High interfacial-energy heterostructure facilitates large-sized lithium nucleation and rapid Li⁺ desolvation process

High interfacial energy Li⁰-electrolyte interface contributes to larger Li⁰ nucleation embryos and a more stable interface, so the interfacial energy is essential for highly reversible Li⁰ deposition/stripping. Herein, a high interfacial-energy artificial solid electrolyte interphase (SEI) with rich LiF embedded in lithiated poly-2-acrylamido-2-methylpropane sulfonic acid (PAMPS-Li) network is designed to realize favorable Li⁰ nucleation and rapid desolvation of Li⁺ simultaneously. The Li-F bonds in LiF (001) exhibit stronger ion-dipole interactions with Li atoms, offering higher interfacial energies. When the growth surface energy and total interfacial energy of Li⁰ are balanced, the high interfacial energy SEI with abundant LiF can promote the formation of larger Li⁰ nucleation embryos. In addition, the PAMPS-Li with immobilized anions presents weaker interaction with Li⁰ and possesses higher polymer-Li interfacial energy, and its amide and sulfonic acid groups exhibit higher binding energies with Li⁺. Therefore, PAMPS-Li can easily promote the Li⁺ to escape from the solvent sheath and weaken the desolvation energy barrier. The highly reversible Li⁰ deposition behavior with restricted side reactions is achieved based on the synergistic modification of high interfacial energy SEI with heterostructure. Most importantly, lifespan of multi-layered Li⁰ pouch cell (330 Wh kg^-1) with a low N/P ratio (1.67) is over 100 cycles, verifying its potential practical application.