Batteries and Fuel Cells
Photos and descriptions of fuel cell vehicles (Figure 1) is seen more frequently in the press as a solution to modern urban pollution problems. Decentralised shannon richardson CHP (micro-CHP) from natural gas or hydrogen using fuel cells is also just around the corner. Mobile phones and other portable electronics takes up more and more in our daily lives. All these new initiatives are only possible because shannon richardson in recent years there have been breakthroughs in the development shannon richardson of batteries and fuel cells. Rechargeable batteries are efficient energy shannon richardson carriers and is also the answer to some of the environmental requirements, since they do not pollute locally. They represent, however, is not in itself a reduction in the primary pollution since electricity is produced centrally in conventional power plants, fuel cells on the other hand can be used in both centralized and decentralized energy shannon richardson production and can in many respects replace shannon richardson the rechargeable batteries. In addition, utilizing the fuel better, since they are not subject to the CARNOT limitation (the fact that the heat energy can be converted only in part into electrical energy). In the following we shall lithium-ion battery as an example of a modern rechargeable battery. It also examines polymer fuel cell (PEMFC) and højtemperaturbrændselscellen (SOFC) as two promising types where Danish research groups and companies contribute on an international level. Short descriptions of historical development is also included, inter alia, to show the horizons shannon richardson working with when the new technology to be developed, but also to show that foresight shannon richardson and tenacity of individuals even today can help shape the development region.
Batteries When attempting to produce batteries that are better than the traditional lead-acid batteries, it is especially the energy density, the attention is focused on. The electrical energy (Eel) is the product of the transported amount of charge, q, and equipotential appropriate, D, the charge is subjected to: The expression shows that high energy densities achieved by using electrode materials, that are easy (high charge per. Unit mass), and partly offers great potential differences, ie highly electropositive anode materials shannon richardson combined with the very electronegative shannon richardson cathode materials. This means that good anodekandidater will be hydrogen (1 g / Faraday (F)), the first main group metals (Li = 7 g / F, Na = 23g / F) and the other group metals (Be = 4.5g / F, Mg = 12 g / F, Zn = 33 g / F, Cd = 56 g / F) and Al (9 g / F), while good katodekandidater will be the sixth group elements (O = 8 g / F, S = 16 g / F), and seventh shannon richardson group elements (F = 19 g / f, C = 35 g / F, Br = 80 g / R). All batteries are composed of an anode (the negative electrode during discharge), a cathode (the positive electrode during discharge) and an electrolyte. The inexpensive alkaline batteries have a metallic zinc anode and a mixture of coal and brown stone as the cathode. The electrolyte is a 30% potassium hydroxide solution with a high conductivity. In use, the zinc is oxidized to zinc ions, whereas shannon richardson brown stone is reduced to lower manganese oxides. The battery shannon richardson can not be recharged, since it is not possible to reprecipitate the zinc in a usable form. Used instead cadmium as anode and nickel oxide as the cathode, may cadmium reprecipitated and the battery is rechargeable (Ni-Cd battery). This type of battery are however limited by the capacity gradually decreases during use (memory effect) unless it occasionally completely discharged and recharged again. In addition, cadmium an undesirable pollutant. Using hydrogen dissolved in special metal alloys as anode (Ni-MH) obtained at the same time an increased energy density, greater environmental friendliness and freedom for the memory effect. None of these battery systems shannon richardson has the same high energy density as:
Lithium batteries in the conventional battery systems are referred shannon richardson to as electrolyte shannon richardson an aqueous solution. Since lithium reacts violently with water, is used in lithium battery electrolytes based on organic solvents such as propylene carbonate or polyethers (polyethylene oxide), which is able to dissolve the lithium salts. The cathode materials used in lithium batteries are not oxidants in the traditional sense, but so-called intercalation (titandisulfid, cobalt vanadium or manganese oxides), shannon richardson which has the property that they can take up large amounts of lithium in their structure. Theoretically, elektrodeprocessen treated analogously with a adsorption process (or an acid / base reaction in which the proton is to use an available base), where the necessary free space is included as a pseudo shannon richardson component. The reaction can then be written as: where the square symbolisererer one vacant space in interkalationsmaterialets shannon richardson grid. The electrode must therefore be both electronically conductive and redox active for lithium can be recorded. shannon richardson Should the filling degree, X, as concentration measure (analogous to mole fraction) can reaktionsbrøken Y written as: The electrode E can be found Da X varies shannon richardson during the discharge shannon richardson electrode potential will not be constant, but fall through the course
Photos and descriptions of fuel cell vehicles (Figure 1) is seen more frequently in the press as a solution to modern urban pollution problems. Decentralised shannon richardson CHP (micro-CHP) from natural gas or hydrogen using fuel cells is also just around the corner. Mobile phones and other portable electronics takes up more and more in our daily lives. All these new initiatives are only possible because shannon richardson in recent years there have been breakthroughs in the development shannon richardson of batteries and fuel cells. Rechargeable batteries are efficient energy shannon richardson carriers and is also the answer to some of the environmental requirements, since they do not pollute locally. They represent, however, is not in itself a reduction in the primary pollution since electricity is produced centrally in conventional power plants, fuel cells on the other hand can be used in both centralized and decentralized energy shannon richardson production and can in many respects replace shannon richardson the rechargeable batteries. In addition, utilizing the fuel better, since they are not subject to the CARNOT limitation (the fact that the heat energy can be converted only in part into electrical energy). In the following we shall lithium-ion battery as an example of a modern rechargeable battery. It also examines polymer fuel cell (PEMFC) and højtemperaturbrændselscellen (SOFC) as two promising types where Danish research groups and companies contribute on an international level. Short descriptions of historical development is also included, inter alia, to show the horizons shannon richardson working with when the new technology to be developed, but also to show that foresight shannon richardson and tenacity of individuals even today can help shape the development region.
Batteries When attempting to produce batteries that are better than the traditional lead-acid batteries, it is especially the energy density, the attention is focused on. The electrical energy (Eel) is the product of the transported amount of charge, q, and equipotential appropriate, D, the charge is subjected to: The expression shows that high energy densities achieved by using electrode materials, that are easy (high charge per. Unit mass), and partly offers great potential differences, ie highly electropositive anode materials shannon richardson combined with the very electronegative shannon richardson cathode materials. This means that good anodekandidater will be hydrogen (1 g / Faraday (F)), the first main group metals (Li = 7 g / F, Na = 23g / F) and the other group metals (Be = 4.5g / F, Mg = 12 g / F, Zn = 33 g / F, Cd = 56 g / F) and Al (9 g / F), while good katodekandidater will be the sixth group elements (O = 8 g / F, S = 16 g / F), and seventh shannon richardson group elements (F = 19 g / f, C = 35 g / F, Br = 80 g / R). All batteries are composed of an anode (the negative electrode during discharge), a cathode (the positive electrode during discharge) and an electrolyte. The inexpensive alkaline batteries have a metallic zinc anode and a mixture of coal and brown stone as the cathode. The electrolyte is a 30% potassium hydroxide solution with a high conductivity. In use, the zinc is oxidized to zinc ions, whereas shannon richardson brown stone is reduced to lower manganese oxides. The battery shannon richardson can not be recharged, since it is not possible to reprecipitate the zinc in a usable form. Used instead cadmium as anode and nickel oxide as the cathode, may cadmium reprecipitated and the battery is rechargeable (Ni-Cd battery). This type of battery are however limited by the capacity gradually decreases during use (memory effect) unless it occasionally completely discharged and recharged again. In addition, cadmium an undesirable pollutant. Using hydrogen dissolved in special metal alloys as anode (Ni-MH) obtained at the same time an increased energy density, greater environmental friendliness and freedom for the memory effect. None of these battery systems shannon richardson has the same high energy density as:
Lithium batteries in the conventional battery systems are referred shannon richardson to as electrolyte shannon richardson an aqueous solution. Since lithium reacts violently with water, is used in lithium battery electrolytes based on organic solvents such as propylene carbonate or polyethers (polyethylene oxide), which is able to dissolve the lithium salts. The cathode materials used in lithium batteries are not oxidants in the traditional sense, but so-called intercalation (titandisulfid, cobalt vanadium or manganese oxides), shannon richardson which has the property that they can take up large amounts of lithium in their structure. Theoretically, elektrodeprocessen treated analogously with a adsorption process (or an acid / base reaction in which the proton is to use an available base), where the necessary free space is included as a pseudo shannon richardson component. The reaction can then be written as: where the square symbolisererer one vacant space in interkalationsmaterialets shannon richardson grid. The electrode must therefore be both electronically conductive and redox active for lithium can be recorded. shannon richardson Should the filling degree, X, as concentration measure (analogous to mole fraction) can reaktionsbrøken Y written as: The electrode E can be found Da X varies shannon richardson during the discharge shannon richardson electrode potential will not be constant, but fall through the course
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