Rational Tuning of a Li₄SiO₄-Based Hybrid Interface with Unique Stepwise Prelithiation for Dendrite-Proof and High-Rate Lithium Anodes

Lithium metal batteries (LMBs) are among the most promising candidates for high energy-density batteries. However, dendrite growth constitutes the biggest stumbling block to its development. Herein, Li4SiO4-dominating organic–inorganic hybrid layers are rationally designed by SiO2 surface modification and the stepwise prelithiation process. SiO2 nanoparticles construct a zigzagged porous structure, where a solid electrolyte interface (SEI) has grown and penetrated to form a conformal and compact hybrid surface. Such a first-of-this-kind structure enables enhanced Li dendrite prohibition and surface stability. The interfacial chemistry reveals a two-step prelithiation process that transfers SiO2 into well-defined Li4SiO4, the components of which exhibits the lowest diffusion barrier (0.12 eV atom–1) among other highlighted SEI species, such as LiF (0.175 eV atom–1) for the current artificial layer. Therefore, the decorated Li allows for an improved high-rate full-cell performance (LiFePO4/modified Li) with a much higher capacity of 65.7 mAh g–1 at 5C (1C = 170 mAh g–1) than its counterpart with bare Li (∼3 mAh g–1). Such a protocol provides insights into the surface architecture and SEI component optimization through prelithiation in the target of stable, dendrite-proof, homogenized Li+ solid-state migration and high electrochemical performance for LMBs.