The big power station could do this with a kitchen coffee maker, but heating air/water takes a ton of power and eats up batteries quick.
If you want to get creative, the heat gun (DCE530B) aimed at a small metal pot might be able to get water boiling. I have one and it does eat up batteries quick (even flexvolt), but supposedly kicks out 990F.
if you can tinker at all - go the power wheels option, as it comes with a step down buck converter and the battery adaptor. Just make sure the tea kettle is less than 180 watts and never let the battery go all the way down. Cut the one end off and wire in a female 12v cigarette lighter adaptor.