Calcium-based electrochemical cells

The electrolyte used by the fuel cell is a solid gas—impermeable zirconia known as zirconium oxide (ZrOj). This ZrOj is doped with calcium oxide (CaO) to supply enough oxide ions to carry the cell current. The oxidant air or oxygen is bubbled through the molten silver cathode, which is held inside the zirconia cup. At the fuel electrode or the carbon-based anode electrode, the oxide ions are combined with carbon monoxide (CO) and give up their electrons to an external circuit. The cell by-products CO and hydrogen, which are formed in the initial fuel decomposition, are burned outside the cell to keep the fuel cell at operating temperature. The hydrogen is not involved in the electrochemical cell reaction. 

Elements such as sodium, potassium and chlorine have primarily an electrochemical or physiological function and are concerned with the maintenance of acid-base balance, membrane permeability and the osmotic control of water distribution within the body. Some elements have a structural role, for example calcium and phosphorus are essential components of the skeleton and sulphur is necessary for the synthesis of structural proteins. Finally, certain elements have a regulatory function in controlling cell replication and differentiation zinc acts in this way by influencing the transcription process, in which genetic information in the nucleotide sequence of DNA is transferred to that of an RNA molecule. It is not uncommon for an element to have a number of different roles for example, magnesium functions catalytically, electrochemically and structurally. 

The antibacterial effect of metal ions and especially silver, copper and zinc ions is well known. Silver and silver ions are used in medicinal treatments ranging from severe burns to Legionnaires Diseases. Silver-based products are also applied in water purification processes. Metal ions achieve their antibacterial effect by two mechanisms First the metal ions influence the electrochemical potential between the internal and external parts of the cell, and second, after penetration of ions into the cell, they compete with other essential ions like magnesium, calcium and potassium and they aggregate with thiol groups of enzymes and proteins. 

One of the constraints in designs of calcium anode-based thermal batteries has been the limited duration at high current densities due to a low electrochemical efficiency of the calcium anode, arising from the existence of side-reactions involving the electrolyte and the electrode active materials. It has been demonstrated by Mine Safety Appliances Ltd that significant improvements in thermal battery performance can be achieved by the use of lithium as the active anode material in the cell, coupled witn new cathodes. These batteries... 

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