Self: Graphene Micro-Supercapacitors

Graphene Micro-Supercapacitors

• Co-I Garrett Frankson and Austin Jeffries
  Current Status: Building Project Page

Project Overview

A capacitor is an electric energy storage device, often constructed with two layers of conducting foil separated by a paper-thin layer of insulator. The capacity is proportional to the area A and inversely proportional to the insulator thickness t, C~A/t. A supercapacitor has a atomic scale insulator thickness given by the solvation layer surrounding an ion in an electrolyte, and a large surface area. Supercapacitor values of 1-1000 F are now available commercially (see https://www.sparkfun.com/products/746) and approach the energy density of batteries while offering fast charge and discharge rates (high power density). For an introduction to graphene based supercapacitors, see http://vimeo.com/51873011. -duncan

Short term budget

Project Goals

Short Term Goals

1. Create graphene micro-supercapacitor material using the methods outlined by El-Kady and Kaner.
2. Conduct a series of tests on how to maximize the amount of charge stored within each graphene micro-supercapacitor.

Long Term Goals

1. Design an apparatus that can hold many graphene micro-supercapcitors in an efficient and usable way for use in application.
2. Experiment with powering small mobile devices (ie. a flash light, a watch, a cellphone)

Relevant Publications

• Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage

  • Maher F. El-Kady & Richard B. Kaner

    • El-Kady and Kaner demonstrate a scalable fabrication of graphene micro-supercapacitors over large areas by direct laser writing on graphite oxide films. More than 100 micro-supercapacitors can be produced on a single disc in 30 min or less. The devices are built on flexible substrates for flexible electronics and on-chip uses. Remarkably, miniaturizing the devices to the microscale results in enhanced charge-storage capacity and rate capability. These microsupercapacitors demonstrate a power density of ~200 W cm^-3, which is among the highest values achieved for any supercapacitor.

  Preparation of Graphitic Oxide

  • William S. Hummers & Richard E. Offema

    • The conventional method for the preparation of graphitic oxide is time consuming and hazardous. Hummers and Offema have developed a rapid, relatively safe method for preparing graphitic oxide from graphite in what is essentially an anhydrous mixture of sulfuric acid, sodium nitrate and potassium permanganate.

  Layer-by-Layer Assembly of Ultrathin Composite Films from Micron-Sized Graphite Oxide Sheets and Polycations

  • Nina I. Kovtyukhova et al.
    • For the synthesis of graphitic oxide, El-Kady and Kaner used a modified Hummers' method developed by Nina I. Kovtyukhova et al.