Supercapacitors can store more energy than and are preferable to batteries because they are able to charge faster, mainly due to the vertical graphene nanosheets (VGNs) that are larger and positioned closer together. VGNs are 3-D networks of carbon nanomaterial that grow in rows of vertical sheets, providing a large surface area for greater charge storage capacity. Also called carbon nanowalls or graphene nanoflakes, VGNs offer promise in high-power energy storage systems, fuel cells, bio sensors and magnetic devices, amongst others.