I'm going to bake a banana cake this weekend and have a load of banana in the freezer - can I use this or would i be better off buying new ones?

If I have leftover bananas, I unpeel them and slice them and store in the freezer - then I just usually chuck them in a blender and use them for smoothies.

Would these be okay if I defrosted them to use in a banana cake or would the freezing affect the quality of the cake and cause the mixture to be too wet?

I'm not desperate to use them up and can just the frozen ones in the future for smoothies so would i be better off buying some more bananas or would these be okay?

There are a few recipes on the internet for frozen banana cake.

Freezing the banana makes it go all mushy once defrosted, but it makes no difference to the cake. I've done this loads of times and I freeze mine in the skins