Researchers have demonstrated a working quantum battery prototype that uses quantum mechanical effects to charge faster and more efficiently than conventional batteries at small scales. The results, published this week, show that quantum entanglement and superposition can be practically harnessed in an energy storage context — something that has been theorized for years but not convincingly demonstrated.

The “sort of” caveat: the prototype operates under highly controlled laboratory conditions and at scales far removed from anything you’d put in a phone or a car. The gap between proof-of-concept and consumer product is wide and filled with engineering problems that quantum elegance doesn’t automatically solve.