Researchers at ETH Zurich and IBM Research Zurich have built a tiny redox flow battery. This means that future computer chip stacks—in which individual chips are stacked like pancakes to save space and energy—could be supplied with electrical power and cooled at the same time by such integrated flow batteries. In a flow battery, an electrochemical reaction is used to produce electricity out of two liquid electrolytes, which are pumped to the battery cell from outside via a closed electrolyte loop.