Supercapacitors

We offer a selection of electric double-layer capacitors (EDLCs), lithium ion capacitors, and miscellaneous types.

A supercapacitor is a double-layer capacitor that has very high capacitance but low voltage limits. Supercapacitors store more energy than electrolytic capacitors and they are rated in farads (F). Supercapacitors store electrical energy at an electrode–electrolyte interface. They consist of two metal plates, which only are coated with a porous material known as activated carbon. As a result, they have a bigger area for storing much more charge.

The plates are immersed in an electrolyte made of positive and negative ions dissolved in a solvent. When a voltage is applied, two separate charged layers are produced on the surface with a small separation distance. This is why supercapacitors are often referred to as electric double-layer capacitors or EDLCs.

A lithium-ion capacitor (LIC or LiC) is a hybrid type of capacitor classified as a type of supercapacitor. It is called a hybrid because the anode is the same as those used in lithium-ion batteries and the cathode is the same as those used in supercapacitors. Their manufacturing process and materials used allow a relatively high output voltage compared to other supercapacitors.

Supercapacitors have many advantages:

1. Long cycle lifetime—they can be cycled hundreds of thousands times with minimal change in performance.
2. A supercapacitor’s lifetime spans 10 to 20 years, and the capacity might reduce from 100% to 80% after 10 or so years.
3. Thanks to their low equivalent series resistance (ESR), supercapacitors provide high power density and high load currents to achieve almost instant charge in seconds.
4. Temperature performance is also strong, delivering energy in temperatures as low as –40°C.

Supercapacitors vs lithium-ion batteries

A supercapacitor of a given weight cannot store nearly as much energy as a lithium-ion battery can. However, a supercapacitor can discharge far faster than a battery can.

So while a supercapacitor (at present) cannot be used to power a car for hundreds of kilometres like a battery can, there are power application where a supercapacitor can serve.

1. Supercapacitors are being used to power buses in Chinese cities, allowing about 15 km on one charge – and recharging takes about five minutes.
2. Supercapacitors can also be used to power the robots used in automated warehouses. This is eminently practical because the robot will never be far from a point where it can be automatically recharged.
3. Because wearable devices are designed to work with very low power, supercapacitors are a natural for their use in such applications.

Supercapacitor energy storage: how much charge can a supercapacitor hold?

A 1-farad capacitor can store one coulomb of charge at 1 volt. A coulomb is 6.25e18 (6.25 * 10^18, or 6.25 billion billion) electrons. One amp represents a rate of electron flow of 1 coulomb of electrons per second, so a 1-farad capacitor can hold 1 amp-second of electrons at 1 volt.