OT New type of rechargable battery

[Chris Hogg]

Doesn't mention cars, but I don't see why not.

[Martin Brown]

Aluminium in its reactive form isn't quite as benign as you might think (although it isn't so inclined to spontaneous combustion).

I suspect these batteries will not be welcome on airlines since the aluminium airframe will not enjoy contact with any electrolyte leaks.

Appears to be a graphite/graphene & aluminium foil construction from what little information is not behind Nature's paywall.

Aluminium is a common enough element that we will not run out.

They don't say what the energy density is either in kJ/kg or kJ/m^3. They do say it will last 100-1000 recharge cycles which is novel for aluminium based batteries.

[nemo]

??? It actually says this:

"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."

[Tim Watts]

Hang an - aluminium's been done before hasn't it - in the 80s?

[Tim+]

I was intrigued by the recharge rate (for mobile phone use anyway). A 30 second recharge rate for any sort of significant capacity battery will surely imply a fairly significant current. Will standard USB leads be up to it?

Tim

[Syd Rumpo]

Well, a 2AH battery from flat in 30 seconds would only need 240A, so a pair of jump leads should do :-)

Cheers

[Dave Plowman (News)]

Bit like the claims for LED life? ;-)

Lots of these sort of things may well work in the lab. It's if they can be put into production that matters. A big if.

[Martin Brown]

It tends to suggest that the battery capacity is closed to 200mAh...(or less). In a sense you might not mind too much if the thing can recharge in a minute or two. The connectors will be interesting.

Unclear how the waste heat from fast charging gets dissipated too.

They need to sort their story out about capacity as a function of number of recharges too. As a general rule fast charging kills good batteries relatively quickly unless *VERY* well controlled.

[290jkl]

Because they aren't big enough for cars.

[Tim Watts]

On a side note, I am really amazed that airlines let you put Li batteries in hold luggage given that once in a blue moon they do go up in smoke spontaneously.

In that respect a safer format would be very welcome.

[The Other Mike]

Just what size do you think the individual cells in something like a Tesla are?

18.5mm × 65.3mm, something close to this:

There might even be something similar in Harry's semi mobile roadblock

[Dave Plowman (News)]

But do wonder just how common this is?

But is anything 100% safe?

[Martin Brown]

Which is odd since the guy talking about his own battery mentions between a few hundred and a couple of thousand as a typical lifetime. Methinks the PR department have exaggerated its charge cycle robustness by an order of magnitude or two.

Anything carrying the chemical (or mechanical) energy density implied by a decent laptop battery is potentially dangerous if shorted out.

It is only safer in the sense that the aluminium is not intrinsically pyrophoric (whereas lithium is borderline). I suspect the electrolyte in an aluminium battery will be seriously bad for aerospace alloys.

[Capitol]

Seemed related to an electrolytic capacitor to me. No mention of charge hold time.

[whisky-dave]

Whn I order even the small lipos

*PLEASE NOTE* - This item can no longer be shipped using standard mail. Roy al Mail will now destroy all parcels containing LiPo Batteries* *You must select Courier (DPD Services) shipping at checkout if this item i s in your basket. If standard mail/Royal Mail/or Royal Mail Special Delive ry is chosen we will not ship this item and the order will be held for manu al review- potentially delaying your order*

[Tim Watts]

No - but Li cells are pretty nasty once they do go up.

[Michael Chare]

Not all of them. Delta say that spare batteries should be carry-on baggage. I think I read this in a bored moment after I had checked my bags in.

[Michael Chare]

I recall a demonstration of burning aluminium in pure Oxygen. Introduced with the comment that someone else had killed some of his audience.

[Chris Hogg]

Aluminium oxidises rapidly and potentially violently. The bulk metal is mostly protected by an oxide film that prevents further oxidation, but the powder can be pyrophoric unless stabilised. Ammonal is a well known explosive made from ammonium nitrate (the oxidiser) and aluminium powder. Thermite is a mixture of aluminium powder and iron oxide, used for in-situ welding of rail track AIUI.

[PeterC]

Yes, nothing is safe.