Researcher at TU Graz demonstrates in Nature Materials that it is possible to combine the high-energy density of batteries with the high-power output of super capacitors in a single system – thanks to liquid energy storage materials. Batteries and super capacitors are electrochemical energy storage media, but they are as different as night and day. Both are capable of energy storage and targeted energy release – and yet there are major differences between the two. Batteries store very large amounts of energy that is released slowly but constantly. By contrast, super capacitors can only store small amounts of energy, but they release this energy much faster and more powerfully with large short-term peak currents.