A Highly Stable Li‐Organic All‐Solid‐State Battery Based on Sulfide Electrolytes

Abstract

Abstract Sulfide solid electrolytes with high conductivity that is close to that of liquid electrolyte have been considered to be one of the most promising electrolytes for all‐solid‐state lithium batteries (ASSLBs). Unfortunately, the narrow electrochemical windows of sulfide electrolyte and contact loss at the interface upon cycles much limits the application of sulfide‐based ASSLBs. In this work, an organic quinone cathode, 5,7,12,14‐pentacenetetrone (PT), is used to fabricate an ASSLB with a sulfide electrolyte of glass ceramic 70Li 2 S‐30P 2 S 5 (LPS). Based on the various in situ/ex situ analyses, it is successfully demonstrated that the decomposition of LPS is negligible and the corresponding effects on interfacial impedance are reversible with optimized carbon additives. In addition, the inherent low Young's modulus of the PT electrode efficiently prevents the contact loss at the interface. As a result, the PT‐based ASSLBs deliver a high specific capacity (312 mAh g −1 ) and an excellent capacity retention (90.6%) over 500 cycles which is superior to previous reports. Moreover, a carbon‐free ASSLB is constructed by employing Mo 6 S 8 as conductive additives in a PT‐based cathode, which shows an improved rate performance and a long life.