Wet-Slurry Fabrication Using PVdF-HFP Binder with Sulfide Electrolytes for All-Solid-State Batteries

Building batteries in the solid state with inorganic solid electrolytes (SEs) have promising opportunities in terms of better safety and higher energy density. Sulfide SEs have been one of the most promising candidates for practical all-solid-state Li-ion batteries (ASLBs), which is attributed to their high conductivities and mechanical sinterability. However, severe reactivities with polar solvents (e.g., N-methyl-2-pyrollidone) complicate the wet-slurry fabrication. The availability of polar solvents are highly limited, which in turn restricts the use of conventional polymeric binders, such as polyvinylidene fluoride (PVdF) or styrene butadiene rubber (SBR)/carboxymethyl cellulose (CMC). Thus, non-polar or less polar organic solvents such as xylene and rubber-based polymeric binders that are soluble to those sovelnts have been positioned as the major choices for the ASSB applications<br/>In this presentation, we report on our new wet-slurry fabrication protocol using cosolvents for employing electrochemically-stable PVDF-hexafluoropropylene (PVdF-HFP) binder into ASLBs. Cosolvents act synergetically so that PVDF-HFP is dissolved while the migration of binder during drying process is suppressed. In addition, the effects of electrochemical stability, density, and the distribution of polymeric binders on the electrochemical performances of ASLBs will be presented.<br/><br/>References<br/>[1] D. Y. Oh, Y. J. Nam, K. H. Park, S. H. Jung, K. T. Kim, A. R. Ha, Y. S. Jung, <i>Adv. Energy Mater.</i>, <b>2019</b>, <i>9</i>, 1802927.<br/>[2] K. T. Kim, D. Y. Oh, S. Jun, Y. B. Song, T. Y. Kwon, Y. Han, Y. S. Jung, <i>Adv. Energy Mater.</i>, <b>2021</b>, <i>11</i>, 2003766.