In situ construction of trinity artificial protective layer between lithium metal and sulfide solid electrolyte interface

Abstract

Sulfide solid electrolytes (SSE) are considered promising alternatives to conventional liquid electrolytes due to their high safety that is inaccessible to common liquid electrolytes and favorable ionic conductivity. Nonetheless, the poor interfacial contacts and stability between SSEs and Li anode, as well as the inhomogeneous dendrite growth severely limit their practical applications. Herein, a trinity artificial solid electrolyte interphase composed of ethyl cellulose, graphene oxide and phosphoric acid was in-situ fabricated on the surface of the Li anode. This Li anode is denoted as EGPL (ethyl-cellulose-graphene-oxide-phosphoric-acid-modified-lithium). The artificial interphase can effectively benefit the uniform deposition of lithium, promote the transport of lithium ions and improve interfacial stability. Therefore, the all-solid-state batteries incorporated with EGPL anode and LiCoO2cathode can maintain 94.6% of initial capacity over 100 cycles at 0.2C, and also deliver excellent rate performance. This work provides a novel approach for the interfacial modification of lithium anodes for applications in all-solid-state batteries.