Talk:Zinc–air battery

Reaction

The reaction at the anode is obviously wrong because the charges don't add up. I'd correct it but I don't know the correct reaction. --Alistair

Well thank you for discovering this, 2 problems

1. The electrochemistry is erroneous, with two sites stating different reactions, it could be that several different zinc air reactions types exist. [1] [2]

2. Zinc-Air Fuel Cells has a reaction of its own. [3]

I think all of these reactions need to be displayed, but information is needed for why they are different. --BerserkerBen 06:17, 3 February 2006 (UTC)

Thank you for trying to fix this. There isn't much knowledge about these reactions on the web, is there! The charges in these reactions still don't add up:

 Anode:  Zn + 2OH- → Zn(OH)42- + 2e- → ZnO + H2O

While I have absolutely no authority for the following reactions, they are at least not transparently wrong:

 Anode:  Zn + 4OH- → Zn(OH)42- + 2e-
 Fluid:  Zn(OH)42- → ZnO + H2O + 2OH-

Can anybody help? --Alistair

Aha! I've found a reference. [4] Its "At the anode" reaction matches mine but omits the zincate intermediate. I'm therefore still not sure what to do to the page. --Alistair

How so don't the charges add up? Zinc should be changes its oxidation state going from zero to +2 and releasing 2 electrons. --BerserkerBen 18:18, 19 February 2006 (UTC)

Neither of the following reactions has balanced charges:

 Zn + 2OH- → Zn(OH)42- + 2e-
 Zn(OH)42- + 2e- → ZnO + H2O

In the former, the total charge on the left is -2 and on the right is -4. In the latter, the total charge on the left is -4 and on the right is zero. The charges are correct for every individual chemical mentioned, but the reaction overall makes no sense. The numbers of hydrogen and oxygen atoms don't balance either, while we're on the subject. --Alistair

Sorry I was looking at the reaction below: Zn + 4OH- → Zn(OH)42- + 2e- → ZnO + H2O + 2OH- The zinc changes charge and gives up 2 electrons, so the charges look good to me, I didn't notices there was a 2 instead of 4 hydroxides on the main page, that needs to be fixed. Maybe it was because 2 hydroxides get recycled but still 4 need to be shown reacting with zinc.

Actually I don't see a big problem between the equations using Zn(OH)₂ or Zn(OH)₄^2-. In practice the whole range of Zn(OH)_x^2-x (x = 0 - 4) will coexist with the proportion of each dictated by the pH. In other words in very alkaline conditions there will be more of the x = 4 species than in acidic conditions (more x = 0). The Zn-air battery operates under fairly strong alkaline conditions, therefore there will certainly be some of the x = 2, 3 and 4 species present. Ahw001 06:31, 1 September 2006 (UTC)

Cost of competing metals has "soared"?

The article claims "The price of zinc in 2008 is $1/lb [2]. Since India and China began rapidly industrializing at the end of 1990s the price of major metals such as nickel, copper, steel, aluminum and zinc has soared." The second sentence might be true but the implication of its juxtaposition with the first is very misleading. Steel continues to be a lot cheaper than zinc, while aluminum is currently trading at $1.20/lb. --Vaughan Pratt (talk) 01:58, 7 September 2008 (UTC)

Specific Energy?

The article says: "High specific energy: up to 370 W·h/kg.". This must be an understatement, as one of the largest producers of hearing aid batteries say 470 for their standard 13-size battery: [5]. One would expect larger values for larger sized batteries. The Duracell page on the technology says 442 Wh/kg (still for button cells), and by the way contains a host of info on reactions and so on for you chemistry guys. It also gives the theoretical energy density: 1,65 V * 0,83 Ah/gram = 1370 Wh/kg ! I'll just change the specific energy, and try to insert a reference or two. 130.227.121.251 (talk) 12:35, 11 June 2009 (UTC)

I also added energy density (calculated from same source), and would add voltage but got a doubt: Earlier this article says 1.65V, but the Duracell source says theoretically 1,4 volt. Practical cells give around 1.1 - 1.2 volts, maybe 1.3 before any use. So I chickened out, and didn't add anything about voltage. But I used the 1.65V figure to give the theoretical specific energy, which the Duracell source gave as 0.82 Ah/kg! And also to give the theoretical energy density (just multiplying specific energy by the specific mass of Zinc: 7.14 g/cm³.

If it shows up that the 1.65V is wrong, we need to correct the figures.130.227.121.251 (talk) 13:22, 11 June 2009 (UTC)

I just separated out the theoretical energy density from the practical. It was misleading.JG17 (talk) 10:22, 21 July 2009 (UTC)

"Re-Charge" Efficiency?

What is the energy efficiency? (energy required to charge divided by energy recovered during discharge)

...Energy Currency?

I altered this to note that Zinc is an alternative to fossil fuels as well as hydrogen because the impression was being erroneously given that Zinc, being solid, was more problematic for distribution than highly compressed hydrogen. In fact solid Zinc would be much safer than hydrogen or fossil fuels in transport and a lot less difficult to handle than hydrogen. However it is sufficient just to mention the Zinc pumping challenge.JG17 (talk) 10:38, 21 July 2009 (UTC)

Zinc economy

I'm deleting the speculation about a future "zinc economy" from the article's lead. The "zinc economy" is a neologism; Google scholar [6] and Google books [7] return titles exploring the economical use of zinc, and the metabolic recyling of zinc in humans, but not a future macroeconomic model. Zinc economy was deleted [8], then redirected here after it was recreated [9]. Since it's coming out of the lead, I thought you'd want to know why. Yappy2bhere (talk) 21:42, 13 January 2010 (UTC)

If it's got no souces, it should come out. Discouraging to find lots of 30 and 40 year old papers on electric cars, but no brave new vision of zinc replacing oil. --Wtshymanski (talk) 16:52, 21 January 2010 (UTC)

Unusual base?

Please read the articles at Ni-cad battery,Nickel-metal hydride battery Alkaline battery, Lithium battery and get back to me on the question of alkaline (basic) electrolytes being the tiniest bit *unusual* in a battery. I venture to say any random Wal-Mart sells more alkaline batteries than automotive or old-timey ammonium chloride batters in any given (recent) year. --Wtshymanski (talk) 16:30, 18 January 2010 (UTC)

Copy-edits

Comments appreciated. Also added material on Revolt's R&D. Lfstevens (talk) 03:18, 16 June 2010 (UTC)