A composite including a base polymer and a surface-treated inorganic moisture absorbent. The surface-treated inorganic moisture absorbent is surface-treated with a surface-treating agent having a solubility parameter difference of less than or equal to about 3.5 from that of the base polymer. An article including the composite, a battery case including the composite or the article, and a battery including the battery case and an electrode assembly including a positive electrode and a negative electrode.