Advanced Aluminium and Graphite Batteries

Source: http://phys.org/news/2015-04-ultra-fast-aluminum-battery-safe-alter...

Ultra-fast charging aluminum battery offers safe alternative to conventional batteries

Stanford scientists have invented a flexible, high-performance aluminum battery that charges in about 1 minute. Credit: Mark Shwartz, Precourt Institute for Energy, Stanford University

Stanford University scientists have invented the first high-performance aluminum battery that's fast-charging, long-lasting and inexpensive. Researchers say the new technology offers a safe alternative to many commercial batteries in wide use today.

"We have developed a rechargeable aluminum that may replace existing storage devices, such as alkaline batteries, which are bad for the environment, and lithium-ion batteries, which occasionally burst into flames," said Hongjie Dai, a professor of chemistry at Stanford. "Our won't catch fire, even if you drill through it."

Dai and his colleagues describe their novel aluminum-ion battery in "An ultrafast rechargeable aluminum-ion battery," in the April 6 advance online edition of the journal Nature.

Aluminum has long been an attractive material for batteries, mainly because of its low cost, low flammability and high-charge storage capacity. For decades, researchers have tried unsuccessfully to develop a commercially viable aluminum-ion battery. A key challenge has been finding materials capable of producing sufficient voltage after repeated cycles of charging and discharging.

Graphite cathode

An aluminum-ion battery consists of two electrodes: a negatively charged anode made of aluminum and a positively charged cathode.

"People have tried different kinds of materials for the cathode," Dai said. "We accidentally discovered that a simple solution is to use graphite, which is basically carbon. In our study, we identified a few types of graphite material that give us very good performance."

For the experimental battery, the Stanford team placed the aluminum anode and graphite cathode, along with an ionic liquid electrolyte, inside a flexible polymer- coated pouch.

"The electrolyte is basically a salt that's liquid at room temperature, so it's very safe," said Stanford graduate student Ming Gong, co-lead author of the Nature study.

Stanford Professor Hongjie Dai's lab has invented an ultra-fast aluminum-ion battery with electrodes made of inexpensive aluminum (Al) and sheets of nanocarbon. Credit: Meng-Chang Lin & Hongjie Dai, Stanford University

Aluminum batteries are safer than conventional lithium-ion batteries used in millions of laptops and cell phones today, Dai added.

"Lithium-ion batteries can be a fire hazard," he said.

As an example, he pointed to recent decisions by United and Delta airlines to ban bulk shipments on passenger planes.

"In our study, we have videos showing that you can drill through the aluminum battery pouch, and it will continue working for a while longer without catching fire," Dai said. "But lithium batteries can go off in an unpredictable manner - in the air, the car or in your pocket. Besides safety, we have achieved major breakthroughs in aluminum battery performance."

One example is ultra-fast charging. Smartphone owners know that it can take hours to charge a lithium-ion battery. But the Stanford team reported "unprecedented charging times" of down to one minute with the aluminum prototype

Durability is another important factor. Aluminum batteries developed at other laboratories usually died after just 100 charge-discharge cycles. But the Stanford battery was able to withstand more than 7,500 cycles without any loss of capacity. "This was the first time an ultra-fast aluminum-ion battery was constructed with stability over thousands of cycles," the authors wrote.

By comparison, a typical lithium-ion battery lasts about 1,000 cycles.

"Another feature of the aluminum battery is flexibility," Gong said. "You can bend it and fold it, so it has the potential for use in flexible electronic devices. Aluminum is also a cheaper metal than lithium."

Applications

In addition to small electronic devices, aluminum batteries could be used to store renewable energy on the electrical grid, Dai said.

"The grid needs a battery with a long cycle life that can rapidly store and release energy," he explained. "Our latest unpublished data suggest that an aluminum battery can be recharged tens of thousands of times. It's hard to imagine building a huge lithium-ion battery for grid storage."

Aluminum-ion technology also offers an environmentally friendly alternative to disposable alkaline batteries, Dai said.

"Millions of consumers use 1.5-volt AA and AAA batteries," he said. "Our rechargeable aluminum battery generates about two volts of electricity. That's higher than anyone has achieved with aluminum."

But more improvements will be needed to match the voltage of , Dai added.

"Our battery produces about half the voltage of a typical lithium battery," he said. "But improving the cathode material could eventually increase the voltage and energy density. Otherwise, our battery has everything else you'd dream that a battery should have: inexpensive electrodes, good safety, high-speed charging, flexibility and long cycle life. I see this as a new battery in its early days. It's quite exciting."


Read more at: http://phys.org/news/2015-04-ultra-fast-aluminum-battery-safe-alter...

More information: An ultrafast rechargeable aluminum-ion battery, DOI: 10.1038/nature14340

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Comment by Spirality on April 22, 2015 at 14:17

One of the Overunity.com members is using a Carbon fiber sheet, with Aluminium foil and some kitchen paper soaked in Potash-water.

Hi Guys,

http://www.overunity.com/13282/carbonfiber-alufoil-selfmade-diy-bat...

Finally I wanted to show you now my new DIY self-made battery technology.
This is very easy to make and puts out quite an amount of small MilliWatts of power.

Not just yet to light up an 1.2 Volts 0.22 Amps incandescent bulb, but at least it blinks it.

With a well built Joule Thief circuit this should be able to really power up many LEDs very brightly.
This will be the next thing I will try.

So how is this battery be made the cheapest way ?

You just need Aluminium foil from the supermarket,
a carbon-fiber sheet ( This is the only thing you probably have to order, as the other parts you will get very easily) and some ashes from a fireplace.
(woodashes or coalashes) or instead of the woodashes you can also get Sodium Carbonate, that is also called Washing Soda. This is also available is every bigger supermarket. You could also use Sodimpercarbonate from spot removal washing solution powders , but this is more aggressive and more expensive, so stick with ashes ( it is free) or buy some washing Soda.

So then you take about 3 to 4 teaspoons of Washing soda or ashes and put it in about 100 MilliLiters of tap water ( about 1/2 drinking glass full of water).
Then you use this solution after stirring to put it onto a paper towel and put this wet paper towel between the alufoil and the carbon-fiber sheet.

Then you have just about 1.4 Volts open circuit voltage and more than 100 milliamps of short circuit current. (from a size of around DinA4 sized sheets, so around 20 x 30 cm).

Now you can stack several cells in series to be able to directly light some LEDs or just use a Joule Thief circuit on ONE cell to light up a few LEDs.
I will soon build my own powerful Joule Thief circuit and will show this also then.

So stay tuned to my channel and please subscribe, rate and comment and share it with your friends.
This is a great battery cell for emergency usage as the only thing that decomposes is the Alufoil ! The carbon-fiber sheet can be washed off with water and always be reused !

This is the way to go to build self-made cheap batteries to power LEDs.

Hope you enjoyed it.

Regards, Stefan.

Link to this video: http://youtu.be/KLjSH8O3cWw

Comment by Spirality on April 22, 2015 at 11:27

There are several different ways to make your own Aluminium and Carbon (graphite) batteries.

Aluminium is widely available in everything from foil and food trays to drink-cans, conduit and heat-sinks.

Carbon is also known as soot, and Graphite (another version) is found in pencil cores and water filters.

You will also need an electrolyte such as salt water, washing soda or potash (wear protective goggles).

Experiment with different configurations of battery, and different densities of electrolyte.

This experiment is known, it can be replicated with ease and without danger.
Needed: salt water, activated carbon for aquariums, aluminium foil 200x150 mm, two contacts of copper wire, soft paper, motor 2-3 volts.
* The Engine 2-3 volts can be retrieved from "cd rom motor".
** To secure the success of this experiment, it is necessary to have an motor that has a low power consumption 15-20 mA max. and a voltage of 2-3 volts. It 'not recommended to use all kinds of motors for toys.

----------

With a electrolyte made from K2CO3 and water you can get almost double the voltage, so you will get around 1.3 to 1.5 Volts per cell and also more current

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