Review—Promises and Challenges of In Situ Transmission Electron Microscopy Electrochemical Techniques in the Studies of Lithium Ion Batteries

Abstract

In situ transmission electron microscopy (TEM) electrochemistry with high-resolution characterization of morphology and microstructure is a powerful and practical technique to observe and analyze the lithiation and delithiation process of Li ions in the cathode and anode for comprehensively understanding the performance of Li-ion batteries (LIB), the formation of a solid electrolyte interphase (SEI), and the aging process during the investigation of LIBs. This review mainly focuses on the development and achievements of in situ TEM electrochemical techniques in investigating the mechanism of LIBs in recent years. Three types of in situ TEM electrochemical holders that are used commonly in the characterization of LIBs are presented. A calculation method for quantitative determination of the lithium diffusion coefficient (D Li ) in electrodes with in situ TEM electrochemical technique is also mentioned. Finally, the challenges, limitations, and future work for during application of the in situ TEM-electrochemistry technique are further discussed and reviewed from the perspective of morphology, influence of electron radiation on the decomposition of electrolyte, configuration of electrode, and determination of The heavy dependence on fossil fuels in modern society has brought serious environmental problems including air pollution, water pollution, CO 2 emissions, and global warming.1-3 These issues, as well as the foreseeable worldwide energy shortage, strongly demand renewable alternative sources and clean energy such as solar cells, hydroelectric power, and wind energy, which require advances in electrical energy conversion and storage technologies.4-6 Electrochemical devices such as batteries and electrochemical capacitors to store and restore electrical energy are possible solutions in the near-term because the conversion between electrical and chemical energy shares a common carrier (electrons).2,7-9 Moreover, compared to traditional batteries, lithium-ion batteries (LIBs) are more compact, portable, and have a high gravimetric capacity and power density, owing to the lighter molecular weight of lithium. 10,11 LIBs are widely used in present-day portable electronic gadgets such as mobile phones, laptops, tablet computers, and video camcorders, and the medical and aerospace industries for storing photovoltaic-generated dc electricity.12,13 Although possessing many advantages and in high demand, radical progress of such devices like LIBs has not been attained as yet because of their intrinsic complexity.14,15 There are many concurrent electrochemical, physical, and mechanical processes during their operation, 14,16 therefore, to enhance the overall properties of LIBs with high energy-density and long cycle-life, these aforementioned processes should operate in a predictable way across multiple environments.14 Until now, many basic principles regarding battery operation, including atomic conversion mechanism, electrode degradation, and evolution of electrolyte, are poorly understood.14 Recently, in situ electroch...

Understanding the conversion mechanism and performance of monodisperse FeF2 nanocrystal cathodes

“…In-situ TEM measurements require a large negative bias between the lithium probe and the sample, which promotes kinetic reaction pathways, making it difficult or impossible to observe transient intermediates that are stable in a real battery. 36,37 Nevertheless, we employ in-situ TEM to help visualize and corroborate larger scale observations from the ex-situ data (Supplementary Video 2, 3). Enlarged TEM images, inverted contrast FFTs, and simulated diffraction patterns for each sample are shown in Supplementary Figures 20-28.…”

Local Substrate Heterogeneity Influences Electrochemical Activity of TEM Grid-Supported Battery Particles

“…The technique can be performed in reflectance mode on opaque current collectors such as Al, Ni, or Cu foil and is not limited to transparent current collectors. This analytical technique leverages a conventional bright field optical microscope to obtain single particle electrochemistry data and is compatible with existing TEM (Huang et al, 2010 ; Liu and Huang, 2011 ; Liu et al, 2012 ; Qi et al, 2016 ; Xie et al, 2017 ; Tu et al, 2018 ; Zhang et al, 2020 ) and X-ray (Totir et al, 1997 ; Ota et al, 2003 ; Deb et al, 2004 ; Kim and Chung, 2004 ; Chao et al, 2010 ; Shearing et al, 2011 ; Nelson et al, 2012 , 2017 ; Shapiro et al, 2014 ; Wolf et al, 2017 ; Yau et al, 2017 ; Li et al, 2018 ; Yu et al, 2018 ) micro-spectroscopy methods.…”

“…On the other hand, several atomic-level imaging methods have been used to study ion insertion kinetics of nanoparticle film or slurry electrodes (De Marco and Veder, 2010 ; Harks et al, 2015 ; Grey and Tarascon, 2017 ; Yuan et al, 2017 ; Tripathi et al, 2018 ; Boebinger et al, 2020 ; Li et al, 2020 ). Transmission electron microscopy (TEM; Huang et al, 2010 ; Liu and Huang, 2011 ; Liu et al, 2012 ; Zeng et al, 2014 , 2020 ; Qi et al, 2016 ; Xie et al, 2017 ) and X-ray (Totir et al, 1997 ; Ota et al, 2003 ; Deb et al, 2004 ; Kim and Chung, 2004 ; Chao et al, 2010 ; Shearing et al, 2011 ; Nelson et al, 2012 , 2017 ; Li et al, 2014 , 2018 ; Shapiro et al, 2014 ; Wolf et al, 2017 ; Yau et al, 2017 ; Yu et al, 2018 ) imaging methods have measured the real-time lithiation kinetics of nanoparticle electrodes and have successfully incorporated material properties such as film porosity, particle shape, orientation, and composition to predict the system's electrochemical response (Garcia et al, 2005 ; Gupta et al, 2011 ; Stephenson et al, 2011 ; Ebner et al, 2014 ; Landesfeind et al, 2018 ). In situ single particle-level TEM measurements have revealed dynamic structural information of battery materials (Huang et al, 2010 ).…”

In Situ TEM of Electrochemical Incidents: Effects of Biasing and Electron Beam on Electrochemistry

“…Many efforts have been made to improve capsulation materials and the design and control of aqueous flow and pumping systems, among many other challenges and opportunities. 15 The steady progress in TEM holder and accessories has enabled the in situ TEM technique to have better and expanded control of experimental conditions. For example, in 2015, Leenheer et al designed a sealed liquid cell with the chips and accessories being capable of controlling electrochemical conditions to have a picoampere level precision.…”