Scientists at the University at Buffalo have identified a fluorescent dye called BODIPY as an ideal material for stockpiling energy in rechargeable, liquid-based batteries that could one day power cars and homes. BODIPY - short for boron-dipyrromethene - shines brightly in the dark under a black light. The dye has unusual chemical properties that enable it to excel at two key tasks: storing electrons and participating in electron transfer. Batteries must perform these functions to save and deliver energy, and BODIPY is very good at them. In experiments, a BODIPY-based test battery operated efficiently and with longevity, running well after researchers drained and recharged it 100 times.