This study presents a novel Li metal host material with a unique hollow nano-spherical structure that incorporates Ag nano-seeds into a graphitic carbon nitride (g-C₃N₄) shell layer, referred to as g-C₃N₄@Ag hollow spheres. The g-C₃N₄@Ag spheres provide a managed internal site for Li metal encapsulation and promote stable Li plating. The g-C₃N₄ spheres are uniformly coated using polydopamine, which has an adhesive nature, to enhance lithium plating/stripping stability. The strategic presence of Ag nano-seeds eliminates the nucleation barrier, properly directing Li growth within the hollow spheres. This design facilitates highly reversible and consistent lithium deposition, offering a promising direction for the production of high-performance lithium metal anodes. These well-designed g-C₃N₄@Ag hollow spheres ensure stable Li plating/stripping kinetics over more than 500 cycles with a high coulombic efficiency of over 97%. Furthermore, a full cell made using LiNi_0.90Co_0.07Mn_0.03O₂ and Li-g-C₃N₄@Ag host electrodes demonstrated highly competitive performance over 200 cycles, providing a guide for the implementation of this technology in advanced lithium metal batteries.