Targeting Si─O Bonds to Fortify the Solid‐Electrolyte Interphase for Stable Lithium Metal Batteries

ABSTRACT Lithium (Li) metal batteries (LMBs) are among the most promising next‐generation high‐energy‐density storage systems. Their commercialization, however, is hampered by severe interfacial side reactions (ISRs) and uncontrolled Li dendrite growth, which degrade cycling life and raise safety concerns. This study addresses these challenges by employing a functional layer of oxygen‐vacancy‐engineered BaTiO 3 pre‐adsorbed with SiO 3 2− (BTOVSi) to modify the Li anode/electrolyte interface. The BTOVSi layer not only enriches Li + concentration at the interface but also incorporates highly stable Si─O bonds into the solid electrolyte interphase (SEI), which synergistically enhances interfacial Li + transport kinetics and suppresses persistent ISRs. As a result, Li‐Li cells achieve an extended cycling lifespan of over 4500 h at 5.0 mA cm −2 and 1.0 mAh cm −2 . Moreover, LiFePO 4 || Li (50 µm) full cells retain 85% of their capacity after 1000 cycles and 70% after 1900 cycles. This work offers a novel strategy for the targeted design of SEI rich in Si─O bonds through a functional layer with pre‐adsorbed anions, effectively regulating interfacial ion distribution and redox reactions.