Nanotech Batteries Deliver High Power at High Energy Density

Electrostatic nanocapacitors formed in nanoporous anodic aluminum oxide (darker yellow) film by sequential atomic layer deposition of metal (blue), insulator (yellow), and metal. Insert: cross-section of actual structure, represented as rescaled scanning electron micrograph. (A. James Clark School of Engineering, U-Md.)

Electricity is normally stored in batteries and capacitors. The problem is, these devices have inherent limitations that prevent them from meeting our electricity needs.

They can't deliver the high power, high energy density, and fast recharge that modern electrical usage demands.

Batteries store energy but can't provide high power or fast recharge. You have to connect a lot of batteries to achieve high power.

Electrochemical capacitors can generate high power but have low energy storage density.

And electrostatic capacitors deliver high power and fast recharge, but like their electrochemical counterparts, suffer from low energy storage density.

High power, high density, fast recharge. You need all 3 -- but can only have 2.

Still, all is not lost. Nanotechnology comes to the rescue.

Researchers at the University of Maryland's NanoCenter have built electrostatic nanocapacitors out of billions of nanostructures, increasing the energy storage capacity of the capacitors by a factor of 10 over that of conventional devices.

According to the story in InTech, a publication of the International Society of Automation:

This advance brings electrostatic devices to a performance level competitive with electrochemical capacitors and introduces a new player into the field of candidates for next-generation electrical energy storage.

These nanocapacitors could be mass-produced as energy storage panels layered one on top of the other. Multiple panels could stack together inside a car battery system or solar panel.

Long term, nanotech could give us new energy capture technology that would integrate with storage devices used in manufacturing.

Tiny Generator Powered by Sunlight and Motion

Take a thin-film solar cell embedded with dye-coated zinc oxide nanowires. Put it on a slice of silicon.

On the other side of the slice, add a nanoscale generator that uses zinc oxide nanowires to turn any kind of motion into electricity. This generator produces electricity using the same principle that a record player uses to convert vibrations in a vinyl LP's groove into electrical impulses.

The result is a tool that harvests energy from sunlight or motion.

Such a tool was recently devised by researchers from the Georgia Institute of Technology, or Georgia Tech as it is affectionately called.

Since the generator can make electricity from any kind of movement -- including biological -- it would thrive near a throbbing environment like a jet engine. Sure enough, according to Zhong Lin Wang, the inventor of the nanoscale generator, these devices would likely be used first in military aircraft brimming with sensors.

Down the road, nanogenerators could eliminate the need for batteries in implantable medical sensors. They would create electricity from simple human motion such as walking, typing or the rise and fall of a person's chest with every breath.