Wet cell

From Wikipedia, the free encyclopedia

A wet cell is a galvanic electrochemical cell with a liquid electrolyte. A dry cell, on the other hand, is a cell with a pasty electrolyte. Wet cells were a precursor to dry cells and are commonly used as a learning tool for electrochemistry. It is often built with common laboratory supplies, like beakers, for demonstrations of how electrochemical cells work. A particular type of wet cell known as a concentration cell is important in understanding corrosion. Wet cells may be primary cells (non-rechargeable) or secondary cells (rechargeable).

While a dry cell's electrolyte is not truly completely free of moisture and must contain some moisture to function, when it was first developed it had the advantage of containing no sloshing liquid that might leak or drip out when inverted or handled roughtly, making it highly suitable for small portable electric devices. By comparison, the first wet cells were typically fragile glass containers with lead rods hanging from the open top, and needed careful handling to avoid spillage. An inverted wet cell would almost certainly leak, while a dry cell would not. Wet-cell Lead-acid batteries would not achieve the safety and portability of the dry cell, until the development of the Gel Battery.

Contents 1 Primary wet cells 1.1 Daniell cell 1.2 Other primary wet cells 2 Secondary wet cells

[edit] Primary wet cells

[edit] Daniell cell

main article: Daniell cell

The most famous wet cell is the Daniell cell, which is sometimes referred to as a crowfoot or gravity cell. The Daniell cell was developed in 1836 by the British chemist (and meteorologist) John Frederic Daniell.

[edit] Other primary wet cells

• Leclanche cell
• Grove cell
• Bunsen cell
• Chromic acid cell
• Clark cell
• Weston cell

[edit] Secondary wet cells

A battery is a collection of several galvanic cells connected in series to produce a greater voltage than a single cell could. Car batteries are wet cells and give a good example of the pros and cons of such systems. A standard 12-V car battery consists of 6 lead acid cells that each produce 2 volts. The most commonly used lead-acid battery consists of a lead metal anode and a lead oxide cathode, both of which are immersed in a solution of sulfuric acid. As seen in car batteries, a disadvantage of such a system is that it is extremely heavy. On the plus side, however, the redox reaction that occurs is readily reversible allowing it to have a long, reliable, and useful life. In a car battery, the cell is recharged by the car's alternator.