Lithium-ion battery (LIB) technology is currently the most important and promising energy storage technology that has captured the portable electronic market, invaded the power tool equipment market, and penetrated the electric vehicle market. The ever-growing demand for its energy capacity necessitates the understanding of (de)lithiation mechanism on a nanoscale, and thus the development of platforms enabling in-situ electrochemical TEM characterization. Sealed liquid cell (SLC) device has been widely recognized as the most desirable platform, since it allows the introduction of commercial volatile electrolytes into TEM. However, a comprehensive review summarizing the current development of SLCs for in-situ TEM LIB research is missing and in urgent need for its benign development. This review article aims to fill this gap.