New Supercapacitor Can Store Electricity on Silicon Chips

A materials research team at Vanderbilt University has designed a new supercapacitor that is made of silicon and has the potential to power many types of devices, from solar cells to mobile devices. The supercapacitor may be made from excess silicon and can provide significant savings in manufacturing costs. The technology cannot store energy the same as lithium-ion batteries, but supercapacitors have promise in consumer devices.

“It is the first supercapacitor that is made out of silicon so it can be built into a silicon chip along with the microelectronic circuitry that it powers,” reports Vanderbilt News. “In fact, it should be possible to construct these power cells out of the excess silicon that exists in the current generation of solar cells, sensors, mobile phones and a variety of other electromechanical devices, providing a considerable cost savings.”

“If you ask experts about making a supercapacitor out of silicon, they will tell you it is a crazy idea,” explains Cary Pint, the assistant professor of mechanical engineering who led the research. “But we’ve found an easy way to do it.”

Pint and his research team coated porous silicon in carbon, and heated it more that 1400 degrees Celsius. The process created a layer of graphene that was only a few nanometers thick that insulated the silicon, and improved its energy storage.

“The researchers found that supercapacitor plates manufactured in this fashion were up to 40 times more energy-dense than those made out of the ‘naked’ silicon, and achieved a performance that significantly improved on current commercial supercapacitors,” explains Gizmag.

Supercapacitors can charge more rapidly and have longer lifespans than traditional batteries. They can be used to save captured energy from regenerative braking systems on buses and electric vehicles, and supply a blast of power needed to adjust large wind turbines during windy conditions.

However, they are not equal to the electrical storage capacity of lithium-ion batteries, and supercapacitors are too bulky for most consumer devices. Yet the technology has been improving.

“All the things that define us in a modern environment require electricity,” said Pint. “The more that we can integrate power storage into existing materials and devices, the more compact and efficient they will become.”

The research paper can be found in the journal Nature Scientific Reports.