BINDER COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERY, SLURRY COMPOSITION FOR ALL-SOLID-STATE SECONDARY BATTERY, SOLID ELECTROLYTE-CONTAINING LAYER, AND ALL-SOLID-STATE SECONDARY BATTERY

Provided is a binder composition for an all-solid-state secondary battery that can produce a slurry composition for an all-solid-state secondary battery having excellent dispersibility and preservation stability and that can cause a solid electrolyte-containing layer to display excellent ion conductivity. The binder composition contains a polymer, ions of a metal belonging to group 1 or group 2 of the periodic table, and a solvent. The solvent includes an organic solvent having a carbon number of 8 or more, and the content of the ions of the metal is not less than 5 mass ppm and not more than 5,000 mass ppm relative to the polymer.