Li Metal Surface

“…In addition, advanced characterization techniques, such as cryo-TEM, have been employed to detect the SEI nanostructure of Li deposits. − Consistent with the SEM observation, the cryo-TEM results showed that spherical Li formed with the assistance of the NC coating (Figure g). The fast Fourier transform (FFT) image (inset of Figure h) confirmed that the main components were Li metal and Li 2 O.…”

Evaluating the effectiveness ofin situcharacterization techniques in overcoming mechanistic limitations in lithium–sulfur batteries

“…In situ cryo-EM is not yet a reality, nonetheless ex situ cryo-EM is proving very powerful when sample preparation is performed carefully. 224,225 Further visualization of the chemical and structure information at the nanoscale should be performed. Should in situ TEM of LSBs with liquid electrolytes never be a reality, cryo-EM may well fill the gap in knowledge.…”

Recent Advances in Solid-Electrolyte Interphase for Li Metal Anode

“…The desired SEI should possess electron insulation, high lithium ions diffusivity, superior mechanical modulus, favorable elasticity, and homogeneous composition to inhibit the growth of treelike lithium dendrites and maintain the controllable interface stability upon repeated cycling ( Zhenxing Wang et al, 2021 ). Many advanced characterization methods (such as cryo-electron microscopy and secondary ion mass spectrometry) have been developed to study the formation process and microstructure evolution of SEI layer during repeated cycling ( Ju et al, 2021 ; Yujing Liu et al, 2021 ). However, the in situ defective SEI layer usually suffers from inferior Li-ions diffusivity, low mechanical strength, and nonuniform composition, which make it difficult to accomplish flat and stable electroplating/stripping of metallic lithium anode ( Aslam et al, 2021 ).…”