Aluminum / Air battery prototype developed

[Borgholio]

http://mashable.com/2015/04/07/aluminum ... ne-minute/

If there's one major issue plaguing smartphones, smartwatches and other gadgets we use every day, it's battery life. Now, a team of researchers at Stanford University has built an aluminum-ion battery prototype which offers several improvements over today's ubiquitous lithium-ion batteries, including super-fast charging times.

The team's aluminum-ion battery sounds like a dream come true for gadget manufacturers — a perfect battery with few flaws.

Until now, aluminum-ion batteries weren't able to produce a high enough voltage, especially after many recharge cycles. But the prototype created by the Stanford researchers consists of an aluminum anode and a cathode made of graphite — a combination of materials that allows for producing sufficient voltage (about two volts), even after thousands of recharge cycles.

The battery can recharge in one minute, it's flexible (meaning it can be bent to fit more snugly into various gadgets), and it's potentially inexpensive, since aluminum is cheaper than lithium. Furthermore, the materials are safer than the ones in lithium-ion batteries, which can catch fire in certain situations. In contrast, the aluminum-ion battery won't catch fire even if you drill a hole through it while it's working.

"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," Hongjie Dai, a chemistry professor at Stanford who's leading the research, told Stanford News. "I see this as a new battery in its early days. It's quite exciting,"

There is one issue that needs to be solved before the battery goes into mass production — while the Stanford team's battery offers voltage higher than any other aluminum-based battery, it's still lower than the voltage of your average smartphone lithium battery, which is typically 3.7V or 4.2V.

Dai believes overcoming this problem is not impossible. "Improving the cathode material could eventually increase the voltage and energy density," he said.

In the video posted on YouTube by the Stanford researchers (below) you can see a prototype of the battery powering an LED light while being bent and drilled through. The battery is also seen powering a smartphone, and another potential application mentioned is storing energy on the electrical grid.

Pretty neat. I'm eager to see if they can make it capable of replacing Li-Ion batteries. If so, that would solve lots of problems.

[Elheru Aran]

Could have applications in aviation and weapons due to the lighter weight. The low voltage is the main problem I see here though. But this is a fun thing to have around. Do they address how long it actually lasts in use, though? Because if it runs down in 30 minutes it doesn't much matter if you can charge it in 1...

[Borgholio]

Yeah they didn't say. It is of course possible that due to it's nature, it can simply accept a very high charging current. If that's the case, so much the better.

[Imperial528]

Could have applications in aviation and weapons due to the lighter weight. The low voltage is the main problem I see here though. But this is a fun thing to have around. Do they address how long it actually lasts in use, though? Because if it runs down in 30 minutes it doesn't much matter if you can charge it in 1...

I could see uses in electronics for it as a component with such short discharge times. Especially if you could make it behave like a long-discharge capacitor.

Or even in just using it as a stop-gap for brownout prevention for equipment being run in areas with unreliable power sources.

[aerius]

Voltage isn't really a problem, just stack a couple cells in series and there's your 4V. I did some more looking around and the energy density appears similar to Li-ion batteries, with better ability to withstand charge-discharge cycles. So it should be pretty sweet if they can mass produce it at a reasonable cost.

[Sea Skimmer]

It will take a while to get them, but this sort of battery should eventually be capable of something like four times the energy to mass ratio of the best possible lithium batteries. However they won't bulk down the same way and smartphones may go to Silver Zinc batteries at some point instead because they should be able to shrink much better on volume. It depends how much people care about weight vs size of the phone. The market is more then big enough to support multiple technologies.

Neither tech can compare well with lithium batteries for power anyway, so for larger devices with high current draws they may not provide much advantage. Lithium batteries are nowhere near fully evolved themselves.

Molten salt batteries by far have the highest power ratings, but they are one use. Those are what you find inside weapons like guided missiles that can need actual kilowatts of battery power.