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

Abstract

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.