Why doesn't anybody make 1.5V rechargeables?

[gnome]

It appears that all rechargeable "AA" batteries are rated at 1.2V.

Why doesn't anybody make 1.5V rechargeables?

 

[AKG]

It appears that all rechargeable "AA" batteries are rated at 1.2V.

Why doesn't anybody make 1.5V rechargeables?

The voltage supplied by an electrochemical cell has to do with the electrodes that are used to make the battery (as well as a few other conditions, such as concentrations of ions, etc). To make a 1.5 V battery, they'd probably have to make the battery out of some other materials, materials that may be expensive, impractical, etc.

Check this page out. If they could make a cell using Chlorine gas and Zinc metal, they could have a cell which produced 1.359V - (-0.763V) = 2.122V, much more powerful than your regular battery, but how could they make a batter where one electrode was Chlorine gas? So, I'm guessing your typical household battery uses two electrodes that produce a decent voltage, but are easy to make a battery out of, and are not rare or expensive, stuff like that.

 

[BoulderHead]

I use energizer AA Hi Energy Lithium cells for the clock and memory functions in one of my shortwave radios. The voltage of each battery is 1.5 yet they are not rechargable. There are, however, Lithium-ion? rechargeable batteries for camcorders available, but I believe there may be a difference between this type and my AA batteries as I seem to recall having researched the matter once but cannot remember what I had found out. Different materials will yield different voltages and I suppose the materials most economically suitable/available just happen to leave many of us longing for that additional 0.3 volts.

 

[zoobyshoe]

If they made a lithium (+3.02) gold (-1.68) battery each cell would produce 4.7 volts! They would also completely eliminate any problem with recycling.

 

[ElementFire]

Gold is expensive, though.

 

[zoobyshoe]

Gold is expensive, though.

That's why it would solve the recycling problem. The recycling problem with batteries is that no one recycles them: all that's in a used battery is a lot of cheap chemicals and elements. It isn't worth the work to recycle them. People throw them away. People drop them on the street.

The gold/lithium battery would be worth recycling. The gold electrode being the stable element, would undergo no chemical change during the life of the battery. A discharged battery would be much too expensive to throw away, so recycling operations would spring up everywhere.

The first gold/lithium battery you buy would be quite expensive. They could enginneer them to be rechargable, and when they wore out their rechargability you could turn them in and get a new one at a much reduced price.

Not that I think any of this would ever happen :-).

 

[ElementFire]

It's a good idea on paper, but people may not want to use them as batteries. They'll find some technique to liquefy the gold in the battery and they'll make jewelry out of them (I'm guessing a necklace made of gold will be more expensive than one battery). :)

 

[zoobyshoe]

It's a good idea on paper, but people may not want to use them as batteries. They'll find some technique to liquefy the gold in the battery and they'll make jewelry out of them (I'm guessing a necklace made of gold will be more expensive than one battery). :)

My thinking was that the gold would be electrodeposited on a porous element just like the platinum in a catalytic converter. This would primariy be to get the most surface area out of the least amount of gold, but it would also deter people from trying to do what you pointed out would inevitably happen: people stealing other people's batteries thinking they can melt down the gold. This way, it would take an industrial process to recover the gold from the porous element, involving nitric and hydrochloric acid, and should really end up being more trouble than it's worth. No one steals catalytic converters and tries to reclaim the platinum, despite the fact it is worth much more than the same weight of gold. Too much trouble for too little platinum.

 

[undefined]

Battery types

In case you were wondering, 1.2 V rechargeable batteries are usually either nickel-cadmium (cadmium and nickel oxyhydroxide electrodes) or nickel-metal hydride (some alloy usually with a rare-earth metal and nickel oxyhydroxide electrodes). 1.5 V cells are called alkaline because the electrolyte is an alkaline paste (potassium hydroxide), but the electrodes are zinc and magnesium dioxide (incidentally the first electrodes ever to be used were zinc and copper).

 

[ElementFire]

My thinking was that the gold would be electrodeposited on a porous element just like the platinum in a catalytic converter. This would primariy be to get the most surface area out of the least amount of gold, but it would also deter people from trying to do what you pointed out would inevitably happen: people stealing other people's batteries thinking they can melt down the gold. This way, it would take an industrial process to recover the gold from the porous element, involving nitric and hydrochloric acid, and should really end up being more trouble than it's worth. No one steals catalytic converters and tries to reclaim the platinum, despite the fact it is worth much more than the same weight of gold. Too much trouble for too little platinum.

That would make it a plausible idea. Might happen someday. :)