Exploring the use of butadiene rubbers as a binder in composite cathodes for all-solid-state lithium batteries

Among the various next-generation battery systems, all-solid-state lithium batteries (ASSLBs) employing sulfide-based solid electrolytes have garnered considerable attention because of their high energy density and enhanced safety compared to conventional lithium-ion batteries (LIBs) with liquid electrolytes. The fabrication of composite cathodes for ASSLBs by the wet-slurry process is highly desirable, because it can be scaled into a large sheet and be applied to the established slurry-processed electrode manufacturing technology of LIBs. A polymer binder in the composite cathode is an important component for maintain-ing good interfacial contacts among the electrode components (active material, solid electrolyte, and con-ducting carbon) during charge and discharge cycles. In this study, we used polybutadiene and acrylonitrile-butadiene rubbers (NBR) with different acrylonitrile (AN) contents as a polymer binder in the composite cathode. Our results demonstrated that a composite cathode employing NBR with 25 wt.% AN (NBR25) showed good elastic properties and superior adhesion without the large deteriora-tion of interfacial contacts during cycling. The solid-state Li-In/Li6PS5Cl/LiNi0.7Co0.1Mn0.2O2 cell assem-bled with the composite cathode employing NBR25 exhibited an initial discharge capacity of 149.0 mAh g-1 with good capacity retention at 0.2 C and 25 degrees C.(c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.