Some Commercial Voltaic Cells

The cell has a zinc anode and a graphite rod with a paste of Mn02,ZnCl2,NH4CI,and Casthe cathode. 

The voltage of this dry cell is initially about 1.5 V, but it decreases as current is drawn off. The voltage also deteriorates rapidly in cold weather. 

The anode is zinc powder and the cathode is Mn02,as in the Leclanche cell however,the electrolyte is KOH. 

White lead(II) sulfate coats each electrode during discharge, and sulfuric acid is consumed. Each cell delivers about 2 V, and a battery consisting of six cells in series gives about 12 V. 

The anode is lithium metal and the cathode is a complex of iodine, I2 the electrodes are separated by a thin crystalline layer of lithium iodide.The battery consists of two cells enclosed in a titanium shell. 

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Table 21.1 lists the voltages of some commercial and natural voltaic cells. Next, we ll see how to measure cell potential. 

Table 21.1 lists the voltages of some commercial and natural voltaic cells. 

The next several sections describe battery cells, or voltaic cells (also called galvanic cells). These are a kind of electrochemical cell. An electrochemical cell is a system consisting of electrodes that dip into an electrolyte and in which a chemical reaction either uses or generates an electric current. A voltaic, or galvanic, cell is an electrochemical cell in which a spontaneous reaction generates an electric current. An electrolytic cell is an electrochemical cell in which an electric current drives an otherwise nonspontaneous reaction. In the next sections, we will discuss the basic principles behind voltaic cells and then explore some of their commercial uses. 

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