Flexible interfacial modification layers towards enhanced performance in LATP-based all-solid-state batteries

Abstract

Interfacial stability is the key factor hindering the application of inorganic solid-state electrolytes. However, the bad interfacial contact and interfacial side reaction lead to severe polarization and contact failure. Herein, a PEO-based interfacial modification interlayer was constructed on the surface of LATP that is generally accepted to be unstable against with the Li metal anode to improve the interfacial stability. With the addition of LZP as the filler to the PEO modification interlayer, the interfacial Li⁺ transport kinetics and stability of the LATP pellet were significantly improved. The modified LATP pellet exhibited a large critical current density of 1.58 mA cm⁻², ∼5 times higher than that of LATP. Furthermore, the modified LATP pellet showed stable Li plating/stripping for more than 5000 h at 0.20 mA cm⁻². The assembled LATP-based all-solid-state lithium batteries had almost no capacity fading after 250 cycles. This study illustrates a simple yet efficient strategy to explore high-safety electrolyte alternatives with reasonable interfacial compatibility and presents huge potential for the usage of polymer-based modification layers for unstable ceramic electrolytes.