Talk:Electrochemical cell

Salt Bridge : What's its use?

I am not sure the salt bridge of the Daniell Cell is meant to let electrons move and close the circuit. As suggested in another Wikipedia's article called "Electrolyte" electrons dont go in the electrolyte. Only ions move which means that a current would appear in the copper circuit (outside the cell)even if the circuit was open (if there wasnt resistance). Actually, I cant find any satisfying explanation about the use of the salt bridge. Could anyone give us a hint?

From Electrolyte : "When electrodes are placed in an electrolyte and a voltage is applied, the electrolyte will conduct electricity. Lone electrons normally cannot pass through the electrolyte; instead, a chemical reaction occurs at the cathode consuming electrons from the cathode, and another reaction occurs at the anode producing electrons to be taken up by the anode. As a result, a negative charge cloud develops in the electrolyte around the cathode, and a positive charge develops around the anode. The ions in the electrolyte move to neutralize these charges so that the reactions can continue and the electrons can keep flowing." —Preceding unsigned comment added by Whalala (talk • contribs) 09:33, 29 April 2008 (UTC)

Yes, free electrons don't exist in water, they are far too reactive. The role of the salt bridge is to allow an electric current to pass between the two half-cells—the current is carried by the ions of the salt bridge, not by free electrons—while preventing the two electrolyte solutions from mixing. Physchim62 (talk) 11:49, 29 April 2008 (UTC)

The salt bridge in an ev cell acts to maintain charge balance primarily as the electrons move from one half-cell to another half-cell (anode to cathode). As mentioned above, electrons actually are not moved from the electrolyte but rather maintain charge neutrality as they are moved from the anode to the cathode. Armankucsd (talk) 00:33, 9 November 2017 (UTC)Armankucsd (talk) 16:32, 8 October 2017 (UTC)

Merge debate

Do not merge. An electrolytic cell can be very different in usage than an electrochemical cell. As an example: electroplating is a use for an electrolytic cell, electrolytic cells are in a neutral energy state and must be driven by an external electrical force where electrochemical is an electrical source and is NOT in a neutral energy state.Jonathan888 (talk) 22:21, 11 January 2006 (UTC)

I think they should not merge. --Cyberman 05:17, 31 December 2005 (UTC)

No. Leave them seperate - Ali

These items should be combined as galvanic/electrolytic cells are a subset of electrochemical cells. I reference any introductory physical chemistry text, but namely the text Physical Chemistry by Atkins/dePaula, 7th Ed.

I agree, many college level textbooks including Zimdahl's 7th edition include these two topics in the same section.

Whilst a galvanic cell and an electrochemical cell may be in the same section of a textbook this does not indicate that they should be merged in Wikipedia. Much in the same way amides and amines are different but are still included in the same sections of many books.

HAHA NO! Most high school students like me need them seperate. And thats mostly who would be looking up this shizz.

They should be kept seprate!

The difference with amides and amines is that amides are the products of amines. With electrolytic/galvanic cells, though, one is not the product of the other. They are both reverse proceses of the same greater phenomena (i.e. electrochemical cells). Therefore, electrolytic and galvanic cells should be merged into Electrochemical Cells. - matchu

Please leave them separate. For a high school student such as myself, they could become confusing when your first learning them.

I could see them merged if they were discussed as disctinct instances of an electrochemical cell. Otherwise, I think they should be kept separate. Galvanic and electrolytic cells are distinct and complimentary entities that could be unintentionally confused if combined into a singe article.

DO NOT MERGE. Electrochemical and electrolytic cells are two very different things.

Keep them separate. Very different ideas, and they all have a decent article, so there's no need for a merge. – Mets501^talk 01:37, 1 May 2006 (UTC)

Do not merge, I repeat, do not merge. Electrochemical and Electrolytic cells are quite different, and easily confused. Do not aid this confusion by merging these two articles. --205.251.157.32 17:41, 17 May 2006 (UTC)

You all seem very confused about Galvanic and Electrolytic. Galvanic cells are exactly the same as electrochemical cells, I don't understand why that is debatable. Just like dye-sensitized solar cells are equivalent to graetzel cells, electrochemical cells are synonomous with galvanic cells. Electrolytic cells, on the other hand, perform electrolysis, as opposed to generating current, and I think that should not be merged. If we are to go in depth in either, it wouldn't do to have them in the same article. Kr5t 22:02, 21 May 2006 (UTC)

As further evidence that Galvanic cells are synonomous with electrochemical cells, note that the lead-acid battery article says that lead-acid batteries are galvanic cells. Really, what is the difference? Can anyone come up with one? Kr5t 00:44, 22 May 2006 (UTC)

It depends on which text you read from or which terminology you use. Some people use "electrochemical cell" to mean an electrolytic cell OR galvanic cell, but some people use it only to mean an "electrochemical cell". Maybe this should go in the article. splintax ^(talk) 07:23, 23 May 2006 (UTC)

Actually, electrochemical cells used to describe both galvanic and electrolytic cells. This is an excerpt from my grade 12 Nelson chemistry textbook: "The term electrochemical cell is often used in chemistry to refer to either a cell with a spontaneous reaction, such as the electric or galvanic cell, or a cell with a nonspontaneous reaction, which we will call an electrolytic cell."

While electrochemical cell is the umbrella term used to describe both galvanic and electrolytic cells, I would not merge the pages. There are several very distinct differences between the two types of cells and to avoid confusion, keep the articles segregated.

I agree they should not be merged, but for different reasons to those given above. Galvanic corrosion of of particular interest in the marine/engineering industry and, although the underlying science is similar, the impact in terms of corrosion is not.

Importance of links

I would prefer, for several reasons, that the two not be merged. However, if you do merge them, make sure all pages that link to Electrochemical cell will instead link to Galvanic cell, or vice versā. This can be accomplished either by means of a redirect or by actually changing the links. Ruff 23:52, 26 July 2006 (UTC)

The vote seems to be not merge. I will remove the merge tags.--Sadi Carnot 00:52, 15 August 2006 (UTC)

Do not merge seems to be the correct verdict here is a main difference between electrolytic cells and galvanic cells is that galvanic cells are actually non-spontaneous that requires electrical energy to occur. The difference between energy released by a spontaneous reaction and energy used to drive a reaction is basis for not merging the two. Armankucsd (talk) 00:39, 9 November 2017 (UTC)Armankucsd (talk) 16:39, 8 October 2017 (UTC)

How galvanic cells work

I am PhD Physics and elec eng. I wish SOMEBODY would EXPLAIN how a galvanic cell works.

People TALK of "closing the external circuit" What IS a "resistive junction", "contact potential" and HOW do you know you have got it?

DOES a galvanic cell "have a voltage" on open circuit? How?

I built all the galvanic cells age 7. But the "explanations" are trash!

OK lets have Zn and Cu in dilute H2SO4. They touch at a point UNDER the liquid. Does a current flow or not? How, where, why, and what is the volts and what gets hot? Why so SOME people, in a Daniel cell, say the Cu is anode while others say it is cathode? Ana is up, so that is where the crazy-positive-charges rise up! QED.

So who would like to be the oNLY person in 60 years ABLE to explain Voltas Pile to me? WHY does the damp film on the Cu/Zn not do EXACTLY what the wet blotting paper does, thus CANCELLING the volts? Thanks,John

Wow, do you mean that you're working on a Ph.D., or that you already have one? Either way (given that you say your field is electrical engineering) I find it hard to believe that you don't get how an electrochemical cell works (or to be completely objective, that you don't understand the standard theory behind it).

Let's be nice here. I also have a "Ph.D." and I'm on the faculty of a well-known university. I'm considered quite bright. But I also find it hard to understand these things. I've always been troubled by devices where electricity (which for me is RLC circuits and field equation) interacts with chemistry - specifically via electron energy levels in conductors. So both batteries and transistors are difficult for me. It ultimately comes down to two other difficult things, namely thermodynamics (chemical potential) and quantum physics (for the energy levels). Both of these are often explained badly. They are difficult, but fundamental and in everyday use. Practical people apply them and calculate with them and still don't really understand them. Remember Feynman's story about an experience in Japan - he asked so many questions that they thought he was really a simpleton, but he was the only one in the room who realized that he didn't understand and eventually he solved the problem.

Anyway I now know the answers to some of these questions, but I look forward to understanding it all, and once I'm there, I'm sure I'll be able to explain it to the satisfaction of people who are as full of curiosity as this guy is. 84.227.230.58 (talk) 10:37, 28 May 2014 (UTC)

From the questions you're asking I'm guessing that you don't really understand what "voltage" is, or what it means in terms of chemical reactions. Wikipedia has a good explanation of redox reactions so I'd suggest that you start there, and hopefully you can piece the rest together. Quantris 21:35, 8 February 2007 (UTC)

Not likely. The Wikipedia articles on this subject (Galvanic Cells, Electrochemical Cells, etc.) suck. (Sorry, but it's true. You know it's pretty bad when a freakin' PhD can't figure out how these things work!) The articles fail to clearly explain what's happening and why. Even the writers/editors of the articles can't seem to agree on what actually is going on inside these cells! (See the discussion page for the Galvanic Cell article.)

Why do different metals create a voltage between them when in contact with an electrolyte? (None of the Wikipedia articles related to this topic explains that. The closest explanation I've seen — and it's totally unsatisfactory — is that one metal "dissolves" at a faster rate than the other. Huh? That makes no sense.)

Does the electrolyte provide the energy for the cell, or merely a conductive medium? Is the electrolyte consumed in the process, or not? Does it have to be a particular chemical that depends on the metals used for the electrodes (as implied in this article), or will any conductive liquids (e.g. salt water) do? Do you have to have two different chemicals (such as zinc sulfate and copper sulfate, as in the example in this article), or will just one do? This article implies that two electrolyte chemicals, matched to the particular electrode metals, are required. Yet as we all know, regular batteries that you buy at the store (including car batteries) use just one single electrolyte solution. (And with the two-electrolyte scenario, why do you need to keep 'em separate with a "porous separator" or "salt bridge"?)

These articles need a lot of work. 24.6.66.193 10:29, 20 April 2007 (UTC)

Types of cells (new section) and page move to electrochemical cell to "Power cell" and accumulator to "secundairy power cell"

New section to implement: types of cells

Primairy power cells are non-rechargable power cells Secundairy power cells are rechargable power cells (also called accumulators)

This subdivision also allows a clearer view and removes the confusing "accumulator" word. As such, perhaps accumulator-can be moved to "Secunairy power cell" and accumulator can be made a redirect.

Look into it, it makes things allot simpler. thanks.

KVDP (talk) 13:10, 26 January 2008 (UTC)

In terms of highlighting differences between primary and secondary cells, here is a good source: http://depts.washington.edu/matseed/batteries/MSE/classification.html. We can find valuable introductory info here on the variations, classifications and differences between primary and secondary cells. Also in regards to this section, could it be tied into cell potential? Armankucsd (talk)Armankucsd (talk), 16:49, 8 October 2017 (UTC)

New section: Alternatives to electromechanical cells

Due to environmental aswell as financial concerns, people are slowly moving away from electrochemical cells and towards capacitors . This, as capacitors are much more environmental and financially attractive (they are rechargable, and made of less damaging materials). Examples to this can be seen with the rise of the Faraday flashlights. Besides these energy carriers, new batteries are emerging which too are more environmentally-friendly. Such cells are created (amongst others) by Susumi Suzuki..

I am already implementing it into the article, if it does not qualify for anyone; please discuss it here.

KVDP (talk) 13:24, 26 January 2008 (UTC)

Now, I've made the odd type on Wikipedia - but do you mean "electromechanical" or "electrochemical" ? There's no such animal as a "capacitator". A reference would be good - sales of flashlight batteries continue at a good pace. --Wtshymanski (talk) 04:36, 27 January 2008 (UTC)~

Reference was added in the section:(Susumi Suzuki building environmentally-friendly cells

I meant electrochemical, changed it in text

I also meant capacitor, also changed it in text, also added extra reference

KVDP (talk) 18:27, 2 March 2008 (UTC)

References

New section: Recharging of alcaline and saline-batteries

Besides NiMh (nickel-metal hydride) and NiCd (Nickel-cadmium) chemical cells, saline and alcaline batteries (which are usually said to be 'non-rechargable cells) may also be recharged. This less-known feature allows users not only to reduce the financial expenses (saline/alcaline cells are usually cheaper) they do yearly on buying chemical cells, but also allows them to achieve environmental advantage as the batteries may be recharged up to 20 times before being exhausted (NiMh/NiCd may be recherged more however).

This recharging of saline/alcaline cells is possible trough the use of low-heat recharging (by special rechargers). Several manufacturers (as provence-piles) exist which produce these devices.

Please include in article as this is of vital information for the environmental community. Also include my previous proposals for new sections. Also check whether using this device with NiMh/NiCd cells may increase their life expenditure aswell (so the 1000 recharges frequently mentioned may actually be achieved or surpassed).

KVDP (talk) 18:25, 2 March 2008 (UTC)

PS: references here are added aswell-->Provence-piles 'Batbooster' able to recharge alcaline/saline cells and Battery Xtender as another device able to recharge alcaline cells

KVDP (talk) 18:29, 2 March 2008 (UTC)

References

CEll

Hi For The Cell Articlle It Says Hl Half Normal Then Half ITalic. I Need You To EXplain. —Preceding unsigned comment added by 66.131.190.6 (talk) 22:51, 6 October 2010 (UTC)

Merge with Galvanic Cell? This article needs work.

I originally was going to suggest that this article be merged with the Galvanic Cell article; galvanic cells should be a section of this article, since a galvanic cell is a type of electrochemical cell. It turns out that the galvanic cell article has references and is replete with consistent information - unlike this article.

I stop short of insisting on a merger for that reason. This article is too poorly constructed to insist that other articles be merged into it.

In the future when people search for "Galvanic cell", assuming things are tidied up here, they will be redirected to the "galvanic cell" section of the "electrochemical cell" article. Unfortunately, that's premature right now.

Please voice your concerns and suggestions here. I nearly added the merge tag to both articles, but stopped so that I could pose the idea to the community. Spiral5800 (talk) 08:17, 12 May 2013 (UTC)

Unclear

In the half-cell that is undergoing oxidation, the closer the equilibrium lies to the ion/atom with the more positive oxidation state the more potential this reaction will provide. Likewise, in the reduction reaction, the closer the equilibrium lies to the ion/atom with the more negative oxidation state the higher the potential.

I don't understand this sentence.

1) ...the closer the equilibrium lies to the ion/atom with the more positive oxidation state.... How can an equilibrium lie close to an atom? Shouldn't it be some thing like "the closer the equilibrium value of X lies to the X of the atom..." where X is some quantity like potential or concentration?

2) the higher the potential - Voltage difference? Between what and what? There is also something called electrochemical potential. — Preceding unsigned comment added by 84.227.230.58 (talk) 10:08, 28 May 2014 (UTC)

generation by facilitation - example?

In the first paragraph, it says an electro chemical cell is capable of facilitating chemical reactions through the introduction of electrical energy. What is an example of this? Thank you. Azulbirdyki (talk) 05:49, 25 January 2016 (UTC)

Wiki Education assignment: CHEM 300

This article was the subject of a Wiki Education Foundation-supported course assignment, between 9 January 2023 and 28 April 2023. Further details are available on the course page. Student editor(s): Bigspace4 (article contribs). Peer reviewers: BigChem.

— Assignment last updated by RS UBC800 (talk) 21:03, 2 April 2023 (UTC)

I plan to go through each section/subsection individually improving clarity in text using (Brogan rules), eliminating unnecessary language, unsourced/irrelevant facts, and adding illuminating figures to help guide the reader in modernity. Here’s my plan for potential sectional edits:

Intro: Improve sourcing, improve transition to a more meaningful example of a standard cell, and briefly explain how cells relate to batteries by briefly elaborating on what a battery is.

Add Heading: “Types of Electrochemical Cells”

Electrolytic Cell: Move component section to first/second paragraph, focusing on structure and function using bullet points, update 19^th century photo to a modern example (or do a side by side).

Galvanic Cell: Provide a modern example, bullet point components and their functions, list relevant half reactions.

Primary Cell: Provide a modern example, half reactions, remove unnecessary history (some ideas have their own main article), or add history to section missing depth, improve referencing.

Secondary Cell: State the biggest chemical difference between a primary and secondary cell, delineating what allows the secondary cell to be rechargeable, add a short sentence to the last idea about alternators, explain (briefly) how it recharges the battery.

Fuel Cell: Re-write first sentence (currently hard to follow), improving sourcing, clearly list common types of reactants and fuel, structure components and their functions using bullet points, add/remove unnecessary history (should be left for “Main Article,” add a better diagram with improved caption, simplify third paragraph concerning fuel cell classification using bullet points and proper sourcing.

Half Cells: move section to top of article, add a modern example and photo, discuss fundamental component of half-cells, improve intro paragraph using main paragraph, synthesize and simplify last paragraph using sourcing.

Equilibrium Reaction: provide an example reaction scheme of an equilibrium reaction.

Cell Potential: Define what cell potential is, what increases and decreases it, provide sourcing for claims (0 to 6 volts), explain what is measured, how its measure, what cell potential values tell you, etc.

Idea for new section: adding info about other/new electrochemical cells on the market/in current research.

- Bigspace4 Bigspace4 (talk) 21:55, 12 March 2023 (UTC)

Applied my proposed changes. Bigspace4 (talk) 03:35, 22 April 2023 (UTC)