Li3PO4-enriched solid electrolyte interphase on Si-based anode for enhanced Li+ transport and interfacial stability in lithium batteries.

Abstract

The structure and composition of the solid electrolyte interphase (SEI) exerts a significant influence on the fast-charging capability and stability of lithium-ion batteries (LIBs). However, elucidating the design principles governing anode interfacial structures and revealing the kinetics and mechanisms of Li⁺ transport remain challenging. SEI layer. Herein, we present an efficient synthesis strategy for fabricating LIBs anodes consisting of silicon nanoparticles coated with a Li₃PO₄-modified carbon shell (Si@C@LPO). Through a combination of comprehensive experimental investigations and density functional theory (DFT) calculations, we elucidate the influence of SEI layer enriched with various inorganic components on Li⁺ transport. The high adsorption energy of the LiPO₄-enriched SEI enhances its affinity for Li⁺ during the cycling process and suppresses solvent decomposition at the anode interface, thereby improving both fast-charging performance and electrode stability. Consequently, the Si@C@LPO anode exhibit a specific capacity of 605.67 mAh g^-1 at 8 A g^-1 and significantly enhanced cycling durability with a higher capacity retention of 73.3 % after 100 cycles at 1 A g^-1. This strategy establishes a clear correlation among SEI components, Li⁺ transport kinetics, and the design of interfacial structures in high performance LIBs anode materials.