Engineering Size-Tunable Lithiophilic Centers into an Ultrathin Deposition Substrate for High Lithium Utilization

The application of lithium metal anodes in high-energy-density batteries is limited by unstable interfacial dynamics and poor Li utilization, particularly in anode-free designs, where the electrolyte is minimal and the Li+ supply is restricted. Herein, a lightweight (0.32 mg cm–2), ultrathin (∼2 μm) interfacial protective layer is constructed using size-tunable Ag nanoparticles adorned with few-layer graphene oxide (Ag NPs@GO) via a facile precipitation process. The Ag NPs regulate the lithium nucleation/growth, and the GO dissipates the volume expansion of the deposited lithium. The introduction of a Ag NPs@GO interfacial layer provides efficient interfacial modification to the Cu substrate, thereby boosting lithium utilization efficiency in both symmetric and 2 mAh full cells paired with the Li[Ni0.8Mn0.1Co0.1]O2 cathode. The full cell delivers an energy density of 513.2 Wh kg–1 and a maximum power energy of 2052.8 W kg–1, calculated with the active materials. Furthermore, Li–Ag NPs@GO substrate establishes its outstanding air-defendable capability, preserving its pristine morphology and color after 100 min of air exposure with a lithium deposition amount of 10 mAh cm–2. This ultrathin interfacial modification approach offers a viable method to achieve a quasi-anode-free design, minimizing excess Li usage while maintaining balanced energy/power densities and enhanced cycling durability.