Single-Step Preparation of Li2S-C Composite Electrode for Sulfide Based All-Solid-State Battery

Abstract

Performance of all-solid-state batteries (ASSBs) is limited by high interfacial resistance as a result of rigid solid-solid contact between electrolyte and electrode particles. Thus, it is necessary to increase the pathways for lithium ion and electrons transport, securing intimate solid-solid contact. Electrode fabrication procedure is one of critical steps to determine kinetic properties of ASSBs. The electrode preparation is usually step-wise and complex so that it needs to be simplified without sacrificing performance. In the present work, ASSB cells, consisting of Indium counter electrode, sulfide-based glass (Li2S-P2S5) electrolyte and lithium sulfide composite (Li2S + acetylene black) working electrode, were fabricated. Lithium sulfide composite electrode was prepared by two different ways, multi-step and single-step. Charge-discharge tests were conducted under a constant current 200 ~ 600 μA (130 ~ 390 μA/cm2) to compare kinetic properties of lithium sulfide composite electrode prepared by multi-step and single-step. SEM (Scanning Electron Microscope), EDS (Energy Dispersive Spectroscopy) mapping and Raman spectroscopy were also performed to analyze particle distribution and morphology of the composite electrodes.