Electrochemical Supercapacitors and Hybrid Systems
An electrochemical capacitor or electric double-layer capacitor (EDLC), also known as supercapacitor, pseudocapacitor, electrochemical double layer capacitor, or ultracapacitor is an energy storage device with high power and relatively high energy density. Compared to conventional electrolytic capacitors the energy density is typically 3 orders of magnitude greater. In comparison with conventional batteries or fuel cells, EDLCs show lower energy density but have a much higher power density. EDLCs have a variety of commercial applications, notably in energy-smoothing and momentary-load devices. They have applications as energy-storage devices used in vehicles, and applications like wind power solar energy systems where extremely fast charging required.
KeywordsHigh Energy Density Negative Electrode High Power Density Energy Storage Device Electrochemical Capacitor
- Activated carbon
Also called activated charcoal or activated coal is a form of carbon that has been processed to make it extremely porous and thus to have a very large surface area available for EDLC, adsorption, or chemical reactions.
- Carbon nanotube
Carbon nanotubes (CNTs), not to be confused with carbon fiber, are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than any other material. These cylindrical carbon molecules have novel properties, making EDLC performances excellent in power capability.
- Electrochemical capacitor (EDLC)
An electric double-layer capacitor, also known as supercapacitor, pseudocapacitor, electric double layer capacitor (EDLC), supercapacitor or ultracapacitor is an electrochemical capacitor with relatively high energy density. Compared to conventional capacitors the energy density is typically on the order of thousands of times greater than an electrolytic capacitor. In comparison with conventional batteries or fuel cells, EDLCs have lower energy density but a much higher power density.
- Energy density
or Specific energy is defined as the energy per unit mass or volume.
- Hybrid (asymmetric) capacitor
A hybrid capacitor consists of a battery-like (faradic) electrode and a capacitor-like (non-faradic) electrode, producing higher working voltage and capacitance. With these systems, one can certainly achieve twice or triple enhancements in energy density compared to the conventional EDLCs.
- Lithium-ion capacitor
A Lithium-Ion Capacitor (LIC) is a hybrid type of capacitor. Activated carbon is used as cathode. The anode of the LIC consists of carbon material which is pre-doped with lithium ion. This pre-doping process lowers the potential of the anode and allows a high output voltage and higher energy density.
- Nanohybrid capacitor
A new lithium-ion–based hybrid capacitor using the lithium titanate (Li4Ti5O12) negative intercalation electrode that can operate at unusually high current densities. The high-rate Li4Ti5O12 negative electrode has a unique nano-structure consisting of extremely small nano-crystalline Li4Ti5O12 nucleated and grafted onto carbon nano-fiber anchors (nc-Li4Ti5O12/CNF).
- Power density
Power density (or volume power density or volume specific power) is the amount of power (time rate of energy transfer) per unit volume.
- 1.Amatucci GG, Badway F, Du. Pasquier A, Zheng T (1999) In: Abstract of 196th meeting of the Electrochemical Society, Honolulu, p 122Google Scholar
- 3.Azaïs P, Tetrais F, Caumont O, Depond JD, Lejosne J (2009) Ageing study of advanced carbon/carbon ultracapacitor cells working in various organic electrolytes. In: Abstract of ISEE’Cap 09, p 19Google Scholar
- 5.Baldsing WG, Puffy NW, Newnham RH, Pandolfo AG (2007) High-energy asymmetric nickel-carbon supercapacitors. In: Proceedings advanced automotive battery and ultracapacitor conference, Long BeachGoogle Scholar
- 10.Hatozaki O (2008) Lithium ion capacitor: electrode materials and cell performance. In: Proceedings advanced capacitor world summit 2008, San Diego (2008)Google Scholar
- 20.Naoi K, Simon P (2008) New materials and new configurations for advanced electrochemical capacitors. Interface 17:34Google Scholar
- 21.Nikkei Electronics (2008) LIC prevails EDLCs?! 991:77Google Scholar