compare the designs of fuel cells and dry cells.?
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The dry cell (Leclanché cell):\n\nThe dry cell dry cell, invented in 1867 by the French engineer Georges Leclanché (1839 - 1889), is widely used as a source of electric energy in electric torches and small appliances such as transistor radios. It makes use of the two reactions, which (in a simplified form) may be described as\n\nDry cell reactions 1\n\nThe manganese is supplied as manganese dioxide, and the actual cathode reaction taking place is\n\nDry cell reactions 2\n\nThe H+ ions are in turn provided by ammonium ions NH4+, through the reaction\n\nDry cell reactions 3\n\nThe dry cell is an example of a primary cell, as once it is discharged it cannot be recharged, and must be discarded.\n\nA typical dry cell is shown below, with a section cut away in order to expose the interior parts.\n\nDiagram of dry cellThe top of the battery is closed with a non-conducting sealing material (A).\n\nThe cathode consists of a graphite (carbon) rod (B)(tipped with a metal contact), which serves as the positive pole of the battery.\n\nThe anode is a cylindrical zinc casing (C) (the bottom of the battery is normally exposed and serves as the negative pole).\n\nThe battery is filled with a mixture of manganese dioxide (MnO2) as oxidant, ammonium chloride (NH4Cl) as a source of H+ ions, and zinc chloride (ZnCl2) (D). These two salts serve as electrolytes.\n\nThe above mixture is separated from the zinc walls of the battery by a porous material soaked in a solution of the two salts. The e.m.f. of the battery is about 1.5 V.\n\nIn 1859, the French physicist Gaston Planté (1834 - 1889) invented a device called the lead-acid accumulator, which, with minor design changes, is still used today as the motor car battery. It is an example of a secondary electrochemical cell, since it can be recharged.\nLead-acid 1 The battery consists of 6 cells connected in series, each cell having an emf of about 2 V, giving 12 V as the overall emf of the battery,\nThe general appearance of the battery is shown on the right, with part of its casing removed to show the individual cells. Lead-acid 2\n\nWhen the battery is discharging, i.e., when it is supplying a current, the reactions are\n\nAt the anode:\n\nLead-acid reaction 1\n\nAt the cathode:\n\nLead-acid reaction 2\n\nThe overall reaction (during discharge) is therefore\n\nLead-acid reaction 3\n\nNote that the electrolyte is sulphuric acid (H2SO4), which is gradually used up. Both electrodes become coated with an insoluble layer of lead sulphate, which, being an insulator, would eventually ruin the battery.\n\nDuring the manufacturing process, the electrodes are filled with litharge (PbO), and immersed in the electrolyte (H2SO4, 6 mol.dm-3). When an electric current is passed through the battery, the negative electrode is converted to lead, while the positive electrode is converted to PbO2. There is no net change in the concentration of acid. This process is called forming the battery.\n\nLead-acid charging\n\nWhen the battery is fully charged, the anode consists of metallic lead in a spongy form (with a high area per unit mass), while the cathode consists of lead dioxide:\n\nCharging reactions\n\nThe electrolyte is an aqueous solution of sulphuric acid, at a concentration of approximately 6 mol.dm-3. This is the battery acid that one can buy at service stations.\n\nAs the battery provides energy, it is discharged and this lead to the gradual formation of lead sulphate at the electrodes, and a steady decrease in the concentration of the sulphuric acid:\n\nLead-acid discharging\n\nAt the anode:\n\nDischarging reaction at anode\n\nAt the cathode:\n\nDischarging reaction at cathode\n\nIf the battery is totally discharged, both electrodes will have been converted to lead sulphate. It will no longer be able to provide a current, and cannot be recharged. It is only good for scrap!\n\nWhen the battery is being charged, (using a battery charger or the motor car's alternator), electrons are supplied to the anode o
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A fuel cell is an electrochemical energy conversion device. The core functioning unit of a fuel cell is a single 'cell' that combines fuel with oxidant in order to generate electricity, heat and waste. Usually, many such cells are combined into a "fuel cell stack". In turn, a fuel cell stack is combined with subsystems such as thermal management and fuel storage/delivery subsystems in order to produce a functional "fuel cell system".\n\nThere are five different types of fuel cell, based on the electrolyte used. In turn, there are further types of fuel cell that share an electrolyte - e.g. Polymer Electrolyte Membrane Fuel Cells (PEMFC) and Direct Methanol Fuel Cells (DMFC). \n\nEach type of fuel cell is suited to different applications, and the configuration of fuel cell system varies widely from application to application. Fuel cells have been produced in the sub 1 Watt range, right through to MegaWatt systems. Therefore, fuel cells have applications in just about every energy usage situation.\n\nThere are a number of significant advantages to using fuel cells in various applications, including diversity of fuels, efficiency, suitability for distributed generation and their quiet operation.\n\nYou will find more about 'What is a Fuel Cell' here: http://www.fuelcellmarkets.com/article_flat.fcm?subsite=1&articleid=696.\n\nDifferent markets (applications) for fuel cells are predicted to commercialise at different times. For example, stationary power plants, portable power packs and micro fuel cell systems for consumer electronics are all either commercial now, or are expected to commercialise this year. Transportation applications, perhaps the most visibly obvious to most people (i.e. fuel cell cars) are one of the furthest applications from commercialisation for a number of reasons.
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fuel cell technology provides huge energy.....that's why they use it in power plants and space crafts....now Mercedes have their technology to reduce this power and use it in "Buses" and they were succeed to do that in 1998.  Now they are trying to implement this tech. in small cars. but they are facing some difficulties in using Hydrogen because it is very dangerous element.....they are trying to solve this issue by using some bi-products of the Hydrogen...as a result of that ...the efficiency will be less.\nso the limitations are :\n*the Huge energy that will be produced should be compatable with the engine been used.\n**using suitable Hidrogen bi-products for safety issues.\nI hope that I answered your question .....please try to answer mine.....\nRegards,\nFouad
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Carbon rods are at the centre of large dry cells. If you can find a battery (dry cell) manufacturer in the Philippines, they may be able to sell you some carbon rods. Also, it depends how big they need to be for your use.
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There are many ways to generate hydrogen outside electrolysis. Steam reforming, methane reforming, propane reforming, etc... Coastal countries may appear to have an advantage but you cannot have a fair comparison of supply and demand.  Consider the following:\n1. Many, many, many countries have access to coastal water, thus competition would be extremely fierce\n2. Countries will be more than self-sufficient and may "sell" excess product at a very low cost.\n3. Rivers, streams, rainwater etc... is available to more countries in the world than petroleum to many. \n \nI would not worry about it, depleting the sea is way way way way off, and besides, using H2 as fuel means that emission is....water. And no, the roads are not going to be slippery from algae (sorry, but I have heard a statement like that in the past)\n\nEver considered that we may come up with the technology to recover and re-use the water emission? Thus less filling up at your local Shell H2 station? \n\nI hope I was able to answer it for you in a objective manner
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dry air conducts static electricity better, and a spark might case a fire???\n\ni know that was the case in old flower mills
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Methanol battery is a fuel cell design.\nSo how does a fuel cell work? "The fuel cell is based on the reverse principle of water electrolysis...[Fuel cells] work by having hydrogen and oxygen react to generate electricity..."
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At anode the reaction taking place is oxidation\nthat is loss of electrons and therefore it gains + charge,wheras at the cathode reduction takes place and hence it gains -ve charge.But in a dry cell,the polarity indicates the terminals to which the cell needs to be  connected.That is cathode to the +ve\nand the anode to the -ve terminal.
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All of them have a source of power (usually solar cells) and batteries for storage.\n\nArrays of solar cells provide power to charge rechargeable batteries. Newer designs include the use of fuel cells. Power on most satellites is precious and very limited. Nuclear power has been used on space probes to other planets. Power systems are constantly monitored, and data on power and all other onboard systems is sent to Earth stations in the form of telemetry signals.
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How does the chemistry of a dry cell battery affect it's voltage yield..\n\nget 2 or 3 types of dry cell batteries, (as in alkaline/nickel, not AA or AAA) research on the chemistry and stuff of it, get 2 or 3 flashlights or something that can use up the batteries, and a voltage meter.\n\nsee which battery runs out fastest (keep the flashlight or whatever you use on 24/7).
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Have a look at my project.  Several links for pictures, wiring, charge controller, and so on.\nhttp://members.rennlist.org/warren/wind.html
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Someone recently sent me a news clip about a man who's developed a blowtorch that runs on water.  He also modified his Ford Escort as a gasoline/water hybrid-- he's patented his technology and has started a company that's been contracted to design a water fueled Hummer for the military.  Totally clean burning and unlimited in supply.  The man should win some kind of Nobel Prize.  \n\nMaybe Google waterpower or something??
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You will find all the answers here:\n\nhttp://library.thinkquest.org/10429/high/eleconfig/electron.htm
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You are thinking of an electrolytic cell, not a fuel cell.\n\nA fuel cell works in the opposite way, taking Hydrogen and Oxygen gas and producing electricity and water.\nAn electrolytic cell takes electricity and splits water in to Hydrogen and Oxygen.\n\nThe electrodes in an electrolyitc cell can be any number of things, pretty much anything that will conduct electricty would work.  However, somethings work much better than others.  Platinum and gold are very inert metals and resist corrosion very well (unlike iron/steel for instance).  Carbon/graphite is a very popular and cheap electrode material in electroltic cells, but they eventually wear out.\n\nIn fuel cells, more specifically PEM fuel cells, platinum us used as a catalyst on a porous carbon electrode which is then connected to a Proten Exchange membrane which allows the passage of H+ ions but forces the electrons around through an electric circuit.  The Platinum is used on the electrodes because it acts as a catalyst to strip the Hydrogen atoms of their electrons from the Hydrogen gas molecules.
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sure. go to a science store or look up schematics on the web.
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I assume you mean electrolysis?  I don't know the exact ratio of energy out to energy in, but I do know that it's not very efficient.  There will be a lot of lost energy.  What kind of H2 on demand system?  Are you trying to run an automobile?  If so, you'd need more than about 10 kilowatts of electricity.  Might as well just build an electric car if you have that much electricity to waste.
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I hope this link may help.  http://www.hefce.ac.uk/news/hefce/2006/perfind.htm