High-performance and high-capacity hydrogen storage compounds have been eagerly pursued as a power supply in renewable energy storage vehicles. With this purpose, carbon self-doped graphitic carbon nitrides-Li2FeMn3O8 (CCN/LFMO) nanocomposites were designed through the straightforward approach as electrode materials for electrochemical hydrogen storage application. The hydrogen storage performances of the samples were identified on the basis of chronopotentiometry charge-discharge techniques in an alkaline medium. Cyclic voltammetry and electrochemical impedance spectroscopy were then used to determine the electrochemical attributes of pristine LFMO, CCN, and representative nanocomposites. As a result, the CCN/LFMO electrode with a ratio of (70:30) exhibited 2275 mA h/g discharge capacity at the 20th cycle, while pristine LFMO and CCN show 180 and 1050 mA h/g discharge capacity, respectively. This strategy is not complicated but is very impressive and executable due to the multifunctional aspect of CCN, and it could be extended to the most efficient metal oxide materials for hydrogen storage.