Recently, the pre-doping of Li⁺ ions (pre-lithiation) into anodes to compensate for the irreversible capacity loss observed during the first charging cycle has gained much attraction from the viewpoint of improving the energy density of lithium ion batteries (LIBs). Many pre-doping methods such as electrochemical and chemical pre-doping, pre-doping with the help of additives or pre-doping by direct contact with the lithium metal have been proposed. However, the only practical pre-doping method was developed by JM Energy in Japan, which was used to fully pre-dope graphite anodes in lithium ion capacitors (LICs). Although this pre-doping method has high originality and high mass productivity for LICs, it is not well-known to the researchers and engineers in the area of batteries and capacitors. In addition, its information is restrictive because most of the information was written in Japanese. Therefore, in this paper, the details of the practical pre-doping method and its recently-developed related technologies are reviewed. The advantages and disadvantages of the pre-doping method are discussed.