Primary Nonrechargeable Batteries

A primary battery cannot be recharged, so it is discarded when the components have reached their equilibrium concentrations, that is, when the cell is dead. We ll discuss the alkaline battery and the mercury and silver button batteries. 

The alkaline battery powers portable radios, toys, flashlights, and so on, is safe, has a long shelf life, and comes in many sizes. 

Mercury and Silver (Button) Batteries Mercury and silver batteries are quite similar. Both use a zinc container as the anode (reducing agent) in a basic medium. The mercury battery employs HgO as the oxidizing agent, the silver uses Ag20, and both use a steel can around the cathode. The solid reactants are compacted with KOH and separated with moist paper. The half-reactions are 

CHAPTER 21 Electrochemistry Chemical Change and Electrical Work 

Cathode (positive) lead grids filled with Pb02 

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Primary (Nonrechargeable) Batteries Secondary (Rechargeable) Batteries Fuel Cells... 

The most common primary (nonrechargeable) battery is the alkaline battery ( Figure 20.20). The anode is powdered zinc metal immobilized in a gel in contact with a concentrated solution of KOH (hence, the name alkaline battery). The cathode is a mixture of Mn02 (s) and graphite, separated from the anode by a porous fabric. The battery is sealed in a steel can to reduce the risk of any of the concentrated KOH escaping. The cell reactions are complex but can be approximately represented as follows ... 

There is a wide choice of materials that can be selected for the positive electrodes of lithium batteries. However, many of these involve reactions which cannot be readily reversed and are limited to primary nonrechargeable batteries. The best cathodes for rechargeable batteries are those where there is litde bonding and structural modification of the active materials during the discharge-charge reaction. ... 

As another matter of convention, a single-use, i.e., nonrechargeable, battery is known also as a primary battery. A rechargeable battery is also known as a secondary battery. 

Ruben cell — This is a zinc-mercuric oxide alkaline cell, more commonly called a mercury -> battery, a type of primary (nonrechargeable) cell, developed by Samuel Ruben during World War II in response to a requirement for batteries with a high capacity-to-volume ratio which would withstand storage under tropical conditions. It was licensed to the RR. Mallory Co., which... 

Batteries. Primary, ie, nonrechargeable, batteries containing silver compounds have gained in popularity through use in miniaturized electronic devices. The silver oxide—zinc cell has a cathode of Ag-O or AgO. These cells are characterized by a high eneigy output per unit weight and a fairly... 

Electrochemical cells and batteries are identified as primary (nonrechargeable) or secondary (rechargeable), depending on their capability of being electrically recharged Within this classification, other classifications are used to identify particular stmctures or designs. The classification used in this handbook for the different types of electrochemical cells and batteries is described in this section. 

The first recorded use of a silver battery was by Volta with his now historic silver-zinc pile battery, which he introduced to the world in 1800. This battery dominated the scene in the early nineteenth century, and during the next 100 years many experiments were made with cells containing silver and zinc electrodes. All these cells, however, were of the primary (nonrechargeable) type. 

Never mix primary (nonrechargeable) and secondary (rechargeable) batteries in equipment at the same time... 

New lithium-based and the more conventional Ni-Zn batteries may eventually replace lead-acid batteries as new technology and advanced manufacturing techniques reduce their costs. Metal-air batteries, both rechargeable (zinc) and nonrechargeable fuel-cell types (aluminum), may ultimately be successful as an economical primary source for short-trip transportation. The demand for increasing electronic equipment will require increased auxiliary power, which may be fulfilled by improved lithium-based and Ni-Zn systems. 

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