Supercapacitors

If you're looking to build electronic circuits which integrate the future of energy storage technology, then supercapacitors have the answer. These can store between 10 and 100 times the energy per unit volume when compared to standard electrolytic capacitors. So, when building a circuit that could use the extra power built-in, supercapacitors could hold the answer for you.

We carry a wide variety of electric double-layer supercapacitors from the leading brands, including Eaton supercapacitors, Vishay supercapacitors, and AVX supercapacitors.

What are supercapacitors?

A supercapacitor is a type of electronic component used to store a large amount of electrical charge within circuits. They can also sometimes be called double-layer capacitors, double-layer supercapacitors, or ultracapacitors.

Due to the large capacitance of supercapacitors, they combine the attributes of both a battery and a capacitor into a single component. The main difference between a capacitor and a supercapacitor is how the supercapacitor stores the electrical charge.

How do supercapacitors work?

The design of a supercapacitor consists of two electrodes which are separated by an ion-permeable membrane, known as a separator, and a supercapacitor electrolyte material that ionically connects the electrodes which are then hermetically sealed.

While their construction may be similar to electrolytic capacitors, the types of components are different in order to achieve the necessary capacitance.

While standard capacitors use a conventional dielectric for their capacitance, supercapacitors use double-layer capacitance and pseudocapacitance to facilitate the storage of power.

Double-layer capacitance

Double-layer capacitance means the capacitor operates electrostatically, where the boundary between each electrode and the electrolyte forms a double-layer of charge. These two layers will be separated by a single layer of solvent molecules - This is why they can also be called double-layer supercapacitors.

Pseudocapacitance

The pseudocapacitance of supercapacitors relates to the use of electrodes that have a high level of electrochemical pseudocapacitance. Faradaic pseudocapacitance is intrinsically linked to double-layer capacitance, as it relates to the interplay between the electrode and electrolyte where the electron charge-transfer occurs.

In order to store the electrical charge, supercapacitors use porous materials for the separators in order to retain those ions until they're needed. Activated carbon is commonly used for this, although there have been breakthroughs with graphene which could power the future of supercapacitor battery technologies.

Will supercapacitors replace batteries?

This depends on the application. There are some circuits where a supercapacitor could replace a battery, depending on the power required by the circuit. However, many still require batteries or some form of hybrid configuration which utilizes both.

However, supercapacitors have properties that could make them viable replacements for batteries in the future. The lifespan of supercapacitors is extensive, while batteries are considerably more limited in how many times they can be charged and discharged. Currently, prohibitive attributes of supercapacitor batteries are:

• Low specific energy which makes them less effective than a battery of the same size
• Linear discharge voltage which affects the output voltage when not fully charged
• Cost of components which makes them more expensive to use than batteries.

If the cost per watt-hour (Wh) can be improved for supercapacitors to be more efficient than Li-ion batteries, then we could see them gradually replace batteries in more applications. The graphene technology which holds promise could help supercapacitors make significant steps into overcoming these obstacles.

Are supercapacitors safe?

When evaluating the safety of supercapacitor batteries, they are considered to be safer than conventional batteries when subject to improper conditions.

Short-circuiting can cause batteries to explode due to the excessive heat levels, while supercapacitors typically don't as their lower internal resistance keeps them cooler.

If a fully charged supercapacitor battery is shorted, then it will result in a quick release of energy which may lead to electrical arcing. This may damage the device but is less damaging than an exploding battery and heat is less of an issue.

What are supercapacitors used for?

There are a range of reasons for the rise in demand for supercapacitors. The growing tech industry makes use of supercapacitors due to a number of useful properties they possess:

• Their operating temperature is typically between -40 and 70°C
• They can be fully charged in a short amount of time compared to batteries
• The charge stored lasts for a considerably long time
• They can be charged repeatedly without losing performance
• They are certified as disposable components due to the lack of harmful materials.

These characteristics, among others, make them well-suited to a variety of applications.

Where are supercapacitors used?

The automotive industry makes use of supercapacitors in Kinetic Energy Recovery Systems (KERS), where the energy from braking can be converted from kinetic to electrical that can then be stored in a supercapacitor.

Portable electronic devices such as photographic flash components and MP3 devices can make use of a supercapacitor battery, as well as static random-access memory (SRAM) devices that rely on low power, constant voltage sources in order to retain the information stored on them.

Supercapacitors can also be incorporated into solar charging devices to store the energy harvested from solar panels.

In the future, we may see supercapacitor batteries used in our cell phones, laptops, and even electric vehicles as the main power supply. The ability to rapidly charge these devices within minutes, rather than hours, could be greatly beneficial to consumers and industry alike.

Although supercapacitors are currently used to stabilize battery power supplies within some of these devices, they could remove the need for batteries in the years to come.

Supplying supercapacitors and all other components you may need

We can connect you with any form of electronic component you might require to complete your project, whether that's a supercapacitor or an alternative form of capacitor - whichever is better for the job.

As a distributor of best-in-class electrical components and electromechanical products serving the Americas for over 90 years, we understand what our customers need and how integral good service is to them.

We can support you through our expert advice hub on a range of topics, or your can contact your local sales office with more specific queries if required. For bulk orders on components, you can complete a part quote form which we can then discuss to get you the best deal on each of your required parts.