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...

NiAl-layered double hydroxide (NiAl-LDH) coatings grown in-situ on AZ31 Mg alloy were prepared for the first time utilizing a facile hydrothermal method. The surface morphologies, structures, and compositions of the NiAl-LDH coatings were characterized by scanning electron microscopy (SEM), three dimensional (3D) optical profilometer, X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FT-IR), and X-ray photoelectron spectroscopy (XPS). The results show that NiAl-LDH coating could be successfully deposited on Mg alloy substrate using different nickel salts, i.e., carbonate, nitrate, and sulfate salts. Different coatings exhibit different surface morphologies, but all of which exhibit remarkable enhancement in corrosion protection in 3.5 wt % NaCl corrosive electrolyte. When nickel nitrate was employed especially, an extremely large impedance modulus at a low frequency of 0.1 Hz (|Z|f = 0.1 Hz), 11.6 MΩ cm2, and a significant low corrosion current density (jcorr) down to 1.06 nA cm−2 are achieved, demonstrating NiAl-LDH coating’s great potential application in harsh reaction conditions, particularly in a marine environment. The best corrosion inhibition of NiAl-LDH/CT coating deposited by carbonate may partially ascribed to the uniform and vertical orientation of the nanosheets in the coating.