Advanced Materials for Energy Storage Devices (Review)

This review examines high performing energy storage devices for high-power applications including heavy electric vehicles, energy-efficient cargo ships and locomotives, aerospace and stationary grid system. Such devices require systematic design and fabrication of composite nanostructured carbon-based material and conductive polymers. Electrochemical capacitors based on nanostructured carbon can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. Composite device of pseudo-capacitive polymeric materials and nanostructured carbon with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries without compromising its specific power density, high capacitance and lifetime cycling stability. Energy storage devices' widespread applications in industrial, hybrid electric vehicles and commodity electronics could be facilitated through careful selection of electrolyte-electrode system. Good understanding of charging mechanism is key to improving device's performance. Charging mechanism includes sequential ion desolations in pores smaller than the solvated ions through ion exchange or ion adsorption. This leads to higher capacitance for such storage devices. This has opened the door to designing advanced high-energy density devices with fast charging and discharging times using a variety of electrolytes and nanostructured carbon-polymer composite.