Scientists from University College London and the Chinese Academy of Sciences have proposed a graphene-based design for supercapacitors, which reportedly increased their density by 10 times.
Supercapacitors charge quickly but also discharge at a high speed. Existing supercapacitors tend to have a low energy density – about 1/20 of the battery capacity. Batteries combined with supercapacitors are already in limited use – for example, in Chinese public transport. But the bus in which such a battery is installed is forced to charge at almost every stop.
In this work, the researchers proposed a new design of the supercapacitor, which uses films of graphene laminate with the same distance between the layers.
The work showed that when the pores in the membranes exactly correspond to the size of the electrolyte ions, the energy density increases drastically — about 10 times compared to conventional supercapacitors.
In addition, the scientists note, the new material has a long service life, retaining 97.8% of its energy intensity after 5000 cycles of charging and discharging. The new supercapacitors are also very flexible – they can be bent up to 180 degrees.