Solid state energy storage systems and devices are provided. A solid state energy storage devices can include an active layer disposed between conductive electrodes, the active layer having one or more quantum confinement species (QCS), such as quantum dots, quantum particles, quantum wells, nanoparticles, nanostructures, nanowires and nanofibers. The solid state energy storage device can have a charge rate of at least about 500 V/s and an energy storage density of at least about 150 Whr/kg.