Solid state electrochemical devices

Electrochemical devices suitable for room temperature, low current density applications are made from a combination of an electrode which is an active light metal, in particular magnesium, and a solid electrolyte of the form Mn(R1R2R4R5N)In+1 or Mn(R1R2R3N(CH2)mNR4R5R6)In+2; where R1, R2, R3, R4, R5, R6 can be straight or branched chains containing, or not containing, heteroatoms, or where R1 and R2 and/or R4 and R5 are opposite ends of a chain or branched chain or branched chain containing, or not containing, heteroatoms, in which case a cyclic structure embodying N is produced; m is 2, 3 etc.; preferred values of n are in the range 0 to 40; M is Cu (copper) or Ag (silver).