Spanish i3 online configurer has a not-yet-available option called "Bateria de mayor potencia" which Google Translate will tell you means "battery more powerful" in English. There isn't a picture for the option and you can't order it - yet. I checked the other BMW models on the site to make sure this wasn't just some kind of phantom option or mistake that was listed on all the BMW cars on the site and it isn't. It was in fact only listed on the i3 options page.
|An inside look of i3 Battery module|
|i3 Battery pack|
Battery tech is constantly evolving. Tesla for example is rumored to be replacing the current batteries they use with higher density cells in the very near future and will soon open the Gigafactory(s) to manufacture them. Over in the BMW ActiveE Facebook group we recently had a fellow ActiveE driver say he had the opportunity to ride in a test MINI-E at BMW's Technology Center that was fitted with BMW's next generation of batteries and the car had about a 200 mile range. This cannot be confirmed but I have no reason to doubt his claim.
So this may be nothing, a simple mistake or misunderstanding on the BMW i3s Spanish website. Or maybe not...