Primary and secondary room temperature molten salt electrochemical cells

Three primary cells (a, b, and c) and two secondary cell candidates (d and e) were examined in room temperature molten salt electrolytes containing either 1-methyl-3-ethylimidazolium chloride (MEICI) (a, b, d, and e), or 1-methyl-3-ethylimidazolium bromide (MEIBr) (c). (a) Al anode/AlCl ₃-MEICl ( N = 0.37)//FeCl ₃-MEICl ( N = 0.33)/W cathode (b) Al anode/AlCl ₃-MEICl ( N = 0.37)//WCl ₆-MEICl ( N = 0.33)/W cathode (c) Al anode/AlBr ₃-MEIBr ( N = 0.33)/Br ₂/RVC, Pt cathode (d) Zn anode/AlCl ₃-MEICl ( N = 0.33)//AlCl ₃-MEICl ( N = 0.60)/Al cathode (e) Cd anode/AlCl ₃-MEICl ( N = 0.33)//AlCl ₃-MEICl ( N = 0.60)/Al cathode where N is the mole fraction of aluminium halide in the melt. An IONACC® anion exchange membrane separated the anolyte and catholyte solutions in cells (a) and (b), while in cells (d) and (e) a NAFION® cation exchange membrane separated the anolyte and catholyte solutions. In cell (c) a phase boundary separated the anolyte and catholyte solutions, with reticulated vitreous carbon (RVC) acting as the anode current carrier.