hi can someone please tell me what are energy portal cells and how hey are used

"A single-use energy cell for the outer network of portals. You will need it to travel to the other levels in explore."

During last december there was an artic island to explore and gather lykos eggs from (it may open again this december). Unlike normal islands the tundra island had levels to it, each level the monsters became stronger and the chance for eggs increased. The cells are used to get to the next level when you stand upon the special portal on the tundra map. If I remember correctly its glow was green instead of the usual pale blue.

As of this moment they have no use, but may soon.