WATER-BASED SLURRY COMPOSITION, ELECTRODE PLATE FOR ELECTRICITY STORAGE DEVICE, AND ELECTRICITY STORAGE DEVICE

A water-based slurry composition contains (1) a water-based medium containing at least water as a polar solvent, (2) at least one polymer selected from cellulose derivatives, alginic acid derivatives, starch derivatives, chitin derivatives, chitosan derivatives, polyallylamine and polyvinylamine, (3) a hydrophobic filler, and (4) a polybasic acid or a derivative thereof. The composition has a water content of 30 mass% or higher. An electrode plate for an electricity storage device, and the electricity storage device are also disclosed.