Monday, April 13, 2015

Can a Battery Park?

The Achilles Heel of electrical power generation is often how to store excess capacity that is generated during certain hours, or in the case of alternative energy systems, at differing times of the day or under differing weather conditions. You can heat water and use that heated water later to generate power, pump water to a higher ground and use the downward flow later to turn a generator turbine or, perhaps, store that surplus via batteries.
The most efficient batteries, often used for example to power everything from smart phones to electric cars, are lithium ion units that are both relatively heavy, a bit dangerous, environmentally damaging to dispose of and pricey. You see lithium is not the cheapest mineral to extract, and the deposits we know about are finite and located all over the world.
Worldwide identified reserves of lithium in 2008 were estimated by the US Geological Survey as 13 million tonnes,though it is extremely difficult to accurately estimate the world's lithium reserves, and some have predicted a Lithium Gold Rush as finite reserves are depleted. Deposits of lithium are found in South America throughout the Andesmountain chain. Chile is the leading lithium producer, followed by Argentina. Both countries recover the lithium from brine pools. In the United States lithium is recovered from brine pools in Nevada. However, half the world's known reserves are located in Bolivia, a nation sitting along the central eastern slope of the Andes. In 2009 Bolivia was negotiating with Japanese, French, and Korean firms to begin extraction. According to the US Geological Survey, Bolivia's Uyuni Desert has 5.4 million tonnes of lithium. A newly discovered deposit in Wyoming's Rock Springs Uplift is estimated at 228,000 tons. Additional deposits in the same formation were extrapolated to be as much as 18 million tons.” Wikipedia.
Wouldn’t it be great if we could replace lithium with a cheaper, more abundant metal, one that is easier to mine and found in more places on earth, and perhaps one that is a whole lot more efficient that lithium? Think about your mobile phone, completely battery dependent with a proclivity to run out when you need it most. Then you have to plug it in for hours to get it back to “full.” If only…
‘We have developed a rechargeable aluminum battery 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 Stanford University chemistry professor Hongjie Dai, the lead researcher of the project, in an article by the Stanford Report. ‘Our new battery won’t catch fire, even if you drill through it.’
An aluminum-ion battery generally consists of two electrodes, one negatively charged anode made of aluminum and a positively charged cathode. Professor Dai said that his team accidentally discovered that a simple solution is using graphite. This is why the Stanford researchers placed the aluminum anode, a graphite cathode and an ionic liquid electrolyte inside of a polymer-coated pouch. The electrolyte is essentially a salt that is liquid at room temperature so it is safe, according to Stanford graduate student and co-lead author Ming Gong.
“Researchers have been interested in developing a commercially viable aluminum-ion battery for decades, but efforts have been largely unsuccessful. What makes aluminum appealing is the low flammability, low cost and high-charge storage capacity. A major challenge with developing aluminum batteries is finding materials that produce sufficient voltage after repeated recharging cycles. The ionic liquid electrolyte products used in Stanford’s aluminum battery pack are also slightly expensive because there is not enough demand for it…
“The aluminum battery developed at Stanford was able to withstand more than 7,500 cycles without any capacity loss. Lithium-ion batteries generally last about 1,000 cycles. The aluminum battery is also flexible so it can be used in electronic devices that can fold and bend…
Lithium-ion batteries are also potentially a fire hazard. This is why United Airlines and Delta Air Lines banned bulk lithium-battery shipments on passenger planes. When Stanford drilled through its aluminum battery pouch, it worked for a while longer without catching fire — which makes it much safer than lithium-ion batteries. Lithium-ion batteries also takes hours to charge, but the aluminum-ion prototype at Stanford takes only one minute. ”, April 7th. Wow!
While the economies of scale will eventually drive down the price of the ionic electrolytes and make the entire process very cost-attractive, this revolutionary change will not happen overnight. On the other hand, this is very good development that will change the way we live… until the next great development in this field.
  I’m Peter Dekom, and it’s good to know that our best minds are still able to invent, discover and rock our world in a very, very good way.

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