High-Performance Garnet-Type Solid-State Lithium Metal Batteries Enabled by Scalable Elastic and Li+-Conducting Interlayer

Promoting the interfacial Li+ transport and suppressing detrimental lithium dendrites are the main challenges for developing practical solid-state lithium metal batteries. In this respect, interface rationalizing to synergize the enhancement of ion transport and suppression of lithium dendrites is of paramount significance. Herein, a novel strategy is demonstrated to address those issues by a designed multifunctional composite interlayer. The photocrosslinkable polymer is introduced in a scalable elastic skeleton, which promotes the migration and diffusion of Li+. Moreover, adding perfluoropolyether in the interlayer benefits to regulating the formation of LiF-rich interface, sufficiently suppress the growth of lithium dendrites. Benefitting from the elasticity, high Li+ conductivity and the lithium dendrites suppression capability, the interlayer can significantly improve the interfacial performance of the solid electrolyte/lithium interface, thus leading to the greatly enhanced electrochemical performance of solid-state lithium metal batteries. A high critical current density of 3.6 mA cm(-2) and a long cycling life at 1.0 mA cm(-2) for >400 h are achieved for the symmetric cells. Besides, when used in a pouch-type full cell coupled with LiNi0.6Co0.2Mn0.2O2 cathode, a high charged capacity of 3.25 mAh cm(-2) can be maintained through 20 cycles, demonstrating its great potentials for practical application.