Researchers have developed a new bendable supercapacitor made from graphene, which charges quickly and safely stores a record-high level of energy for use over a long period.
While at the proof-of-concept stage, it shows enormous potential as a portable power supply in several practical applications including electric vehicles, phones and wearable technology.
This discovery is published in the journal Nature Energy. It overcomes the issue faced by high-powered, fast-charging supercapacitors – that they usually cannot hold a large amount of energy in a small space.
This new supercapacitor is extremely promising for next-generation energy storage technology as either a replacement for current battery technology, or for use alongside it, to provide the user with more power.
This supercapacitor is designed such that it has both high power density and high energy density. It is a critical breakthrough because normally the existing super capacitors will have only one of these characteristics, not the both.
Moreover, the supercapacitor can bend to 180 degrees without affecting performance and doesn’t use a liquid electrolyte, which minimises any risk of explosion and makes it perfect for integrating into bendy phones or wearable electronics.
The new design uses an innovative graphene electrode material with pores that can be changed in size to store the charge more efficiently. This tuning maximises the energy density of the supercapacitor to a record 88.1 Wh/L (Watt-hour per litre), which is the highest ever reported energy density for carbon-based supercapacitors.
Similar fast-charging commercial technology has a relatively poor energy density of 5-8 Wh/L and traditional slow-charging but long-running lead-acid batteries used in electric vehicles typically have 50-90 Wh/L
.
While the supercapacitor developed by the team has a comparable energy density to state-of-the-art value of lead-acid batteries, its power density is two orders of magnitude higher at over 10,000 Watt per litre.
Successfully storing a huge amount of energy safely in a compact system is a significant step towards improved energy storage technology.
The researchers made electrodes from multiple layers of graphene, creating a dense, but porous material capable of trapping charged ions of different sizes. They characterised it using a range of techniques and found it performed best when the pore sizes matched the diameter of the ions in the electrolyte.
News Source: Eurekalert
