Reaction Distribution in Composite Electrodes for All-Solid-State Lithium-Ion Batteries with Sulfide-Based Solid Electrolyte

Abstract

All-solid-state lithium-ion batteries, which use solid phase electrolyte as electrolyte have potentials to realize high safety and larger energy density in comparison with the conventional lithium-ion batteries using a liquid electrolyte. The composite electrodes in the all-solid-state lithium-ion batteries consist of active cathode materials, solid electrolyte, conduction additives, and binder materials. The composite electrodes are obtained by drying slurries, which are pasted on current collector after mixing those materials with a solvent. The binder materials play a role to combine active materials, conductive additives and solid electrolytes, and they are generally used for preparing for the composite electrodes. One of the reasons for the insufficient rate capacity of the all-solid-state lithium-ion batteries is the inhomogeneous reaction distribution in the composite electrodes. In this study, we prepared sheet-type composite electrodes for all-solid-state lithium ion batteries with sulfide-based solid electrolyte using different binder materials with different solvents and investigated the reaction distribution within the electrodes using the 2D-imaging X-ray absorption spectroscopy (2D-XAS).