Summarize the following:
You may have to open the back of the casing of your phone to remove the battery.  If you're using an iPhone, check out this article to see how you can remove the battery. For some Samsung Galaxy models you can check out this article for instructions on how to take out the battery. For detailed Android instructions, please refer to your manufacturer's website or manual. Completely wrap your battery to protect it from water or other liquids. Make sure your battery is completely protected from ice, water and all the wet surfaces inside your freezer. Getting the battery wet will surely damage it. Protect the battery from moisture at all costs.  Exposing the battery to low temperatures for a while may allow it to recharge a little, and hold sufficient energy to connect to a regular phone charger. When you're ready to try and see if your battery works, take it out of the freezer and unwrap the coverings. If there's any moisture on the battery, make sure to carefully wipe it all dry. This will allow the battery to adjust to normal temperatures.  If this doesn't work for you, you can also try wiping off all the moisture, and inserting the battery when it's still cold. Make sure to protect the battery from direct sunlight. This may cause irreparable damage. Leave the phone turned off for now. Do not turn your phone on before charging it with your standard phone charger. Use your regular charging cable, and plug the phone into charging before trying to turn it on again. Leave the phone on the charger for at least 48 hours before attempting to turn it on. After charging for 48 hours, try turning on your phone, and check the battery level to see if the freezing method worked. You may find that your once dead battery is revived, and is now able to hold a bit of power again.
Remove the battery from your phone. Wrap the battery with paper or plastic film. Place the battery inside a sealed plastic bag. Place the sealed battery inside the freezer's ice compartment. Leave the battery in the freezer for 3 days. Remove the battery from the freezer after 3 days. Wipe any moisture off of the battery. Leave the battery in room temperature for a day. Insert the battery back into your phone. Charge your phone with your standard charger cable. Turn on your phone.