Context: Recently, Scientists at the Institute of Nano Science and Technology (INST), Mohali, an autonomous institute under the Department of Science & Technology, Govt. of India, have developed a stable material for pseudocapacitors or supercapacitors which store electrical energy by electron charge transfer.
About Organic Pseudo-capacitor

• Pseudo-capacitors are a type of super-capacitors which store electrical energy by electron charge transfer.
• The material can offer a low-cost scalable energy storage solution as an alternative to batteries.
• The team has developed the pseudocapacitive material, a hybrid xerogel structure (a solid formed from a gel by drying with unhindered shrinkage), for the very first time.
• The hybrid material was fabricated by the integration of a well-known organic molecule, dopamine onto a conductive matrix, like graphene.
• The pseudocapacitive material, an organic-inorganic hybrid xerogel, shows great promise as a low-cost and scalable energy storage solution for commercial applications.

Procedure of its formation

• The scientists invented the pseudocapacitive material through a unique two-step synthesis procedure that is tailored accordingly to take maximum structural advantages of the hybrid material.
• First, they followed a quintessential hydrothermal synthesis method for the anchoring of the redox moiety on the carbon support. However, they introduced a unique in situ electrochemical polymerization approach, in the second step of the synthesis, in an attempt to boost the overall storage capacity as well as cycling stability.
• As a proof of concept, to endorse the development of the self-supported smart electronics, the group fabricated an all-solid-state supercapacitor with this active material and a tandem configuration of the devices to serve as a power source to light up 1.7 Volt commercial LED bulbs.

Significance

• The novel synthesis approach, as well as the study of the mechanism of redox supercapacitors at the molecular level, will offer new insights into improving the long-standing issue of stability and inferior power output of pseudocapacitors.

About Supercapacitors

• Supercapacitors, also known as the Ultracapacitors, are high-capacity capacitor with a capacitance value much higher than other capacitors, but with lower voltage limits, that bridges the gap between electrolytic capacitors and rechargeable batteries.
• These typically stores 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries.

Application of supercapacitors

• Supercapacitors are used in applications requiring many rapid charge/discharge cycles, rather than long term compact energy storage — in automobiles, buses, trains, cranes and elevators, where they are used for regenerative braking, short-term energy storage, or burst-mode power delivery.

Types of Supercapacitors

There are three types of supercapacitors based on storage principle:

• Double-layer capacitors (EDLCs) — with activated carbon electrodes or derivatives with much higher electrostatic double-layer capacitance than electrochemical pseudocapacitance.
• Pseudocapacitors — with transition metal oxide or conducting polymer electrodes with a high electrochemical pseudocapacitance.
• Hybrid capacitors — with asymmetric electrodes, one of which exhibits mostly electrostatic and the other mostly electrochemical capacitance, such as lithium-ion capacitors.