A graphene-based device, which lasts as long as a conventional battery, has been developed by researchers
Researchers from Monash University in Australia have developed a compact graphene-based next generation energy storage device capable of lasting as long as a conventional battery.
Their graphene-based supercapacitors (SC) could be used in renewable energy storage, portable electronics and electric vehicles.
Developing compact and affordable storage systems is seem as critical to the widespread deployment of wind and solar systems, which rely on the weather and can be erratic.
“Supercapacitors are particularly good for their fast charging/discharging ability and long life span, which makes it particularly promising for electricity grid levelling (smoothing fluctuation),” project leader Professor Dan Li told RTCC.
“It has long been a challenge to make SCs smaller, lighter and compact to meet the increasingly demanding needs of many commercial uses,” he added.
Graphene is formed when graphite is broken down into layers one atom thick. It is very strong, chemically stable and an excellent conductor of electricity.
The A$2 million funding from the Australian Research Council to conduct research relating to graphene-based materials helped the team create an SC with an energy density of 60 watt-hours per litre – around 12 times higher than commercially available SCs.
To make their uniquely compact electrode, Professor Li’s team used an adaptive graphene gel film they had developed previously.
They used liquid electrolytes – generally the conductor in traditional SCs – to control the spacing between graphene sheets on the sub-nanometre scale.
In this way the liquid electrolyte played a dual role: maintaining the minute space between the graphene sheets and conducting electricity.
Unlike in traditional ‘hard’ porous carbon, where space is wasted with unnecessarily large ‘pores’, density is maximised without compromising porosity in the electrode.
To create their material, the research team used a method similar to that used in traditional paper making, meaning the process could be easily and cost-effectively scaled up for industrial use.
“We have created a macroscopic graphene material that is a step beyond what has been achieved previously. It is almost at the stage of moving from the lab to commercial development,” Professor Li said.
Although Professor Li said it was too early to tell how long it would take to bring the device to market, he acknowledged that in the short term, the cost could be an issue for large scale deployment.
“Once the cost is reduced by scaling up, it is highly likely that our materials would be used in consumer electronics, electric vehicles, in a longer term, for renewable energy storage.”