Would it be possible to vacuum seal the battery before placing it in the frig? Thinking Food Saver
yes, but then it'd need to be left in the bag for several hours after removal to prevent the condensation issues
people misunderstand what batteries in the fridge does, all the lower temperatures do is keep the battery CHARGED for longer, it doesnt make its overall lifespan any longer
Sure, you can vacuum seal the battery but for the reasons Mussels note, I see no advantage to it. As Mussels noted, all the cold does is slow down the inevitable discharge process by slowing down the chemical reaction going on inside a battery. Decades ago, before alkaline batteries (which tend to have a long "shelf-life" of several
years), this was a big deal because "brand new" old technology batteries would go dead sitting sealed in their packaging in a drawer after just a few months. So folks would put them in the "ice box" in the hopes they would last a little longer. Note those were NOT rechargeable batteries.
Unless you start talking extreme colds (like outer space and absolute zero temps), the freezing cold itself does not hurt the battery, but it does not help the battery either.
In fact, it is likely to get moved about in the freezer, possibly taken in and out multiple times, and subject to other abuse as people go digging for that last Eggo buried in the back or bottom of the freezer. Every time the freezer door is opened, warm, moist air gets in which is also not good. It would be better to just cover the battery (to protect it from dust) and put it on a closet shelf where it can remain undisturbed until needed again.