Abstract Conventional lithium (Li) ion batteries (LIBs) are approaching the limit imposed by their theoretical energy density, and they urgently require advanced strategies to transcend this boundary. Li‐ion/Li metal hybrid systems, which leverage reversible Li metal deposition within void spaces in the anode during charging, offer a significant leap forward for capacity enhancement without the need for complex structural modifications. However, the uncontrolled growth of Li dendrites at the electrode surfaces remains a critical barrier to practical adoption. Here, a protection strategy based on a lithio‐amphiphilic bilayer for graphite (Gr) anodes is proposed, engineered via the sequential deposition of silver (Ag) and chromium (Cr) thin films. The lithiophilic Ag layer functions as a nucleation template for homogenized Li plating across the electrode surface, whereas the lithiophobic Cr layer forms a robust barrier to suppress dendrite propagation. This Gr‐AgCr architecture enabled stable cycling at an ultralow negative‐to‐positive electrode capacity ratio (N/P ratio) of 0.4 and an electrolyte‐to‐capacity ratio (E/C ratio) of 1.1 g Ah −1 , achieving a 49% increase in energy density compared to conventional LIBs. This design provides a scalable pathway toward high‐energy‐density hybrid battery systems within existing LIB manufacturing frameworks, bridging the gap between Li metal and conventional intercalation chemistries.
Oh et al. (Thu,) studied this question.