Supercapacitors are emerging as alternatives to lithium-ion batteries, offering higher power densities and longer lifetimes (number of cycles where capacity is maintained). A supercapacitor is like a cross between a battery (with high energy storage) and a regular capacitor (with high power discharge).
New research from the City University of Hong Kong published March 21 in Nano Research Energy demonstrates outstanding performance of a capacitor built with MXene compounds. MXenes are two-dimensional inorganic compounds whose large molecular surface areas for energy storage give them ultrahigh conductivity and storage capacity.
Supercapacitors can store lots of energy in a small space and release it at a high current; for example, they can supply power for mini devices such as wearable electronics. However, when made with organic molecules, supercapacitors risk catching fire.
The new study explored supercapacitors made with inorganic MXene molecules to reduce fire risk. Instead of the more expensive lithium, they used potassium. The potassium ion or K-ion is one of the most frequently used electrolytes to allow electrical current to flow in a battery. Guojin Liang, lead author of the paper and researcher from the Department of Materials Science and Engineering says that they "have investigated the aqueous supercapacitors by utilizing the intrinsic safe water-based electrolytes and focused on K-ion storage, which is cheaper and more abundant in earth to benefit for safe and low-cost applications."
To read more, click here.