Aluminium air battery

izwozral

Full Member
Posts
10,751
Likes
16,912

I know there has been a thread about this battery technology before, what I don't remember reading was the battle that had to be fought and is still being fought, to actually get this new technology recognised by the government. When you read the article, it comes across quite clearly that there has been too much vested interest in Lithium technology to the exclusion of all else and all the governmental utterances about the climate crisis is merely playing lip service to the problem.

Why has Britain got this habit of not backing it's scientists, inventors and entrepreneurs, who then take their expertise elsewhere to enrich another countries economy? Madness.
 

Fazerloz

Full Member
Posts
5,192
Likes
7,653
Because politicians no matter which party will ever admit they were wrong or even might possibly be wrong, no matter the cost.
 

colinmd

Full Member
Posts
2,299
Likes
1,925
Remember when all the conspiracy theorists would say the oil companies where killing off any new tech? Always got to blame something.
 

Okta

Full Member
Posts
208
Likes
302
Lobbyists. Those with the money pay very clever lobbyists to promote their case and talk down anything that might threaten their position. A bit like our confrontational legal system, those who can afford the best lawyers and experts win. We need a cultural change to investigative systems. Ban the lobbying organisations and give our MPs researchers who can dig through all the claims and counter claims for them.
 

Sharpie

Full Member
Posts
304
Likes
246
No conspiracy theories necessary. This is a "primary" cell. Not re-chargeable.

Much like the zinc-air cells that power my hearing aids.

The concept is to put in place an infrastructure to swap out depleted standardised battery modules which then get laboriously taken to bits and the contents recycled.

Never going to happen.

The so-called inventor has not come up with anything new, all these ideas have been tried for over 100 years, and a few have proved useful. But as long as he is on a good gig and can persuade gullible investors or get grants to continue research, I suppose it's worth it. Perhaps he even truly believes in it.

There may be some potential for one-time-use in very specific applications, but I doubt it.

However for example fuel cells, fed by either hydrogen or methanol, using air to provide the oxygen are interesting. At least with these the feedstock is liquid or gaseous so they can be practical.

PS: does anyone use, or has used, an Efoy fuel cell ? Their website https://www.efoy.com seems to be down, which is usually a bad sign.
 
Last edited:

Sharpie

Full Member
Posts
304
Likes
246
Must have been a glitch when I tried a while ago, several times, just a load of Apache server error messages. Good to hear that they are still in business.

Their product does interest me, but I can't afford or justify it for my uses. However it could be extremely useful for other scenarios.
 
Last edited:

Okta

Full Member
Posts
208
Likes
302
Yes I have an Efoy. It is not a cheap option but I love the sense of security I get from it. I know it will cut in whenever needed and works when cloudy, winter, night time or parked under a tree. Great bit of kit with good software to manage it and the battery.

We store our motorhome on a storage site with no ehu. The Efoy keeps the leisure battery topped up and that trickle charges the engine battery. Peace of mind, well worth spending a bit of the children’s inheritance.
 

izwozral

Full Member
Posts
10,751
Likes
16,912
Just so I am clear on this: the Efoy is basically a battery charger, pretty much the same as a CTEK charger but minus the need to plug into a power supply?

If so, isn't the Efoy a totally different animal to what the article is about?

I am not knocking the Efoy or why it was brought up, I just don't get the correlation between the Efoy and alternative battery types. My understanding of the aluminium-air battery is that it would replace the lead acid, lithium or gel battery, or have I got that wrong?
 

colinmd

Full Member
Posts
2,299
Likes
1,925
My understanding of the aluminium-air battery is that it would replace the lead acid, lithium or gel battery, or have I got that wrong?
Aluminium Air is a non rechargeable battery, this would require a lot of cooperation across the industry re swapping out batteries. They also self discharge when not in use.
 

Nabsim

Full Member
Posts
3,050
Likes
2,728
Yes an efoy generates electricity by burning off methanol, you have to replenish fuel in the same way you need petrol in a genny but efoy is silent.

it does sort of come under the same as the metal/air battery is a fuel cell that burns the metal to generate electricity but you cannot replenish it.

comparing metal/air to lithium is like comparing the old alkaline cells that were single use to rechargeable nicadtyres. They all produce a current, some are rechargeable and others aren’t.

I quite liked the look of the ones you posted Ral but it was too far away from the market to be an option for me at the moment. Plentiful constituent parts, cheap to produce, easy to recycle and good for the environment, what’s not to like. Until you can actually get hold of one and compare it’s all moot for now though 👍
 

izwozral

Full Member
Posts
10,751
Likes
16,912
Aluminium Air is a non rechargeable battery, this would require a lot of cooperation across the industry re swapping out batteries. They also self discharge when not in use.
I understand about the non rechargeable aspect and the need for recycling them. As for self discharging, does anyone yet know the rate of discharge or the lifetime of a battery? I read that this battery could power a car for a 1000 miles or so, I assume that would decrease with battery age but at what rate?
 

Sharpie

Full Member
Posts
304
Likes
246
To be clear, re-chargeable batteries contain all the chemicals needed internally, and move them from one electrode to the other as they charge, or discharge.

Fuel cells, of which Aluminium Air is I suppose one, contain or are fed with a feedstock that is "burned" typically using oxygen from the air. Or if on a spacecraft hydrogen and oxygen, with useful H2O as the byproduct.

Things like an Efoy are fed with methanol, take in air, then exhaust the waste as CO2 and water. Keep them topped up with methanol and air, they continue to work.

Things like Al/air, or Zinc/air use metal as the feedstock, use atmospheric oxygen to react with it as the other electrode, but the reaction products remain trapped in the cell. Simplistically you start off with Aluminium (or Zinc), then end up with aluminium (or zinc) oxides. Solid. Once depleted they are useless. Recycle them perhaps, extract the elements, turn them back to metal (this takes energy, from where ? Renewable ?, Then turn them into new ones again ?

Their advantage over ordinary primary batteries is simply that they do not contain the oxidiser, so can have a greater capacity than an ordinary primary cell, for the same mass, or volume.
 

Okta

Full Member
Posts
208
Likes
302
Fuel cells get a mention in the original article and so bringing up the Efoy seems fair. As a fuel cell the Efoy turns the methanol into electricity by a chemical process rather than by internal combustion and in that sense it behaves like an aluminium air battery. In one the aluminium gets consumed and in the other methanol.

The article claims the aluminium air battery has 8 times the energy density of lithium-ion. I think the Efoy is broadly similar but I am not an Engineer and the density calculation is beyond me. However I do know that my 100Ah LiFePO4 battery weighs in at 13kg and my Efoy plus 10 litres of fuel weighs in at 16Kg but stores 760Ah of power. Again I would say there is a fair comparison between the technologies.
 

Sharpie

Full Member
Posts
304
Likes
246
According to efoy, one 10L canister of methanol, weighing 8.4 kg, should deliver 920 Ah to charge your battery (at 12V nominal I presume). Earlier models less. Over those ten charges, on average you will have about half that weight of fuel as it goes from full to empty.

So could charge up a 100 Ah battery about ten times. Of course you need both the Efoy and the battery.


I did a quick search and those canisters seem to cost about £50. So say 100 Ah of charge costs £5.43 in fuel.

Or as efoy state, 0.9l per kWh, i.e. £4.50 per unit (Kwh) of electricity.

The efoy itself is supposed to have a design life of 5000 hours. 200 days. At about £5000 to buy, that suggests that they cost maybe £1/hour to buy and run, if you use them sufficiently to wear them out.

In terms of efficiency, the lower calorific value of methanol is 5.54 kWh/kg, density is 0.791 kg/l, therefore 4.38 kWh/l. Efoy's specification suggests that it extracts 1.1 kWh from a litre, i.e. 25% efficient in conversion, which is actually quite impressive.
 
Last edited:

Sharpie

Full Member
Posts
304
Likes
246
I understand about the non rechargeable aspect and the need for recycling them. As for self discharging, does anyone yet know the rate of discharge or the lifetime of a battery? I read that this battery could power a car for a 1000 miles or so, I assume that would decrease with battery age but at what rate?
Nobody can tell you that yet, unless and until a commercial product is made, and has been proven. AFAIK they are still at the research stage.

The tiny zinc air batteries that I use last a couple of weeks as soon as the seal is removed, whether or not any current is taken from them. I'm sure that a battery big enough to power an EV for 1000 miles would have to do much better than that.

Making aluminium from bauxite is a very energy intensive process. Perhaps 15 kWh to make one kilo. Sometimes referred to as "solid electricity".

E.g. one drinks can, weighing maybe 15 grams, takes 0.225 kWh of electricity (plus the energy to mine and transport the ore). If done using renewable hydro that's perhaps not so bad. If the electricity is generated otherwise, well that's another matter.

Once made it is readily recycled in metallic form. So please recycle them.

That is part of the attraction, if the metal can be oxidised again in a cell, efficiently, there is potentially a lot of energy available in a small mass of this relatively light metal. But to complete the cycle, swap an old battery for a new one, and turn the oxidised material back into metal is quite another matter. Energy out vs. energy in ? And where does this energy come from, renewables hopefully.

Now, If I could make a little thing that I just fed with old pop cans to keep my camper powered, that would be nice.

We don't yet really have a recycling process for worn out Lithium rechargeables, it is far cheaper just to make new ones with fresh material, though that might have to change eventually, but it will be economics that drive that.

Whereas with lead batteries the recycling chain is long established and economically viable, New batteries are made with about 50% recycled lead from old ones.

You might even like to think that putting e.g your old AA batteries into recycling bins means that they are re-processed into new ones, hence saving the planet, but that isn't necessarily what happens to them. Shops are obliged to collect them if they also sell them, but in reality it is quite uneconomic to process them.

 

izwozral

Full Member
Posts
10,751
Likes
16,912
If 200 days costs £5000 then the maths I get is £7500+ a year + the cost of fuel, that's quite a chunk of money. Unless I am missing the point, it will cost you about £150 a week to produce electricity.
That sounds scary rather than impressive.
 

oppy

Full Member
Posts
3,013
Likes
4,445
Don't you just hate a smarty pants that's either been on the course or even worse-----------------------university
 

Sharpie

Full Member
Posts
304
Likes
246
If 200 days costs £5000 then the maths I get is £7500+ a year + the cost of fuel, that's quite a chunk of money. Unless I am missing the point, it will cost you about £150 a week to produce electricity.
That sounds scary rather than impressive.

No that's 5000 hours / 200 days life expectancy whilst running.

In e.g. casual motorhome use that should be OK. They shouldn't be running continuously anyway, only as needed, kicking in when they think the battery needs a boost.

There may be other bits and pieces that degrade just with time, not use. I wouldn't know. There is another consumable that you have to top up when demanded. No idea what that is for.

If full-timing it could be quite different. Or the expensive bit, the fuel cell, might last much longer. Efoy say that under test conditions were still tip-top after 6000 hours. That would have taken 35 weeks continuous running on a test bench. I must assume that they are durable and possibly far better. Who really knows ?

Either way it is very expensive 'leccy. And a big up-front investment.

Solar is rather different.

They are guaranteed for two years (actually that's the law) but you can pay extra to extend that.
 
Last edited:

Users who viewed this discussion (Total:0)

Top