By conventional thinking, heat will speed up chemical reactions, so reducing the temperature of the reaction will also reduce the reaction speed.
But consider if you freeze the batteries, that whatever liquid there is inside might crystalise (though there is usually very little and all that usually in the form of a gel or paste). That is generally very bad news for seals which means your batteries will probably leak once you take them out. Of course, there is the possibility that the liquid freezing point is below that of your freezer, so you're safe.