Lithium-coordinated polyaromatic anions such as tetrareduced corannulene, Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed., are useful substrates to model and ultimately improve the graphitic electrodes in lithium-ion (Li+) batteries. Previous studies suggested that 14- forms dimers encasing four Li+ ions in solution. Here, we report a single-crystal x-ray diffraction analysis confirming the formation of a sandwich-type supramolecular aggregate with a high degree of alkali metal intercalation. In contrast to the prior model, our data reveal that five Li+ ions are sandwiched between the two tetrareduced corannulene decks, and 7Li nuclear magnetic resonance spectroscopy delineates a conserved structure in tetrahydrofuran solution. Remarkably, the sandwich is robust in both solution and solid states even in the presence of crown ethers that compete for Li+ coordination. These results should help elucidate Li+ intercalation motifs between curved carbon surfaces more broadly. [ABSTRACT FROM AUTHOR]