Grove element

The Grove cell is a historic galvanic cell consisting of a zinc - and platinum - half cell is and is among the no longer in use wet-cell batteries . The galvanic element is named after its inventor William Grove , who developed it in 1844.

construction

Grove Element (1897)

The Grove element consists of a central platinum rod, which represents the positive electrode in the form of the cathode and is marked with (P) in the figure, and this is immersed in a solution of dilute nitric acid . In the original design, the diluted nitric acid is filled in a container (T) made of porous earthenware , which in turn is immersed in a solution of sulfuric acid on the outside . In the outer area there is the negative electrode as an anode made of a bent metal plate made of zinc, marked with (Z) in the illustration, which is immersed in the area of ​​the sulfuric acid. The entire arrangement is located in a carrier vessel. The platinum rod and the zinc sheet are provided with appropriate terminals for the electrical connection. The diaphragm , also known as the salt conductor , is used to prevent the diffusion mixing of the two acids and still enable a charge balance through anions through the porous material.

The cell voltage of the Grove element is 1.9  V , which is almost double that of the similarly constructed Daniell element with 1.1 V. Because of this higher voltage, the Grove element was used as a source of electrical energy for the first telegraphic connections from 1844 to 1860, especially in North America . The disadvantage of the Grove element is the formation of toxic nitrogen dioxide during discharge, and the comparatively expensive platinum was also a disadvantage in practical use. Therefore, the Grove element was used as an electrical energy source in telegraphy from the 1860s by Gravity-Daniell Elements replaced.

Reaction equation

The redox reaction during discharge is:

${\displaystyle \mathrm {\ Zn+H_{2}SO_{4}+2HNO_{3}\rightarrow ZnSO_{4}+2H_{2}O+2NO_{2}} }$

literature

• John Wilson, William Wilson, James M. Wilson: William Robert Grove: The Lawyer Who Invented the Fuel Cell . Metolius Ltd, 2000, ISBN 978-0-9557193-0-1 (English).
• William Edward Ayrton: Practical Electricity . Cassell, London 1891, p. 214 ff . ( Online ).

Web links

Commons : Grove cell  - collection of pictures, videos and audio files

Individual evidence

1. ^ The Electromagnetic Telegraph. (No longer available online.) Archived from the original on August 4, 2007 ; accessed on January 24, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.