Batteries work done

Work (W) is done by a battery whenever it pushes a positive charge (+q) away from the ( + ) terminal (through space outside the batteiy) to the (-) terminal. The potential or emf or voltage (V) of a batteiy is defined as the work done in this process divided by... 

This section gives a brief overview of the structure of nickel hydroxide battery electrodes and a more detailed review of the solid-state chemistry and electrochemistry of the electrode materials. Emphasis is on work done since 1989. 

Electrical energy is considered to allow us to discuss batteries and electrochemical cells, as well as motors and resistance heating. If a charge Q is transferred to a system at an electrostatic potential (voltage) < ) with respect to the surroundings, the work done is Q ... 

If the two plates are connected by a wire there will be a current. through the wire. Let us suppose that there are 200 cells in the battery so that the P.D. between the plates is 300 volts or one electrostatic unit of P.D. If the current in the wire is one ampere this means that 3,000,000,000 electrostatic units of electricity flow from one plate to the other in one second. The work done on the electricity in one second will then be 3,000,000,000 ergs because when the P.D. is one electrostatic unit of P.D. the work required to take one electrostatic unit of charge across is one erg. 

A 6.00-V battery delivers a steady current of 1.25 A for a period of 1.50 hours. Calculate the total charge Q, in coulombs, that passes through the circuit and the electrical work done by the battery. 

This is the work done on the battery, so the work done by the battery is the negative of this, or -1-40.5 kj. 

The decrease in free energy of the system in a spontaneous redox reaction is equal to the electrical work done by the system on the surroundings, or AG = nFE. The equilibrium constant for a redox reaction can be found from the standard electromotive force of a cell. 10. The Nernst equation gives the relationship between the cell emf and the concentrations of the reactants and products under non-standard-state conditions. Batteries, which consist of one or more galvanic cells, are used widely as self-contained power sources. Some of the better-known batteries are the dry cell, such as the Leclanche cell, the mercury battery, and the lead storage battery used in automobiles. Fuel cells produce electrical energy from a continuous supply of reactants. 

Chemical work. For example, a battery can be used to do work, because a chemical reaction occurs in it which produces a voltage. The work done by chemical reactions is of course a principal focus of chemical thermodynamics, and the equations for it will be developed in later chapters. 

The Lawrence Livermore National Laboratory, Argonne National Laboratory and Los Alamos National Laboratory as well as the University of California at Berkeley are collaborating on the R D of small, lead alloy cooled battery type reactors. R D that is specific to the ENHS reactor is being carried out at the University of California at Berkeley and LLNL supported, at a low level, by the US DOE Generation IV programme as part of the work done on lead alloy cooled nuclear battery type fast reactors. The ENHS R D is also partially supported by the Lawrence Livermore National Laboratory. 

The aluminum-air battery has recently received some attention as a result of work done by the Lawrence Livermore National Laboratory. It was estimated that a 60-cell system with 230 kg of aluminum can power a VW for 5,000 km before requiring mechanical recharging. Periodic refill with water and removal of Al(OH)3 would be required after 400 km. The conversion of the Al(OH)3 back to Al at an electrolytic refinery completes the recycling process. In 1986, an Al-air battery producing 1,680 W was shown to power an electric golf cart for 8 h. 

In parallel with the large amount of work done to study the mechanism and operating features of methanol fuel cells with proton-conducting membranes, operating models of such fuel cells started to appear in the mid-1990s, first as laboratory-type small single-element fuel cells and finally, in the form of multielement batteries of relatively large power. 

The paper can be crumpled, folded, even soaked in acid with no noticeable degradation in performance as a battery. The work done by the research scientists is also best suited for energy storage devices with minimum cost and complexity. The scientists are conducting more tests on these paper batteries. 

A FIGURE 17.12 Energy Loss in a Battery When current is drawn from a battery to do work, some energy is lost as heat due to resistance in the wire. Consequently, the quantity of energy required to recharge the battery will be more than the quantity of work done. 

The force between the mirror and the counter-electrode is attractive, so that work is done by the mirror when the distance between them decreases. The work done by the mirror plus the work done by the battery must be equal to the change in the potential energy of the mirror. If the voltage on the actuator is held constant, as the mirror rotates toward the counter-electrode, the battery will have to supply charge AQ to keep the voltage constant as the capacitance increases, where AQ is give by... 

The work done by the actuator plus the work done by the battery must be equal to the change in the potential energy of the mirror ... 

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