CT: Ionic substances contain charged particles called ions. For example, lead bromide contains positively charged lead ions and negatively charged bromide ions.
Electrolysis is the process by which ionic substances are decomposed (broken down) into simpler substances when an electric current is passed through them.
For electrolysis to work, the ions must be free to move. Ions are free to move when an ionic substance is dissolved in water or when melted. For example, if electricity is passed through molten lead bromide, the lead bromide is broken down to form lead and bromine.
S: http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa/electrolysis/electrolysisrev1.shtml (last access: 13 February 2015)
N: 1. 1834; the name was introduced by Faraday on the suggestion of the Rev. William Whewell (1794-1866), English polymath, from electro- + Greek lysis “a loosening,” from lyein “to loosen, set free” (see lose). Originally of tumors, later (1879) of hair removal. Related: electrolytic.
2. One of the chief advantages of electrolysis is that it can be applied at a great range of scales. The report first examines its use at smaller scales, in off-grid or localised power generation, where it is a key component to enable smart, secure and flexible distributed energy systems that include renewables such as wind and solar power. True independence from the grid is difficult to achieve and in many instances electrolysis can be the crucial missing link.
3. One of the most exciting aspects of the technology currently is its emergence as a candidate for large-scale renewable energy storage – without a doubt one of the biggest challenges facing society in its efforts to move away from fossil fuels. Many nations support an increased contribution from wind and solar power, which are difficult to harness but potentially ‘unlimited’, unlike bioenergy. However, these sources provide a variable output which is difficult for the electricity grid to accept while maintaining its stability, and this places a real and fundamental limit on how much of this energy can currently be incorporated into the supply.
S: 1. OED – http://www.etymonline.com/index.php?allowed_in_frame=0&search=electrolysis&searchmode=none (last access: 13 February 2015). 2 & 3. http://www.fuelcelltoday.com/analysis/surveys/2013/water-electrolysis-renewable-energy-systems (last access: 13 February 2015).