Stories tagged batteries

Feb
05
2007

Batteries recalled

Ultracapacitors to replace batteries
Ultracapacitors to replace batteries
Batteries start fires. Batteries pollute. Batteries wear out. Batteries can leak acid. What the world needs is a better way to store electic energy. The people who invested in Google, Amazon, and AOL are now putting their money in ultracapacitors.

New ultracapacitors can replace batteries

If a new company called EEStor delivers on its promises, storing electric power in what it calls ultracapacitors will change the world.

Among EEStor's claims is that its "electrical energy storage unit" (EESU) could pack nearly 10 times the energy punch of a lead-acid battery of similar weight and, under mass production, would cost half as much.
It also says its technology more than doubles the energy density of lithium-ion batteries in most portable computer and mobile gadgets today, but could be produced at one-eighth the cost. TreeHugger

EEStore has contracted to deliver its first EESUs to ZENN Motor Company in 2007 to use in their electric vehicles. It also has patented "Electrical-energy-storage unit (EESU) utilizing ceramic and integrated-circuit technologies for replacement of electrochemical batteries."

What is an ultracapacitor and how does it work?

According to Clean Break via The Energy Blog

  • It is a parallel plate capacitor with barium titanate as the dielectric.
  • It claims that it can make a battery at half the cost per kilowatt-hour and one-tenth the weight of lead-acid batteries.
  • As of last year selling price would start at $3,200 and fall to $2,100 in high-volume production
  • The product weighs 400 pounds and delivers 52 kilowatt-hours.
  • The batteries fully charge in minutes as opposed to hours.
  • The EEStor technology has been tested up to a million cycles with no material degradation compared to lead acid batteries that optimistically have 500 to 700 recharge cycles,
  • Because it's a solid state battery rather than a chemical battery, such being the case for lithium ion technology, there would be no overheating and thus safety concerns with using it in a vehicle.

A capacitor is like a grilled cheese sandwich. The electrical energy is stored in the bread slices. The cheese needs to prevent the stored electricity from leaking across to the other side. In ultracapacitors the pressure will be over a thousand volts. The company that can solve ultracapacitor size, weight, leakage, cost, and safety issues will have the "holy grail" of electric storage.

Apr
17
2006


Watch Battery: Courtesy BatteryWeb

Researchers are turning to nature to develop miniature batteries. In a recent issue of Science, it was reported that an international team of researchers, led by a group at Massachusetts Institute of Technology, has used a virus to build miniature batteries.

How does a virus build a battery?

The batteries are being built from nanowires constructed from the M13 virus. Researchers modified the M13 virus’ genetic code so its outer coat would bond to certain metals. They incubated the modified virus in a cobalt chloride solution to allow cobalt oxide crystals to form uniformly along its length then sprinkled it with gold to produce electrical effects. Thus, the final nanowires worked as positive battery electrodes.

So why use a virus?
A virus is capable of forming tons of genetically similar copies of itself when grown under appropriate conditions. In the case of the M13 virus, it was harvested (or grown) in a bacteria. The M13 virus, in the bacteria environment, multiplied recreating tons of genetically similar copies of itself. Researchers reported that viruses form orderly layers yielding nanowires.

Future goals…
The researchers reported they have already used viruses to construct semiconductors and magnetic nanowires. Next on the agenda, they are hoping to use viruses to construct batteries ranging from the size of a grain of rice up to the size of a hearing aid battery. That’s pretty tiny!

Feb
16
2006

That's the promise of a new battery developed by researchers at MIT's Laboratory for Electromagnetic and Electronic Systems. They're using nanotechnology to improve an energy storage device called an ultracapacitor.


Nanotubes: (Photo courtesy Riccardo Signorelli, Laboratory for Electromagnetic and Electrical Studies, MIT)

Unlike regular batteries, which can generate electricity from a chemical reaction, capacitors store energy as an electrical field. Ultracapacitors can store lots of energy for a long time, but they need to be much bigger than regular batteries to hold the same amount of electricity. The new MIT technique, uses nanotechnology to improve the storage capacity of existing capacitors and may eventually help to make them smaller.

How does it work?

A battery has two electrodes, or terminals, one positive and one negative. Inside the battery are chemicals that react with each other to produce electrons. The electrons collect on the negative terminal of the battery. When you connect the terminals with a wire, you can use the flow of electrons to power things. A capacitor also has two electrodes-metal plates separated by a material that doesn't conduct electricity. A positive charge builds up on one plate, and a negative charge builds up on the other. When you connect the two electrodes, they discharge their energy. A battery can actually "create" energy by changing chemicals into electricity while a capacitor can only store energy it has been charged with.


Ultracapacitor in a hybrid engine: An ultracapacitor in a hybrid gas/electric engine for a car.

Today's ultracapacitors use electrodes made of activated carbon; the carbon is porous, so it has lots of surface area for the electrons to build up on. But the pores are irregular in size and shape, which reduces efficiency. That's why capacitors have to be big. But the MIT ultracapacitor has electrodes of vertically aligned carbon nanotubes, each one thirty-thousandth the width of a human hair. The regular shape and alignment of the nanotubes greatly increases the surface area, making the ultracapacitor very efficient at storing electrons.


Carbon nanotubes: Vertically aligned carbon nanotubes have lots of surface area to store electrons. (Photo courtesy Riccardo Signorelli, Laboratory for Electromagnetic and Electrical Systems, MIT)

Smaller is better

Ultracapacitors are long lasting and quick-charging. Storing energy at the atomic level with nanotubes means that they can finally be small, too, perhaps eventually powering everything from flashlights and cell phones to hybrid cars and missile-guidance systems.

Make it at the Museum

Stop by the Museum on Saturday, February 18th. You can make a pop can flashlight and test some conventional batteries. Experiment with electricity, circuits, and capacitors more at the AC/DC electricity bench in the Experiment Gallery.

Sep
02
2005


Urine Power: A credit card-size battery powered by urine. Photograph courtesy Institute of Bioengineering and Nanotechnology

This is another story where I can only imagine what the lab that does this research is like...

Scientists in Singapore have reported that they have invented a small, credit card sized battery that is activated using urine.

The government funded Institute of Bioengineering and Nanotechnology developed the battery for use in medical diagnostic test kits. These test kits are often used to study the chemical composition of a person's urine to detect an illness. Researchers studying ways to make a small, efficient and inexpensive battery to power these test kits realized that the substance being tested - urine - could also be used to provide power for the test kit.

To make the battery, pieces of paper are soaked in a solution of copper chloride and then sandwiched between strips of magnesium and copper. This "sandwich" is then laminated between two sheets of plastic. When a drop of urine is added to the paper through a slit in the plastic, a chemical reaction takes place that produces about 1.5 volts of electricity - about the same as a AA battery - for about 90 minutes.

The research team who developed the battery describes their work in the current issue of the Journal of Micromechanics and Microengineering.

Given the high cost of energy lately, a cheap and plentiful energy source would be welcome. If these batteries could be successfully scaled up they could be used for larger applications, such as laptops, mp3 players or even cars.

Fueling up the car may never be the same.