Electronics depend on chemistry more than you can imagine. In order to generate electricity there are many methods used, one of them is chemical. Remember batteries, where electricity is generated because of chemical reactions inside cell. Also in conductors like liquids and gases electricity is carried not by electrons as it is in solid constructions(copper, aluminum, etc.), but by ions â€“ molecules with electric charges. Even non distiled water contain enough ions to be conductive. Lets go through several chemical effects of electricity.
Electrolysis is a decomposition of liquid compound by passing electric current through liquid called electrolyte(salt water, copper sulphate, sulphuric acid). Electrolysis is used very widely in industry like electroplating of metals, refining of copper and extraction of aluminum from ore. To make electrolysis happen there are two conductors used cathode(-) and anode(-).
Electrolysis is one of simplest ways to produce hydrogen, but this process require too much electrical power that makes this process inefficient (about 40%) to be used in industry. Alternative would be to use regenerative electrical plants(solar, wind, geothermal) to accumulate energy by producing hydrogen.
Is a same electrolysis, jus there is used special electrolyte like copper sulphate. So this enable for instance tin-plating of steel and depending on electrodes and anodes there can be various plating alternatives like silver-plating, chromium-plating. Material to be plated should be connected as cathode while anode usually loses material.
According to this principal all batteries are generating electric power. Chemical cells converts chemical energy in to electrical. If there are two different conductors(eg. Copper and zinc) placed in electrolyte, electric current starts flowing between electrodes.
Each different pair of electrodes generate different potential. As long as there is an external circuit, electrons can flow through it from one electrode to another. Because zinc tends to lose electrons more readily than copper, zinc atoms in the zinc electrode lose electrons to produce zinc ions. The net result is that zinc metal reacts with copper ions to produce zinc ions and copper metal.
Corrosion is a gradual destruction of metal in environment where is a conditions for simple cell reactions. Also there are tow electrodes required for corrosion. So if there metals are in contact with each other and there is presence of electrolytes â€“ the corrosion will occur. In order to prevent corrosion there are coating used like iron is coated by zinc. Or simply grease, paint, plastic is used. In many cases there are cathode protection used where a noble metal is connected to a less noble and potential applied.
Non rechargeable LechlanchÃ¨ cells
These are cells that generate about 1.5V of EMS, but if falls in continuous use due to polarisation of electrode. These cells are better to us for intermittent purposes like torches, bells, indicators etc. These cells are cheap and has a shelf life about 2 years.
There are more dry cell technologies that enables to remain EMF constant for longer times. Ones are Mercury cells. These cells provide 1.3V for longer time than LechlanchÃ¨ cells.
Rechargeable cells are mo commonly used today as main factor â€“ the price is becoming acceptable fior everyone. And there is another practical approach â€“ these cells can be recharged after use. In other words the conversion of chemical energy to electrical is reversible. There are many types of rechargeable cell technologies. Ones of common are lead-acid and the alkaline cells. These cells are usually used in cars. Bout other Rechargeable batteries I would suggest reading in Wikipedia.