Supercapacitors give battery life a boost

[ruimegas]

Supercapacitors give battery life a boost (enviado pelo nosso mui respeitado e admirado #1 Filipe)

"As their name suggests, supercapacitors can store enormous amounts of charge relative to their conventional counterparts. These devices, which are also known as ultracapacitors or electric double-layer capacitors range in size from miniature surface-mount components for portable electronics to large-scale devices rated for several thousand farads for use in high-powered applications such as electric vehicles (EVs.)

They are electrochemical in nature using a wet electrolyte as an ion source to enable charge accumulation on a double layer of electrodes when a voltage is applied. Each electrode is made of a nanoporous material that provides an enormous inner surface area in which to store charge. It is typically made from activated carbon, but recent advances in the makeup and structure using graphene and carbon nanotubes have dramatically increased storage capacity.

While the energy density of supercapacitors is still not on par with batteries, their storage levels have increased to the point where they can assume some of the latter’s functions. Advantageously, this has also given designers the opportunity to address some of the performance shortfalls of batteries by putting into play many of the other advantages offered by supercapacitors. These include:

• High energy density the ability to rapidly absorb or distribute energy almost instantaneously.

• High cycling capability the virtually unlimited ability to charge and discharge energy without degrading the component. This also eliminates the need for replacement.

• Environmental safety the devices do not contain dangerous chemicals so they do not pose a toxic threat during disposal.

• Weight reduction units are inherently light weight. They can further decrease system weight by reducing the size or number of batteries used in applications when taking over their functions.

The most practical application where supercapacitors can be used in place of batteries are those requiring frequent high-current short-duration power bursts. These are typical in portable electronic devices using on-board flash, auto-focus/zoom functions, and high-speed data transmission. In EVs, this can take the form of absorbing energy during regenerative braking or by rapid energy outlay to enable immediate acceleration.

These demanding functions can put severe load stress on batteries and eat into their limited life cycle. By transferring them to the more ideally suited supercapacitor, the battery can be left to supply bulk, steady-state power to other areas its ideal situation. Successfully integrating these two technologies into systems as complementary partners not only optimizes power management, but significantly improves the overall system performance. In the process, battery life and run-time can be considerably extended.

Michael J. Kawa"

Em: http://www2.electronicproducts.com/Supe ... -html.aspx