UC Riverside successfully developed new graphene supercapacitors

Researchers at the University of California, Riverside (UCR) have recently developed a type of graphene supercapacitor that uses a nanostructure to double the energy efficiency compared to existing substitutes on the market. This discovery is another important step to unlock the potential of using supercapacitors on electric vehicles (EV) and personal electronic devices with high performance and fast charging.

Super capacitors are very stable and durable energy storage devices with high energy density (power / mass unit) but very low specific energy (energy storage / mass unit). This means supercapacitors can provide a large amount of electricity but only in a few seconds.

From left to right are researchers Mihrimah Ozkan, Cengiz Ozkan and Zachary Favors.

A group of researchers led by Professor Cengiz S. Ozkan at UCR recently developed a new design for supercapacitors with a specific energy level of 39.3 Wh / kg and an energy density of 128 kW / kg, near double the performance of commercial supercapacitors on both indicators.

To achieve this, the team created a pore-shaped foam block containing carbon nanotubes. Nano holes provide a large contact area to help electrolytes permeate easily and allow it to store thicker energy than conventional designs.

Foam blocks are produced by chemical vapor deposition process of graphene and carbon nanotubes on a nickel (Ni) substrate and continue to deposit hydrated ruthenium oxide nanoparticles (RuO ₂ ), in which each particle size less than 5nm. Inside the foam block, graphene has just played the role of collecting electricity and acts as a cushion to conduct electrons and isolate the foam from the electrolyte.

One of the advantages of supercapacitor over conventional batteries is that the superior charging / discharging efficiency and the super capacitor design of UCR are no exception. Strangely, its capacitance is not only more stable but also actually improved by 6% after 8100 charge / discharge times. The researchers believe that this improvement is due to the electrochemical performance of activated materials.

The high performance, stability and ease of fabrication of this system make it very potential for mass production in the future. And although its own energy is still not comparable to Li-ion battery technology, this is an important step to develop in the right direction.

The detailed report of the supercapacitor of UCR has just been published in Nature Scientific Reports.