Chapter openers battery

A battery (or galvanic or voltaic cell) is a device that uses oxidation and reduction reactions to produce an electric current. In an electrolytic cell, an external source of electric current is used to drive a chemical reaction. This process is called electrolysis. When the electric potential applied to an electrochemical cell is just sufficient to balance the potential produced by reactions in the cell, we have an electrochemical cell at equilibrium. This state also occurs if there is no connections between the terminals of the cell (open-circuit condition). Our discussion in this chapter will be limited to electrochemical cells at equilibrium. 

The experimenter should construct the circuit of Fig. 10,5 on the next page. At first, the wires shown as dashed lines are not connected. The experiment is done as on page 7 of the first chapter, where the "switch" is opened suddenly, and there is a bright flash in the neon bulb. Then the short circuiting clip lead (dashed line in the diagram) is attached to the transformer s 120 volt coil (heavily insulated black wires or soldered-on power cord). Now when the switch is opened, there is no neon flash. What is happening is that current is induced in the "shorted" coil, as the battery current suddenly decreases. This new current has a magnetic field... 

The various designations for the different cell constructions are formulated in the International Electrotechnical Vocabulary, Chapter 486 Secondary cells and batteries . Valve-regulated cells are closed by a valve. It prevents the admission of air into the cell, but opens during normal operation when the internal pressure has increased to the opening value of the valve. 

IN THIS CHAPTER, we apply the equilibrium concepts learned in the previous chapter to acid-base phenomena. Acids are common in many foods, such as limes, lemons, and vinegar, and in a number of consumer products, such as toilet cleaners and batteries. Bases are less common in foods but are key ingredients in consumer products such as drain openers and antacids. We will examine three different models for acid-base behavior, all of which define that behavior differently. In spite of their differences, the three models coexist, each being useful at explaining a particular range of acid-base phenomena. We also examine how to calculate the acidity or basicity of solutions and define a useful scale, called the pH scale, to quantify acidity and basicity. These types of calculations often involve solving the kind of equilibrium problems that we explored in Chapter 14. 

Largely for reasons of cost, low maintenance requirements and proven technology, lead-acid batteries continue to dominate the traction battery market. The closest competitors, in specialist applications, are various nickel-based systems. For stationary batteries, used as a standby power source, the market is more closely divided between lead-acid and nickel-cadmium batteries. At the same time, new applieations have opened up in recent years for lead-acid batteries in electric-powered support vehicles (in recreational and industrial uses) and a potentially large new market in electric cars beckons (see Chapter 18, for a discussion of this and other new... 

This book opens with an exhaustively complete chapter by Aurbach on the role of surface films in the stability and operation of lithium-ion batteries. His discussion lays the groundwork for the rest of the book because it puts many of the required properties of anode, cathode, solvent, salt, or polymer electrolyte into perspective in regards to their reactivity and passivation. Development of new electrolytes, anodes, and cathodes must account for this reactivity and indeed some new and promising electrode materials may continuously lose capacity due to their inability to passivate with the electrolytes employed. 

Yamaki presents an extensive review of the extensive efforts in various laboratories to improve the electrolyte solvent systems and studies of their reactivity with anodes and cathodes. This chapter, combined with Aurbach s opening chapter, the chapter on temperature effects in lithium-ion batteries (Salomon, Lin, Plichta, and Hendrickson) and Broussely s chapter on aging mechanisms and calendar life predictions gives a comprehensive insight into the reactivity of the systems that constitute commercial cells. 

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