How Flow Batteries Work (VIDEO) DOE/Pacific Northwest National Laboratory This video is under embargo. Please login to access this video. To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Caption Flow batteries produce power by pumping electrolytes - liquid solutions with dissolved chemicals -- from external tanks into a central stack. PNNL's new zinc-polyiodide flow battery's electrolytes carry positively charged zinc ions and the negatively charged ions iodide and polyiodide. Credit Pacific Northwest National Laboratory Usage Restrictions Credit PNNL License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.