Foundations Solid state ionics

michael faraday in 1842

in 1830s, michael faraday laid foundations of electrochemistry , solid-state ionics discovering motion of ions in liquid , solid electrolytes. earlier, around 1800, alessandro volta used liquid electrolyte in voltaic pile, first electrochemical battery, failed realize ions involved in process. meanwhile, in work on decomposition of solutions electric current, faraday used not ideas of ion, cation, anion, electrode, anode, cathode, electrolyte , electrolysis, present-day terms them. faraday associated electric current in electrolyte motion of ions, , discovered ions can exchange charges electrode while transformed elements electrolysis. quantified processes 2 laws of electrolysis. first law (1832) stated mass of product @ electrode, Δm, increases linearly amount of charge passed through electrolyte, Δq. second law (1833) established proportionality between Δm , “electrochemical equivalent” , defined faraday constant f f = (Δq/Δm)(m/z), m molar mass , z charge of ion.

in 1834, faraday discovered ionic conductivity in heated solid electrolytes ag2s , pbf2. in pbf2, conductivity increase upon heating not sudden, spread on hundred degrees celsius. such behavior, called faraday transition, observed in cation conductors na2s , li4sio4 , anion conductors pbf2, caf2, srf2, srcl2 , laf3.

later in 1891, johann wilhelm hittorf reported on ion transport numbers in electrochemical cells, , in 20th century numbers determined solid electrolytes.